Pattern for a Steam Engine

Discussion in 'Pattern making' started by PatJ, Feb 25, 2019.

  1. PatJ

    PatJ Silver

    Nope, this model will ultimately be a 40% scale model of a Speedy Twin, which is an engine that will fit on top of a 11"x17" piece of paper, and not related to the previous prints.

    I have perhaps 8 steam engine and IC designs going in 3D, with some models being complete and some not.

    Full size bore on this engine I think is 5", so the 40% model will have a 2" bore.

    I printed these just as a small dispay for the Soule Maker's Faire show, but the model prints will be much larger.

    Also, the supports are still on the full print, and so it will look a bit cleaner once those are removed (it will look like the partial vertical print).

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  2. DavidF

    DavidF Administrator Staff Member Banner Member

    That speedy twin looks like a pita to cast.. how about a picture of the original engine?
     
  3. PatJ

    PatJ Silver

    The cool thing about the Speedy Twin is that the factory/foundry where they were made still exists in Meridian MS, and is the Soule Museum.
    The Speedy Twin was made up until perhaps the 1950's or later, and when the factory/foundry was shut down, much of what was in it was left in place, such as the huge collection of patterns, the large cupola, the induction furnace, the engine assembly area, and the large line-shaft-driven machine shop with all of the machines.

    The assembly area for the Speedy Twin is frozen in time, and the parts for the engine are just laying around on tables and in bins (photos below).
    It is as if the workers went out for lunch, and never came back.
    If you had a frame, you could literally assemble a new Speedy Twin in the assembly area from the stacks of parts.

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  4. PatJ

    PatJ Silver

    The engine was patented in 1923, and it is a very advanced steam engine design, and one of the more advanced designs for steam engines before people stopped using them.

    The thing that makes the engine very unique is that it uses a single eccentric for each cylinder, and each eccentric drives its respective D-valve.
    The D-valves are triple-D design, and are semi-balanced.
    A steam valve on top the engine swaps the steam and exhaust passages for reversing the engine, and unlike most other D-valve engines, this one does not lift the D-valve off its seat when the steam and exhaust are reversed, which is a real trick to do.

    It took me a long time to map out all those passages and figure out exactly how the engine worked.

    Whoever thought up the design was a true genius (Mr. Soule, I think from France).

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  5. PatJ

    PatJ Silver

    Here is the cupola that was used to cast these engines.

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  6. PatJ

    PatJ Silver

    Some of the match plates for parts for the Speedy Twin engine hanging on the wall of the pattern area.

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  7. PatJ

    PatJ Silver

    The large line-shaft-driven machine shop where the engines and other parts were machined, and all still fully functional, and operating during the big show that is held every year during the first week of November.
    Seems like they said this was the largest line-shaft-driven machine shop still in operation in the US.

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  8. PatJ

    PatJ Silver

    Here is the Speedy Twin being operated under steam during the slow.
    They have a large package boiler at the museum, and all the engines on display are running on live steam, which is most impressive.

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  9. PatJ

    PatJ Silver

    Here is the core box for the frame.

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  10. PatJ

    PatJ Silver

    The pattern for the frame.

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  11. PatJ

    PatJ Silver

    And here are some photos of the Speedy Twin in use.
    It was designed for the lumber industry specifically to drive the carriage of a sawmill, and its selling points were that it was very compact, very powerful, and could reverse almost instantly.
    The advertisement said that this engine would earn a sawmill more money than any other steam engine, and it was reported that some sawmill operators removed their electric motors and replaced them with this engine, since it worked so well.

    One of the photos below shows the engine installed on some sort of mill machine, to perhaps drive the feed rolls, or the cutter heads.

    The engine was remotely operated by the carriage operator via a shaft and lever.

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  12. PatJ

    PatJ Silver

    And here is a Speedy Twin running.



     
  13. PatJ

    PatJ Silver

    I have a video from the Soule show in 2015, and I am uploading it and will post it in a minute.
    A Speedy Twin can be seen running at 4:42 and 5:10.


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    Last edited: Mar 28, 2019
  14. PatJ

    PatJ Silver

    Here is the print with the supports cleaned off.

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    oldironfarmer likes this.
  15. Very cool. You may have me hooked.

    Do you pour babbit?
     
  16. PatJ

    PatJ Silver

    Absolutely; I bought several bars of it a few years ago (not cheap stuff).

    Everything on the engines I build is pretty much exactly as it was on the original full sized engine, ie: babbitt bearings, cast iron piston rings, cast iron frame/block, etc.
    My models don't just resemble the full sized engines, they are pretty much exact in every detail.

    Its a fun little challenge, and a nice hobby.
    Beats paying all that money for therapy.

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    oldironfarmer likes this.
  17. I've got several bars of old babbit. One says Frictionless in script. I can't bear to melt them down so I guess they're worthless. I bought new babbit to pour my trip hammer bearings several years ago.
     
  18. PatJ

    PatJ Silver

    Babbitt is quite pricey, but luckily the smaller engines do not require much of it.
    It does make a great bearing, and if kept oiled, they will outlast pretty much any other bearing.

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  19. I guess all automotive engines still use babbitt bearings. Just with steel backing, or am I wrong. I know we only refer to poured bearings as babbitt.
     
  20. DavidF

    DavidF Administrator Staff Member Banner Member

    I think its something else now a days... possibly aluminum???
     

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