# 1/8 Rider Ericsson - Home build



## creast (Jul 20, 2022)

To be honest I am surprised I am starting yet another engine after completing the Twin Horizontal steam engine just recently so I must have my mojo back again  
I have decided to attempt a 1/8 scale Rider Ericsson pumping engine but I will be doing the cast parts myself because a) These are not readily available in the UK and b) I always like a challenge!
It's been a bumpy start really since I downloaded a 1/4 scale model off GrabCad and during the re-scaling to 1/8th on SolidWorks I have discovered numerous errors in that model which has slowed me way down on creating the correct solid model to work from. This always happens!
I do have the build manual for the 1/4 scale (Steam and Stirling engines you can build) but I was relying on the GrabCad model being accurate for the casting details as these are not fully dimensioned in the text. So be warned that all on that site is not always accurate.
I will persevere however and re-work as required.
So far I have remodelled the frame legs and will hopefully cast these using the 'Lost PLA method' but I have never attempted such a thin section and wide casting before.
The Flywheel will be sand cast and so far I have created one half of the split pattern.


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## GreenTwin (Jul 20, 2022)

One thing I learned the hard way is that you often have to add draft angle, and machining allowances to 3D model, when making a pattern.

Most 3D models I have seen are not set up as patterns, but instead represent the as-machined dimensions of the parts.

And you have to add shrinkage when you 3D print the patterns, since the castings will be smaller than the patterns.
I think I normally use a factor of about 1.015 multiplier on patterns.

I have not done a lot of thin castings, but the ones I have done I fed from gates on both sides.

For the Rider legs, I would probably have two wide knife gates on either side (perhaps 1.5" wide), and a U-shaped runner sytem.

Good luck.
You got a furnace?

.


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## creast (Jul 21, 2022)

Green Twin, I do exactly the same for the patterns and usually add a little extra on faces requiring machining to ensure clean up.
With lost wax/PLA there is no need for draft as the pattern is sacrificed. This method is great for small and/or difficult to sand cast.
I have both electric and propane furnaces which are home built and used for some 10 years. I mostly cast aluminium, brass and tin bronze but may do the legs in a zinc aluminium alloy.
Rich


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## GreenTwin (Jul 21, 2022)

Rich-
It sounds like you have a lot of casting experience, in which case we need a lot more photos of your casting work and equipment.

I have not done lost-PLA, but have seen others do it with very respectable results.

I use resin-bound sand, and so I can get away with no draft sometimes, or very little draft.

Some parts do lend themselves to the lost wax/PLA process.

If you are doing brass and tin bronze, then you may be able to do gray iron, depending on the rating of the refractory in your furnace and on your lid.
Gray iron is not much hotter than brass/bronze.
Gray iron needs a Morgan clay-graphite Salamander-Super ferrous-metal-rated crucible, rated at 2,900 F, or equivalent.

I really like casting metal, and it opens up a lot of possibilities for me.
I routinely cast gray iron using resin-bound sand, and a diesel-fired burner.

Good luck.
We need pictures !

Pat J


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## creast (Jul 21, 2022)

Pat,
I have quite some experience in casting but still make silly errors and am constantly learning and revising techniques.

I would dearly love to try resin bonded sand as I do have problems with edges being fragile in Petrobond .
Petrobond is also useless when its cold weather as it seems to behave more powdery and needs warming up to get a good mould strength.
Supplies of resin bonded sand seem to be only available to commercial foundries here in UK.

It has been on my bucket list to do Iron and I did make a waste oil burner for that purpose but got sick of the noisy air compressor cutting in all the time and altering the regulator setting so I never progressed from Bronze
I know you can do Iron with Propane but it uses an awful lot of gas so maybe I will revisit the oil burner some time.

I use Salamander Super crucibles and most work is with A2 size as I tend to cast smaller items.

Attached is a pic of some of my furnaces which are crude but work for me.
The large one is quite old and of the rammed up refractory design (its dirty inside as I used it to burn off paint on some scrap). This furnace has served me well but the initial heat up time is longer due to heating the thick liner.
The smaller black furnace is a recent build and is lined with ceramic blanket and coated with high temperature refractory paint and heats up very quickly again on Propane.
The small electric furnace, of which I made two, has a cast 'Arelcrete' refractory liner and wrapped simply with ceramic blanket. Elements are self wound from Kanthal A1 and is around 1700 watts and takes around 40 mins to melt an A2 crucible of Brass. I usually have to replace the elements every year depending on use.
In use I simply switch off the supply and lift the furnace off the base to gain access to the crucible which saves risking elements touching the crucible tongs.
The second identical electric furnace I use for burnout of PLA flasks under PID control.
Also attached is sample of lost PLA casting. You can see how the process picks up all the layer lines but these were going to be machined so I didn't bother sanding the patterns.
I always use vacuum assist on this technique.

Oh, and I will try to cover the casting side as this project develops.
Cheers
Rich


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## GreenTwin (Jul 21, 2022)

Rich-
I think I have gotten beyond the mistake phase (I hope) after many years.
I started backyard casting in 2011.

For years I made every conceivable mistake that one can make when doing foundry work, or so it would seem.

I finally have the process and setup down to memory, and so I don't have to think about what needs to be done.

The resin bound sand is not very easy to find unless you know someone who will sell a small quantity of it.
The art-iron folks around here purchase kits with 3,500 lbs of OK85 commercial sand (very dry), and 5 gallons of resin, plus 1 gallon of hardener, and some catalyst.
That is the smallest amount I have found for sale, so that quantity will set you back a bit, and that much sand is difficult to handle.
The sand has to stay absolutely dry, so I repack it from a large bag into individual 5 gallon plastic buckets.

The coated furnaces seem to be very popular these days.
I have heard of some ceramic blanket failures on the lid, even if coated, when melting iron.
I know of one person who melts iron in a coated ceramic blanket furnace.

I used a 1" Mizzou cast refractory as my hot face on my latest furnace, backed up with a layer of insulating fire brick, and then two layers of ceramic blanket.
My latest furnace looks rough, but it performs well, and is pretty much impervious to iron temperatures.

What sort of slurry do you use?
I looked at slurry, but it had a shelf life of perhaps 1 year, and so I did not purchase any.

I use a Delavan siphon nozzle, with compressed air, and a Toro leaf blower for combustion air.
I run diesel only, and have run it down to about 28 F with no problems.
Diesel self-lights with a siphon nozzle, and so no need for propane.

I have a pressure nozzle burner under design/construction, and that uses a gear pump from a commercial heating unit.
The motor driving the gear pump is a small fractional hp unit, and so one day I will phase out the siphon nozzle/compressed air and use the pressure nozzle burner.

I tried propane, but always had trouble keeping the vapor pressure up, and it was difficult to judge level in the tank.
The cooler the outside ambient, the worse the propane problem became.

