# Rudy Kouhoupt's Open Column Steam Engine - Cast & Double Size



## vederstein

Well, time to start another steam engine, but first some background...

Generally I like working with castings.  I like the look of them.  I like the fact that I don't have to screw around with machining non-critical dimensions and I can focus on the precision parts that matter is appealing to me.

The problem is that I've run out of casting vendors in the price range to which I'm willing to pay.  I simply cannot justify spending over $300 US on what is essentially a toy.  Also, I like larger models.  The tiny fiddly bits on the small engines are simply annoying to me.

Therefore I'm moving in a new direction and am going to (try) cast my own components.  I built a furnace which I documented here on Instructables.  For material I have an old engine (in pieces) from my '65 Corvair in the shed that I cam melt down.

In a month (Christmas gift to myself) or so I'll be obtaining a 3D printer to do lost PLA or lost wax casting on the components.

So I needed to choose an engine.

I have a book of model engine plans by Rudy Kouhoupt.  Those engines are simple in design but a bit small.  Flipping through the pages, it looked like the Rudy's Open Column Engine would look good double sized and it can be gussied up by using castings.

So here's my proposed engine.  2-1/2" bore x 2" stroke.  Single Acting.  Many parts from cast aluminum.

I plan on documenting the casting process and my experiences in machining said castings.  As for the bar stock components, I will probably not document those because It's nothing new that I haven't documented in the past with my other builds.

I _would_  post the design drawings but the original design is from a copyrighted book.  Even though I heavily modified the original design, I don't believe I can legally post the design without permission from The Village Press.

Wish me luck....

...Ved. 







View attachment Assy - Open Column Steam Engine.pdf


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## bmac2

Hi Ved thats a good looking engine Ill definitely be following along. Could you post some pictures of your patterns along the way?


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## Herbiev

I'll be following this one. Sounds great.


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## Cogsy

I'll be following too. I hope to get some casting done myself this summer, if all goes to plan (it rarely does).


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## vederstein

I've started some of the barstock parts, but the meat of the matter will have to wait until January when I get set up with the printer.


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## Engineville

Vederstein,


Which of the Rudy Kouhoupt's books are you referring for this project?  I&#8217;d like to purchase my own copy of this book.


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## bazmak

Looks good but a little lop sided with 1 flywheel.If you are making major changes to the design can you not add another flywheel and make them a touch smaller?  Just a thought


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## vederstein

Engineville said:


> Vederstein,
> 
> 
> Which of the Rudy Kouhoupt's books are you referring for this project?  Id like to purchase my own copy of this book.



Here's the Amazon Page to purchase the book.

https://www.amazon.com/dp/B01FELXRKO/?tag=skimlinks_replacement-20


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## vederstein

bazmak said:


> Looks good but a little lop sided with 1 flywheel.If you are making major changes to the design can you not add another flywheel and make them a touch smaller?  Just a thought



I like them to run slow.  But I'll consider your comments and see how it looks.

Thanks for the suggestion.

...Ved.


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## abby

Being a foundryman at heart I like all casting projects but I can't help wondering what metals you are going to get from an old car engine.
I would think that only the aluminium will be within your melting capabilities , hardly ideal for a steam engine .
Wouldn't an IC engine be more sensible ?
Have you investigated lost wax or lost PLA casting ? 
What investment are you planning to use ?
Dan.


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## vederstein

The Corvair engine was an all aluminum engine with cast iron cylinder sleeves.

Aluminum is what I plan on using except for perhaps the flywheel where I may purchase some zinc for the heavier mass.

I know that cast iron is preferred, but this is just a model and it's not intended to do any real work.  It would be very out of the ordinary if it ran for more than 30 minutes a year.

A few years ago I tried making my first IC engine, the venerable Webster.  I think I'm the only person on earth that has failed at getting it to run.  That was a bummer and I'm intimidated to try another IC.

As for my experience, I have none other than making aluminum muffin ingots.  I've been learning what I can on the Internet and have learned a few things thus far:


Pouring temperature must be considerably higher than melt temperature.
Pour in a single shot. Do not stop until the vent holes start filling.
Aluminum shrinkage will be about 2-3 percent, so 3D print the parts 2.5% larger than final dimensions.
Apply vents at any "peaks" in the wax or PLA part.
Ensure all wax or PLA is burned out and blow out the ash with an air gun.
The burn out process should happen slowly, incrementally raising the temperature to prevent cracking the investment.
Try to complete the pour while the investment is hot.
So I have _some_  knowledge.  What I totally lack is experience.  But then ten years ago I had a total lack of experience in machining.  Now I suck much less.

Thanks,

...Ved.


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## charlesfitton

Might I suggest H Greenly's engine?  Much better looking...


[ame]https://www.youtube.com/watch?v=PHhOG2E0g0U[/ame]


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## abby

Ved I think your project is a great way to start investment casting , in fact I started in a similar way casting in aluminium.
However the route is fraught with problems to overcome the least of which is melting the metal.
Most importantly , the heating cycle for your investment mould requires a controllable kiln ,  not just temperature but time cycles too , they are expensive items but it is possible to build your own .
I made my first using the elements from an electric storage heater fitted inside a ceramic lined steel box , control was via an Apple IIe with a homemade i/o board and software written in basic.
You can now get a programmable controller for under 100 USD , VERTEX make a good one although programming can be a brain teaser.
I wish you well with your project and will try to help when you hit problems.
Dan.


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## MRA

Hi Dan - still not done anything with the wax you sent me.  Do you have a site to recommend for reading up on cooking the investment?  

Meanwhile - in repsonse to the OP - why not have a go at sand casting first?  I've had a lot of success (and quite a few failures), it's a lot of fun and the pattern-making itself is an interesting part of the whole thing.  I use oil-bonded sand (because I bought some in a job lot from someone giving up home casting).

My furnace is forced-air and waste oil.  I get hot enough for bronze - the guy I copied does cast iron but I haven't the nerve yet.  

Zinc - I pick up all the wheel-balancing weights I find in the street, which in these parts are no longer made of lead   Perhaps I'll try chatting them up at the tyre place.


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## abby

I would recommend the Hoben Davis website , they are manufacturers of several types of investment cement and the heating cycles are published there , along with info on mixing etc.
Dan.


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## deeferdog

Hi Charles,

Really liked the look of the engine you posted, are there any plans available? Cheers, Peter


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## vederstein

Thank you all for your comments and help.  I'm sure I'll be making loads of scrap.  But this is a learning project and I expect many failures.

This build may take me well over six months for a relatively simple engine.  It's just the process I expect to go through.

As a side note I find it very strange that the replies/interest on this project is far more than what I expect to get on this site.  Yet I haven't done anything other than a CAD model/drawings that I legally cannot share.  Most of my builds here have garnered relatively low interest except for one large flame war.

...Ved.


