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Level of skill req'd. to build model steam engine??

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  • Level of skill req'd. to build model steam engine??

    How many of you have built a working model steam engine? I have looked at some SIMPLE kits that are relatively inexpensive (as in under $100). According to the sales litrature, they contain "sand castings", all required fasteners, and all necessary gaskets. I have done enough with my lathe to feel fairly confident about #1-turning a shaft to a finished diameter. #2-facing a part. #3-drilling and boring to a finished inner diameter. My capability to get a real smooth finish is still somewhat questionable, My success in threading a 3/4" diameter rod was very "iffy"---couldn't get the lathe to run slow enough--when "picking up the thread" I was okay for the first 3 or 4 passes, then messed up and started cutting in a different place. (slowest my lathe will turn is 115 RPM.) Just how good does your skill level have to be before trying to machine one of these kits?
    Brian Rupnow
    Design engineer
    Barrie, Ontario, Canada

  • #2
    Any completed project is nothing more than the culmination of a series of simple machining procedures. A steam engine is no different.

    It does help to have a concept of how the completed project functions. This gives an understanding of the relative accuracy neded in each step. As a general rule, a larger engine is simpler than a smaller engine as they are somewhat more forgiving. A simple oscillating engine is a good place to start. Once a working engine has been completed, you are usually hooked, and can move on to more complex styles.
    Jim H.


    • #3
      Skill doesnt matter. Its porportionatly sized after your scrap box. After some scrap your your scrap box will be much smaller. Either that or your not learning anything.

      p.s. scrap parts are used to make smaller usefull pieces or ineviably smaller scrap up to the point of 100% chips!!!


      • #4
        My first real project was a steam engine. It came out fine. The more difficult parts you just take slow and easy.
        Good luck
        John R


        • #5
          I don't have any problem with understanding the concept of how a steam engine works. I am a design engineer, and I design custom built machinery for a living. I do however, wonder about my own machining capabilities. I have been designing machinery for 43 years. I have been playing at my new lathe for 3 months. Believe me, there is a big difference between knowing the theory behind using a lathe, and the actual hands on experience of running one. I am a pretty handy fellow with "hands on" machine building, and I see building a model steam engine as a good way of improving my skill level. Just not sure I'm ready to take that step yet.
          Brian Rupnow
          Design engineer
          Barrie, Ontario, Canada


          • #6
            You might want to try a simple engine made from barstock first; then if you spoil a piece you won't need to go through the hassle of getting another casting, and you won't have the difficulty of setting up castings for machining.

            Or try a simple kit. You need to start somewhere! The most simple kit will teach you more than you might believe possible. The first engine I tried to build, I never did finish...but I learned enough so I could build the second one.

            What kits are you looking at?

            On threading: if your lathe doesn't have a thread dial, you can always leave the halfnuts engaged and run the lathe in reverse to get back to the start. However, that's not always possible to do if you're threading up to a shoulder.
            Try to make a living, not a killing. -- Utah Phillips
            Don't believe everything you know. -- Bumper sticker
            Everybody is ignorant, only on different subjects. -- Will Rogers
            There are lots of people who mistake their imagination for their memory. - Josh Billings
            Law of Logical Argument - Anything is possible if you don't know what you are talking about.
            Don't own anything you have to feed or paint. - Hood River Blackie


            • #7
              The hardest part to make will be the crankshaft and there are several ways to do that. Doing machine work requres some common sense to figure out a solution. Think everything out and work out all the problems before you start on each part.

              Yep, you can do it but don't get in a hurry. Also, it's not easy working with castings. I am working on a small steam engine and a hit and miss engine for two friends now. You have to do carefull planing when machining a casting so know the overall end result BEFORE you start to machine it. Things don't always come out as planed with a casting.

              BTW, you can change the pulleys on the motor and headstock to slow the lathe down and that won't affect the feeds and threading.
              Last edited by Carld; 05-19-2008, 02:19 PM.
              It's only ink and paper


              • #8
                hello. looks like we share a common background (
                I had a look at your site and got a real kick out of that "guard-railer"
                (name?) listed as "Prototype Machinery"! To be completely honest
                I couldn't stop laughing -- very clever! (Maybe its me, I've never seen
                such a thing before) -- whats the min turn radius on that thing??