I use propane for aluminum only for smaller melts.

The slurry dip, burnout, vacuum assist, etc. are a lot of extra steps, but the results I have seen are shockingly good, like your castings.

An alternative to resin bound sand is sand bound with sodium silicate.
They sell it at the pottery supply houses, and you can set it with either CO2, or a catalyst.
The SS molds must not be overgassed, else they will be very weak.

SS does not have the bad fumes that the resin has.
I wear a commercial chemical respirator with the resin mixing.

It seems hard to believe that PLA will burn out that cleanly (I guess you are using PLA), but I have seen it done, and it seems to work well.

Pat J


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## creast (Jul 21, 2022)

Pat
Standard PLA burns out pretty good at 500 deg C but 600 is better. I usually let the mould cool and then blow out with compressed air before re-heating to around 300 deg C prior to pouring. Sometimes you do get some residual contaminants that show as a stain in the metal but nothing serious. Yes it is a long winded process but a must on small pieces.
I use SRS Industrial 'A' refractory plaster for the moulds In stainless tubular flasks as per jewellery casting. Its in powder form and mine is still ok after 2 years.
I have used Silicate mainly for cores and on one occasion for a mould but I do find it harder to extract the pattern from SS sand.
Today was still printing patterns and hope to start some casting soon but need to make a special rectangular flask for the leg components.


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## GreenTwin (Jul 21, 2022)

The powdered refractory is a superb idea.

For filling patterns, I changed to a powdered filler, which is a wall patching material, after constantly having the pre-mixed filler go bad before I could use it.

How does the vacuum work?
I guess that is applied when you pour in the refractory?

Sodium silicate is very sticky, and a lot of wax has to be used on the pattern.

Resin bound molds are not as sticky as SS.
Resin has a "set" time, and a "strip" time.
The patterns are pulled during the strip time.
I forgot and did not pull the patterns from the resin sand one time, and they were basically glued permanently into the sand.
Most of those patterns were ruined when I tried to extract them.

Between the set time and the strip time, the mold is still hardening, and it has to be on a flat surface, else it will warp just enough to cause a runout.  Resin molds are suppose to sit for 24 hours prior to use, to allow full cure, but you can get around that by lightly flaming the molds with a gentle propane flame, and pour right after making the mold.
I use a ceramic mold coat, and get an excellent finish with that product.

I use a small automotive slide hammer to pull patterns from resin sand.
A light impact is all it takes to break the pattern away from the mold.

I looked at one of those small electric furnaces, but my buddy says the store bought crucibles don't last very long, and are expensive.
I think you have the right idea with building your own electric furnace, and using a Morgan.

The beauty of the electric furnace is that one does not have to drag all the heavy equipment outside, and then worry about rain, etc.

It is great to compare notes with others who are making castings.
You have a great setup, and a nice selection of funaces.

I have my first furnace, which was built too heavy, and so is now retired, a small hard-fire brick furnace for quick aluminum melts, and then a lower-mass iron furnace.  I have a mini oil-fired iron furnace in the works.

One really can't have too many furnaces.

Good luck.  Post photos.

Pat J


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## awake (Jul 22, 2022)

Pat, I've seen a few videos where someone uses plain epoxy (like one would use in wooden boat construction) with plain sand. Any idea how that would compare with the product you are using?


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## creast (Jul 22, 2022)

Pat,
The vacuum is used several times in the process.
1. Vacuum after mixing for 5 mins
2. Vacuum the mould when filled for 5mins
3. The burnt out flask, preheated, is vacuumed from the bottom during filling with molten metal. This assists filling under atmospheric pressure. The refractory plaster is quite permeable which allows this method to work.

Today I have printed a couple of further patterns.
The walking beam was printed in two halves and glued together to avoid using horrible supports during printing.
The Yoke was printed and the circular bosses glued on, again to avoid printing problems. Buildplate support was required but this was unavoidable and can be cleaned up.
Both parts have been lightly sanded, which I try to avoid, to improve as cast finish. PLA is awful to sand!!!
The yoke is going to be a challenge to cast due to the shape and I am unsure I will be able to use my normal technique..hmmm needs some thought


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## GreenTwin (Jul 22, 2022)

awake said:


> Pat, I've seen a few videos where someone uses plain epoxy (like one would use in wooden boat construction) with plain sand. Any idea how that would compare with the product you are using?


I have read about a few using epoxy in lieu of a resin binder, but have not heard the outcome.
There are a number of different binder types, and I forget the exact technical name for the one I use.

The trick is to bind the grains of sand together, but beyond that there are some issues with what happens during and after the pour, and I have heard that molds that are too strong will not expand during the pour, and can damage the casting.

Keep in mind that handling resin binder requires a commercial chemical respirator, and so epoxy may also require precautions, and don't assume the smoke/fumes after a pour are safe either.

The percentage of resin binder to sand is small, and I suspect the same would apply to epoxy.
And you would want to pay attention to set time and strip time, else the epoxy will do the same as the resin, ie: glue your pattern to the sand.

The resin binder instructions do mention that the sand must be very dry, and I think the commercial sand I use (OK85) is baked in an oven.
Moisture in the sand will cause a mold failure with resin binder.
.


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## creast (Jul 24, 2022)

Today was more 3D printing, hours of it!
The baseplate is still printing (3 hours worth) and this, like the flywheel, is a pattern for sand casting.
I have printed the linkage parts and assembled them on a common sprue ready for investing and ultimately casting in brass.
Yes they could have been machined but they are fiddly and I am a bit lazy. There will be some machining of these afterwards anyway.
In the meantime, the flywheel pattern halves have been painted to improve release from the sand.


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## GreenTwin (Jul 24, 2022)

The more I use a 3D printer, the less desire I have to manually make patterns.
I did learn the manual pattern making process, but it is slow and tedious, and usually not as accurate as a 3D printed pattern.

I would like to learn the lost PLA process.
I can see a place for that with some castings.

I use to paint my patterns, but the paint generally takes 24 hours to dry, which really slows things down.
I have started using shellac, and I much prefer it due to less fumes, easy sanding, and dry times as low as 30 minutes.

I was initially going to adhere to some variation on pattern color coding scheme, but these tend to vary, and I realized that nobody ever sees my patterns anyway, and so color coding is wasted effort.
Better to focus on making quality castings.

Do you have a runner and gate plan for the flywheel ?
Some use the flywheel rim as the runner, and while that works, I can't bring myself to do that (although in the beginning, that is actually how I did it, because everyone else was doing it that way).
.


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## creast (Jul 24, 2022)

Pat, I am the same. I hate making patterns when I can let the printer churn away for hours and do it for me.
However, I hate sanding PLA, its awful stuff and I hate filling and sanding too so I decided for once to paint to help reduce the lines. It probably doesn't matter as the finished model will be painted anyway so maybe high build primer may work?
I did a test ram up on one half on the bare print and it was encouraging.

