# MAN Diesel engine from 1907 "DM 2 * 100"



## MuellerNick (Oct 5, 2012)

Hi!

Today, I had a break-trough with casting a center-piece of my scale Diesel engine. For me, that's a milestone. And enough reason to show off!

About the engine:
This is a 200 hp Diesel engine off the "DM"-series. DM stands for Diesel Motor. It was built by MAN. The DM series was the second generation of diesel engines that were sold in volumes and they were the first ones that worked quite reliably. There were different sizes. To my knowledge a DM 8 (8hp), DM 50 (50 hp) DM 75, DM 100 and DM 200. At least the bigger ones (starting from DM 50) were available in 1, 2, 3 and 4 cylinder configurations.
My model is a 2 cylinder version with 200 hp (100 hp per cylinder).
These engines worked with compressed air injection.

How that project started:
January 2005, I got a tip that there is an old Diesel engine at Passau. I found a tiny picture and decided to have a look at it.
Having seen it, I realized that this will be my next project.
I tried to get plans from MAN's archive, but they no longer had them. They lost all of them during a fire.
But I'm stubborn!
I contacted the municipal works (owner of the engine) and asked for permission to take dimensions. They were NOT happy. It took some time, and then they allowed me to take pictures, dimensions and even step on the engine.
Together with a friend, we went there. 'Till noon, we sticked about 1500 dots onto the engine, took pictures from all perspectives (IIRC 200) and removed the dots again.
200 hours of photogrammetry work followed ... even more hours on the CAD. And endless hours hunting for books that showed something of the internals.

The result will be a model in scale 1:10.

Here is a picture of the original engine:



You can see the dots that were sticked onto masking tape to increase contract.



And one that shows a detail of the cylinder head. Just so you can imagine the work involved to re-model all those points. :wall:

It didn't take too long for me to realize, that I will fail with my equipment and my knowledge.
So I bought a used and MAHO MH 700 C mill with a broken controll and replaced that with LinuxCNC.
Bought a Myford cylindrical grinder and completely restored it. Bought X and Y and Z and repaired it.

Then, finally, when I realized that I somehow forgot what I initially wanted to do, started with castings. That was spring of 2011. Built  furnaces (2 of them have retiered), built a muller, built a core sand mixer, built ... ahhhh ... tools to make tools to make tools!

Long story short. Here is my A-frame I succeeded in casting today:

















These are the cores that go inside. I had to mill channels as gates and a pool that takes the first shot of cold pour.
This casting has a split pattern with two loose inserts and 7 cores. These cores are made out of 10 parts.
Wall thickness is 3 mm in most places!


I'll show more pictures. But now it's time to go to bed. Will have an other casting session tomorrow and take the chance to show more castings I have made.

If you do have questions, feel free to ask!

Nick


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## hi speed scrap (Oct 5, 2012)

Well done Nick, I'm impessed with your work and a 
nice choice of model.
Castings are Aluminium I assume?
I will follow your build with great interest

Dave


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## MuellerNick (Oct 5, 2012)

Yes, all aluminium castings. Except the flywheel. But I don't get enough temperature yet. I can melt CI, but it is not hot enough for pouring.

I use oil bound sand. OBB-sand (local brand here in Germany), similar to PetroBond.

The cores are PU-bound (cold box). Two components mixed into the sand. Then massaged into the core boxes and the PU activated with amin (SP?) gas (stinks like ammonia and is chemically similar). The cores are very durable and detailed and do have sharp corners that withstand the heat of the pour.
Unfortunately, the cores have to burned out (4 hours at 500 °C) afterwards. Stinks a second time.

Thankfully, I get a lot of the casting chemicals from a friend and generous supporter.


Nick


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## Herbiev (Oct 5, 2012)

Wow. That is superb casting.


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## Speedy (Oct 5, 2012)

do you have the injectors figured out? and pump assuming it uses them, curious.


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## cfellows (Oct 6, 2012)

Very ambitious project.  Will it be a true diesel?  What are the bore and stroke of the model?

Chuck


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## skyline1 (Oct 6, 2012)

Very impressive, the patternmaking alone is a major achievement with no proper drawings to go on

Regards Mark


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## Niceonetidy (Oct 6, 2012)

How does the dot photograph method work for making patterns please?

Really great job, well done,

Colin


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## AussieJimG (Oct 6, 2012)

What a wonderfully ambitious project!! From measurement through photogrammetry to multi-cored castings. I am awe-struck and will follow this build.

Jim


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## MuellerNick (Oct 6, 2012)

I have been asked wether I sell the castings. No.
 I would have to charge a lot. There are IiIRC 45 different castings per engine. Makes about 150 cast parts for a two cylinder engine.
Making the mold for this cylinder takes over an hour. Making the cores an other hour. Milling the pattern for the cylinder took about 40 hours. Plus the patterns for the cores.
Every part that is a casting in the original, is a casting in the model. No matter now small it is.
And then, there are no plans. If I would draw plans, I would have to spend something like a month for them.

The dots are not used to make patterns. At least not directly. This method is called photogrammetry. Each dot has to be taken at least 3 pictures from different perspectives. Then, you need to know one single dimension. And MAGIC! the dots are all precisely position in space. Import them into CAD and model the shapes, so the do touch the dots. Will drive you nuts!

I do know how the injectors work. I think there is a sectional drawing in Cummin's book. The compressor is two-staged and has something like 70 bar. Won't work in this scale. There are too many losses.

I will try to let it run as a true Diesel, but I have my doubts. I'm thinking about an electronic injection with open jets.

I'll post pictures of all the patterns and cores for the A-frame tonight.

I have about 30 patterns finished. The few remaining aren't complicated.


Nick


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## MuellerNick (Oct 6, 2012)

While I jave my morning coffee (well a bit late), I sized two more pictures of the original:






I have to prepare for the casting session now. No new parts, just "production" work (need spares for machining the model).
And a few castings of a little side project: A Deckel FP1 in scale 10:1, with just 5 castings. Shall I start a new thread about that one? It's not an engine, so would be off-topic.
But I have a teaser:





That's how detailed my casting get. Shows part of a lever of the Deckel.

See you later ..
Nick


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## MuellerNick (Oct 6, 2012)

Just came to my mind:
This specific engine was personally adjusted by Rudolf Diesel. So I was told.
It ran until the '80. Obviously only in rare cases. They used it to heat the water of the municipal pool. It is quite effective at generating heat and capturing it. The exhaust pipes are water cooled. I'll cast them the same way with an inside liner and a water jacket.
Even if you can't see the details, they have to be done right.


Nick


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## billmac (Oct 6, 2012)

Nick -
That is a great project. The range of skills and the level of sheer tenacity that will be needed to complete it is very large. Please keep us all up to date as you go along. I am particularly interested in your methods for photogrammetry and for pattern making, but I'm sure that the machining side will be equally interesting.

Bill


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## MuellerNick (Oct 6, 2012)

Short coffee-break:
Well, re photogrammetry, it's best if you google that. 
Takes a bit practice to learn that, but is no black art. The trick is to place the dots at the right spot and make two times more photographs than you think.
The resolution you get is above 1:5000. That means if the object is 5 m big, you can get down to 1 mm. The rails measured exactly 25.6 mm. Must have been the layer of paint.
Needs a software I had access to at that time. Meanwhile, that company I used the software at went TU.

Don't worry, patterns will be shown lathe at night (here).


Nick


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## ZAPJACK (Oct 6, 2012)

Hi Nick, this is a great project, I will follow de post.
Pls communicate some technical data. 
That's incredible to ear that the municial employees unhappy when somebody is intrested by a unique project like yours!
I start the building of the RR Merlin V12, and I try to get permission to check size of internal component but like in Germany
.........No way!!! 
LeZap


 municipal works (owner of the engine) and asked for permission to take dimensions. They were NOT happy.


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## MuellerNick (Oct 6, 2012)

> That's incredible to ear that the municial employees unhappy when somebody is intrested by a unique project like yours!



I do understand them. They would be responsible if something happens, I might fall down from the engine.
I offered them, that they get a written declaration that they are not responsible. Both parties quickly realized, that this would imply that they allowed me to step on that motor. Nogo!
So I shook his hand, gave him a Bavarian promise that he won't be responsible, that he further does NOT allow me to step onto the motor. But in return, he will close his eyes when he sees me on the motor.
The other thing that opened doors was, that I gave away a few posters of my Ellwe 2FB and told them, that I have built it and blablabla.


Pictures:


4 failures and finally the success. Ordered from left to right, first try to last try.



The core box for the inner two cores (they are almost symmetrical. The only difference is filled out with oil bound sand.



Cores and core box for the three pockets (near the top of the A-frame).
Right half pattern of the next picture. Core prints are marked black.



And the splitt pattern itself. The flash made a funny color out of it.
Where my finger points to, there are loose inserts. They are attached from the rear by long screws. After ramming the screws are removed, the pattern pulled and the inserts first pulled inwards and then out of the mould.


Nick


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## petertha (Oct 6, 2012)

MuellerNick said:


> And a few castings of a little side project: A Deckel FP1 in scale 10:1, with just 5 castings. Shall I start a new thread about that one? It's not an engine, so would be off-topic.
> Nick


 
Incredible. Yes, please start a dedicated new post... wherever! I think scaled miniature machines are so neat & your casting & mold pictures are fascinating.


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## Rustkolector (Oct 6, 2012)

Nick,
I saw you posting regarding your MAN diesel engine project. Your project looked very familiar to me. A few years ago I found a website of an Italian model builder named Emidio Gattafoni who built a working model of an early Sulzer 2D-30 air injection diesel enigne. He also built a Sulzer one cylinder version also driving an alternator. His Sulzer engines look very much like the air injection MAN DM series engine you are working on. I believe he built his Sulzer models as a spark ignition engines due to the complexities of compression ignition in small scale. He has built a solid injection diesel model of an Ellwe 2 stroke marine diesel that runs well. You might want study his website or possibly contact him. 

Jeff Conner

http://digilander.libero.it/liguori/sulzer.htm


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## MuellerNick (Oct 7, 2012)

I know Emidio personally, have met him a few times at model enginering expositions.
I have seen his Sulzer, but just the castings. It was WIP at that moment. I was very impressed of his castings. He is a son out of a foundry family. So his casting know how was a challenge to me at that time (2005). I think now I'm better than he is.
I do know his Ellwe and I have built it (see my introducory thread for a video of mine). I still remember when I displayed my finished Ellwe a year after having bought his castings. When Emidio saw my built, he stared at it in disbeliev. He didn't like his after having seen mine.

His Sulzer is of the same time, so it looks similar.

Edit:


> He has built a solid injection diesel model of an Ellwe 2 stroke marine diesel


His Ellwe runs on Propane gas. I have changed mine to run on gasoline.


Nick


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## MuellerNick (Oct 7, 2012)

That was not the only casting I have. I'll add more over time.
It looks like you guys want to see the patterns and the cores involved.

Base plate:


Top view.



From the bottom. Nobody will see that, but I know these details are there.
That dark spot in the lower right is not a void, but some speck.



Pattern (simple, not split). Black is the core print. Part is casted in the position as shown.



Core boxes. The center one is symmetrical. So two of them go into one casting.



Cores arranged in as how they go into the mould.

There's even an video.
[ame="http://www.youtube.com/watch?v=gmGfbw95Ohk"]BasePlate[/ame].

Nick


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## kutzdibutz (Oct 8, 2012)

Nick,
WOW! That is some marvellous work! :bow:
Makes me want to start casting as well! Must be quite a joy to dig this parts out of the sand. 

With this precision and finish you could cast cogs for watches! 

