I have had this engine for a long time, a hefty piece with 1 inch bore cylinders. I would have posted this in the "collections" section but since I am seeking information and comments, I thought it better to throw it out for general discussion.
This is apparently a very well-machined engine, with the entire cylinder head and base made of some non-ferrous alloy (maybe aluminum, but maybe not, and the rest brass and steel). Everything turns as it should, great precision, but also very stiff. No way have I ever had enough PSI to make it run (not that I have ever tried very hard, either). All together one very heavy lump of an engine, and in my opinion, a very handsome one also.
Obviously the details of who made it, and when, are right there on display. I know nothing more, other than that it came out of a small town in Tennessee. I was wondering if anyone might be familiar with the maker's name? Or the design of "geared eccentrics"? I am guessing that this design is probably something well-known in steam engine history (?) but I am not familiar with it.
I am also guessing that possibly this is an "apprentice" engine, built as part of a machinist course, maybe? And that, if so, it must have been a pretty advanced class!
Any comments appreciated - Thanks.
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Re: "one very heavy lump of an engine, and in my opinion, a very handsome one also." I agree fully , nice indeed.
What am I missing here?. It looks as though there are steam inlet pipes to only 2 of the 3 cylinders on the valve chest side. But 3 steam exhausts on the other side?
Jim in Minnesota
Bonjour Greg,
Like Jim, I am surpized by the number of inlet pipes.
Besides this, the "reversing gear" could be a Maudsley reverse (because of the sprockets on the crankshaft) but incomplete I would suggest.
An example on a Cheddar Proteus :
https://www.youtube.com/watch?v=J8KDyS69M3c
Thank you Jim and Raphael for the comments and video. I deliberately did not mention the odd detail of only two intakes but three exhausts, as I was wondering if anyone would notice that!
I can't offer much explanation, but internally the third cylinder is there (and moves as it should), and has at least the upper steam port. I believe that there must be some internal channel that feeds into that third cylinder. Also, if you look at the three exhaust pipes, they are all offset to one side of each cylinder, not centrally located as would be typical. The intake pipe notably does not have any threading to indicate that it was made to accept any solid and permanent source of steam or air. Almost as if it only needed to work briefly, maybe only attached to a steam or air source with a hose clamp. Which might make sense if it was some sort of machinist apprentice "exam" project?
As for the similarity to the reversing gear, I loved seeing the video, thanks so much for sharing that, I have never heard of that before. You might be right, but since this engine would appear to be a finished project (with a name plate), I can only assume that it is what it was made to be, in its entirety as it is now.
Here are three more photos that I took shortly after I got this engine, one gives a better impression of the size, compared to a Stuart twin launch and a 10V.
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You have an interesting engine!
If you remove the steam chest cover you will be able to figure out the porting.
Regarding a gear driven cam or eccentric shaft, the design is an older one.
The New England Wireless and Steam Museum has a Herreshoff Triple Expansion Marine steam engine built 1904. These were originally designed and built as torpedo boat engines in the late 1800's.
Here:
https://newsm.org/steam/herreshoff-triple-expansion-steam-engine-1904/Gil
Thanks Gil, that Herreshoff engine is one powerful beast, very impressive, and if I am up that way in the future I will have to consider a visit.
Curiosity finally got the best of me and so I took the valve chest cover off as you suggested (and partially the whole valve chest, as it turned out); I was a bit concerned that the whole thing was going to go "boing" and spit out a pile of parts, but proceeded anyway!
Here are photos of what I found - and sure enough there are fully three offset valves, and channels in the cylinder head. Somehow, I don't believe that this is a very efficient design, but there it is. Also oiled the valves and got it all back together again. It now turns a bit smoother and easier. So, mystery solved (sort of)!
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Wow, that really is a very interesting engine. Only needs the two steam line input ports as the slide valves are not centerline to the cylinder bores, so the two inlets are just in between the three slide valves. Not intuitive, but it ought to work just fine!
I like it ;c)
I agree, very interesting. Thanks
Jim in Minnesota
Thank you for the photo update.
Certainly is interesting. By the looks of things, you could probably get away with just one inlet pipe... or am I missing something?
Don't think you're missing anything Gil, as the full-length open gallery of the steam chest services all slide valves equally in theory, though having two steam entry points in between the three slide valve assemblies probably is a better way to go in actuality.
It looks like the cylinders and pistons re aluminum . There may be piston rings too but unknown material . I coud see excessive drag if cast iron. I might suggest converting to Teflon rings. My little steamer has them they are square Teflon angle cut at the gaps this reduces friction to near 0 . These will work ok on steam if not too hot 400 deg f compressed air should work very easy . I’ve not seen gear eccentrics but assuming they are adjustable I’d hunk they would be ok . I’m just getting into timing issues . I’m hoping to be able to make a second test run today . The Allen driver set came with the one driver I needed cut too. small to work in the hex screw . I got a customer satisfaction request today by email . Well being un happy was putting it very gently
I ordered a replacement today . I only have one Mickey Mouse bent Allen wrench that will work for now . So I’ll see what happens in the next day or so . I may be able to salvage a temporary tool from the misc box the too small hex is tapered so I may just cut it off so the larger part fits I hate doing this as I then will have a modified tool that just takes up valuable space.