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## ja2tn

Ved,

I will be following the build.  Thank you for posting.

If you've run out of engines to build, casting your own seems like a good next step.  I look forward to when you design your own and hopefully will share the opportunity to the rest of us to perhaps purchase a unique casting from you to build. 

Just wondering, have you looked at any of the castings from Rowland Manufacturing Company?  I just ordered two from Nick.  Seems like a very nice guy with a true passion for this hobby.  If you haven't already, search him out and give him a look.  You can also see some of his engines on YouTube. 

Look forward to watching your build,
Jerry


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## pp2076

ja2tn said:


> Ved,
> 
> I will be following the build.  Thank you for posting.
> 
> If you've run out of engines to build, casting your own seems like a good next step.  I look forward to when you design your own and hopefully will share the opportunity to the rest of us to perhaps purchase a unique casting from you to build.
> 
> Just wondering, have you looked at any of the castings from Rowland Manufacturing Company?  I just ordered two from Nick.  Seems like a very nice guy with a true passion for this hobby.  If you haven't already, search him out and give him a look.  You can also see some of his engines on YouTube.
> 
> Look forward to watching your build,
> Jerry


If you want a challenge (run out of engines to build), try building this: http://www.haarlemmermeermuseum.nl/en/cruquius-museum--world-largest-steam-engine


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## vederstein

bazmak said:


> Looks good but a little lop sided with 1 flywheel.If you are making major changes to the design can you not add another flywheel and make them a touch smaller?  Just a thought



I quickly modeled a double flywheel version with two 4" flywheels to get an idea of  how it looked.  To me it's starting to look more like a coke bottle engine of which I already have two.

It was a good exercise, but I think I'll stick with the lopsided design.  For some reason it appeals to me more.

Thank you for your suggestion.

...Ved.


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## Brookesy

I'm keen to see where this goes since it will probably cover a lot of stuff I want to learn. Excellent project.


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## vederstein

Well, I have the 3D printer on order.  It's a Cetus 3D extended with the heated bed.  The printer is on back order so I will be several weeks before I get it.

Equipment on backorder isn't necessarily a bad thing.  If it's due to a high volume of orders (as Cetus claims), then the product is apparently successful and there's less of a chance that the company goes belly up leaving my with an anchor when parts need replaced.

I've read many reviews and there have been very few gripes about it considering the price point (~ $450 US).

Yes this video is from the manufacturer's website, but its a decent overview of the machine..

Next up:  Taking my part models and modifying them for casting molds.  This will entail:

removing/resizing holes
adding sprues
ganging parts together (where appropriate for either machining or casting)
scaling 2.4% larger to account for shrinkage
I don't think adding a draft is really necessary here because the lost was method doesn't have any split mold to pull apart.

...Ved.

[ame]http://www.youtube.com/watch?v=fZTYfo1o7Lg[/ame]


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## Brian Rupnow

Be careful--Many old Volkswagen blocks were made from magnesium, and when heated to a near melt temperature would burst into flame and burn with a very intense white heat. You can do a web search to verify this.---Brian
[ame]https://www.youtube.com/watch?v=nhY0xzKcPoE[/ame]


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## Brookesy

Definitely be very careful with any old Volkswagen parts. High magnesium content and extremely dangerous. Also, I've been told that the first thing to print on a 3D printer is spare parts for the printer if you can find files for them... Just a thought


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## bmac2

Magnesium is very simple to test for. Just clean a spot with emery and put a few drops of vinegar, If it bubbles up it magnesium.


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## vederstein

I went back to the CAD and modeled up some castings:

I scaled the CAD files 1.024 for a 2.4% oversize to account for shrinkage.
I put like parts together where it seemed to make sense (e.g. cast the main bearings together).
I added flow paths.
I'm going to start with what seems to be the simpler parts (cylinder head & bearings) then as I figure out what I'm doing , I'll modify my molds as I learn and then go onto the more difficult parts (e.g. flywheel, base plate, cylinder).  Some of these will require printing separate parts then sticking them together.  This isn't a problem because I plan on using printable wax and can therefore melt the bits together.


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## pp2076

Just to play the Devil's Advocate here, how do you reconcile this statement:


vederstein said:


> In a month (Christmas gift to myself) or so I'll be obtaining a 3D printer to do lost PLA or lost wax casting on the components.


with this one from the same post?


vederstein said:


> I simply cannot justify spending over $300 US on what is essentially a toy.



:hDe:


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## vederstein

How do I justify?  Easy:  This project will expand my capabilities.  Buying another casting kit would be more of the same.  To do my own castings is a learning experience.

The 3D printer has the possibility of being more than a dust collector.

You raise a good point.  Perhaps I`m a bit hypocritical.

...Ved.


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## pp2076

I'm just pulling your leg mate


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## vederstein

Well I've been a bit quiet on this project.

I received the 3D printer four days ago.  Yesterday the electronics took a crap, so I'm further delayed as I wrangle with the Chinese company to get some sort of fix.

But all is not lost.  I have been working on the barstock parts.

The picture below is of the eccentric & valve rod with a 6" (~300mm) scale next to it.  This is going to be one big engine for a model....


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## Cogsy

Hope your printer fix goes well. Touch wood, so far my cheap Chinese printer (Anet A8) has been virtually flawless, bar a few teething issues and with some printed upgrades, but I have heard horror stories.

I have to mention your scale though - 6" is reasonably close to 150mm, but a bit of a stretch for 300mm. You did say approximately though...


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## vederstein

150mm, you're correct.  DUH....


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## ddmckee54

Ved:

When you do start printing parts, print a part with known dimensions and then measure that part carefully. I recently discovered that my printer was printing parts about 2% oversized. It's a Prusa I3 clone that I had to assemble since it was a kit and I've had it for about 2 years now. It was only about $300 at the time so I really wasn't expecting that great of prints from it.

I am now scaling the models to 98% in the slicer and I'm actually getting the fit between the printed parts that I wanted to get. If I want an interference fit, or a sliding fit, I can get it.

Don


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## vederstein

ddmckee54 said:


> When you do start printing parts, print a part with known dimensions and then measure that part carefully. I recently discovered that my printer was printing parts about 2% oversized.



The one and only thing that I was able to print (and even then I had bed adhesion issues) was a 25mm cube.  Amazingly it was within plus/minus 0.4mm of nominal.  For casting purposes, I thought this was very good.  So if I can actually get this thing to work, I think printing tolerances will be fine.

As for an update, I requested from Cetus an RMA to return the faulty unit.  They offered an alternative of sending new electronics and a monetary discount of the purchase price.  I accepted the offer.

Time will tell.

...Ved.


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## ddmckee54

Ved:

When I started printing I felt the exact same way. What I was printing was within a few tenths of a millimeter of the specified size and for most of what I printed the size difference didn't really matter. I tried printing the one-piece crescent wrench and I was able to get it to work, although I did de-laminate it in one spot when cracking the parts loose. I made a test fidget spinner for a guy that I work with who collects them.  The fit was OK, barely, everything was loose.