Cheers, Karsten


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## MuellerNick (Oct 9, 2012)

Castings #3 & #4:
Camshaft mount. Basically, these are mirrored parts. Left and right. But one has a few details added.
First, I tried this casting with a split pattern. But after I didn't get the pattern out of the sand for four times, I converted it to use a core.



The left and simpler one as cast.



And the pattern. Needs one core. The core is mirrored too. I'll go into more detail about the core in the right casting.



The right camshaft mount.



Other view into the recess.



Detailed view of the added detail.



Same detail, but with the tiny core in place.



Pattern for the right one,



Detail where the tiny core goes to.

follow up in a few minutes ...


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## MuellerNick (Oct 9, 2012)

The core and core box:


Core box (with just the lower half).



Core in the core box and with the brass insert. The split plane are in fact two planes, so that's what the brass insert is good for.



Core. What you see near my pinky (concave part) and looks like some burr/flash, is in fact the inner radius of the pocket in this casting.




This is the radius. Well, at a different spot. Where the radius ends, the core ends too. You can see a bit of flash in the casting. Inserting this core and pushing it down just the right amount is a bit of a lottery. But it works most of the time.



The core sticking in the upper half of the core box, with the pocket for the brass insert (obviously without the insert). Here you can see how the insert makes the second splitting plane.

Part #5:
That goes on top of part 3 & 4 and is the cover of the camshaft bearing.


Easy!

Edit:
The silvery color on some of the core parts is a wash. Alcohol wash in fact. Makes a bit finer finish. The sand I do have for the cores is not as fine as the oil bound sand. IIRC, it is 0.036 mm average size. Already makes a visible difference.


Nick


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## ksor (Oct 10, 2012)

A very fine job you did here  !


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## mu38&Bg# (Oct 10, 2012)

Nick do you use new ingot for castings? Or do you recycle aluminum engine heads and such? Your castings are always spectacular. I've been following your youtube for some time. I see European castings are often marked with the alloy used, at least in some of the BMW parts I've handled.


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## MuellerNick (Oct 10, 2012)

Greg, I'm just recycling (I'm green ) scrap aluminium castings. Whatever it is. Cylinder heads, rims, gear boxes, ... you name it, I melt it!
The most common alloy is something near AlSi8. That's what the big foundries do have in their standard program. If it is AlSi12 (detailed castings), it doesn't hurt.
A few of the castings are marked.

I make ingots out of them, so they do get cleaner. I also do use degassing tablets and a skimming salt (for the dross).
Those degassing-tables are getting hard to obtain, so I'll have to switch to nitrogen (argon would work too, but is more expensive).

Nick


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## MuellerNick (Oct 12, 2012)

Castings #6 & #7: The outer generator bearing housing ...


The lower part (runner and gate still in place).



Look into the upper cavity



and the lower cavity.



The upper half of the bearing housing, with the core still in place.



Pattern for the lower half. Casting position is upside down.



Core and core box #1. Core is mirrored, halves glued together.



Core and core box #2 for the lower half. Also symmetrical.



Here is a cut-though of a previous version of the lower half. Where I marked with a red felt, there was too much material.



Here's the result of the shrinkage on the outside. I couldn't get rid of the shrinkage, no matter how I placed the gates. And I don't know what putty has to do on castings. So I changed the upper core (core #2), to leave less material in that place.



That's the core box of the previous version. If you compare both cores, you see what made the difference.

Note:
Do NOT think that I cast parts in the speed I present them here. Some patterns take a week to make, some take several tries to get them running. Some are a pain to get out of the sand. Even how you rattle them free makes a difference.
I do have a pattern that I may only rattle in one direction. Perpendicular to that, the sand breaks. Took some time to find that out ... :fan:

Nick


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## jasonh (Oct 12, 2012)

Nick:

Thanks for posting this. I cast parts as well, but I'm not at your level (yet!). Watching your video gave me 3-4 ideas to try out that might improve the quality of my castings.

Question - Magnesium in the riser? The Mg burns and keeps the riser hot while the casting solidifies, thereby avoiding shrinkage? Is that right?

Thanks- Jason H


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## MuellerNick (Oct 12, 2012)

> The Mg burns and keeps the riser hot while the casting solidifies, thereby avoiding shrinkage? Is that right?



Yep! Keeping it liquid for a longer time, so it can feed and solidifies as the last part.
But it is not pure magnesium! It only contains about 30% and something (whatever) that slows down the burning. It is a ready-made product.

Anyhow, it is more of a last resort, if all fails. I'm only using it with the A-frame, not on other parts.
You could blame me for not making a better mold design. But with the A-frame, there were only a few places to place a riser that would not show later. I don't want to do any work on visible surfaces. Also, I won't use filler on my castings. That destroys the visual appearance of a casting (in my eyes).

The Deckel FP!s (other thread of mine), were just slightly blasted with glass beads and then directly spray painted with a 2K-paint. So that works.


Nick


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## MuellerNick (Oct 13, 2012)

I had a new break-through today.

Making tiny parts in sand is a real pain. So I decided to make the moulds out of core sand, and embed these molds into oil bound sand (for the runners etc.).
That worked to some extent, but the failures still were too many. And it didn't work for very intricate parts.

So I experimented with pressure casting into core sand moulds. But that failed miserably. With hot chamber, the plunger seized, with cold chamber, the metal froze.

So I thought about vacuum assisted casting. But I didn't have a vacuum pump with enough volume and pressure. When I went buying my milk at the farmer over the road, the vane pum in his milking chamber hit my eyes. Next day to the service tech for milking stations in the next village, and home I went with a pump.

Made a vacuum chamber out of MDF and cast a lid. The first tries worked somehow, but the surface was terrible. The molten aluminium diffused into the sand. Some moulds bursted (within the box, so no harm).

So I needed some simple means to adjust the pressure. This is the result:



The vacuum chamber



The lid. The array of M6 screws is for adjusting the pressure by experimenting. In the center, the molten metal is poured in.



Back of the lid and how a mould is fixed.

Results:


This is the batch of tries I made today. Only the pour in the lower right has some shrinkage, but the temperature was too low.
The others came out real nice.

So I have casting #7. A lid for a bearing housing.



Thickness is only 2 mm.



From the rear with the gate sawn off. The "A" is from an experiment with the wash. Just to know witch one went where.



Casting in the mold, one half hammered off.



Seen from the rear, with the "runner" still in place.



Cores and core boxes involved for that casting.



A similar, albeit a bit bigger mould assembled.


Nick


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## MuellerNick (Oct 14, 2012)

I made a cut-through with casting #7, the lid for a bearing housing.
This casting is a reject from previous trials. Way too rough surface.







1: 2 mm thickness
2: 0.5 * 0.5 mm
3: 1.5 mm

I get so few comments. So leave my explanations/pictures no questions, or am I teaching granny blowing eggs?


Nick


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## Cogsy (Oct 14, 2012)

MuellerNick said:


> I made a cut-through with casting #7, the lid for a bearing housing.
> I get so few comments. So leave my explanations/pictures no questions, or am I teaching granny blowing eggs?


 
Personally, this stuff just blows my mind! From the first post of all the dots to the intricate castings, I'm in awe. So I just sit back and watch with interest, but I really don't have anything to add.

Nice work though and please keep posting!


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## lee9966 (Oct 14, 2012)

I find your work amazing.  It is great to see such nice work along with explanations. Keep going!

Lee


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## kvom (Oct 14, 2012)

Rather than comments, watch the number of views on this thread.  That's what shows real interest.

Keep up the good work!


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## MuellerNick (Oct 14, 2012)

So I made a video on this lazy sunday afternoon:

[ame="http://www.youtube.com/watch?v=QijGV2G26JI"]Vacuum supported casting[/ame]

Nick


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## AussieJimG (Oct 15, 2012)

Cogsy and Kvom have said it all. I am watching as well but I have nothing to add.

But one question: What is the moulding material in the video? I thought moulding sand was much coarser and more brittle.

Thanks for the journey, I am enjoying it.

Jim


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## gus (Oct 16, 2012)

Hi Nick,
Did have in-gate shrinking and pulling castings. Thanks for the tip. Never thought of using magnezium powder.
Done some gravity casting into casting iron molds in 1980s and 90s. Was never a professional Aluminium Foundry Man. My uncles were doing it and they made it look so easy. Seen car engine pistons casted in China and again they made it look so easy.


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## MuellerNick (Oct 16, 2012)

> What is the moulding material in the video? I thought moulding sand was much coarser and more brittle.



That is core sand/material.
Cores are made either cold box or hot box. That means, that the mould for the core is cold, or is heated up. In the later, the heat is what starts the binding reaction. Hot box cores have that typical burnt yellow to brown color.
I'm using cold box (no heat resistant core sand moulds required). Typical binders are (were) weed, molasses, water glass, or polyurethane.
With water glass or PU, the binding reaction is started with a gas. Weed, molasses are moulded cold, removed from the mould and then baked.
I'm using PU. The cores with PU are quite tuff, as you can see when hammering them apart.
Grain size of my core sand is 0.035 (or so) mm.



> My uncles were doing it and they made it look so easy.


Casting isn't very complicated. As long as you know all the tricks. 


Thanks for the likes!

Nick


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## gus (Oct 16, 2012)

Yes.All the trade secrets.Too bad, in my hour of need,all my aluminium/brass foundry uncles were dead and gone.They were old tradesmen who read temperatures by eyeball.No pyrometers.
Happened to be visiting Shanghai Heavy Air Compressor Plant,China 1989. Sneaked into the foundry shop,to watch them pouring aluminium pistons in C.I.Molds.Was an asset when you could speak your mother dialect.Got all my questions answered. Melt temperature,pouring temperature,cast iron mold temperature etc. Degassing chemicals and grain refining chemicals.Dinner and beer sessions yielded so much info that poor Gus could not retain.They even gave me tips to cast brass,bronze etc.

I did think about casting brass abd bronze but the higher temperatures put me off.

Foundry Supply salesman also gave some tips too.

After some trial and error and tears ,got the first batch of gravity cast trap bodies out for machining. Must say again Gus know nuts about aluminium casting.Had a major order which require 200 pcs "Champion" Condensate traps.Kept a reject demo sample to celebrate US$100,000order completion.Foto attached.

Nick,You are my maestro. Now thinking about building a very mini aluminium furnace.Your expertise is sought.


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## skyline1 (Oct 18, 2012)

You can't beat the old MK1 eyeball Gus


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## gus (Oct 18, 2012)

skyline1 said:


> You can't beat the old MK1 eyeball Gus




Hi Skyline,

Way back 2001 when I went around Central China to audit foundry suppliers.I sure hated myself for putting a foundry owner and his "expert" into a tight spot. Asked owner how do they read cupola furnace melt temperature and has he got a pyrometer. The reply was pyrometers no good,not accurate,expensive and require calibration.My assistant has 40 years experience and he can read within plus/minus 50 degees C. by eyeball!!!! And every now and then we borrow neighbour's pyrometer to calibrate him.Ha Ha.We took off the "Certified Suppliers" List.

We had to go back to him as he supplies best Nodular Iron for our con-rods.
Suppliers with pyrometers that we qualified did not.We had to rewrite our ISO 9002 Procedures and Work Instructions to qualify/certify him as Suppier.
His Nodular Con Rods rang like a bell.Others sound like dead C.I.

So much about eyeball temperature reading.


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## MuellerNick (Oct 19, 2012)

Please keep the thread on topic.

I'll post new pictures at Sunday. Tomorrow will be casting day with two friends. And I'll do "production casting" (no new patterns). But I do have a lot left to show.


Nick


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## MuellerNick (Oct 19, 2012)

I milled a core box today. So I couldn't resist to make a test-cast with it.
It is one of the small core sand moulds that are vacuum assist cast.