All my flywheels so far (six in total) I have done just that and run a riser from the central hub and got away with it. Occasional defects have been where sand has either washed out or dropped into the cavity but these were tiny defects and most removed during machining.

A tricky casting for me was on a beam engine frame in Brass which took me quite a few goes to get right (ish)


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## GreenTwin (Jul 24, 2022)

Those are great looking castings.

The lines in PLA prints are something I have yet to work out easily.
I bought some automotive skim coat, but have not tried it yet.

It is surprising how deep the lines go too.

One approach I have considered is to just make the castings with the lines in them, and use a sanding and/or a ceramic sponge 2"dia. disk in a tool and die grinder to buff out the lines.

They make some Relok stuff for a 2" disk.
The coarse sponges will remove a lot of material relatively quickly without digging or leaving sanding lines.

.


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## creast (Jul 25, 2022)

Most times I follow the same approach and machine/sand the casting as it's easier.
Fillers are ok for sand patterns but to be avoided with investment patterns due to burnt out ash. I sometimes us wax to fill major defects on these parts.


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## creast (Jul 25, 2022)

Today I had a trial at the flywheel casting. The old wooden flask was really a bit too small to say the least with about 5mm to spare.
As usual I found the edges of the Petrobond lifting so I knew there was going to be plenty of flash to dress. Am thinking of trying green sand again or maybe my Petrobond needs rejuvenating?
None the less, I decided to try it.
First disaster was the electric furnace failed just as the melt was commencing. A quick switch to furnace number two sorted that.
Next was a messy pour and the mould stopped accepting metal whilst the riser was only half full so I wasn't optimistic.
However, the result was successful with only a few minor defects where sand broke away.
I think the result is very usable and will be ultimately painted so these defects can be addressed in the prep.
The alloy used was from a car wheel which I have found is quite soft as cast and my attempts to heat treat didn't work previously so any small tapped threads are pretty weak and awful.


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## GreenTwin (Jul 25, 2022)

I am not sure what alloy is used in cast wheels, but a quick internet check says they are mostly A356.

I used petrobond sand first, and always had problems with it.
I added non-detergent motor oil to it, and I think I ruined the entire batch.
I am saving it in case I can figure out how to de-oil it.

Petrobond dries out very easily.
I have been told that generally one should add alcohol to Petrobond, and almost never add oil.
I will have to look up the exact alcohol they recommend using.

A muller makes quick work of Petrobond, but I have seen some put it in a tarp, and walk on it on the floor, with good results.
Petrobond does give a very nice surface finish if you don't overheat your metal.

Petrobond seems to be prone to washouts, and so a good runner and gate system is important to keep the velocity of the molten metal down.
I have had breakouts even with resin bound sand, and as long as it is an additive thing that can easily be machined off, I just leave the mold as-is.  Generally speaking, if you have your draft angle and fillets right, you will not break off resin-bound sand.

Some folks use a tall sprue, and I think that is a mistake.  I started out using very tall sprues, and learned that you really only need to get the sprue out the top of the mold, and perhaps put a pouring ring around it.

Before I figured out gray iron, I thought I would always have to use A356, and so I researched how to heat treat/temper it (not sure what the correct term is).

I use the method described in the "Foseco Non-Ferrous Foundryman's Handbook", and it seemed to make the aluminum much harder, and cleaner to machine and drill.

The Foesco method for a T6 rating on A356 is as follows:
*Step 1:*
Solution Treatment is 950 F (510 C) for eight hours, followed by a water quench.
_(I use a cold water quench.  Some use a hot water quench to reduce warpage, but I don't get warpage with a cold water quench.)_
*Step 2:*
Precipitation Treatment is 325 F (163 C) for six hours, followed by a normal cool down in air.

I have heard many say that 8 hours is not needed to heat treat aluminum, but the white papers say that the solution treating process does not begin until after 6 hours at 950 F, and so I think 8 hours is needed at 950 F.

I did get some aluminum parts too close to the kiln heating elements, and the radiant heat melted the parts, so you may need to shield the parts.  I did not have electronic heat control, and so I think that was my biggest problem.

Treated aluminum parts have a dull finish to them.

I tried greensand, and had terrible results with it, but I was pouring iron.
I have seen some superb results with greensand and aluminum, so I know for a fact that you can achieve Petrobond quality using greensand.

Greensand really needs to be mulled too, just like Petrobond, so I am not sure you are gaining anything by using greensand.

I have also heard numerous times that burned Petrobond must be discarded, but a local art-iron foundry uses Petrobond by the ton, and they never discard the burned Petrobond sand.  They use new Petrobond as a facing sand, and then backfill the flask with used Petrobond.
There are a lot of myths in the backyard casting world, and people adhere to them religiously, even if they are false.


.


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## GreenTwin (Jul 25, 2022)

There are actually two types of Petrobond, and one uses a catalyst.
I am not sure if the catalyst is required or not.  I tend to think not.


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## GreenTwin (Jul 25, 2022)

Some report that they have mulled a small amount of Isopropyl Alcohol (90%?) into their Petrobond, with good results, using a spray bottle.

Here is some information I found online about making your own oil-based sand:

_K-BOND was developed in about 1995 at Kent State University. _

_We set about to find a suitable alternative (_oil-based sand_). After about 3 months of testing, we had evaluated many sources of bentone and many sources of "smokeless" oils. (By the way, Petrobond is also made with Bentone.) We found that virtually all organo-bentones will work well. With this in mind, we bought the cheapest one we could find. 
For the oil, we settled on AMOCO Indopol L-100. This was listed as being a "food grade" material that burned cleanly. Later, we found out that Indopol is the main ingredient of most smokeless 2-stroke oils. 

The basic recipe for K-BOND is: 100 lb. of very fine silica sand (100 to 150 GFN)
6 - 7 lb. of Bentone (cheapest you can find)
3 lb. of Indopol L-100 oil
0.10 to 0.20 lb. of Propylene Carbonate (or Methanol or Isopropanol)

If the sand become too dry to mold, we add more Indopol. If it lacks any strength, first we add more Propylene Carbonate. If that does not bring up the strength, we add more Bentone. 
We have used this stuff several times a week for aluminum, bronze and iron castings. We have never thrown out the pile, we just add too it. We don't get a room full of blue haze when we pour our molds.
...the best part, we make castings that are incredibly smooth with extremely fine detail. 
I am personally very pleased that some of you have taken the initiative to use K-BOND.

Dedicated to Metal Casting Education... 