This year I decided to make fidget spinners for my great niece and great nephews for Christmas stocking stuffers. The version I was printing uses 1/2-13 nuts as the weights for the spinner. Some of the kids have pretty small fingers and I didn't want them getting their finger stuck in the threads of the nuts so I decided to make a plug for the nuts. I'm new to 3D and hadn't tried drawing a 3D thread, let alone printing one. No matter what you might believe drawing an imperial thread in a CAD program that thinks in metric is not easy. After the fourth prototype not fitting, and WAY more than that many hours I decided to run the plug through a 1/2-13 die to see how bad my thread design actually was. It was when I saw that I was cutting threads on the un-threaded portion of the plug, which was supposed to be smaller than the minor diameter of the threads by at least 0.1mm, that I realized something was definitely off. I broke out the micrometer and found that the plug was about 2% larger, in all dimensions, than it was supposed to be.

It took me 2 years of frustration with the printed parts not fitting correctly before I finally realized what was happening. All that time I was blaming it on my printer not being of that high of a quality, it's a Sunhokey Prusa I3 clone, along with my in-experience in 3D printing. I was also thinking that this was what I had to expect from 3D printed parts. I have since re-printed the one piece crescent wrench scaled to 98%. While it still required a bit of fettling to get it to work properly, the difference between this wrench and the first was like night and day. Just trying NOT to share the grief.

Don


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## Cogsy

For bed adhesion with PLA I initially had quite a few problems until settling on 50 degree bed temp and mobs of glue stick, over 2" wide 3M blue painters tape. The downside was a horribly pitted finish on the face touching the bed. Eventually I discovered a 50 degree bed (might not even need the heat) over the same blue painters tape was all that is required, as long as your first layer is laid down close enough to the bed. I now never have lifting on PLA parts and sometimes have the opposite problem of getting the things to come off the bed after the print is finished. There is a learning curve to 3D printing that can be very frustrating but you'll get there in the end.


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## ddmckee54

I also print PLA on blue painters tape. Some people say heat the bed, others say don't heat the bed. On small-ish parts, 25mm square or less, I don't use any bed heating and normally don't have any problems with print bed adhesion. On larger parts where the print head travels more than 50-75mm of linear travel before the next filament is laid down, I've found that with my printer I need to heat the bed(I use 60°C) - otherwise no matter what I do the first layer won't stick. After you get the 1st layer successfully stuck down, the rest of the print is usually a piece of cake. When I'm printing something where quality matters, I'll watch the 1st layer as it prints. If it screw ups, I'll abort the print, fix the problem, and re-print.

Of course now that I think about it, I've got a cold drafty old house that was built in 1890 and my printer is sitting in the corner next to 2 outside walls. That could explain some of my 1st layer problems, maybe not such a great location for the printer? YMMV - depending on your printer. Your printer may or may not respond exactly the same way as somebody else's machine, even if the machines are supposedly identical. I print at 215°C for the 1st layer and 210° for the rest. I know this is supposedly too hot, but if I go much lower I can hear the extruder drive gear popping as it slips and grinds on the filament. You'll find that you'll print a lot of test cubes. I made mine look like dice, that way I know how the cube was oriented when it was printed - helps when troubleshooting problems with an axis. Everybody at the office that wanted any has 3D printed dice on their desk.

Have fun with your machine and don't expect flawless prints right away - maybe never. After all, these things are just glorified hot glue guns.

Don


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## vederstein

After about three weeks of haggling with the printer manufacturer they've _finally_ shipped the replacement electronics. I should receive them in about a week.

In the meantime I made a hot wire foam cutter so I can cast some of the simpler parts via the lost foam technique.

It's currently an ice/snow storm as I type is in central Indiana, USA. So who knows? If the weather is decent enough I might actually be able to cast some engine parts in a few days.

I started making my melting furnace September 2017. Therefore considering I've been making tools for the last five months, it'll be a big milestone if/when I cast some actual parts.

To be continued....


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## vederstein

Using the hot wire cutter I made my first lost foam molds today.

The results were bad as expected considering I`ve never done this before..

I tried first using green flower arrangement foam.  It had too high of a melt temperature and didn't cut very good.

Therefore I went to cheapo white foam. It cuts easily (low melt temperature) but I've seen others use this foam on Youtube and they tend to get lousy casting finish.

Anyways, printed the drawings full size, cut out the paper doll and traced around on the foam. Then I free handed cutting the foam on the hot wire cutter.  I've never had a very steady hand, so after gluing the sections together I sanded the edges.

I don't expect a good pour, but I'm going forth anyway as a learning exercise...


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## Cogsy

I haven't cast anything with it yet, but I've picked up some quite dense insulation foam from the local hardware store and I expect it to work better than normal Styrofoam. I have cast quite a few pieces using Styrofoam and the results were really good - so good in fact, that you can make out each circle of Styrofoam on the finished surface. So basically the finished part looks just like it is made from the foam. The denser insulation foam slices very smoothly and I anticipate more of a uniform surface finish. It's quite surprising the results you can get from lost foam.


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## vederstein

Cogsy said:


> ... I've picked up some quite dense insulation foam from the local hardware store and I expect it to work better than normal Styrofoam...



Prior to purchasing the flower arrangement foam, the wife and I did stop at Home Depot for insulation foam.  We took her car.  the pink foam boards were 4x8 ft sheets (1.2 x 2.4 m).  Far too big to fit in the car.  Also far too much for this project.

So that's when we drove to a hobby store and purchased the flower foam.

Live and learn....

I'm thinking of liberating some packing foam from the trash at work.  Does anyone have any experience with that material?

...Ved.


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## vederstein

I went to Home Depot to pick up some 5 gallon contractor buckets and this time they had 2 ft x 2 ft  sheets of pink insulation foam.  So I purchased a sheet and made a mold from that material.

Then I embedded the two molds into sand and performed the pour.  I thought I could control the pour better, but I melted the bucket.  As a side note, I guess there's a yin and yang performing an aluminum pour in 15 deg F (-9 deg C) weather with snow on the ground.Yin:  It's damned cold outside.
Yang: I can use the snow on the ground to cool the parts.​After pulling the castings, I was a bit astonished how good they came out considering how inexperienced I am.  There were no voids due to bad mold positioning.  The first part, made from polystyrene was the worse of the two and I decided not to mess with that one anymore.  The laminated construction of the mold was clearly visible and my cutout looked bad.  Also the coarseness of the polystyrene gave a bad surface finish.

The other part, made from the pink foam matched the mold.  As Cogsy said, the finish matched the finish of the foam.  It was a bit coarse for my liking, yet not near as rough as the polystyrene.  I continued to machine one part to see...