Machining time was about 6 hours. As the box is quite deep, I had bought a new mill. Diameter 1.5 mm, 16 mm long (plus the shaft). Full carbide, costs 40 &#8364; a piece. They will make you cry if you break one. They are so sensible, that they do have an RPM limit of 30000. I milled with 20000 RPM.

This is casting #8, an arm for the collector brushes of the generator.




The part, sawn off.



Other view.



This mould casts two parts (I need more of them). The block marked red gets sawn off. But first, it helps clamping and machining the part.



Core box and cores. One core box makes two halves. The core sand mould lacks a gate. I drill that later (that's more efficient). You can see the hole in the upper mould half.



An assembled mould.

Unfortunately, both test castings are a bit shifted at the splitting plane in the same direction. Have to find the reason for that.
With these core sand moulds (their boxes), you have almost no chance to repair them. They either work, or you throw away at least a day's work.

There are some areas with which I'm not completely happy with, but I didn't have a release agent in the box yet. And, the boxes get a bit better with some usage (and experience, how to rattle that specific core out)..


Nick


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## MuellerNick (Oct 20, 2012)

A few more castings ...

Casting #9, post for rocker-arm shaft.



A simple piece cast in sand. You might ask why I don't make that on the lathe. Well, only castings look like castings.



The split pattern.

Casting #10. The housing for the injector pump. With this size, I don't think it will work. But in the original, it was low pressure, as the injection system was with blast air. They didn't get a high pressure diesel pump working. They had enough accidents around that.



The casting (sand) ...



... and the pattern.

Castings #10 &#8230; #12. Rocker arms.
I'm a bit lost now wich one is witch. But one is for intake and exhaust, the one with the 90° bend for the blast air and one is for the fuel.



All three of them, cast in sand.



One of them from the side.



And the patterns.
Initially, I had a set of patterns, that looked quite similar, but didn't work, or with a 90% reject. The problem was the gate, as I didn't had any good place for that. The other problem was, that they kept falling out from the sand. They were to shallow. So I added the cylindrical part (no draft). That is a machining surface, so the extra material doesn't hurt. Now the cylindrical part plays two roles: Keep the pattern in the sand and act as a gate. They always work now.


Nick


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## MuellerNick (Oct 21, 2012)

Casting #12, cylinder head.

The cylinder head of the original is water cooled, so the head of the model has to be water cooled too. I had no information of how it looked at the inside. I only found a picture of that time of a cylinder head repair that allowed a look inside. But if you look at the features of the visible outside, consider where the valves, injector and compressed air starter go, it isn't too complicate to construct a water jacked from these constrains. At least, the water jacket is reasonable, but certainly off in some details.
The biggest challenge here was to find a way how to integrate the water jacket into the pattern, get it into the mold (without falling out), finding a way that it doesn't float during the pour and finally get the core sand out again.
All that are a few days staring at the drawing and scratching my head over and over again.

But here we go 


The cylinder head as cast.



Other view (of a reject) with bottom and top milled flat. The original had those faces milled too.



Other view (reject). Those two "nibbles" required a core just to get them. I found no other way to solve that detail.



Other view (reject) into the inlet/exhaust port. The heads are symmetrical, there is no distinction between inlet and exhaust port. On the two-cylinder version, both inlet ports are face to face.
Left from the port is the inlet for the cooling water. After drilling, it will have access to the water jacket. The little feature right and below of the port is a passage to the cylinder (A-frame) for cooling water.



A reject that has some part milled off to show the inside and the port.



The pattern for the cylinder head.



A view that shows where all the cores go to.

TBC


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## MuellerNick (Oct 21, 2012)

Now to the cores 

The water jacket.
As I described above, getting that thing into the casting was a bit tricky. My solution after some experiments was to "nail" it into the mould's sand. Initially, I glued the "nails" into the oil bound sand with CA. Sounds like that doesn't work, but it does. But then, I found that it is good enough to push the core (with the nails) into the sand and be done.
To avoid the core to swim to the top (the core is fixed in the cope), it has four "nipples" at the "nails" that have contact to the cope. So the core for the water jacket hangs down from the ceiling, so to speak.



Seen from the top, with the four nails (Al filler rod) and the four nipples at the root of the nails.



From below.

The core for the water jacket is made out of three parts that get glued together.



The top part's core box. It has two loose inserts. This core box requires an additional fixture for the nails to guide and stick out from the bottom of the core box (not shown).



The core box for the lower two parts of the water jacket.
These boxes are from my early days where I painted them. I no longer do it this way. The binder actually sticks to the paint. Now, I just mill the boxes and they get a wash of release agent (some PTFE I guess in an evaporating agent).



Left and right cores for the port features and the coolant inlet. Port glued in place.



Core box for the core from above. One assembled, the other one disassembled.



Core box for the port (inlet/exhaust).



Jig to glue the two cores together properly.



How the ports and the water jacket cores are located in respect to each other.



Different view.

TBC


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## MuellerNick (Oct 21, 2012)

... and the core and core box for the "nibble" feature on the outside:


Core



and core box. It is open on two sides, so I lay it on a flat surface, ram the core sand, activate the binder and split the box.

All that is quite logical. Problem is to find the logic. 

Here is a video about the cylinder head:
[ame="http://www.youtube.com/watch?v=_M0DxxlIK3I"]YouTube[/ame]

Enjoy!
Nick


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## CF-EKM (Oct 21, 2012)

Fantastic work!
Thanks for sharing your ongoing project!
The cylinder head is very nice, it must require an enormous work and time to earn these results.

Christian


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## MuellerNick (Oct 21, 2012)

Just came to my mind:
My melting furnace is oil fired. It is "a bit" oversized for these parts. It has about 200 kW at full throttle. But I don't let it run full open, because most of the time I use an iron crucible (that won't make it much longer). Capacity is about 10 kg. The advantage is, that I can make moulds until I run out of boxes or sand, and pour them the next day with about two melts. I also have a pattern (spindle mount) that needs almost 5 kg of melt.

I measure the temperature of the molten aluminium with a thermocouple directly in the melt. Pouring temperature is between 660 °C and 680 °C, depending on what I cast. The above mentioned spindle mount works best at 640 °C. With these temperatures, I get less shrinkage and a better surface finish. Initially, I have cast with up to 720 °C, but that is nonsense.

For repeatable and predictable results, you need precise and repeatable temperatures.

BTW thermocouple:
The pyrometers you can get for a few dollars are absolute crap! They work in just one spectrum and rely on the emission rate of the material. For aluminium (and all metals) the emission is unpredictable. If the measuring spot (in case you know its correct location and size) is on a thin layer of oxide (you always do have that), the reading is off to a useless value. A real and working pyrometer costs well above 1000 $.

Nick


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## kvom (Oct 21, 2012)

After watching the video, I gather that the molten metal goes down the hole from the top, through the filter, and then through the "tunnel" to go up into the mold.  what is the reason for doing this vs. going directly from the top into the mold cavity?

Also, how do you get all the core material out afterwards?


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## MuellerNick (Oct 21, 2012)

It is better to fill the cavity from bottom to top. If you fill it the other way round, the melt splashes, picks up sand, the oxide layer tears apart, etc, etc.
Sometimes that is impossible or would make more work like in the engine's base. The engine's base in an example of bad design from a foundry POV. Huge sprue, huge gate, cast from the top. I cast the base with 660 °C, but next time I'll try it with 640 °C and I'm sure it will work too and give a better surface finish.

The cores are baked out in an electric furnace at 480 °C &#8230; 500 °C for about 4 hours. I can save some time when I hammer out/off most of the cores. But with the cylinder head's water jacket, the only solution is to wait. And then shake out the sand through 4 small holes.


Nick


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## billmac (Oct 22, 2012)

Nick -

In cast iron blocks and cylinder heads we used to use chaplets to stabilise cores and to prevent them floating out of position (maybe still done this way?). The chaplets became part of the casting itself, the size being chosen so that they retained just enough strength to hold the core but form a a properly fused part of the cast iron. 

I'm not sure if you could use chaplets in Aluminium castings; they would have to be made of Aluminium of course and getting the right size would need some trials.

I'm not sure how 'chaplet' translates in German, so if not clear let me know.


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## MuellerNick (Oct 22, 2012)

Chaplets are called "Kernstützen" in German.
But with the dimensions I work at, they seem to be of little help for me.
For the A-frame, I made a set of special boxes (for cope and $forgotIt) where I screw in the core. It is a bit odd, but works perfect.


Nick


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## MuellerNick (Oct 22, 2012)

This vacuum assisted casting is going to blow my mind!

When I started this project, I didn't know how I could cast certain parts. They were out of the boundaries of sand casting. When I switched to core sand moulds, it opened new ways. The lid (above) worked at about 50%. When I switched to vacuum assistance, the lid jumped up to 100%. I couldn't ask for more.

But there was one part, that was behind my imagination. It was too thin-walled and a year ago, impossible for me to make.
I kicked my own ass and said to me: If you don't try, you'll never know. So I milled the core box, made a bunch of cores (including other ones) and gave it a try.

Here is my first try. Casting #13, bearing block for speed lever axle:


Without wash, without release agent, without tuning parameters, just the plain first try.
The wall thickness of the ribs is 1.4 mm.



One mould makes two of them, mirrored. The runner also serves for workholding and referencing.



Core box and core sand mold.

I need a beer now!
Nick


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## AussieJimG (Oct 22, 2012)

Thanks for that beautiful video. I was getting a bit lost in the detail of that very complex head.

Jim


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## gunna (Oct 23, 2012)

This is just amazing! I find it very interesting as I am presently involved with the restoration of a 12" scale engine of almost identical design to the MAN. If anyone would like to see pictures of the full size components that Nick is modelling from, perhaps I could start a new thread in the Break Room? I guess that would be the best place.

Ian.


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## MuellerNick (Oct 23, 2012)

> If anyone would like to see pictures of the full size components that Nick is modelling from, perhaps I could start a new thread in the Break Room?



Sure I would!
Similar design? If it is *very* similar, that would be a Langen & Cie from Italy. They have stolen the MAN design and ran into legal fights with MAN. Or a license build from USA (have no names in my head, just in Cummings book).


Nick


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## gunna (Oct 23, 2012)

Hi Nick, the engine I am working on is a 3 cylinder Willans made in England in 1927! However, it appears they designed it in 1911 and never upgraded the design. As all diesels being manufactured at this time (1911) had to be made to Herr Diesels licence or not at all, they all tend to be very similar. It will take me a few days to get suitable pictures, but I will try to get the same image direction as the pieces you have made as that will make for an interesting comparison. This engine is 15"/380mm bore and 22"/560mm stroke. That seems to be the same as "your" MAN. Do you want me to continue in this thread or should I start a new one as I originally suggested?
Ian,
in Melbourne, Australia.


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## MuellerNick (Oct 23, 2012)

> Do you want me to continue in this thread or should I start a new one as I originally suggested?



I'd prefer if you start a new thread.
But you sure can set several links to yours (as progress goes on on both sides) here and back from your side. And if you want, you can take as many pictures from this thread as you want.

This sounds like a very interesting and promising parallel-thread!

Nick


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## gunna (Oct 24, 2012)

Ok, I have started over in the Break Room with my pictures. 
http://www.homemodelenginemachinist.com/f16/willans-blast-injection-engine-19174/


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## MuellerNick (Oct 26, 2012)

Casting #14. Guide for the plunger of the fuel pump.

Nothing exciting. I have cast that part in sand before, but it got too blurry.
Disregarding the fact that I had to remake the core box (ruined it in the last 5 minutes of milling), all went well:




Core box. Sorry, no core, used them up before taking a picture.






4 on a tree. Makes machining easier.
Also made these with vacuum assisted casting (currently my favorite process).


Nick


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## MuellerNick (Oct 26, 2012)

I have a little more to show[tm]!