Tom Cobett_
_Cleveland, Ohio_


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## creast (Jul 26, 2022)

Pat
Many thanks for the information on Petrobond and its equivalents.
Personally, I have remixed the burnt sand back into the mix and Luckygen of Youtube also says he does the same. I am guessing I may need to rejuvenate my batch but I will try on a sample bucketful first.
I do not have a muller as I really am only a casual foundry enthusiast and that often means I never really get to master the art but I do finally get what  want when there is a project on the go  .
All I do is rub the whole batch of sand through a garden sieve with quite small mesh and hand mix it together.
Cheer
Rich


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## creast (Jul 26, 2022)

Today was 'bitting and bobbing' day.
The small brass parts have been invested and vacuumed to reduce entrained bubbles (not always successful I add).
The baseplate was invested in an old butter carton, something I have not done before. I was hoping to remove the print after the plaster set but there is no way it's coming out so I will burn it out and do a combined investment and sand casting. Not something I have tried before but Myfordboy has demonstrated the technique.
All the investment plaster moulds need to rest overnight before entering the burn out schedule.
In the meantime I started machining the flywheel which was tricky to hold and my chuck does not open wide enough so I clamped it to a diy mini face plate and did my best to get it running true which is tricky on a casting.
Very small cuts were required to ensure it didn't disturb the alignment but the wheel is now mounted on its spindle.


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## creast (Jul 27, 2022)

Not a lot to report today as I visited my Mum. She's 91 but still independent and active.
This afternoon I started to burn out the PLA patterns.
Prior to putting the cylindrical flasks in the kiln/furnace I now burn out the sprue with a blowtorch to aid breathing of the pattern.
I say 'breathing', the fact is on two occasions I had flasks explode and because I simply have ceramic wool over the furnace this offered no resistance and the workshop ceiling was covered in plaster debris. In fact the whole workshop was covered with bits.
I am guessing moisture had found its way into the pattern during vacuuming of the plaster and then built up vapour pressure in the pattern itself.
I tend to print patterns with low infill to reduce the amount of ash and allow the pattern to flex more easily during melting. Small prints are not usually any problem.
The moulds are too hot to show just now after the 4 hour process and will be examined in the morning.


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## GreenTwin (Jul 27, 2022)

I seem to recall some folks warning that plain plaster of paris can contain water trapped internally and explode.

I guess if the pattern itself had a bit of moisture in it, that could also cause problems, expecially if eveything got very hot, and then the moisture was released from a pocket somewhere.

I have seen people use concrete as a refractory for a funace, and that will explode (there are some videos out there of this happening).

People tell me constantly to never pour over concrete, but it depends on the concrete.
I have tons of photos of where I spilled aluminim, brass/bronze, and cast iron on my concrete, and have never had an explosion.
Some concrete will explode if you spill molten metal on it, so don't assume that spilling molten metal on bare concrete is necessarily a good or safe thing.

From a practical standpoint, if you have a nice concrete driveway (I don't have very good concrete), then you don't want to ruin it by spilling molten metal on it.

And steel ingot molds can have residual surface moisture on them, and those must be taken up to perhaps 500 F, else they tend to eject molten metal violently in your face (don't ask me how I know this, but I have some good burn photos if anyone is into backyard casting gore).

The low infill is a great idea, and speeds up printing a lot too.

I have been very impressed with the lost-PLA process, and I have seen it work very well with both aluminum and gray iron.

How difficult is the breakout?

.


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## creast (Jul 28, 2022)

Breakout couldn't be easier. After quenching in water the refractory simply disintegrates and goes like soft putty. I just use an old toothbrush and water to finish them off.


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## creast (Jul 28, 2022)

Well, not an encouraging day.
On cooling I inspected the open moulded baseplate. It was a pretty clean burnout as you can see but a couple of very cracks and flakes on the thinner sides. Not too serious.
I am not convinced the small lettering will fill though due to surface tension.
Second fail was on a flask cast which I decided to vacuum test and due to lack of support the base failed under the vacuum and pulled free. Oh well!


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## GreenTwin (Jul 29, 2022)

Seems like you could band or clamp the mold to keep the cracks closed long enough to pour.

The only way to learn how to cast things is to have failures.
I could win some sort of major failure award for my past blunders.

I would guess the letters would fill, depending on your pour temperature.
I generally pour aluminum at 1,350 F.

.


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## creast (Jul 29, 2022)

Well, things couldn't get worse as I dropped the damn mould and broke it badly so it's start again.
This means printing another base and so I have decided to go back to petrobond casting so at least I have a pattern for future errors!
This will not have the lettering which I may add as a separate lost PLA plaque on the base.
However, The lost PLA linkages came out good. Just a few micro bubbles which is quite normal and knock off easily.
Attached is also short video showing how permeable this plaster is.


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## GreenTwin (Jul 30, 2022)

Luckily resin-bound molds are quite sturdy, and they can be transported long distances in a car without damage, since they cure in a hard state.

I guess that is one downside to the lost-anything methods, is that you lose the pattern with each casting.
Its a fair trade if you need the accuracy, have a very complex shape, or can make multiple castings on a tree.

The parts look great.
Are those bronze?  They look more like brass.

I have seen folks 3D print their own letters, but a plaque with letters sounds like an every better idea, since that would fix the letters and keep them from shifting around or getting glued on crooked.

The video is very interesting.
I was not sure exactly how that was done.

I have seen some centrifuge demonstrations, which I guess accomplishes about the same thing.

.


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## creast (Jul 30, 2022)

Pat,
The parts are brass as per the plans.
The video shows just how well the plaster can allow a vacuum to pull the melt in.
Yes it is a more compact method than centrifugal equipment.
At the moment I get away with vacuuming from the base but I hope to use perforated flasks soon. This will improve fill but will require new vacuum vessel.
The cheap Chinese vac pump works ok but it would be better with one that pulls a bit harder . I work on a skinflint budget


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## GreenTwin (Jul 30, 2022)

I envy the convenience of a tabletop furnace.
If they did iron, I would definitely build or buy one one.
I have seen the smaller induction units, but they are very complex, and so would be prone to breaking down.

My mini iron furnace will be more convenient, but I still plan on using outdoors.
I guess I could build an outdoor fireprooof metal box to contain the mini furnace, and use a powered respirator to avoid carbon monoxide poisoning.

.


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## creast (Jul 30, 2022)

The revised base pattern was printed with ingates and not sanded or filled for the first cast. I had problems with the sand core in the boss and it started to break away when removing the pattern so I reinserted the pattern and pressed some screws into the sand.
It was only partially successful but this bore detail has to be machined anyway,
Likewise some sand lift at the base of the circular boss too.
There are a few but minor anomalies of surface skin on and near the square boss.
I admit I went a bid mad with riser feeders but I was wary of the thick and thin areas.
All in all its a workable part and the finished part will be painted.


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## creast (Jul 30, 2022)

I have just noticed that my last photos when viewed and zoomed seem to zoom in massively. Any ideas how to prevent this?
Should I check image size etc or attach in a different way?