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## vederstein

As I machined one of the bearing blocks, again I was a bit astonished how acceptable the casting quality actually was.  There was no porosity!

The casting, like all castings, have a hard crust that my carbide tooling made quick work of.  As I was removing the crust I found that a bit of grinding would smooth out the roughness of the finish and make it look more like a sand cast part.

My biggest disappointment was that the part wasn't symmetrical.  It's functional, but that flaw may be too much for me to accept.  I blame the fault on my unsteady hand when creating the mold.

I plan on creating the part a third time using the lost wax (or PLA) method when I figure out how to use the 3D printer.

Overall I'm pleased with today's outcome.  It's certainly not perfect, but better than I expected for a first ever lost foam pour of molten aluminum.

As a side note, does anyone remember how to put photos within the text instead of always at the end of the text block?

...Ved.


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## Cogsy

Before I get to the picture placement, I have a potential tip for the foam finish. I have made some molds from the insulation foam (it was yellow, not pink and the 'flat' surface as purchased is perfectly smooth) and spent a bit of time sanding them, as well as also filling any imperfection/joins with a foam dust and PVA glue mixture. I also ran a thin coat over all the cut edges. The molds are now quite smooth and I'm hoping for some good surface finishes from them. Now I just need some finer sand than I have in stock, and some time combined with nice weather to test it out.

For the pictures, upload them through the 'manage attachments' button as usual. As you get to a point in your post where you want a picture, click on the paperclip icon on the top of the post box and a dropdown will show with the names of your uploaded pics. Click on the one you want to add and it will insert. It's best to leave a blank line before and after each pic and pay attention to the names of your pictures - it's possible to add the same one multiple times in the same post.


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## vederstein

I've had the 3D printer up and running for a couple days now after receiving the new electronics.  Now that I have the catastrophic issues taken care of, it's just normal 3D printing issues.

I'm having raft curling issues which eventually blow up the prints..  The printer does not have a heated bed yet.  I have the actual heated bed, but it requires a separate, external power supply.  That's something I'm working on and should have resolved in about one week.  Therefore I'm making some design changes to split some of the taller components into smaller pieces that I'll glue together prior to casting.


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## vederstein

ddmckee54 said:


> ...I've got a cold drafty old house that was built in 1890 and my printer is sitting in the corner next to 2 outside walls....



My house is a split level built in 1974.  Not as old as yours, but approaching 50.  With the frigid weather lately,  I'm probably in the same boat as you.

...Ved.


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## Cogsy

vederstein said:


> My house is a split level built in 1974. Not as old as yours, but approaching 50..


 
This line gave me shivers - I was born in 1974  . I don't feel like I'm approaching 50 yet


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## vederstein

The print of the half posts was successful.  I glued them together trying both hot melt glue and white school glue.

Either way I have some crevices in the juncture. This will be a lost PLA pour. Therefore I need to encapsulate the posts in investment (a 1:1 mixture of plaster of paris & sand) and every little crevice will be filled.  Therefore I'll run a bead of hot melt in the crevice and machine the excess material on the lathe after the aluminum pour.


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## vederstein

Cogsy said:


> ...Now I just need some finer sand than I have in stock...



I've read that aquarium sand is very fine in texture.

...Ved.


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## vederstein

Investment Pour:

I took some cardboard packaging and taped up a cylinder.  You will notice that I pushed through some nails to keep the mold in place so I didn't float to the top.




Then I mixed in about 1-1/2 to 1 ratio of plaster of paris and sand in a freezer storage bag.  I thought I was being clean, but more on that after the photo.




After adding water and kneading the investment.  I poured the investment into the mold.  Everything went wrong.  I didn't mix the material enough so it was globby.  The bottom of the cylinder, which was made of duct tape began to leak.  Then investment broke through the side of the cylinder and plaster got everywhere.  I don't have a picture of the mess because I was too busy cleaning it up.




So what does one do?  Examine the failure and try again!!!  I remade the cardboard cylinder re-enforcing it where it broke out.  I mixed the investment in a bucket and large spoon.

After the much more successful investment pour, I used an oscillating tool to vibrate the cardboard cylinder to try to eliminate bubbles.




Coming next:  Burnout.

...Ved.


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## vederstein

Today I did the burnout and aluminum pour of the posts.

The burnout went fairly well.  I placed the cured investment in the furnace upside down.  The burn started at a low fire for 30 minutes then I jacked it up to a roaring burn for about an hour.








I noticed that the investment didn't fully fill the below the mold, but I forged ahead anyway embedding the investment into sand after blowing it out with compressed air.  (The black bars are from the pieces of steel roundstock I had under the investment to let the heat in.)




Here's a video of the pour and breakdown.

[ame]http://www.youtube.com/watch?v=oRYpEzD8nVY[/ame]

As you can see, I had not a useable part out of the four posts. :wall:  I guess I should pour one at a time.    Perhaps a taller sprue?  Perhaps a mold that fills from the bottom with an air vent to the top?  I welcome comments and insight.

On the plus side, where the casting did come out well, it was so well defined I could see the layers from the 3D print.






On the other hand, perhaps I should start modelling ruins from the Classical Age (ancient Greece & Rome).  ;D

...Ved.


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## WSMkid

vederstein said:


> Today I did the burnout and aluminum pour of the posts.
> 
> The burnout went fairly well.  I placed the cured investment in the furnace upside down.  The burn started at a low fire for 30 minutes then I jacked it up to a roaring burn for about an hour.
> 
> View attachment 92985
> 
> View attachment 92986
> 
> View attachment 92991
> 
> 
> I noticed that the investment didn't fully fill the below the mold, but I forged ahead anyway embedding the investment into sand after blowing it out with compressed air.  (The black bars are from the pieces of steel roundstock I had under the investment to let the heat in.)
> 
> View attachment 92988
> 
> 
> Here's a video of the pour and breakdown.
> 
> http://www.youtube.com/watch?v=oRYpEzD8nVY
> 
> As you can see, I had not a useable part out of the four posts. :wall:  I guess I should pour one at a time.    Perhaps a taller sprue?  Perhaps a mold that fills from the bottom with an air vent to the top?  I welcome comments and insight.
> 
> On the plus side, where the casting did come out well, it was so well defined I could see the layers from the 3D print.
> 
> View attachment 92989
> 
> View attachment 92990
> 
> 
> On the other hand, perhaps I should start modelling ruins from the Classical Age (ancient Greece & Rome).  ;D
> 
> ...Ved.





Was your investment pre heated at the time of pour? 

No personal experience but that seems to be a must to help prevent flashing. 

Thank you for sharing. 
Always following,

GJ


----------



## vederstein

WSMkid said:


> Was your investment pre heated at the time of pour?
> GJ


 
It was about 15-25 minutes between pulling out the glowing hot investment from the furnace to the pour. I embedded the investment in the sand while the furnace was melting the aluminum. Being that the investment is a good heat insulator, Just prior to the pour, I looked inside the investment, the glow was just about extinguished. Therefore I'm quite sure it was hot during the actual pour.