Had to re-make the core box for casting #8. I misplaced the alignment cones, so they were mis-alignment cones and the casting was offset by 0.8 mm.



#8, version 2. As I had issues with shrinkage, I reconfigured the runner/gate part. Reduced volume of the gate and increased the surface of it. That pushed the shrinkage where it doesn't hurt.

Casting #15. Oil pump.
This is, I thinkt the smalles part. It has two separation planes, and milling them at that dimension requires some planing ahead, because you have to consider the width of the milling bit and still have to get it right.



As cast. The red line shows where the part will be cut off. These two "antennas" (1.2 * 1.5 mm) are artifacts of shifted separation plane.
The oval detail is 1.5 mm wide.



An other look at it, at the two separation planes. Here you see why they are needed.



Core box and core. Arrows point to the shifted plane.


Casting #16. An other different arm for the generator. This one holds the timing ring.



As cast, all features still in place.



Other view. Shrinkage is where I wanted it to be.



Core box and core.

The parts of todays postings were made this week.

Next, I'll post some pictures that show "assembled" subgroups.

Edit:
All parts of this posting were vacuum assisted castings.


Nick


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## kvom (Oct 26, 2012)

The casting stuff is fascinating, but I can't wait to see how you finish machine these parts.  They don't look too easy.


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## MuellerNick (Oct 26, 2012)

> but I can't wait to see how you finish machine these parts.



You and I have to wait until I have all castings.
At night, I dream of machining setups. Some end in nightmares. 

I will make soft jaws for all milling ops. That are jaws for the vise that have milled pockets for the parts to go in. Thus, I do have a precise reference (jaws are indexed).
I used that, and it works great. You can even clamp painted parts and mill them, close the vise with full power (40kN) without hurting the paint (as long it is a decent paint; I'll use 2K PU industrial paint).


Nick


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## MuellerNick (Oct 26, 2012)

Thought I could make a sub-assembly.
So I took the biggest file and some CA-glue. 



For your convenience, I have written the casting # and the page of this thread close to the part. In case you want to refresh your memories.



I tried to find a picture that shows all parts involved. Won't be possible for all following sub-assemblies. But this time it worked.




Roughly the same perspective like the original's photo.

You have to bear in mind, that I didn't remove all finishing allowances (most of the time 2mm). So parts look distorted, offset or a bit wrong.

Edit:
Dammit! I just saw that I placed the fuel's pump nipple at the wrong place. Well, this will be the only mishap I guess.


Nick


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## canadianhorsepower (Oct 26, 2012)

this kind of work excedd what my medication is allowing me to see
awsome work


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## skyline1 (Oct 27, 2012)

Hi Nick

This is coming along at an amazing speed, how do you make all these patterns and core boxes so quickly ? It would take me simply ages to make all those. Do you CNC machine them or 3D print them or something. Even a professional pattern shop would be hard pressed to keep up this kind of output by "old school" patternmaking.

I like your magnesium reheat technique and your vacuum assisted casting setup is super.

A commonly used practice in foundries to help with shrinkage is to use extended sprues or feeders which give the metal more "head" and a body of metal to "Draw" from as it solidifies. I am probably "teaching my granny to suck eggs" on this one so I apologise if this is something you already know.

Keep up the good work at this rate you will have a finished engine before any of us can blink.

Regards Mark


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## MuellerNick (Oct 27, 2012)

> This is coming along at an amazing speed, how do you make all these patterns and core boxes so quickly ?



Some work is realtime, other is old work.
Those vacuum assisted castings are realtime (but not showing them every day). The ones shown take about a day from start to finish. Milling time is about 3  4 hours. But before, I have to generate the G-code.
After the core box exists, I have to make the cores. Takes another 2 hours. Because when I'm at making cores, I also do make others.
While making cores, I melt small crucibles for pouring the moulds.

Other patterns (for sand casting) take machining time from 5 hours to 40 hours. Finishing them an hour to a few days. I have to make a test pour to see where there are faults. Some patterns needed about 4 tries.



> A commonly used practice in foundries to help with shrinkage is to use extended sprues or feeders


Those vacuum assisted castings work a bit different. The melt cools down quite quickly. And it has two gates. The first one going into the mould is just 3 mm in diameter. If I would make that bigger, the finish suffers because the melt rushes in too quickly. So the cavity is cut off from the pouring hole after a second or even less. Thus shrinkage will always be inside of the mould. I just have to get it into the runner/feeding system. But I'm getting good at that.


Nick


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## MuellerNick (Oct 28, 2012)

Valve-related castings ...

Casting #17. Coolant in/out for the blast air injector body:


This one is a vacuum assisted casting.



But they work the same when I embed the core sand moulds in oil bound sand.



Core boxes and cores. Not the most economic design, as this takes two different cores. I just could have drilled the missing gate. Well, I learn along the way ...


Casting #18. Valve body for inlet and/or exhaust.



As cast. Gets cut off at the red line.



An other view. The mould is made of 3 parts.



Core box and core for part 1.



Core boxes for part 2 & 3.
Also not one of my most clever designs. I should have added alignment cones. But I learned that later.



Cores of part 2 & 3, roughly held together to show how they mate.



Part 1 & 2 held together, a look into the cavity. The outside of that mould is a bit odd-shaped. But who cares, only the inner values count.



And that's how it looks like, if the mould bursts with vacuum-assisted casting. This happened inside the vacuum-chamber, so nobody harmed.


Nick


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## gus (Oct 28, 2012)

Hi Maestro.

Your  thread very educational. Was Nick a professional foundryman? Your patterns and sand molds very well done.
The best Ferrous Foundries we have in USA were run by German Ethnic Americans. Help audit Great Lakes Iron/Steel Foundry in Michigan. They still operated Cupola Furnaces. Quality and C.I. composition very well controlled.They use US equivalent "Toyoda"
Auto Squeeze Mold Machine. 
Gus now planning to make a mini Gas fired Aluminium Furnace.Now also looking for Oil Sands.Hope I won't end up burning my apartment.


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## MuellerNick (Oct 29, 2012)

Oil sand in your appartment? You will regret that!
Casting in oil sand in your appartment? You will regret that!

I never learned that trade, I started casting in last year's spring.

Nick


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## gus (Oct 29, 2012)

MuellerNick said:


> Oil sand in your appartment? You will regret that!
> Casting in oil sand in your appartment? You will regret that!
> 
> I never learned that trade, I started casting in last year's spring.
> ...



Hi Nick.

Please tell me more about oil sand. My aluminium casting limited to gravity cast with cast iron molds for qty of 100---200. Did watch my uncles using green sand.

May go into clay sand. Or perhaps Clay/sand/cement.

Your expert advice appreciated.


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## MuellerNick (Oct 31, 2012)

So I got some news ...

I wanted to cast a new part today (Compressor), but then found that I made one of the casting's core sand boxes wrong. 3 hours milling time in the bin. Even before casting a single piece. :fan:

So here we go with new and old parts:

Casting #19. Injector main body.



As cast. Core sand mold, embedded in sand works best with this.



Core box. I have no cores left, all already assembled.



But I quickly machined one for you. Just drilled through and faced off at the bottom.

Assembly (with CA) of the cylinder head.


I had to leave out some parts, because I'd have to machine them completely to make them fit. It is quite crammed on the cylinder head. So only the exhaust valve body, the injector, coolant connection for injector, rocker arm for injector and the two rocker arm shaft posts.

And a new casting. Casting #19. Coolant passages for the compressor to come.



6 in one go. The footprint of one of them is 5 * 10 mm, about 4 mm high. They will be cut off at the black line. The two rearmost ones failed (sand broke).



Core box and core. This one is the most pickiest to get out of the core box, as you can see by the traces from hammering.

Nick


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## gus (Oct 31, 2012)

I admire your craftsmanship and dedication to detail. Are you retired and now pursuing this hobby full time.
The foundry patterns would have taken a lot of time to make.
Wish I have the time too but I have too many other hobbies. Fishing takes over the weekend.

You are the Maestro!!!!!!


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## MuellerNick (Nov 1, 2012)

While the putty on the next pattern hardens &#8230;

&#8230; I wanted to come back to #19 to explain a trick:


If you see such a casting, you will think it is impossibly to do. Maybe with spin casting in pewter. But not in aluminium with sand.

Well, you see that it works. And I'd bet that this part can be cast in oil bound sand too.
The very simple trick is to have much more material in the back of the desired part. This helps to get enough heat (or: prevents cold material) into the desired cavity.
If I'd have to cast this wee part in oil sand, this would be the design-procedure for the pattern:
Start with the finished shape.
Add about 2 mm to the back (the face that faces my finger). Just enough room for a 1 mm slitting saw.
Repeat the detail for maybe 4 times (you'll have rejects, and you need more of those).
Add a massive block of material behind it. That block can well be 20 mm thick, and, looking from the top, be 5&#8230;10 mm wider all around. This eases pulling the pattern from the sand. That block acts as a  guide/alignment feature when pulling the pattern and makes carving a runner to the cavity an easy thing.

You also should think about work holding when designing a pattern. It doesn't help that much if you have a tiny thing that needs further machining, but there is no way to clamp it in the vice. The waste of material won't kill you. You can re-melt it.

What is the difference between a baker-man and a foundry-man?
The baker-man has to eat his rejects, the foundry-man remelts them.

I even came up with a procedure for to make tiny fake-bolts. That part needs 4, one in each corner.


Nick


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## MuellerNick (Nov 1, 2012)

So I made a test-cast of the compressor today.
Even if it was a failure, I count it as success.

I have an issue with shrinkage, but I wanted to give it a try.
I also wanted to see, wether a steel core would come out easily (without taper). It doesn't. I expected that too.
The cure for both is making a core out of sand, the way I initially thought I should do.
But you don't learn if you don't try.

The pattern needs refinements in two places, but that is no mishap, it happens often (at least to me).


So here we go &#8230;
Casting #20. Compressor.
This is a two staged compressor. Diesel initially had planned a one stage compressor in his previous engines. But they simply worked as Diesel engines, as they had a CR of about 1:70. The oil that was unavoidable for lubrication ignited from time to time.



As cast.



An "impossible" feature. The three cylinders sticking out. The middle one is no problem, as it is in the splitting plane. But the upper and lower ones prevent a simple split pattern to go out from the mould. Without breaking it, that is.



Lower end of the casting. It will be cut off at the black line, machined and both parts bolted back together. So that is two castings as one. Yes, I added enough machining allowance.



The top with the compressor's head that I made wrong and the wee coolant passage. All roughly cut to size, so no perfect fit.



The pattern with the tool to pull the inserts. I'll come back to this in a moment &#8230;



Core box and core.




I needed a way to precisely index onto the lose inserts' axis. So I added a pointy cone that was milled 3D (and 3-axis). Tilted the head and matched the center drill's point with the pattern's cone. Set all to zero and retracted with G0 X-50 Z-50, put in a drill and drilled with G1 X0 Z0.



Pattern in the sand. Before pulling it, I first have to un-tighten a grub screw and pull out the insert. Then the pattern moves out.



Mould with core and steel core in place. Here you see, why I had shrinkage. There simply is too much material at the right side and there is no way to add a feeder. So I need a core the way it has to be.

I talked about embedding core sand moulds in oil sand. That's the way it looks. On the cope, I just carve rough runners that cover the holes in the core sand moulds and that's it.




Enjoy!
Nick


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## canadianhorsepower (Nov 1, 2012)

did someone check your DNA to make sure your a NORMAL human being
awesome work


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## MuellerNick (Nov 2, 2012)

> did someone check your DNA


Last time they checked, they said that my gears did get some backlash, but my compression ratio is very good. 