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## GreenTwin (Jul 31, 2022)

The photos look fine, I don't see a problem.

The pour temperature looks to be on the money.
Nice shiny finish with no burning into the sand.

Everyone has their favorite sprue/runner/gate configuration.
I will mention how I would do it for comparison purposes.

I would use a U-shaped runner with sprue at the center of the U.

One knife gate at the center of the pattern on each side (total of 2 knife gates).

Maybe a small riser over that thick square part.

Vents out the high points in the cope to assist with mold fill.

Knife gates would be maybe 2.5" long, 1/4" tall (not sure exactly how thick your piece is, so maybe not so tall).

Looks like you got a very good casting.

.


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## aka9950202 (Jul 31, 2022)

Love your work. 

Are you using the plans published in the Model engineering magazine? 

Will you be making the 3d printed files available? 

Cheers 

Andrew in Melbourne.


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## creast (Jul 31, 2022)

Hi Andrew. 
Thank you for your kind comments.
Yes, eventually I will publish the files as I usually do on GrabCad when I have completed the project.
Because I am casting a lot of parts I have to create patterns slightly oversize but I will include finished parts.
I am working from those plans but they are 1/4 scale and mine is 1/8th
Cheers
 Rich


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## creast (Jul 31, 2022)

GreenTwin said:


> The photos look fine, I don't see a problem.
> 
> The pour temperature looks to be on the money.
> Nice shiny finish with no burning into the sand.
> ...


Pat,
Thanks for the input.
The part is roughly 4x2 inches and the sides 1/4" high. The recessed area is 0.16" thick.


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## creast (Jul 31, 2022)

Today I printed the main bracket as a split pattern. Some light sanding but no filler or paint as I am a bit impatient 
As usual I got lifting of the Petrobond at the edges...grrrrr. It is so fragile at the edges no matter how hard I ram the damn stuff!
Oh well just a little more flash to file off!
Opening the flasks after casting looked encouraging but as you can see the cope side wasn't great.
Guess a re-cast is in order.


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## creast (Aug 2, 2022)

Forgive me Father for I have sinned!
But in sinning I actually got a great result for the Rider crank bracket
Yesterday I spent countless hours revisiting greensand and in the end gave up, sand slightly too moist and evidence of tiny steam bubbles on the drag side. Avoiding the moisture simply made removing the patterns without breakout impossible so I resorted to Petrobond.
Again I had incomplete fill at the exact same point as the first casting. 
I modified the patterns to give slightly more draft and printed them off.
This is were I sinned. I simply used one sprue/feeder with an extension to give more head as per Myfordboy.
Now, Olfoundryman on Youtube would scream at me for doing this as it encourages turbulence and air entrainment but I thought if Myfordboy gets such good results then it's worth punt.
I will let the pics speak for themselves


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## GreenTwin (Aug 2, 2022)

Everyone has their favorite casting methods, and while I see a lot of debate online about the "right way" to do it, the fact is that a lot of ways work, and so it is about getting good casting results, and not pleasing someone on youtube.

I am in the John Campbell camp, mainly because my sand is not reuable, and so I have to nail it the first time.
I err on the side of caution, and I don't take chances with iron, since a defect in an iron casting would cost me a lot of time and effort, not to mention expense.  I can melt aluminum in 12 minutes.  A typical iron melt is 1 hour.

Aluminum seems to be more tolerant of sprue/runner/gate layouts, and it would seem that most anything will work.

I have found iron to be not nearly as forgiving, for whatever reasons.
It is not that easy to get superheat with iron like you can with aluminum, and aluminum seems to be more fluid generally than iron.
I am not sure if the 3X mass of iron (compared with aluminum) causes more turbulence and air entrainment, or what, but the mass may come into play.

Foundry and pattern work has been a lot of fun for me.
It is exciting to see folks casting engine parts.

In the end, the proof is in the pudding, and your pudding looks really good !
.


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## lee webster (Aug 2, 2022)

creast, I prefer to use "proper" gates and spues etc. But when I tried to cast a thin section aluminium picture frame using very old salvaged metal meant for die casting, I ended up using the Myfordboy method. It worked and looks good. If there are any bubbles they are either below the surface on invisible to the eye.
Yours is a good casting that will do the job. That works for me.


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## creast (Aug 2, 2022)

Thanks Pat.
Just killed some time and did the lost PLA plaque (x2) in some scrap zinc alloy of unknown analysis.
This time no sagas.
Rich


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## creast (Aug 4, 2022)

I started to mill the crank bracket but my Y axis DRO has been playing up so have ordered a replacement.
The baseplate has now been bored and faced but needs the DRO for the bolt pitch circle drilling.
In the meantime I prepped the walking beam for lost pla casting which required a new slim tube which is too long for my vacuum pot so I resorted to vibrating to help reduce trapped bubbles. This will be the longest casting I have tried using this method.
The piston centre has been part machined and milled for the pivot bosses which I will solder in-situ.
I have decided to try to do the main cylinder as lost pla as it is quite tricky to sand cast due to the bosses at funny angles and to reduce the hassle of supports I have adopted the fabrication method where the bosses and flange are added and glued in place. I will seal the joins with wax before investing.
If this works it will be the largest lost pla I have attempted.


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## GreenTwin (Aug 4, 2022)

Some clever ideas there !

.


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## creast (Aug 6, 2022)

Well, the replacement DRO arrived and has been fitted so milling can continue .
Today I cast the walking beam in a zinc alloy but I wish I had used Brass. This unknown zinc alloy has terrible shrinkage on thick sections and I should have known better really. The part would have been more successful I am sure if I had put the holes in which are on the finished part. This would have given a more uniform section.
However it was encouraging the mould filled being long and slender. I could possible repair the casting but I may re-cast.

The cylinder pattern was prepped and secured into an old food can. The pattern has to be prevented from floating up when the plaster is poured, hence the lolly stick glued to it and the can.
This is currently cooling down from burn-out.
I hasten to add that once the plaster is set it is vital to drill holes in the can base to prevent any pressure build up. First time I forgot, the can pushed out like a pneumatic ram and wedged itself across the kiln walls!


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## creast (Aug 7, 2022)

If at first you don't succeed....
Well as the saying goes it looks like another try again time.
The cylinder casting was a fail but to be honest I wasn't that confident really.
I had my suspicions that vac fill on such a large casting would have its problems, enough so for me to seal the top surface to reduce loss of vacuum but really this needed a proper perforated flask or an extender sprue/riser.
As you can see, the bottom filled great and so did the bosses with no shrinkage faults but the cast failed to fill towards the top.
There are a few bubble blobs but these are not a problem.
Pre-heat of the mould was rather low at 200 deg C but I poured hotter than normal at 760 deg C.
I will repeat but next time will feed right from the bottom and use an extended sprue/riser and possible venting stringers.
Will have to see!