How hot? No idea. Perhaps I should bring back home my infrared thermometer from that I keep at work.

I guess another option is that I can make a second burner so I can perform the burnout and the melt at the same time. Opinions?

As for other items on this project, I received the power supply for the 3D printer's heated bed and will be installing it in a day or two. Also I managed to print a single entire post. This is my next post mold. Info to follow...




My wife said the part looks like a toilet paper roll holder.   I can't say she's really wrong on that account.

...Ved.


----------



## WSMkid

Ved,
Glowing investment, to me, would be hot enough at a guess. I want to say the guy in the YouTube vids I've watched was keeping them in his kiln at 900(or was it 1800) degF until seconds before the pore. I'm not sure if this is the proper way or not but he had spectacular results. 

After looking more at your last pour it does look like freezing. Keep in mind I had a three hour lecture/lab on casting freshman year (about 4 years ago now) so I'm for sure not an expert, just sharing thoughts. 

I was thinking a paint roller holder spindle but I can see the toilet paper holder. 

Keep us posted!

GJ


----------



## vederstein

WSMkid said:


> Ved,
> ... looking more at your last pour it does look like freezing. ...



Freezing is a term I'm unfamiliar with.  (Remember I'm a complete newbie at this.)  Can you please elaborate?

Thanks,

Ved.


----------



## charlesfitton

On the other hand, perhaps I should start modelling ruins from the Classical Age (ancient Greece & Rome).  ;D

...Ved.[/QUOTE]

Yep - sell them online to the wargamer/fantasy gaming crowd...


----------



## WSMkid

In my terms its when the metal solidifies in a mold as its being poured leaving voids and such. 
There may be a better/real term for this, if there is someone please correct me. 
I'm delighted to hear that burning out your models worked so well just using your furnace (in terms of cleaning everything out).

GJ


----------



## bouch

vederstein said:


> Today I did the burnout and aluminum pour of the posts.
> 
> As you can see, I had not a useable part out of the four posts. :wall:  I guess I should pour one at a time.    Perhaps a taller sprue?  Perhaps a mold that fills from the bottom with an air vent to the top?  I welcome comments and insight.
> 
> On the plus side, where the casting did come out well, it was so well defined I could see the layers from the 3D print.
> 
> ...Ved.



I'm no expert, but it seems like none of the columns had the lower part of the mold filled.  That suggests to me trapped air which prevented the metal from filling the mold.

I think you're going down the right path thinking about adding air vents.  Seems like you could either add vents from the bottom to the top of the sand or your idea of a central "shaft" to fill the columns from the bottom and then the air vents at the top.

You would know your mold is filled when metal comes out of the air vents.


----------



## vederstein

bouch said:


> ... I think you're going down the right path thinking about adding air vents...



I talked to a co-worker that has some limited casting experience from college.  (which is strange because he's an electrical engineer).  He said to fill from the top with a bottom vent.

That will be my next pour.


----------



## vederstein

I got the heated bed installed and took a big leap.  I printed off the cylinder head and steam valve.  This was the first truly large part I printed.  It's a little over 3-3/4" diameter.




The orientation on the bed certainly was risky with all the support material and not very material efficient.  But I wanted the text on the cylinder head not marred by support material and I have these round bosses that I want concentric so I can chuck on to them when the parts get machined.







I'm quickly getting to to point where I need to pour a lot of investment and start melting down my Corvair engine.

...Ved.


----------



## bmac2

Hi Ved
Im following your build with great interest. Its hitting a lot of my favorite things, model engine, fire, molten metal, and I keep hearing the sirens song of 3D printing.

I havent done much with plaster investment casting but have had good results using I use one part plaster/ one part fine sand/ one part grog (its just pulverized used investment). You can avoid air bubbles forming on the surface of the pattern by first brushing it with a mix of water with a couple drops of  (Propylene glycol) the stuff you put in the dishwasher to eliminate spots.


----------



## vederstein

bmac2 said:


> Hi Ved
> Im following your build with great interest.



Thanks for following the trials and tribulations of someone who has an extremely limited idea of what the hell he's doing.

I printed off the two flywheel halves.  I'm going to give the printer a rest for a while.  I need to pour lots of investment over the upcoming weekend and probably make lots of scrap.





...Ved.


----------



## vederstein

ddmckee54 said:


> I also print PLA on blue painters tape. Some people say heat the bed, others say don't heat the bed. On small-ish parts, 25mm square or less, I don't use any bed heating and normally don't have any problems with print bed adhesion. On larger parts where the print head travels more than 50-75mm of linear travel before the next filament is laid down, I've found that with my printer I need to heat the bed(I use 60°C)
> Don



Now that I have the heated bed working, I've have the same experiences as you.  Some of those larger parts I've printed lately wouldn't have a chance without the heated bed.

Everything printed has been PLA thus far because my previous PLA burnout was fairly successful (and the wax filament is expensive) although the pour was a complete failure.

...Ved.


----------



## bobs7-62steamair

Just received the Rudy K book, "Working Steam Engines" Open column in 2x scale up looks like a fascinating project. Do you happen to have any detail parts drawings in the 2X size available? Would be happy to pay reproduction and shipping cost. 
Regards.
Bob


----------



## vederstein

bobs7-62steamair said:


> Just received the Rudy K book, "Working Steam Engines" Open column in 2x scale up looks like a fascinating project. Do you happen to have any detail parts drawings in the 2X size available? Would be happy to pay reproduction and shipping cost.
> Regards.
> Bob



I sent you a PM.  Let's please continue this discussion off the forum.

Thanks,
...Ved.


----------



## vederstein

I've been very ill lately and that's why I missed my window for what was to be my second pour.  It will happen later.  I did manage to add the sprues to the next set of molds though...


----------



## Wolfie01

I did notice you had no vents. When I did my first pour, I had vents for each pillar, I didn't have my mould glowing hot either...


----------



## vederstein

As I'm preparing my molds for tomorrow's pour I have one mold in the furnace burning out.  I figure that I might was well use the waste heat and put another mold on top the furnace for preheating the second mold.


----------



## vederstein

Ok, now I'm losing my patience.

First of all, the burn out from yesterday:I put it into a bucket full of sand.  After several hours of cool down I gently grasped it.  It disintegrated.  I guess heat stress?  That's one mold down the tubes.​So I burned out another item, a post with a vent in the mold.  To increase hydraulic pressure, I printed a PLA sprue and when embedding the mold & sprue into the sand it looked ok.  During the pour the sprue lifted off and no material went into the mold.







Third pour, third mold.  The burn out look ok.  I enbedded another PLA sprue.  On the pour, the system began to bubble (boil?) splashing molten aluminum.  This is only one where some material made it into the mold.  But it wasn't good enough and the burn out was insufficient.  Don't know what caused the bubbling but it was a dangerous situation.