I forgot, I do have a video about the castings #4 and #7, both on page 3 of that thread.
SmallCastings

But I changed the process for #7 (the lid) to vacuum assisted casting. The core sand mould is still the same.


Nick


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## Diversion900 (Nov 3, 2012)

Magic to watch it all come together, those castings are a work of art in their own right.
I am following along, fascinated.
Keep up the good work....

Cheers, Neil


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## MuellerNick (Nov 4, 2012)

So I had to make some repairs.

First of all, my heating. Got a bit cold.

Then, I repaired/fixed three castings:

Casting #10 of page 5, where I misplaced a feature.


Taking the chance to add a feature. The tiny tongue (3 * 1.5 mm).



Other view. The core box needs a bit of finishing up.



And I changed it to core sand mould embedded in sand (vacuum doesn't work that well there).

The compressor head. Casting #21. Have already shown that one, but it was wrong, so got no number yet.


Casting.



Core box and core. Cast embedded in sand.


And a better core for the compressor.


Core box and two cores glued together. Yes, it is long and slim. No, it does not break.



Cores in the mold. This time, I placed the upper core the right way round. 
Still have a slight shrinkage in the area at the red circle, so I'll change the upper core. Not that tragic.


Nick


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## AussieJimG (Nov 4, 2012)

It just keeps getting more amazing

Jim


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## MuellerNick (Nov 4, 2012)

Oh, here is a very short video of a smaller one, but also from the "DM"-series:
[ame="http://www.youtube.com/watch?v=VTppEG59xcs&feature=endscreen"]YouTube[/ame]
Maybe the 20 hp-version. Hard to say without an overview. Certainly not the 8 hp version, as that one had the A-frame and the base plate cast as one piece.

You will recognize the fuel-pump and the little feature I added. Also to be seen is a part of the compressor (at the left) with the coolant-passage (the smallest casting so far). It is just above the spring sticking out the fuel pump. Stop the video at 0:33 to see better.

Edit:
And here is the smallest version, the DM8.
This engine can be seen in Augsburg, where MAN has his museum and archive.
[ame="http://www.youtube.com/watch?v=ykKooloIafg&feature=related"]YouTube[/ame]


Nick


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## MuellerNick (Nov 5, 2012)

Re-reading the whole thread, there are some questions left unanswered:

Bore/stroke is 450/680 mm. That makes for 108 liters displacement. At an scale of 1:10 that will be 45 * 68 mm with 108 cm^3.
The plan is to make a true running diesel.
But first, I'll make a static display model with two cylinders as shown. All parts moving, but not running on its own. Next step will be the one-cylinder version. On that one, I'll try to get it running. I do not intend to place the fuel pump etc. where the original is, because that would not work, or in other words, I'd have to leave the scale appearance. Most important part is the scale. Functionality will be hidden in the model's base. So all the injector things, lubrication etc. will be in the base.

3D-printing for patterns:
All 3D-prints I have seen are not worth considering as patterns. Way to rough and staircases in slightly off-horizontal areas. They would need more rework than milled patterns and cost more money.

I'm using block material from Renshape. One (the beige one) is with 700 g/l density for the core boxes. The other one (green) is for matchboards (funny number hard to remember). The beige one is more sensible than the green one, but cheaper. Until now, I have spent 600 &#8364; on block material (and will have to order new one).

If I have left out to answer question related to that model, just ask again or PN me as a reminder.


Nick


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## MuellerNick (Nov 5, 2012)

The reason why I started vacuum assisted was this casting:

Casting #22. Protective cover for compressor linkage.
Since I started experimenting with the vacuum assisted casting, that thing never worked. First, because of wrong parameters. But I found them two weeks ago. And second, because for an still unexplainable reason, the inner core was too big. So I took that one, measured, compared it with the CAD. Too big. Verified it against the G-code, too big also.
So today, I milled it again &#8230;




As cast, with the gate still in place.



A old reject, with the gate sawn off. The problem of that casting is the thin shell (2 mm) and the fact, that the melt has a long way to reach the end of the cavity.



3 core boxes. The lower one is for the core. A core out of core sand to go into a mould out of core sand.



The cores. The core I'm holding in my hand is the core. The half cones match into the core moulds and align that core within.



One half of the core mould with the core sitting at its place. The slanted face at the lower left, I have to manually sand down. Or the core box would have been gotten more complicated. Sanding down is quick, I just rub the part on the table, the core provides its own sand for sanding.


And today, while having a walk to lunch, I made an invention.
DTC. Short for DeskTopCasting.
You already know, that I do embed core sand molds in oil sand and cast them there. This is for castings that need more feeding like the compressor head. They don't work with vacuum assisted casting (unless I change the mould and make it much bigger).

The idea was to cast a pot for the melt that is glued on the mould and provide enough room for hot metal to feed the casting while cooling.


Well that's such a pot glued to a mould.



Two tests, all worked like I wanted them. One is the head for the compressor, the other one the fuel pump.


Time to have a beer ...
Nick


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## mu38&Bg# (Nov 7, 2012)

At 108cc diesel injection is possible without making the injection system entirely too small. What is the original compression ratio? Will you increase it to account for the greater heat loss at scale size?


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## MuellerNick (Nov 7, 2012)

I don't know what the original CR was. But with 108 cm^3, a CR of 20 should work.

Again, I intend to make a scale model. With the focus on scale.
If things don't work without disturbing the scale-ishm, they have to be hidden somewhere.
I have put a lot of effort into getting the right dimensions, and not just some guesswork with 3 pictures and thousand dimensions guessed. So I would be quite nuts to throw away that work (I'm nuts, but not stupid. Well most of the time). 

Mill is just cutting its final paths for a new pattern, so hopefully two new castings this night ...


Nick


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## canadianhorsepower (Nov 7, 2012)

AWsome work. are you going to put them in a tumbler after
 are they will remain the way they are now


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## MuellerNick (Nov 7, 2012)

> are you going to put them in a tumbler after
> are they will remain the way they are now



I will slightly glass-bead them. Helps to improve for the lacquer to stick on. I tried it with etch primer, but the coat is way too thick. I have 30% thinner in the lacquer, but it is a high quality one and a single layer is enough.

Casting #23. T-joint for coolant, fresh from today's first test pour.



Admittedly, I was a bit too violent when hammering out of the core sand mould (DTC) and it broke off (you can see the CA).



Core box and core. Takes two of them, part is symmetrical.

Well, lame! I can do better!

Casting #24. T-joint for intake. Also cast with DTC.



Out of the mold. Fail?



Not at all! Wall thickness in the pockets must be something less than 1 mm.
Edit: Way wrong! It is 2.5 mm!



Different view. The scratches in the bore are from removing the core.



And an other view, because I'm quite proud of it!



Core box and core for the mould. Also takes two of them.



Core box and core for the core. I'll add pins for aligning the two box halves.



Core in the core sand mould. Needs no fixing or aligning. Just drop it in.

I'll make a little modification to the core box of the mould to get more wall thickness at the gate. Just to be sure.


Well, can't complain!

I'll have a beer now &#8230;
Nick


----------



## MuellerNick (Nov 9, 2012)

So you are lost in What-goes-where-city?
I do have a map for you:



Additions around the cylinder head. The second cylinder head will be left of part #24, just symmetrical.
#23 is roughly placed where it will be.



The A-frame with a few parts. The compressor is already known as a sub-assambly. But at that one, I had a wrong part.



And an other view, also with a Deckel FP1 mill (same scale) for size comparison.


Things will slow down a bit, as I have more patterns to make. I'm working at the gear-housing for the cam shaft (3 castings) plus the cam shaft mount that also serves as a mount for the cam shaft gear. Will be at about symmetrical to "/7" in the first picture of this post.

But don't worry, I have enough old castings to fill the gap!


Nick


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## MuellerNick (Nov 15, 2012)

Got some news ...

Helped a friend to build a barn in the last few days. Scaffolding, filling concrete, etc. He told me, he is building a foundry. That was a lie! Now I tell everybody, he is building a Mosque. In the catholic Bavaria! 
After that, I caught a flu. Hope to be back tomorrow or the day after.

But I got enough material to show. So two "new old" castings:

Casting #25. Generator housing, upper half.



The casting.



The pattern.



And the pattern (a split one) from the other side. This side goes up when casting.
One pattern part (the left one) in place, the other one sitting left of the index pins' bores.



The core. Where my indicator finger points to, there is a recess in the core. that shapes the oval mounting surface for the generator's collector ring arms (already shown).



The core box. The middle part has those pockets. The lower one is facing the wrong direction, it will close the mold.

This core is also used for the next casting ...


----------



## MuellerNick (Nov 15, 2012)

Casting #26. Generator housing lower half.
That one is a bit more complicated.



The casting.
I had to bore two holes into the core (same as above casting) to insert wood screws into the core so I could lower it into the mould. These are the remains.



Detailed view. There is a pocket where the arrow points to. Also note, that my thump also slips into a pocket. That was necessary because the original was cast that way and to avoid shrinkage (that's why they did it).



Look into the pocked my thump slipped into.



The pattern. The face facing downwards looks the same like the upper half, also with two parts to go into the cope.



That's where one core goes to (black = core print).
This one makes the upper pocket.
The one for the other side is not the same, but mirrored.



Other core that makes the lower pocket (with my thump).
Same for the left side.
The two red lines meet in the mould.



Core box for the upper core (upper pocket). This one got a bit complicated. By exchanging two parts (in the upper left & right), it makes either the left or right  core.



Partially disassembled ...


And completely disassembled.



Core box and core for the lower pocket (thump ...).


----------



## MuellerNick (Nov 15, 2012)

And one picture missing ...


Core box for the lower pocket.
These two core boxes look quite odd. But the problem was, that the draft was either inward or outward. In this picture, part 3.1 was outward, and parts 3.2 and 3.3 were inward (or the other way round.

Here's a video, that might make it more clear how parts match ...
[ame="http://www.youtube.com/watch?v=L_Ppd_LJ5tM"]YouTube[/ame].

Edit:
That was my old core sand mixer. I have built a vibratory one in the meantime:
[ame="http://www.youtube.com/watch?v=7dFqHGV12is"]YouTube[/ame]


Nick


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## MuellerNick (Nov 24, 2012)

That stupid not-a-foundry-barn is almost ready now, at least for this winter to come. And I'm way behind my schedule.

So a new old casting and some assembling (with hot glue).

Casting #27. Timing ring for the generator.



It takes two of them to make a ring (I think). Where I marked with the felt tip, that part gets milled off, just the lever is left. I did it that way, because there needs to be a groove around the circumference. In that groove, rolls go in that allow the ring only to rotate.
The two rings are bolted together in that small pocket near the end of the arc.



The pattern, a simple one.

And two assemblies:


The timing ring together with the arms for the brushes (to the collector).



And the generator housing with two of the arms that guide the timing ring.
The housing is about 230 mm wide, the inner diameter is 130 mm (IIRC).
The two blocks the housing stands on are ground level.



and the previous two sub-assemblies held together.


Nick


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## MuellerNick (Nov 24, 2012)

... and a similar view of the original:


The lever for the timing ring to adjust is in the lower left, almost disappearing.
Someone has taken that one off, but I do have a drawing how it should look like.


Nick


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## stevehuckss396 (Nov 24, 2012)

outstanding!!!


----------



## starnovice (Nov 25, 2012)

WOW Nick! 

I have been doing castings for years and I just realized that I am still in kindergarten. You sure have given me some new directions to go.  

What kind of glue do you use for your cores, especially when you glued them together for you "desk top casting"?

Thank you for making a little less ignorant than I was yesterday. 

Pat


----------



## MuellerNick (Nov 25, 2012)

Initially, I glued the cores with high viscosity super glue. That works, but not too well.
After having tried some different glues, I like the brand "Kolper 7" the most. That is a quick glue for cores. All core glues I have tried are water glass based.