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## dnalot (Aug 7, 2022)

I see in the photos above that you are getting some beads caused by air bubbles in your investment plaster. I struggled with this and have started putting my flask in a pressure pot while the plaster sets up. Squeezes the bubbles down to near nothing. I got the bubbles largely under control by proper mixing of the plaster but sometimes the shape of the part will trap some air. The pressure pot also forced plaster into tiny holes in the pattern or tube shaped patterns. .  

Watching this thread with great interest. Keep up the good work. 

Mark T


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## dnalot (Aug 7, 2022)

creast said:


> really this needed a proper perforated flask



I am using the solid flask type and have taped several soda straws that travel 2/3s of the way up the flask to aid with the vacuuming of the flask during a pour. Helped a lot.

Mark T


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## creast (Aug 7, 2022)

Mark,
Many thanks for your advice. I will take it on board.
Bubbles can be annoying but better than cavities as they can be dressed off.
My normal investment castings are quite small and predictable in casting. 
On this project I guess I am pushing things on a larger scale and things work differently.
I did make a pressure casting rig but this relies on holding the melt in a reservoir under surface tension before pressurising into the cavity.
Any advice is most welcome 
Rich


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## creast (Aug 9, 2022)

Not much to report today apart from it's been pretty hot here in the UK and looks to get hotter again.
I re-printed the cylinder and incorporated a large sprue feed straight to the bottom with a spider of gates.
Now the dilemma, do I still use vacuum and incorporate some straws as suggested by Mark or do I vent in a similar way with straws as vents rising from the various pockets to aid flow?
I will ponder on it a while but I would like to see how the addition of straws aids vacuuming.
The base was grit blasted and machined/ drilled etc.
I keep finding more and more errors on the 3D model I have based my work on so since I have progressed this far I will have to make adjustments on the fly.


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## creast (Aug 12, 2022)

Another hot day so I took advantage of the cooler morning and re-cast the walking beam this time in Brass and with undersize hole features to reduce bulk shrinkage problems.
The result was much improved. 
There were a few bubble blobs which I expected as I couldn't vacuum degass the mould as it was too long for my pot and of course the dreaded print lines on this particular profile are pretty pronounced.
The original pump on this model is fabricated and soldered but I have chosen to try my cast method and this pattern is made up of five separate parts.
The main cylinder which failed has been re-invested and this time I have inverted the mould orientation and added stringers which when burn out will assist the vacuum fill further up. This will be burnt out tomorrow and probably cast at the same time without vacuum checking for permeability because I am getting impatient!


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## creast (Aug 18, 2022)

Well it's been a while.
The second lost PLA cylinder was a disaster. However, adding the stringers did give me a complete fill!
As you can see though, the casting is rubbish and has serious porosity problems.
My thoughts are twofold, the large sprue would have caused much entrained air and also any hydrogen absorbed in the melt is probably encouraged to come out even more so under vacuum.
I didn't de-gas the melt as I only have the chemical type de-gasser and haven't always seen much improvement in the past.
So, a rethink was in order and after looking at the model in more detail I thought an odd-side moulding of the pattern would maybe work so a wooden pattern was made.
I have never tried odd-side moulding before and the pattern didn't pull cleanly but I decided to still cast it. The surplus areas of sand breakout just means more fettling.
A sodium silicate core was formed in a card tube.
The result isn't fantastic but looks workable. I simplified the pattern to give as uniform section as possible
I did de-gas and flux the melt this time,


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## GreenTwin (Aug 19, 2022)

Nice looking casting.
The shiny surface indicates a good pour temperature.

.


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## stanstocker (Aug 19, 2022)

Some days you dance through a job with great elegance, other days you just slog forward on will power and brute force.

Either way, you kept dancing and pulled it off, so it's a win for the home team!


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## creast (Aug 19, 2022)

Today was spent mainly machining the cylinder casting but no time for photos.
I also cast the pump body, some revised piston links and bearing holder which did not fill due to vacuuming problems during casting.


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## creast (Aug 20, 2022)

Machining the cylinder casting has been a messy and lengthy process resulting in a lot of gritty swarf.
The internal bore details were machined first. Since I didn't create a stepped core to create the water jacket cavity this had to bored out.
Supporting the part on an expanding mandrel allowed the flange and necked section to be turned.
Milling finished off the lugs.
The part will grit blasted prior to the paint job.


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## creast (Aug 26, 2022)

The last couple of days have been spent reviewing how to cast the legs for the Rider.
Originally I intended to lost PLA cast them and had produced the prints a while back. On reflection of my experiences lately on aluminium in plaster casting and the fact I would need a special shaped flask to cast it in I decided to try odd side moulding again.
To do this I decided to print the legs with the apertures filled in and after initial trials added a continuous beam across the feet to act as a runner.
These details will be cut out after casting. The main face is only 2mm thick so quite a challenge I thought on filling issues and the melt freezing too early.
With the Petrobond I found the sand core of the rear cavity was too fragile so I created a Sodium Silicate sand core which would tied into the sand mould with screws which proved be ineffective as the core remained stuck in the pattern but was manually placed back in the drag. The second had sheet metal tabs entrained with wooden lolly sticks glued on to hold more securely.
An extended sprue was used but no riser. The aluminium was cast slightly hot at 750 deg C.
The flask leaked at the joint during the pour which caused some panic but all worked out.
The second casting also leaked at the flask joint but again successful despite excessive flash etc.
Time to make new flasks!


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## GreenTwin (Aug 30, 2022)

I was greatly confused about how to mold windows in casting, but I think I understand it now, and I think I could do it successfully.

As you mention, there may be some concerns about filling thin parts around the windows.

.


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## creast (Aug 30, 2022)

The legs have had their apertures cut out and mount surfaces skimmed. I decided to grit blast these to help reduce the layer lines.
A trial fit to the base was in order and some additional fettling is required.


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## GreenTwin (Aug 30, 2022)

Its looking very good !

.


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## creast (Aug 30, 2022)

Thanks Pat 
The finish needs improving but as most of the engine is paint finish I can get a bit of Bondo out .
Will be having a break for a few days and then back to some fiddly bits.
Rich


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## creast (Sep 7, 2022)

I have had a break from the workshop but will now crack on with the project.
I am hoping that someone here may be able to answer my question regarding the displacer cylinder materials specified in the build manual.
The cylinder is specified copper with a steel flange silver soldered in place and the end cap/ diaphragm is thin stainless steel.
I have previously built a Ky-Ko fan which had an all stainless displacer cylinder and runs very well and an insulating gasket reduces heat loss to the framework.
In the build log it mentions reducing the wall thickness of the copper to reduce heat losses to the mounting flange. 
So why use copper in the first place and why not copper instead of stainless for the end cap where the heat is to be taken in???