[ame]http://www.youtube.com/watch?v=ER8jDn9RmaA[/ame]






I guess it's time to switch to the wax filament and try again.  Other things learned:

A plastic sprue don't get it.
Make the burn out longer
Bury the investment when it's hot and pour when it's hot.
Anybody else have some insights?  I'm learning but this is getting annoying.  I really thought I would have had a good part by now.


----------



## abby

It is very unlikely that you will have a successful burnout without a controlled kiln.
The free moisture needs to be removed first , this is done at around 180°C for about 5 hours , chemically combined water then needs removing at around 350°C for a couple of hours with a gradual increase to 550°C.
Final burnout should be at 725°C for 3 to 5 hours.
Any pattern media whether it be wax or plastic will expand during the heating cycle , wax melts quickly thus avoiding expansion pressure on the investment mould. Many plastics do not melt and the mould is cracked as a result.
Investments cements are formulated from carefully selected refractories with known expansion characteristics , they are designed to withstand the rigours of the heating cycle with a minimum of cracking.
Homemade recipes are rarely succesful on a repeatable basis but re-inforcing with something like chicken wire can help , the addition of chopped glass fibre strand may also work.
Commercially produced investment is not cheap but compare the cost against the cost of patterns , time , fuel and effort .
You may find some tips on my website/forum
http://www.unionsteammodels.co.uk/
Dan.


----------



## vederstein

After some dejection at my failures I have to agree with Abby that my method just isn't going to get there.  So it's time to take a step back and retool.

First,  I'm going to try some open molding for some components (like the cylinder head) where one entire side gets machined anyways.




Second, I guess I'm going to have to learn about sand casting.  This will be a project all in itself.  To start, I need to make a flask and some green sand.  I'll be following this guy's recipe.

[ame]http://www.youtube.com/watch?v=2rAQxw6X6uc[/ame]


Then I'll be printing some split patterns (the picture shown is of the posts).  Because of this, I need to check for undercuts when pulling the patterns out.  So for example, the flutes on the posts are gone.  





That's all for now.


----------



## vederstein

Today I made the green sand and a casting flask.  To see what kind of difference I would have, I made an open mold of the cylinder head from both plaster which baked in the oven for three hours and the sand.

The sand mold, though not quite good enough, was much improved over the plaster mold.  It's still a failure, but less of one.  Now I feel like I'm making _some_  progress.

I did make a two part mold, but the sand wasn't sticky enough.  I think I need to add a little bit more water and/or clay.

I'll need to re-evaluate some of the smaller details I have in the parts and simplify as required.  For example, I'm going to need to remove the text on the cylinder head.

...Ved.


----------



## bobs7-62steamair

Ved has embarked on casting parts for the 2x Vertical originally designed by Rudy K. I am off building the same type engine using one purchased casting, the Flywheel. Have first seven parts made to date. Support columns were lathe made using a combination of Knurling and grooving to achieve some different column design that can be easily made--see pics. Will send additional picks and potential pitfalls to avoid building this engine.
Bob


----------



## Engineville

Sir,
Disclaimer: The following in an opinion.
	I watched your video panel #69 of pouring molten Al  . . .  massive and intense gas formation begins immediately upon Al pouring; gas is coming from combusting sprue and then from the PLA.
To reduce the formation of gas, need to reduce the mass that the molten Al needs to burn as it flows in to resulting cavity.  
	Consider setting the 3D printer on a setting of internal part structure that is as much open space and as little PLA as you can get away with and still maintain part shape with a smooth surface.  In effect you&#8217;re trying to produce a result similar to lost-foam casting that uses highly expanded polystyrene beads.
	The 3D printer that I messed with three years ago was a very simple one. But the software had different setting for internal structure, e.g., 75%, 50%, 25% void-open space.


----------



## vederstein

Engineville said:


> Sir,
> Disclaimer: The following in an opinion.
> I watched your video panel #69 of pouring molten Al  . . .  massive and intense gas formation begins immediately upon Al pouring; gas is coming from combusting sprue and then from the PLA...



I'm giving up on the lost PLA route.  After my experiences, I have to agree with Abbey that I'm just not properly tooled for it.  I did try printing some components with the wax filament.  The wax printed ok for small components.  Parts for this engine are too big though.  Even with the heated bed, the wax filament warps and it warps a lot.

I'm focusing on sand molding at this time.  I'm going to lose some of the smaller details, but it's the only method (save for the lost foam) thus far where I've made something of an improvement over earlier tries.

I'll get there, but this learning curve is much steeper than I was expecting.

I will persevere!

Also, I wish Bob the best in his barstock version of the same engine.  At this rate, he'll be finished before I.

...Ved.


----------



## vederstein

Another Sunday another set of pours.

This time was my first try at a closed mold sand cast and my experience was much much improved.  The video shows the first pour. The cylinder head is a flat back pattern.  The bearing block is a split pattern.

[ame]http://www.youtube.com/watch?v=TZ5PH-MRqEs[/ame]

In the photo, the casting on the left is the first pour.  The casting on the right is a bearing block and one of the posts.  The post was created with the "cope down" molding technique.




All of them are a bit rough, but with some work can actually be used.  Eventually I'll machine them up and see what I get.  Overall today was a much improved day.

It took me several tries to get to this point.  I learned that the sand need to have more water in it than I originally thought.  In the end I had it a little damp.

That's it for today.

...Ved.


----------



## vederstein

My wife is out of town this upcoming weekend so I hope to get a lot done.

Tonight I gave it a go at machining the one post casting I have.  The casting itself isn't great, but it did machine ok.  The bad casting side I can rotate to the inside of the engine to hide it.  Eventually I may have a go at re-creating this one.

I found myself flipping the part several times in the lathe.

I first worked one end round.
Then I flipped and worked the other end.
Then I cut off the end.
Then I flipped it a last time and cut the opposite end to length.

The ends aren't even, but I think if I proceed with the same pattern on the other three, they'll look somewhat similar.

...Ved.


----------



## vederstein

Got a couple of pours done today after work.

I made two posts in the first pour and in the second pour I made another post and a bearing block.







All of them are better than my earlier tries.

I initially made 50 pounds of green sand.  It really doesn't go very far.  I cannot fill two flasks entirely full.  I guess I need to make more sand.

In the video I was trying to make the cylinder mold.  My cylinder pattern doesn't have any draft where the core goes and that's why it breaks away when I pull the pattern out.  It's no big deal though considering that's the core anyway.   Not knowing anything about cores, I made it out of the same sand.  As you can see, it falls apart.  More learning is involved in how to make cores.

[ame]http://www.youtube.com/watch?v=w5xRXzioBk0[/ame]

My technique is improving...


----------



## vederstein

I've machined up the four posts.