Nick


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## Dave Sohlstrom (Dec 2, 2012)

Nick

We need an update. I know I am going into withdrawal. 

I tried to find information on Kolper 7 but came up with nothing.

Dave


----------



## aonemarine (Dec 2, 2012)

Dave Sohlstrom said:


> Nick
> 
> We need an update. I know I am going into withdrawal.
> 
> ...


 
Me too
Its sunday and I have to go to work, an update would cheer me up a bit while there.


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## MuellerNick (Dec 2, 2012)

Hmmm ... update!?
I do have made 3 new core sand molds. One worked perfect, one was a close miss and the third one a complete miss. Then, I have made three more patterns with each having a core. But I didn't cast these as I had to catch up with other things.

I think you'll have to wait until Tuesday for updates ... I'm sorry. But also happy that you are still reading.

Re the core sand glue:
Well, it looks like I have something top secret. I couldn't find it either.
It is best if you contact your local foundry equipment company and ask for a quick core sand glue. The one I use takes less than 1/2 hour until you can cast. There certainly is more than just one manufacturer.


Nick


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## starnovice (Dec 2, 2012)

MuellerNick said:


> Hmmm ... update!?
> Re the core sand glue:
> Well, it looks like I have something top secret. I couldn't find it either.
> It is best if you contact your local foundry equipment company and ask for a quick core sand glue. The one I use takes less than 1/2 hour until you can cast. There certainly is more than just one manufacturer.
> ...



OK Thanks Nick.

Pat


----------



## Herbiev (Dec 2, 2012)

Pat have you tried sodium silicate (water glass) and then apply carbon dioxide gas. Its been years since I've cast anything but from memory it sets very rapidly once the Co2 is applied


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## starnovice (Dec 2, 2012)

Don't want to steal Nick's thread, but yes I have used waterglass and it is good for making cores.  

However the issue is that sometimes you need to make your cores in multiple parts and then glue them together to get a complete core.  Think of all of the cores that go into a water jacket on a V8 for instance.

Pat


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## MuellerNick (Dec 3, 2012)

Once more to the core glue:
The problem is, what you can get locally. I do not know what manufacturers are available at your country. Here, we have at least Hüttenes-Albertus and foseco. foseco seems to be a global player, and so maybe doesn't care of you unless you order 1 ton. You still can phone them and ask for dealers. An other way is to visit/phone a local foundry and ask where they buy. If you visit them, don't forget to take some of your castings with you, that often opens the doors.

Both of the manufacturers mentioned do have a fast core sand glue. They both do contain acetone and sand. Both are waterglass based, but both do not need CO2 from a tank to react.

If all fails, high viscous CA glue works too. But you have to pay attention that it doesn't come in contact with the melt, or it would generate a lot of gas and you'll get blow holes. You also need an activator.

I know, that it is a problem to get professional foundry chemicals. Finding a source is just part of the whole process. Again, your biggest chances are at a local foundry (if still available) and being a bit penetrant and whiny to find the right person that gives you the good stuff. An other weak point to break the chain would be a local representative of a foundry chemicals company. They do have samples, and you can go a long way with what they call "sample". Big foundries need tons of the chemicals per week, you only need a kilogram a year.


Hope that helped,
Nick


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## MuellerNick (Dec 4, 2012)

I hope that was worth waiting for!

Casting #28. Con-rod for the fuel pump, at the right cylinder.




As cast on the tree. Vacuum assisted casting.



Core.



Core box. Here you can see clearly, that I added a venting (better: vacuum) channel around the cavity.

Casting #29. Arm for the regulator.



As cast. The red line is where it will be cut off. Right from the blue line sits a core that makes a slot.
The two cylindrical features will be bored.



Other view where you see the slot. Wall thickness is 1.5 mm.



Core box. Makes one more core than necessary, but they are easy to throw away.



Core sand mould. In the upper mould, the cores are missing. In the lower, they are inserted. In my left hand, I'm holding such a core.


More in a few moments


----------



## MuellerNick (Dec 4, 2012)

Casting #30. Con-rod for the fuel pump, left cylinder. As that one has to slip over the cam shaft (the other one sits on the end), it has to be bigger and has a split big end (con-rod is "upside down")



As cast, vacuum assisted.



Sawn off. That's how the parts belong together.



That's where that con rod goes to.



Core sand mould.



And the core box. Nothing exciting.

As you had to wait so long, I'll have something special for you. It's not for this engine, but it shows how far you can push it with the vacuum assisted casting.
More in a few moments


----------



## MuellerNick (Dec 4, 2012)

Here's something to make you drool!

I have to admit, I didn't expect that to work. But I had to try. Well, the first two tries failed miserably, but I had enough headroom to tune the parameters and try once more.
So I cranked up the vacuum to the maximum and casted with 710°C. That worked. An other try with a bit less vacuum and 700°C also worked.
That means, I still have some room to get a better surface finish. But as it is now, slight sandblasting will give me what I want.

Handwheel for my Deckel FP1 model.
This handwheel is the bigger one. It only differs in diameter, the spokes etc. have the same dimensions.



The brown spot on the left of the rim is a cast bore. ø1.5 mm, 1mm deep. Diameter of the wheel is 16 mm.
The spokes are ellipses with 2mm mayor and 1 mm minor diameter.
There is some flash on the inner of the rim. That resulted from the milling bit being "too big". I'll tune the core box by hand at that place.



Other view. The axle also is the ingate. Diameter 2.5 mm.
At the remains of the runner, you see that the molt is succed out again. I had a spot in the mold that wasn't completely closed.



Crank for the Deckel. 13 mm wide. The handle is 8 mm long and has a diameter of 2 mm at the narrowest spot.



Handle that goes into the handweel (the cast bore).
Right from the handle is the switch for the spindle motor. Gets sawn off, so that the platen is just 0.3 mm thick.



Core box and core sand mould, one half ...



... and the other one.

Was that worth waiting for?

Nick


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## Herbiev (Dec 4, 2012)

How do you do the vacuum casting?


----------



## MuellerNick (Dec 4, 2012)

> How do you do the vacuum casting?



It is top secret, unless you read posting #30.


Nick


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## Herbiev (Dec 4, 2012)

Thanks Nick. Tried the search function "vacuum" but got nothing. 
Never did have much luck with the search function


----------



## aonemarine (Dec 4, 2012)

Well worth the wait.  What size end mill have you been using, and how long of a run time on a mold?


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## abby (Dec 4, 2012)

Nick I think your work is amazing but I am puzzled as to why you use sand castings for such small items.
It is obvious from the pictures that due to the coarsness of sand the surface quality of very small items is not as good as might be achieved by other means.
This locomotive valve hand wheel is by chance the same diameter (16 mm ) and cast in brass using the "lost wax" process




It is obvious that you possess great skill in CNC machining and could make wax injection dies as easily as core boxes so is there a particular reason why not ?


----------



## aonemarine (Dec 4, 2012)

abby said:


> Nick I think your work is amazing but I am puzzled as to why you use sand castings for such small items.
> It is obvious from the pictures that due to the coarsness of sand the surface quality of very small items is not as good as might be achieved by other means.
> This locomotive valve hand wheel is by chance the same diameter (16 mm ) and cast in brass using the "lost wax" process
> 
> ...



  I was wondering the same thing, once my CNC  mill arrives that's what I'm planning on doing.


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## MuellerNick (Dec 4, 2012)

That's the endmill I'm using:



Diameter is 1.5 mm, can cut 16 mm deep (not DOC, that is 2 mm IIRC). The funny thing is, that it is intended for hardmilling up to 64 HRC.
A friend gave me the tip to buy these, he uses them a lot for milling engineering samples in plastics. Compared to what he is milling, my work looks clumsy. But he is using 0.4 mm endmills 10 mm long.
They get more expensive the smaller they get. :hDe:

Both core boxes for the Deckel took 6 hours. I roughed them with a 4 mm endmill.


Nick


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## MuellerNick (Dec 4, 2012)

> It is obvious from the pictures that due to the coarsness of sand the surface quality of very small items is not as good as might be achieved by other means.



That's a valid question!

There are severals answers:
The simple one: Because I can.
An other one: I wanted to know wether that works.
A third one: I have that process at hand, but not the lost wax casting in that I didn't want to invest (a friend could cast these parts for me).
And a last and the mayor reason for me: I want a casting structure. After glass bead blasting and painting, the structure almost disappears but is still visible. I want that effect, you have to see that it is a casting. The outer side of the rim can be polished (hoping I don't bend the parts).


Nick


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## starnovice (Dec 4, 2012)

I was going to point out that while the surface looks rough if you compare the pits to Nicks finger prints they are about the same size as the lines on his fingers.  It is just good macro photography that makes them look big.

Pat


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## MuellerNick (Dec 4, 2012)

Addition:

This is not intended as an insult, this is just my personal attitude towards scale modeling:
All parts do have some character. A milled part looks like it is milled, a turned part looks like being turned and a cast part like being cast. Often, that are small details, or very obvious details.
With castings, it is the shape, the surface structure and the radii in corners.
If you look at the lost wax cast handwheel, it has lost all of it. Sharp corners where they don't belong to, smooth surface. It looks as someone has built it up from 5 pieces, soldering the spokes into the outer ring and the hub. Looks perfect as a work, but wrong as a casting.

An other thing is, that some details don't scale to scale. Means: If the roughness of the original is of value 10 (to whatever scale), that of the 1:10 model is not 1, but more. The reason is, that the human eye is scaling that different and has some prejudice about the process how it was made. If it is too smooth, casting gets excluded and it is seen as being machined.

Also, color do have a scale. A flat black just looks wrong on the model. It looks like a deep sump of black, where details are lost.

But that's just my philosophy&#8230;


Nick


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## Dave Sohlstrom (Dec 4, 2012)

Nick

Did a search on those end mills. Expensive is an under statement I think you could buy gold cheaper but it does not make a very good end mill.

I think I am working with small end mills at 3/32" but they are giants by comparison.

Dave


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## aonemarine (Dec 4, 2012)

They say,  a picture is worth a thousand words.  But they also say a picture doesn't do it justice.
Nick, your castings fall into both.  Personally i need to feel one in person to get a real idea of what your doing.
I really hope to do work like yours someday. Maybe in iron too. Time will tell....


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## MuellerNick (Dec 5, 2012)

> Personally i need to feel one in person to get a real idea of what your doing.



Yes, it is hard to tell from pictures how the real thing looks like. I always try to show part of a reference (hand), but it still is difficult.

These Deckel parts are more from the R&D-department than being really useful. The handheels are OK, I'm happy with them and I'll keep them. The crank and the handle is ... um ... well it is a casting. In the original, they are polished and chromed parts, so the casting structure makes no sense and is no gain. I think I'll shop them out or at least let make the RTV mould as I do have a spin caster (that is collecting dust).


Nick


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## ZAPJACK (Dec 5, 2012)

MuellerNick said:


> All parts do have some character.


I fully agree your point of view Nick. It's very complicated to build a scale model as close possible to the reality.
Thats also one of reason why, I prefer Cast Iron insted of Aluminium castings. It's a world of difference. The material choice and the material mix also very important. To much brass or an engine in full brass is not definitively not beautifull. Also the choice of screws & bold
Here one of my produced engine, if you look good, there a lot of fault
Question Nick, are you going to Karlsruhe in Jan 2013 ??
LeZap


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## MuellerNick (Dec 5, 2012)

> Question Nick, are you going to Karlsruhe in Jan 2013 ??



I will try.
I have no reservation, but maybe pictures of all the castings mocked together convince them to make an exception. There are always people that do not show up, so I hope to catch their place (keeping fingers crossed).
I was at Sinsheim several times, and my Ellwe was admired quite a bit.