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## creast (Sep 9, 2022)

Had a chance to try another casting today but took me three goes to get a reasonable result.
The yoke casting was an awkward one and so I decided to use a core to help and odd sided the mould.
Yet again plenty of flash as the mould didn't separate clean but in the end I got a casting.


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## creast (Sep 16, 2022)

Another week has passed and has been mainly machining parts that were cast earlier or from stock material.
Today I cast some home made tin bronze for the walking beam bearings and decided to re-do the support in the same material as it was there and needed re-casting from the last failure.
I was surprised that the lost PLA casting actually came out great as the melt seemed very sticky and I did not pre-heat the mould.
There are a few questions I have regarding home brew alloys but I will post them in the foundry section.
I have to wait for some material to be delivered for the power piston and cylinder flange.


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## creast (Sep 22, 2022)

I have been busy machining  pivots, shoulder pivot screws and also probably cast the final casting of the project which is a mounting frame/rim to hold the firebox.
This will be silver soldered to the firebox and suspended below the baseplate so Brass was order of the day.
Quite a fine casting which was made in Petrobond sand, its only 2mm section by 2.5mm depth. 
First cast failed to fill so an extended sprue was used on the 2nd attempt and success! 
The cross feeders help the fill and also support the rim for subsequent machining before being removed.

I now have to tackle the power piston.


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## GreenTwin (Sep 23, 2022)

I use knife gates quite a bit, and find them effective at spreading out the metal flow, lowering the metal velocity, and helping to completely fill thin sections.

I typically use multiple gates on a part too, to fill from both sides.

That is a nice frame, and so tricky to cast.
Hats off to you sir !!!

.


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## creast (Sep 23, 2022)

GreenTwin said:


> I use knife gates quite a bit, and find them effective at spreading out the metal flow, lowering the metal velocity, and helping to completely fill thin sections.
> 
> I typically use multiple gates on a part too, to fill from both sides.
> 
> ...


Thanks Pat.
First attempt failed to flow more than 10mm from the gates so I extended the sprue height and made sure the brass was well hot.
Even at this scale there was very slight contraction dimpling at the lugs but it cleaned up ok


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## GreenTwin (Sep 24, 2022)

Every part seems to mold up and cast a little differently.
I always lament that if I only had known last year what I know today, I could have done it differently/better.

I watch every casting thread and video I can find, because better to learn others mistakes and successes, and perhaps save myself some time.

I am quite sure I will never learn it all, but if I can get consistent castings, that is really all I want.

Your success rate seems quite good.

.


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## creast (Sep 27, 2022)

Progress is slow but that usually is the case.
The last couple of days , when possible, I have machined the power piston apart from final OD skim to fit which will be done on a mandrel.
Broaching the  two slots was done on the lathe.
The displacer yoke arms were bent from 2.5mm square brass and the end details dado jointed and soft soldered in place.
In a similar way the pivot boss was all turned and milled in the lathe using my tool post mill attachment and a soldered boss added.


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## GreenTwin (Sep 28, 2022)

creast said:


> Broaching the two slots was done on the lathe.


How did you do that?

.


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## creast (Sep 28, 2022)

GreenTwin said:


> How did you do that?
> 
> .


I should have taken photos.. lol!
Basically, I set a piece of 1/4" square HSS steel into the tool post and squared it up to the workpiece and set the height so it was dead centre.
The tool had just a basic rake of about 5 degrees.
I use a homemade indexing jig on my Myford which allows me to lock the spindle and index using a 60 tooth gear.
The tool is simply driven into the part using the carriage/saddle movement to shave off a few thou at a time.
It's slow but it saves taking the part off the lathe.
I use this indexing method a lot on the lathe for simple splines, keyway and flats on turned pieces using my rather crude (and not safety compliant) milling attachment.


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## creast (Oct 10, 2022)

Well time flies!
I have still been plodding on, when time permits, constructing the displacer and its cylinder.
I followed on with my initial plan and made the cylinder from stainless with a copper hot cap silver soldered in place.
Lapping the power piston cylinder has been a chore as I have no real suitable lap available so have decided to make one but this time as a helical design.
The pattern has been printed and will be cast in brass. Copper would probably be better but may be too soft when cast to maintain wall pressure.
It's almost at the stage to trial assemble and see if it will run and if it does I can proceed with the pump and firebox,
Fingers crossed


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## Richard Hed (Oct 11, 2022)

creast said:


> Well time flies!
> I have still been plodding on, when time permits, constructing the displacer and its cylinder.
> I followed on with my initial plan and made the cylinder from stainless with a copper hot cap silver soldered in place.
> Lapping the power piston cylinder has been a chore as I have no real suitable lap available so have decided to make one but this time as a helical design.
> ...


Hold on,  Isn't it dangerous to silversolder stainless?  I thimpfks it will not hold.


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## creast (Oct 11, 2022)

Richard Hed said:


> Hold on,  Isn't it dangerous to silversolder stainless?  I thimpfks it will not hold.


I have never had a problem silver soldering / brazing stainless .
Where have you seen reference to it being a problem?
Rich


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## Richard Hed (Oct 11, 2022)

creast said:


> I have never had a problem silver soldering / brazing stainless .
> Where have you seen reference to it being a problem?
> Rich


I have no experience with this at all.  The guys on this forum (me thimpfks) have said so.


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## Chiptosser (Oct 11, 2022)

Problem silver soldering Brass and stainless????????????
Not at all.
Maybe someone has had bad luck because of inexperience.  Practice practice!


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## creast (Oct 12, 2022)

She runs!!  
The lapping tool didn't completely fill on casting but was suffice to get the rather slow lapping process done.
I decided to assemble and see if she would run and despite more friction than I liked for a hot air engine she does run, even on a spirit burner!
I am well chuffed.
Now to finish the pump and firebox etc as well as start the job.


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## GreenTwin (Oct 12, 2022)

Most excellent work across the board, patterns/molding/casting/machining, etc.

Very nice running too !

.


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## creast (Oct 12, 2022)

Thanks Pat.
So far I have mostly enjoyed this project and the challenges it has presented and as you know it is always a learning process that makes it more worthwhile.
Rich


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## Richard Hed (Oct 12, 2022)

Chiptosser said:


> Problem silver soldering Brass and stainless????????????
> Not at all.
> Maybe someone has had bad luck because of inexperience.  Practice practice!


Well you guys are correct.   I viewed a utub vid where the fellow did stainless silver soldering all the time for a living.  It works well.  Good to know


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## GreenTwin (Oct 12, 2022)

That is the first I have heard of silver soldering stainless.
I have heard of silver soldering steel, copper, brass, and bronze.

I have welded stainless steel with a nickel stick rod.
I would hate to think what nickel rod goes for these days.

.