They aren't perfect, but as I've mentioned before, I'm not a perfectionist.  Overall, I think they look ok for a first self cast engine.


----------



## bobs7-62steamair

Hi Ved: Your columns look great. Sand casting is not all that bad and with experience I am sure it will get better. Have a couple of questions i will address off line.
Regards.
Bob


----------



## vederstein

Today I poured another cylinder head and  bearing block.  The casting quality continues to improve.

Now that I've done a few pours, I've been noticing a few things:

1.  I need to add water to the green sand much more often that I was expecting.  I new the moisture would evaporate over time, but not to this extent.  It's not a big deal though.  Just add a little water and mix with a drill.

2. Draft is important.  In areas where I didn't have draft (usually areas that don't matter or get cut off during machining) the sand breaks every time.  I need to remember this as I create more patterns on the 3D printer.

3.  Sand gets _everywhere!_  I'm trying to improve my practices, but a sand dust is coating my garage.

Today's pour completes the smaller cast parts.  Now I have three large ones left:

     The Cylinder
     The Base
     The Flywheel

Doing these larger castings I anticipate will be a challenge in itself.

Happy modeling...

...Ved.


----------



## vederstein

Today I machined the bearing blocks.

From machining cast bearing blocks on other engines, I've learned to machine the blocks at the same time wherever possible.  This results in more consistent critical dimensions.

First I clamped the two block in the milling vise and eyeballed them parallel with the vise.

After indexing from the crown of the blocks (bottom surface) I milled both block to the proper height at the same time.  Then I milled around them to get four square faces on each block.  I should have drill/tapped the mounting holes at the time, but forgot to.  Therefore I'll transfer punch when assembling to the base.








I re-positioned the blocks for drilling/reaming the shaft journal.  I did need to find the center line of each block, but the height from the block bottom to the center of the hole is consistent.










After drilling/tapping a 10-32 hole in the crown for an oil cup, I put each block in the lathe to face off a surface.  This operation is strictly for aesthetics.


----------



## bmac2

Hi Ved green sand works great for straight round cores it just needs a little help with support. This core if I remember right is 12(304mm) long 3(76mm) in diameter with 3 or 4 pieces of stiff wire running the full length (think rebar in concrete). 
Oh and ram the crap out of it! *club*

Green Sand is the nemeses of the hobby caster but once you get it dialed in its great stuff. For the surface finish its never going to be smoother than your sand. I think my sand if about 25% my original sifted play sand from Homer Depot, 50% 50-100 blasting media and 25% 100-200 blasting media. The 100-200 is mostly from facing sand I but directly against the pattern. Its just the Myfordboy green sand recipe with the 100-200 media.


----------



## vederstein

bmac2 said:


> ... 3 or 4 pieces of stiff wire running the full length (think rebar in concrete).
> Oh and ram the crap out of it!
> 
> ...25% my original sifted play sand from Homer Depot, 50% 50-100 blasting media and 25% 100-200 blasting media....



Thanks for the good info.

I have some water glass on order.  Depending on what gets delivered will dictate my next casting core try.

As for the sand, I realized that my sand is too coarse after a few pours.  But I'll keep soldiering on partly because I want to see where this goes, but mostly because I don't have any desire to spend another long afternoon pulverizing clay kitty litter.

Necessity is the mother of invention.  Laziness is the mother of "It's good enough."

...Ved.


----------



## bmac2

I hear ya on the kitty litter. When I got started I spent an entire Saturday morning grinding up litter in a small flea market blender only to find a pottery supply place less than a half hour from my house that sold bentonite clay for couple bucks a pound.
And I do agree that a casting should look like a casting.


----------



## vederstein

Three pours today.

First one was the base.  It was salvageable, but not good enough, so I tried again.  The second attempt was much improved and good enough for me.




The third pour was the cylinder.  It's total failure.  The static pressure from the molten aluminum separated the molds and molten aluminum poured out between them.




Lesson learned.

To be continued...

...Ved.


----------



## vederstein

Also today, I tried to mold up the flywheel.  The six spokes were too close to each other and on every try of removing the pattern the mold would break apart.




So I gave up on that design and redesigned to flywheel with three, but thicker diameter spokes.




Time to waste more plastic on a 3D print...


----------



## vederstein

Successful day today.

First I had a successful pour of the steam engine cylinder.  It took three tries pouring and four tries making a core, but I finally got there.

[ame]http://www.youtube.com/watch?v=Y74ngR8Phk4[/ame]

Second (on my second try) I had a successful flywheel pour.







I have a decent amount of flash to grind off, but this flywheel, made of zinc, I can definitely work with.

Thirdly, I started machining the base.  There's some porosity, but It's nothing I can manage.








That's it for the casting.  From here on out it's machining for this project (I hope).

...Ved.


----------



## vederstein

Today was a big step:  Machining the cylinder.

This is what it looked like after removing the gates, sprue and sand core:




First I fixtured it into the four jaw and machined the top of the cylinder.










Then I switched to the three jaw chuck and flipped the cylinder.  Upon I faced off the bottom end and bored out the cylinder.







That was it for lathe work...


----------



## vederstein

Next up was mill work.

First I clamped the cylinder into the vise with the valve port face up.  There was not good way to indicate this, so I eyeballed it.  Then I roughed of the valve face.




Then I used a flycutter for a better surface then faced off the inlet and outlet face.  It's important to face them off at this time because it allows the cylinder to be rotated 90 degrees with 123 blocks.







Next was drilling out the valve, inlet and exit ports.










I neglected to take photos, but then I drilled out the bottom for the posts.  I couldn't resist at this point, I had to do a dry fit.




That's it for this week.

...Ved.


----------



## Herbiev

Coming along nicely


----------



## deverett

I admire your tenacity.

Dave
The Emerald Isle


----------



## vederstein

Today was dedicated to machining the flywheel.  This is really the first time I've machined zinc.  It was quite enjoyable.  The chips were small and not stringy.  I've added a short video of an OD pass to show.  It cut easily and it shiny.  Good stuff.

[ame]http://www.youtube.com/watch?v=LniYlGs9z24[/ame]

No need for a bunch of descriptions here.  The photographs should be self-explanatory.

...Ved.


----------



## vederstein

It took four tries at making the valve, but I finally got the engine to somewhat run.

Being single acting engine with the rotating face valve that Rudy K.  designed, this engine will never make real power.

But hell.. IT RUNS!!!!!!!!!!!!!!

I hope that as it breaks in it will improve.  Though the biggest issue is for such a large diameter piston, the porting is small.  Therefore the 180-190 degrees of non-powered movement is restricted by the exhaust valve ports making the engine far less efficient.  The small porting also contributes to the jerky motion.

[ame]http://www.youtube.com/watch?v=_hNspgr1xwk[/ame]


----------



## vederstein

After my successful test run it's time to disassemble the engine for painting.