Nick


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## MuellerNick (Dec 9, 2012)

Desaster-week!
I made 5 core boxes, three of them were wrong.

2 core boxes for the platform's support arms. I confused positive and negative. A long story to explain how easy that can be done. And so (there are three separation planes) core sand molds didn't fit together. I realized that yesterday when I made the core sand moulds. Changed the core boxes and milled them again 'til 2 o'clock this morning.

Then I made two core boxes for fence posts (around the flywheel and the generator). Having made the cores sand moulds, I realized that one of the posts should be shorter, but it wasn't. Didn't make that core box new yet. Anyhow, casting that posts is a challenge. I do get them cast, but with a rough surface. So I need more tries to show these.

Then I made a core sand mould for the steps up to the platform. That one doesn't cast that well either. I got only one 'til now. Will have to make more attempts. Luckily, when watching the mill, I realized that I made an error in the G-code. Now one of the steps (out of four) comes out of the mould already ruined.

So I do have just one casting to show. It is the platform's arm. There are two different ones (one just shorter), but I only have casted the longer one. The short one should work too (but with my bad luck this week )

Casting #31. platform's support arm, long version. Vacuum assisted casting.



Will be cut off at the red line. The lower arm is upside down.



Detail of the arm's end.



Core box and core sand mould. The red exclamation marks are a reminder for me to pay attention at this spot when ramming in the sand.


Hope I do get all that mess fixed until Tuesday
I had completely different plans for this sunday. I wanted to show an overview of all the castings arranged on a wooden base.
Well, things sometimes go wrong. :fan:


Nick


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## petertha (Dec 9, 2012)

MuellerNick said:


> ..out or at least let make the RTV mould as I do have a spin caster (that is collecting dust)...
> Nick


 
I for one would be very interested in this aspect (molding, rtv, spincasting etc). should you decide to post similar pictures & explanations in the future.

Your casting stuff is just fascinating. I came to realize I really had no idea how this stuff was produced. The work involved - jigs, technique, materials.. its like alchemy. I dont see myself going down this path for those reasons, but I certainly appreciate the work that goes into 'chunks of metal' castings we sometimes take for granted.


----------



## vcutajar (Dec 9, 2012)

Hi Nick

I am very sorry to hear about your casting mishaps you had this week. All I can say is that these things happen (don't ask how I know).

Although I know next to nothing about casting, I still find this thread fascinating. It gives me a glimpse at how it is made and makes me appreciate the extra effort one has to go through to just get a good casting.

Keep up the good work.

Vince


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## ZAPJACK (Dec 10, 2012)

MuellerNick said:


> Desaster-week!
> I made 5 core boxes, three of them were wrong.


Nick, It's not the end of the world !:hDe:;D


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## kvom (Dec 10, 2012)

Batting .400 makes you an all-star in baseball.


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## MuellerNick (Dec 15, 2012)

Long time no see! 

Casting #32. Short version of the platform's support arm.




No more pictures about that one, as the core box and core sand mould are very similar to #31.

More in a moment &#8230;


----------



## MuellerNick (Dec 15, 2012)

Casting #33. Long version of fence post.
This was the trickiest casting until now. I thought it will be a piece of cake &#8230;
I had to tweak parameters more than I would like to know. Just one notch up or down with the vacuum, and it fails. Just 10 °C off with the temperature, and it fails. I also had to go up to 750 °C, I normally cast the vacuum assisted parts  with 680 °C.



As cast. No, that would not work as a lathe part.



Different stages of failure. I do have more of them!



The core box. No pictures of the mould, I used up all of them.

Casting #34. Step of the platform's ladder.
This one also drove me nuts. But it wasn't as hard to crack than the fence post.
I also do have to cast that one very hot.



From the top. Ingate still in place. There will be a bore instead of it.



From the bottom.



With the gate and runner system in casting position.



Different failures. Here too, I do have more than I dare to know.



Core box for the lower layer, will be flipped over.



Core box of the middle layer, with the gates (bores going through).



And core box for the runner system (top layer). All three layers will be stacked and glued together.
Yes, initially I wanted to cast four in a go. But that didn't work that well. So I changed the runner's core box to feed just two cavities.


With the previous two castings, the model gets some visual scale reference.

Next, I'll mill the core box for the short version of the fence post. I think I learned a bit to make that one better. And I think I have found a way to cast the double walled exhaust tube&#8230;


Nick


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## MuellerNick (Dec 16, 2012)

Casting #35. Arm for the camshaft, for the left cylinder with mounting plate for camshaft gear-case. It is similar to castings #3 & #4 on page 3.



As cast in oil bound sand.



Other side with gate sawn off. The area where the gate goes in will be machined.



A bit tricky pattern. It has a shifted separation plane (hand carved) and a loose insert.



Both pattern parts, the right one with the loose insert in place.



The loose insert taken out. When pulling the pattern, I have to press down that insert through one of the two holes. Then there is a thread (backside) to screw a bolt in, pull it inwards and lift it out.

I'll have more today after the pizza.

Nick


----------



## MuellerNick (Dec 16, 2012)

Forgot these two pictures that belong to the previous casting:



Core box. No cores left, so use your imagination. Works like casting #3 & #4.



That is how the loose insert looks like after the pattern is pulled and it still sitting in the mould. It has to be slid inwards by about 1 mm and then lifted out.


More after the break


----------



## MuellerNick (Dec 16, 2012)

Casting #36. Lower half of the camshafts gear box.
Cast in sand, with a core and a loose insert.



As cast.



A look inside where the gears will go to.




Rear side. Arrow points to machining surface. The ingate (largish) is still in place, that's not a defect.



Pattern. The left one has a loose insert.



Here, loose insert removed and flipped over. The thread is for pulling it out of its pocket.



The loose insert still in its place in the mold. It is quite a close call to get it out. I had to add that ear for the thread. Fortunately, there was just enough room for the ear in the pattern itself.

Casting #37. Upper half of the gearbox.



As cast.



A look inside.



The pattern. Nothing fancy here.



And the core box for both.

Just a moment ...


----------



## MuellerNick (Dec 16, 2012)

And casting #36 & #37 "assembled" after roughly grinding off the gates:



There are 2 mm machining allowance on both mating surfaces, so things look a bit offset.

That's it 
Nick


----------



## stevehuckss396 (Dec 16, 2012)

You sure have mastered the art of casting.


----------



## MuellerNick (Dec 16, 2012)

And here is a picture of the original:



Nick


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## starnovice (Dec 16, 2012)

MuellerNick said:


> Casting #36. Lower half of the camshafts gear box.
> Cast in sand, with a core and a loose insert.
> 
> View attachment 59112
> ...



Edit - This is supposed to be the picture of the camshaft gear box pattern.  Somehow I did not get it right.

Nick,
What material did you use for these patterns?  Are you milling them directly or creating a mold for them.

Thank you for putting so much work into documenting this.  It is truly fascinating.  Having done a fair amount of Al casting I am just flabbergasted at the levels you have taken this.  I am hunting up a vacuum pump so I can try the vacuum casting.

Thank you again.
Pat


----------



## MuellerNick (Dec 16, 2012)

That is blockmaterial from Renshape. Don't remember the type, but it is for matchboards.
I directly 3d-mill it and then use it. Very good to mill, sand, polish, bore, tap, glue ...

Nick


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## starnovice (Dec 16, 2012)

Thanks Nick, I am aware of blockmaterial I have just never used it.

Pat


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## MuellerNick (Dec 16, 2012)

It is "RenShape BM 5172-1".

Nick


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## AussieJimG (Dec 17, 2012)

Still following, still amazed

Jim


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## MuellerNick (Dec 20, 2012)

Clamping those patterns:

You might ask yourself how I do clamp all those patterns, no matter how small or big.

Easy for core boxes, they can be clamped in a vise.

Well, I asked that when I started milling them. The most obvious option is using a vacuum chuck. I didn't like that for two reasons:
I don't have one (might cast one next year).
I don't like the idea of having a pump running for hours. Making noise, costing money, and what happens if you have to pause a job?

So I thought about a way to clamp that block material in a way that is solvent based. Well, I had no good idea exactly like that, but something along the line:
I use cut-offs of the block material, mill ribs and glue the stock onto the ribs with CA glue.
Why ribs and block material?
This has four advantages:
I can easily saw off the work with a saw blade (hack saw),
The CA is harder than the block material, so it works like a shield that prevents cutting into the work. Going too much down, you cut the solid material -> blade goes up. Cutting too high -> cut into the hard CA -> blade goes down.
Furthermore, the ribs do give room for the clue the be squeezed to the side, thus making a very small layer of glue (precise reference).
Also, I do have a precise reference for Z = 0, as I mill the surface with that milling bit.
And last but not least, you can mill into the chuck. That's a requirement if you use ball nose/bull nose mills.

After cutting off the work from the "chuck", I file off the remains of the ribs and dissolve the CA with acetone.

Medium viscosity CA works best.

While milling those tiny parts today, I thought I make some pictures.




This is the smallest part I milled for the patterns. Its footprint is 5.5 * 8 mm, 4.5 mm high. Mill is 1.5 diameter, and the cigarette lighter is scale 1:1.



Different view of that part. You can see the thin skin that remained from roughing and the fact that I cut into the ribs while finishing.

Usually, I make those ribs 1 mm wide. Width of the groove depends on the mill's size. Here it was 1.5 mm. Usually, it is 4 or 6 mm wide.


Nick


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## idahoan (Dec 20, 2012)

Hi Nick

I wanted to tell you that I have really been enjoying this thread; your pattern making skills are amazing.


Thanks for taking the time to share your project with us.



Dave



PS. we run quite a bit of Renshape 460 at work making industrial design models. We pretty much tape every thing down to an aluminum fixture plate with 3M double sided tape. 

When parts get very small as yours the surface area becomes an issue as the parts want to move around so the fixture with the CA glue would probably be better; I will have to remember that one.


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## MuellerNick (Dec 21, 2012)

Yes, double sided tape is an other option. Doesn't work too well for parts that are high compared to their footprint.

I have used my method for more than 100 times and only once, a part came loose. That was, when I didn't give enough time for the clue to settle (was an old one that got quite slow). No matter what shape, all parts came off easily without breaking them.

For "big" parts, I don't put glue on every rib, but leave out two or three.


Nick


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## MuellerNick (Dec 21, 2012)

The shape of things to come &#8230;

Won't be able to cast that tomorrow, as one half takes 8 hours to mill. And the first one is still making chips. 50 minutes per spoke to finish mill.

After roughing:


Will be much more elegant, the spokes are quite rough. No wonder, it is just roughed. 

Diameter of the pattern is 430 mm!


Nick


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## johanvanzanten (Dec 21, 2012)

*Hello Nick,*

*I follow your thread for some time and I must say that I admire your work. I made a working diesel engine myself  for a few years ago and I know the amount of work involved. I have experimented  1 1/2  year to get it running. Blast injection became a fiasco; I even was unable to get compressed air at 80 Bar safely. At last I switched to solide injection which worked rather well at the end. The engine involved is a 1**:10 schale model of the 250/400 engine made by the Diesel team. Please browse my album on the Model-Engineer page to see some photo's.*

http://www.model-engineer.co.uk/albums/member_photo.asp?a=6778&p=123122

*I* *whish you lots of succes with this ambitious and interesting project.*

*Kind regards,  Johan van Zanten  (The Netherlands)*


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## AussieJimG (Dec 21, 2012)

This is a wonderful thread. Merry xmas Nick.

Jim


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## MuellerNick (Dec 21, 2012)

Hi Johan!
Thanks for your wishes! I already knew your wonderful work. And I have read about your tries to get blast injection working.
I already learned that it is almost impossible to make a compressor to 80 bar working at that scale. Getting him tight is not the problem, but dead volume is.