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## Richard Hed (Oct 12, 2022)

GreenTwin said:


> That is the first I have heard of silver soldering stainless.
> I have heard of silver soldering steel, copper, brass, and bronze.
> 
> I have welded stainless steel with a nickel stick rod.
> ...


I bought a Tig machine last year and managed to finally get it set up and running a couple days ago.  Tigged a few siphon devices  in stainless that I am making for wine making.  That's why I bought some stainless sheet -- for making some dedicated fermenters.  So if I needs to connect some stainless, hope that it will be amenable to tigging.  The connections  in the case of wine making need to be "food compatible".

Nickel rod probably is sold by the piece.


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## creast (Oct 14, 2022)

I refer to the Johnson Matthey site and quote
"
SILVER-FLO filler metals​ 
*SILVER-FLOTM *products can be used to join the common engineering metals such as copper, copper alloys (brass, bronze, nickel silver, aluminium bronze, copper nickel), nickel alloys, steel,* stainless steel* and tungsten carbide.


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## propclock (Oct 14, 2022)

Thank You, fabulous build,
 and although I have never cast it is still a dream.
Perhaps I missed it, you asked for advice on the displacer material choices.
What did you actually use? It is an excellent runner!!


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## creast (Oct 14, 2022)

propclock said:


> Thank You, fabulous build,
> and although I have never cast it is still a dream.
> Perhaps I missed it, you asked for advice on the displacer material choices.
> What did you actually use? It is an excellent runner!!


Hi, thanks for the compliment.
I made the displacer as per the plans but scaled for 1/8th. That is, it's made as a stainless cylinder with sealed ends. 
The tube was machined down to about 0.6mm thick wall thickness and I was still concerned that the weight was too much even then.
Feeling how it runs it would probably be a bit better if lighter but it does work. maybe more mass in the flywheel would help too as this is just made in  aluminium.
I normally add a brass rim or lead infill on my flywheels to boost the mass and depending how it goes when the water pump is added I may revise this.
Cheers
Rich


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## creast (Oct 19, 2022)

Not much time in the workshop of late but the engine has been dismantled for painting which to be truthful hasn't gone well due to indecisions on colour but that's another story.
I managed to cast a few small parts today which are faux pipe fittings and some valve bodies.
I think working drain valves will be a challenge to make at this scale!
Brass parts on the engine have been buffed up and for once I have tried clear lacquer over them to retain the shine.
Another few days away so cannot proceed for a while.


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## creast (Oct 26, 2022)

Advice sought.
So, after dismantling the engine to paint it I had days of niggles to get it to run again.
First fault was a crack in the displacer cylinder silver soldered joint but not really a crack but bad soldering which was probably sealed by the flux first time around. That's fixed now and the cylinder vacuum tested to ensure its integrity.
Next was linkage misalignments which on these models can result in a no run.
Four days later and she runs again but now my big question... lubrication!
This is the third Stirling engine in my collection and the first had a graphite piston running in anodised aluminium cylinder and sometimes I used a light oil on the displace rod and it still runs after all this time.
The second was a Jonkman stirling 60 made mainly from Brass with steel rods.
 I learnt from this smaller engine how lubrication can kill a Stirling from running.
So, at present I have used a little grease on the displacer rod and PTFE spray on the aluminium piston in stainless cylinder and it runs but for how long?
Any advice on lubrication of 1/8th scale engines much appreciated.
I have posted on Stirlingengineforum.com but so far no real answers,
Cheers
Rich


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## propclock (Oct 26, 2022)

I have had good luck with Gore-tex Piston rings, both circular cut or strip cut
to fit in a piston ring groove.  Gore-Tex is expanded PTFE. Also graphite lube is good 
with no oil. Just the powder form and mix with alcohol if needed.  FWIW


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## creast (Oct 26, 2022)

propclock said:


> I have had good luck with Gore-tex Piston rings, both circular cut or strip cut
> to fit in a piston ring groove.  Gore-Tex is expanded PTFE. Also graphite lube is good
> with no oil. Just the powder form and mix with alcohol if needed.  FWIW


Thanks for your input.
There are no rings on this engine, it's just a close fit and does work fine but for how long?
I have been advised to anodise the piston after running a while but would still prefer security of some lubrication.
I have also heard of graphite powder (as used on door locks) and will look into that too.
Maybe a dry lube graphite or moybdenum spray coat??
Cheers
Rich


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## molekel (Nov 12, 2022)

I think the original used leather for the seals.. Anyway still looking for plans of the improved Rider Ericsson. Even better 3d scans or handmade drawings of a disassembled machine


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## creast (Nov 14, 2022)

Rider or Ericsson??
After reading the reprint of the Domestic Water Supply catalogue of hot air pumping engines I now question whether my assumption that the engine I am constructing should be simply called 'The Ericsson pumping engine'.
However, I know the two companies merged eventually and would be badged under the new collective name but in reality the design really is Ericsson.
Any comments?
My engine is nearing completion even though I have not been posting and will next appear on the completed engines section hopefully before Christmas!
Rich


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## creast (Nov 14, 2022)

molekel said:


> I think the original used leather for the seals.. Anyway still looking for plans of the improved Rider Ericsson. Even better 3d scans or handmade drawings of a disassembled machine


I have not found any models or plans on this particular engine.
Here in the UK on youtube, Barumman is a master of Stirling and Steam and he built one way back in 1992 and scaled it from the archived drawings in the book mentioned in the video.


Rich


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## molekel (Nov 15, 2022)

thats the one I'm looking for ... not sure if the book is available anymore ...


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## molekel (Nov 15, 2022)

He posted a video 5 Months ago ... I will try to reach out to him. But if you have any ideas on how he might have built the seals and the regenerator I am all ears.

I can burnish or precision grind my new cylinders It's really down to a few technical questions before I can build my first working engine. Tried once with a not-too-nice fit and a copper tube filled with copper wires to connnect the cylinders but it didn't run even with a glowing hot cylinder.

It looks like the seal is some kind of stuffing box assembly.  Looking forward to your build.

Thanks for your tip it's really the first one that is pointing into the right direction without buying a set of castings for 500$ that I don't really need.


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## creast (Nov 15, 2022)

molekel said:


> thats the one I'm looking for ... not sure if the book is available anymore ...


The book is still available.





						Rider-Ericsson Hot Air Pumping Engine Catalogue 1906 | Camden Miniature Steam Services
					

High quality reprint of the 1906 catalogue issued by the “Rider-Ericsson Engine Co.” covering their improved Rider and Ericsson Hot Air Pumping Engines for domestic water supply - IE covers two distinct types of engine. Lots of fascinating information, and if you thought hot air engines couldn’t...



					camdenmin.co.uk
				



Rich


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## molekel (Nov 15, 2022)

A must have for my lbrary... Thank you soo much.


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## creast (Nov 30, 2022)

Project finished and now in the finished engines section of the forum


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