My wife wasn't too keen on painting it because she wanted the raw cast surface to show people that I was one who make the castings.

But alas, this is my hobby.  Not hers.  So we have paint.  This time I went for blue.

Instead of a rattle can, I went with a brush this time.  With a brush I hope I can control the edges a bit better and fill in the rough casting surface a bit.



That's it for this week.

...Ved.


----------



## vederstein

Being that's it's exhibition time of the year I broke out my boiler and did a test run to see if it survived the winter.  Everything was good so I told myself what the hell, it's worth a try to see if this engine (which was never meant to) would run on live steam.

Amazingly it did.  As expected it leaked profusely and my steam is quite wet.  It didn't run well, but it did run.  I'm calling that a win.

For all you haters out there.  If you're going to b][tch, please don't.  It's not helpful.  I'm well aware of it's issues.
For the rest of you, enjoy...


----------



## bmac2

I love it! No question that it's running is steam. Reminds me of the old Hollywood movies where engines belched steam from every seam.
All due respect to your wife but I like the blue. 
You have inspired me to get back into the shop and make some chips . . . Well as soon as I get caught up on the spring "honey do" lest


----------



## Cogsy

Isn't that how steam engines are supposed to run - slow and billowing steam? I think it looks great. Be proud!


----------



## ShopShoe

That turned out well. It does look good running on steam. No complaints here about the color.

--ShopShoe


----------



## JohnBDownunder

Looks like a seam driven engine, sounds like a steam engine (old paddle steamer comes to mind). I do prefer the sound it made on air but that may  just be the position of the microphone and where it was recorded.
Either way is is a jolly good effort, so congrats.


----------



## terryd

vederstein said:


> After my successful test run it's time to disassemble the engine for painting.
> 
> My wife wasn't too keen on painting it because she wanted the raw cast surface to show people that I was one who make the castings.
> 
> But alas, this is my hobby.  Not hers.  So we have paint.  This time I went for blue.
> 
> Instead of a rattle can, I went with a brush this time.  With a brush I hope I can control the edges a bit better and fill in the rough casting surface a bit.
> 
> 
> 
> That's it for this week.
> 
> ...Ved.
> 
> 
> 
> Great  to see the engine running but just a couple of comments on your methods of casting.  I've made the following on one of your videos
> 
> You will not have such a problem with the cope lifting if you add a riser(vent) which allows excess metal to both drive out all of the air but acts as a feeder to prevent shrinkage.  You should also vent the mould with a long thin rod (such as a fine knitting needle) by poking through the sand to the highest parts of the pattern after ramming the sand but before removing the pattern, this allows the steam from the sand to escape and prevent voids in the casting.
> You should also be getting a much better surface finish on your sand castings.  It is worth watching the excellent videos by Myfordboy, such as this  - - also watch the second of the two to see the quality of casting you should be aiming for in a simple home based foundry. and note his use of a runner and riser.
> 
> Having said that a great effort in keeping going.


----------



## terryd

vederstein said:


> Being that's it's exhibition time of the year I broke out my boiler and did a test run to see if it survived the winter.  Everything was good so I told myself what the hell, it's worth a try to see if this engine (which was never meant to) would run on live steam.
> 
> Amazingly it did.  As expected it leaked profusely and my steam is quite wet.  It didn't run well, but it did run.  I'm calling that a win.
> 
> For all you haters out there.  If you're going to b][tch, please don't.  It's not helpful.  I'm well aware of it's issues.
> For the rest of you, enjoy...
> 
> Hi, I forgot to mention in an previous comment that the sand used for greensand should not be too fine - one video I  saw said that it should be like flour.  This is wrong as if it is too fine the steam cannot easily escape and can lead to voids and blowholes in teh casting.
> 
> Terry


----------



## vederstein

Terry,

Thank you for the comments.

When I get to the next casting project, I intend to make more green sand using fine aquarium sand.  I'll use this new sand to just over the pattern and hopefully my casting quality will improve.

I'll also try some of the other techniques (poking small holes & a riser) on future projects and see the changes.

I'm still very much a novice at the casting side of things.  It'll get less crappy.

...Ved.


----------



## Aussie

bmac2 said:


> Magnesium is very simple to test for. Just clean a spot with emery and put a few drops of vinegar, If it bubbles up it magnesium.


Probably a bit late to comment, but I've only recently discovered this site, and even more recently this thread.

As a retired Firefighter / Officer, I can confirm the risk with Volkswagen parts.

If you do get to the point where the magnesium ignites,  DO NOT USE WATER,  as that creates an explosive mix.  Use  DRY SAND   only, or a specialist Fire Extinguisher.  Not sure exactly where you are, but in Australia, the Specialist extinguisher is known as  "Purple K".  You could achieve knockdown with an ordinary dry powder extinguisher, but will need three to four times what would be normally required.

Ian Munro
Senior Station Officer - Retired
Metropolitan Fire Brigade
Melbourne, Australia.


----------



## vederstein

The information about the Volkwagen parts and magnesium is all very good for those that are working with those components.  I appreciate the warnings, but please note that I'm not using Volkwagen components to melt down.  It's an engine from the Chevy Corvair.  If someone knows that it's high in magnesium, then I certainly need to take the necessary precautions.

Perhaps I should do the vinegar test though...

Thanks,

...Ved.


----------



## Aussie

vederstein said:


> The information about the Volkwagen parts and magnesium is all very good for those that are working with those components.  I appreciate the warnings, but please note that I'm not using Volkwagen components to melt down.  It's an engine from the Chevy Corvair.  If someone knows that it's high in magnesium, then I certainly need to take the necessary precautions.
> 
> Perhaps I should do the vinegar test though...
> 
> Thanks,
> 
> ...Ved.



Apology Ved;

I wasn't having a go at you, but just highlighting issues, as I've had to clean up the mess a bloke made of himself, and his garage, doing something similar to this, as well as a few Volkswagens, over 40  or so years.  _ 

(Good trick to play on the  "Probie,"   if the car is basically stuffed, give him / her the hose, and tell them to put it out, stand back, and watch the fireworks, but be close enough to grab the collar of their tunic coat, and pull them back to safety.   -  Nothing teaches like a controlled mistake.  -  Years later watched one of my former  "Probies,"   now an Officer himself, doing exactly the same thing to the latest generation  !!) )_

The main point I was trying to make is, that if it gets going, you're going to have trouble putting it out, on your own, without back up, and the average garden hose isn't going to have enough flow to do other than stoke it up.

Not sure about the alloy mix of the Corvair engines, not a model that was big in Australia.  But we've had a few aluminium, and other alloy engines out here, over the years, and probably going to get more as the push to make cars lighter increases.  _ (Might mean more useful material in the wrecking yards, that can be repurposed cheaply  !!)_

Just all be careful, and check,   e.g.  the vinegar test, before rushing in.

Cheers

Ian


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