I'll see how injection works. I have collected a lot of ideas over the time. They "just" have to work. 


Nick


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## MuellerNick (Dec 23, 2012)

It is Sunday, and you deserve new pictures!

The not-that-much-shape of things to come:


That's how it looked when I came back from dinner. I started a roughing job right before leaving.

Casting #38. Fence post, the short one.
After having too much trouble with the long version, I thought what I could improve. Added more ingates. I tried that with the long version, but also thought that I should try it with gravity feeding. So I did that with the long version and it worked. Being confident, I did the same with the short version. And it worked too!



As cast.



Detail of the crown, no deburring etc.!



Core box and core.

Next two parts will need more pictures, so a new posting. I'll be right back


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## MuellerNick (Dec 23, 2012)

Casting #39 & #40. Elbow for the exhaust pipe.
I have to admit, it is not finished. But casting-wise it is. The pattern needs some re-work and I need to make a mandrel and a roll for my mandrel bender. More about that later.



This is the left and right one.



Left one held at the cylinder head (a reject).



This is the core box for the outer contour of the pipe. On my left finger sits a tiny loose insert. It is color coded, as the left and right one are different.



After rattling out the core, the loose insert still sits in the core. Pulled out inwards. It just slips out of its pocked in the core box, so that's why they call it loose insert.



The core box for the inner contour. In the lower left cavity, the core still sits in. The two red circles are reminders for me. The two red lines is the "ingate" for the sand. This is the only access, because part of that core will be a stainless steel tube ...



That SS tube (to come) will replace the cylindrical part (red rectangle of the core) and keep the core in place. That core is a shell around the tube and builds a water jacket. Yes, the exhaust pipe was water cooled.
On the left core that I'm holding, you see pockets that allow enough wall thickness for the pockets you can see on the outside of the casting.



Cores for left and right (cast both in one go) and with the cores inserted. Just the cores alone doesn't work that well, the construction of the mold relies on the tube. That tube will close all accesses to the outside, just leaving one bore for the metal do go in (middle bore at the very lowest end of the picture).

Well, that's it for today!

I have two more patterns finished. Maybe I'll cast them tomorrow. They are too big (one of them) to be cast inside. Depends on the weather. Forecast is 12 °C. 


Nick
... and a merry X-mas to all!


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## MuellerNick (Dec 25, 2012)

I thought, I'll make myself a Christmas present  but it went wrong.



This should be the exhaust pipe. Here, with all the runners and ingates etc.
It wouldn't be me, if I wouldn't cast it double walled like the original. There is a waterjacket around the inner tube, and I wanted that too! Wall thicknesses would have gotten too small, so I cast that around a stainless tube with 10 mm OD.
Does look like a near miss.



But from the rear, it is a clear fail.



Looking at the face, the SS tube shifted. It was bent by the heat of the melt. The reason was (I guess), that the runners weren't fed with the same timing. One got the melt a bit earlier.



Core around SS tube in the cavity. Yes, it is almost 400 mm long.
You see a gap in the core that allows access of the melt to the tube. That was intentionally. It seves as a runner and to make all a bit stiffer. Maybe that was a bad idea and I should isolate the inner tube completely. I'll partially patch up that gap with oil bound sand the next time.



Detail.



Pattern and core & tube. The nibble on the core points upwards when casting.


Nick


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## AussieJimG (Dec 25, 2012)

Still absolutely amazing. Merry Xmas.

Jim


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## Banjoe (Dec 26, 2012)

What an incredible journey. Many thanks for bringing us along on this adventure!


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## starnovice (Dec 26, 2012)

Do you need to pour at the middle of the pattern instead of at the end?

Pat


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## MuellerNick (Dec 26, 2012)

> Do you need to pour at the middle of the pattern instead of at the end?



I think the runners on both sides distribute to the ingates evenly enough. The runner going to one end at just one side was more like a test wether it makes a difference. It didn't.
As far as I see for now, the main problem was the core. I rushed that a bit too much and didn't pay enough attention to equal thickness. Also, the way I glued the core to the tube was a bit counter-productive. I used CA. The problem with CA is, that I made that at the place where I cast the cores. The amin (ammonia) activates the CA in a funny way, so it expands a bit. I'll try a different clue and pay more attention that the OD of the core is to specs. Also a better runner (pay attention to equal timing) and the runner in the core different (haven't decided yet how exactly). And higher temperature (700°C).

I'll have a mid-year's party tomorrow with some of my friends. So I desperately need to clean my shop (doesn't hurt at all). I'll have time for casting this Saturday.


Nick


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## MuellerNick (Dec 28, 2012)

25 minutes ago, I dropped the last pattern/core box in the vise.
Just now, I made the last toolchange!

Supposed all works well, I should add.

I'll have a beer now. When my Maho is finished at 2 o'clock in the morning (30 minutes from now), she'll get a real strong hug and a big kiss on here oily spindle. 


Nick


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## metalmad (Dec 29, 2012)

Hi Nick
Does this mean your nearing the end of the project?
Please say its not so!
I love this Thread
Pete


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## MuellerNick (Dec 29, 2012)

> Does this mean your nearing the end of the project?



Do you think I'm finished when I have a pile of un-machined castings?

I've got 4 more small casting, fresh from the foundry. All were cast with vacuum-assistance.

Casting #41. Coolant passage between cylinder head and A-frame. That one is similar to the passage on the compressor. But it is a bit bigger.



Two with one shot. Will be cut off at the red line.



Different view.



Core and core box in the background. I need one passage per cylinder.

Casting #42. Lid for the flywheel bearing. It should look familiar to you, but it is a bit bigger than the other one.



Two of them.



View from the back. The right one is the smaller (old) one.



Core box. No, that's not a crack in the lower left. I patched up some cutoff. The gap doesn't hurt in that place.



And core.

More in a moment


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## MuellerNick (Dec 29, 2012)

Casting #43 and #44. This are two different parts, so they do have different numbers. But they are cast in one mold. Both belong to the service platform.



This is a clever (by my standards) mould. One part has a split line, and I don't need that much of them. The other one is a simple pattern and I need more of them. So the split one went to the side of the runner, the simple one to the top. As two of the core molds are needed (same, just flip one over), I get 6 of the simple one.

Casting #43. Mount for the ladder to the platform.



It needs some milling and fitting at the red line.

Casting #44. Mount for the platform's fence posts.



Will be cut off at the red line. The eyelet will be bored, and the post will go into that bore.



Core box and core.

Well, that's it for today. I'll prepare a bit for casting tomorrow. I'll see how far I get.


Nick


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## MuellerNick (Dec 30, 2012)

Things not always work as planned &#8230;

On this Sunday, I thought I'll cast my last parts (at least for the first time, The A-frame, the flywheel and the cylinder head need one more casting). So a nice coffee, some relaxing, smoothly prepare the moulds&#8230;
Smoothly?!
The cope for the flywheel broke when I assembled the mold. But it looked like it still works. So I fired up the furnace outside and waited for the melt.
While pouring, I knew that this won't work. I throtteled the gate, as there is a lot of mass to be cast. But not that much! It took to long and I had my doubts about the volume.

Breaking the mould, it didn't look too bad &#8230;



Until I turned it over.



So I decided to make an other mould for it, while cranking up the furnace to try that one in CI.
I made the mould, assembled it, and &#8230; it broke. So I went out to have a look at the furnace. It burned. It burned inside and at the outside. Oil dripped out of it and started to burn on the floor. Disconnected the fuel and let that crap burn.

Saturday, I had prepared a new core for the exhaust pipe. This one, I can cast in my shop. All went good. Mould did not break. Casted it and &#8230; well. At least it got way better:


There is an other void on the back, even smaller than the small one. Judging from the surface, I have left room for an even hotter pour. This one was 700 °C.

Hah!
I have an other casting to do. This is the dumbest of the whole project! Maybe this one works. Lets see&#8230;

Casting #45. Coupling between flywheel and generator. I need two of them.



I think I don't need to show the pattern for it. The pattern was made in the kindergarden (right here in my shop, I guess).

Tomorrow is another day. :fan:
Nick


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## MuellerNick (Dec 31, 2012)

Thought I like this. Maybe you like it too.

Note: There are a lot of rejects in this mockup. And hot-melt glue doesn't allow precise alignment.






















And a happy 2013 with no rejects to all!

Nick


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## aonemarine (Dec 31, 2012)

I am a difficult person to impress, but you have done it many times over with this project. I have also learned quit a bit from your posts and that's something you can't put a price on. Keep up the great work.


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## MuellerNick (Jan 1, 2013)

Took a few shots of it outside. The flash doesn't make that good pictures.
Also added two rocker arms (of 4), fence posts and steps for the ladder to the platform (2 steps missing).

















Again, hot glued with quite some rejects, so don't complain about the crap. I have better parts I just don't want to ruin for this mockup.


Nick


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## aonemarine (Jan 1, 2013)

even with all the shrinks and shorts it still looks good, maybe go ahead and put it together as a post apocolyps model?


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## MuellerNick (Jan 1, 2013)

> and put it together as a post apocolyps model?



I will keep the failed A-frames and put a light inside. Makes a great bedside lamp.


Nick


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## AussieJimG (Jan 1, 2013)

And a Happy New Year to you too Nick, what a stunning achievement in 2012; if I had not been following the thread, I would not have believed that you started with 
photographs and photogrammetry. And you have pushed casting to new levels.

If 2013 follows this pattern (sorry) it will be a great year.

Jim


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## MuellerNick (Jan 7, 2013)

Long time no read.

I'll leave for Karlsruhe (steam model fair and stationary engines) this week. So I have a schedule that is getting tighter every day. 

But I tried the exhaust pipe again today.
Now I can select what types of holes I want in the tube. From cold runs or from core gassing.
Looks like I need to add venting holes. After breaking the mould, it looked very good. Then I saw little cracks. When I scratched with my fingernail, I broke through. Just a skin of aluminium and a hole behind it. Happened in three places. Surface also looked like there is a gassing problem.

Well, you'll hear more next week. Or maybe we see us in Karlsruhe.


Nick


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## Dave Sohlstrom (Jan 29, 2013)

Nick

Are there any updates for this build.

Dave


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## MuellerNick (Jan 29, 2013)

> Are there any updates for this build.



Currently not. I need a bit of a break from that (pushed quite hard for the fair in Karlsruhe).
So I made the accessories for the Deckel FP1 model (done), cleaned that Stirling (done), bought a used wheldresser (an Optidress) that I repaired (done) but have to mount to my T&C grinder (not yet) to make grinding special tooling easier.
Also will have to make castings that I was asked for (this week), ...

But don't worry! I made the Deckel patterns with the background of trying techniques for turning and milling tiny parts.

Edit:
I'll also have to make small bolts. I think I have found an effective way (while doing the Deckel parts) to do them completely in the lathe (including the hex). That will require gang-tooling and I'll need to make a fixture for that.


Nick


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## Dave Sohlstrom (Jan 29, 2013)

Thanks Nick for the update. Sounds like you have your hands full.

Dave


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## Dave Sohlstrom (Mar 5, 2013)

Nick

New question. Can your method for casting be used for bronze and cast iron castings also.
Have you ever measured the amount of vacuum you are pulling on the chamber.

Dave


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## Holgi (Dec 25, 2013)

Just registered for this forum to express my respect for Nicks work! What kind of amazing skills! Really fascinating.


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## Grigg (Aug 21, 2014)

Any progress lately on this project? 
I have really enjoyed following along, eager to see and learn more.

Grigg


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## Dave Sohlstrom (Aug 21, 2014)

Nicks last activity was on 5-12-13, so hard to say if he will be updating this thread.

Dave


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