The Steamboating Forum

I worked on this engine since 2012, and was beginning to think I would never complete it.
I cast the flywheel in gray iron, and the remaining cast parts in 356 aluminum.

COVID hit and worked slowed down just long enough for me to finish it all.

I made full 2D drawings, and published the entire thing in Live Steam this year (a multi-part series that is still in progress).

This is the first complete steam engine I have made.
All derived from 3 photos that a buddy of mine found on Preston's Services steam engine website in the UK.
What a journey it was, but boy did I learn a lot.

I can cast gray iron parts with impunity now, defect free, accurately cast, and easily machinable.

Somehow, the attachement gets shown twice.
Not sure how to fix that.

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Pouring some gray iron.
It takes a lot of leather to pour iron, since the radian heat is significant.
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Nice job! What bore and stroke?

Thanks.
Bore is 1.25", stroke is 2.0".

Here is a photo of the original engine that was on the Preston's Services site in the UK.

My engine is 60% of the original.

I got it as close as I could get it, but only had three photos, and I think they were all from skewed angles, so tricky to get it exact.
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Here is the 3D model that I made.

Many of the patterns were 3D printed from the 3D model, including the flywheel.
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That's quite a useful size, somewhere in the 0.75HP range at 100psi.

What a beautiful replica! Did you cronical your journey anywhere online for those of us that don't have Live Steam subscriptions anymore?

Thanks.
Yes, I have a thread about it online, but I am waiting until the last article is published before opening it up.
The next Part in Live Steam will be Part 5, and that may be the last part, or perhaps one more.

I furnished all the Green Twin information to Live Steam free of charge, so I don't have a dog in the hunt as far as whether people purchasing the magazine or not.

It started out on a whim, where a buddy of mine from Canada sent me one of the original Preston's photos, and he was trying to 3D model it.
I was trying to learn 3D modeling, and he was ready to throw in the towel, so I tried my hand at modeling it, and luckily succeeded.

Then we started scheming about building some barstock models (we never initially considered casting this engine), and after looking at the 3D model for a few days, I told him "we have to cast this engine".
I always wanted to build a foundry, and this was a good excuse to do that.

At first we considered gray iron castings to be totally out of reach for a backyard hobbyist, and then I started looling around online for backyard iron casters, found some unkown guy who figured out how to melt iron with an oil burner, and decided to go for iron castings.

At the time (I think this was 2012) I did not understand the iron melting/pouring process or the sand moldning process well enough to consistently pour iron, and so the only two items I was able to cast in iron were two flywheels.
I went ahead with casting 356 aluminum for the remaining parts because I did not know if I would ever figure out how to cast iron.

There are not many who cast iron on a hobby level, and even fewer who will tell you exactly how to do it, so it took me six years and two furnace builds to finally figure out exaxctly how to consistently cast iron parts.

I had to up my game with machining engine parts, and figure out the sequence of machining all the parts.

It was very challenging in many ways, and most of what I did was my first time doing it.

This was the website I saw, and this was when I realized iron could be melted and poured in the backyard.

https://www.backyardmetalcasting.com/ironcasting01.html

This guy has since vanished from the internet, and his backyard casting forum has also vanished from the internet, taking a lot of good information with it.

I do have a detailed written description of how to melt and pour gray iron, if anyone ever wants to give it a try.

Melting and pouring aluminum 356 is simple, and can be done with a propane burner with a very small budget.
Melting and pouring gray iron required iron-temperature-rated components, and so it not really cheap.
Casting gray iron is not that difficult if you know exactly how to handle the melt as it progresses, and know exactly how to tune an oil burner (I burn diesel).

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The 2D drawings for the green twin are included in the Live Steam article, but some of them are not to scale.

I have to-scale 11x17 drawings for the green twin, and when the Live Steam series is complete, I will probably post those for free online in pdf format (I do everything open sourced).

I made two sets of castings, and I build a green twin; my buddy in Canada painted his twin gray, I guess just to differentiate between the two engines.

I use resin-bound sand that works very well with iron, and here is an example of how it can be used.
This is not my video, but just an example of resin-bound sand molds.

https://www.youtube.com/watch?v=EFMXF7szrj4

With resin-bound sand, you can consistently make professional grade iron castings (assuming you have everything else correct).

I use a ceramic mold coat, with gives a clean shiny finish when the castings come out of the sand.

As far as rules for making castings, I pretty much adhere to John Campbell's 10 rules for good castings, which can be found in abbreviated form here:
(select the highlighted text at the bottom of the paragraph to cycle to the other 9 rules)

http://www.atlasfdry.com/10rules.htm

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