                As far as the steam engines go -- there are much more experienced
                people here than I, but I have tried my hand at a few of the
                Elmer's Engines. Really fun. I've got a biggish lathe and turning some
                of the smaller parts was a real challenge.

                Plans are available online, just try a search engine. I've never
                tried my hand at anything that required castings, though.



                • #9
                  Tony---That critter had a turn radius of about 8 foot. It was intended to be a "cross over" machine, something between the very small curb laying machines that do an 8" high curb, powered by a 3 HP. gas engine, and the big industial curb machines powered by a 4 or 6 cylinder engine that do up to 16" curbs. It did work, but the man who was developing it either ran out of money or got caught up in other enterprises. I find that happens a lot. People come to me with some great idea they wish to develop, have enough money to build one 80% successful prototype, then fade away before the final 20% is fully worked out to the point where the machine is marketable.
                  Brian Rupnow
                  Design engineer
                  Barrie, Ontario, Canada


                  • #10
                    i built a wobbler as my first engine.. there are lots of plans on the internet for really simple bar stock engines. with the wobbler, my first one needed almost 100psi to run, now im on my third and i can blow into it and it will run. it was good practice at making things smooth ans fit properly. the first one didn't fit very well, the piston was too loose inside the cylinder, and i lost lots of air pressure around the cylinder.

                    i would give that a try, it uses about $0.30 in scrap to make, and you can use almost any material you wish. theres one called "Lucy" (i don't remember who made it) where the crankcase is machined out of a block of Lucite (Plexiglas).

                    and seeing an engine that you made form bar stock run for the first time is pretty cool too...

                    these are pics of the first one i made, after the aluminum piston and cylinder welded together.. i sleeved them just so i wouldnt have to use a solid block of brass. and the flywheel is made from a VCR head....


                    • #11
                      This is the first steam engine I built:

                      I was fortunate in picking this as my first engine rather than one of Ray's other designs. Since that engine I have built several more of his engines and they were all a challenge. But, they do use barstock and the plans are very reasonably priced. There is also a Yahoo newsgroup that covers these engines:


                      • #12
                        I'm also an engineer. Your drawings that you create in solid works will improve in the dimension/ease of fabrication area. You'll be thinking more about how the parts will be manufactured vs make it like this and dimensioning accordingly


                        • #13

                          have a look round my site

                          I started a few years ago on a Stuart Turner kit (10v) and i only had a tiny Unimat SL lathe and zero knowledge of machining. Admittedly i had to ask a friend to help with the bigger bits.

                          When i got a decent lathe i built a Stuart beam engine as practice for my main desire:- a 3" scale traction engine. This engine is now nearly done and i have even written and published a two part series of books dialoguing the build progress from a beginners point of view.

                          As soon as this one's running, I'm starting a 6" scale one!

                          What i am trying to say is, get a bit of practice, read lots, ask lots and dive in. It seems daunting to look at a running engine but when you take it all apart, most of the bits are quite basic.

                          As others have said, a simple wobble-engine from scrap is great, i made one at school and still have it somewhere, it was ugly as hell but did work.

                          Good luck
                          If it does'nt fit, hit it.


                          • #14
                            Don't think it's so much a matter of skill, rather more patience. If you can comfortably run your machine you're skilled. If you know how to set up and cut your work, you have the knowlege. When you can build your part without any boo boo's to exacting tolerances, then, you have mastered the art. Unfortunately for most, that's a lifetime of experience.

                            For the rest of us, and its just my opinion. Jump in head first and give it a try knowing your going to make mistakes. I agree 100% with ahidley. Works for me and sometimes I even surprise myself. Still using scrap with partially cut cam lobes and journals in it.

                            Built this last fall after several attempts just so i could say I did it. Would it ever run? Don't know. Didn't have any plans but researched the concept. Hardest thing was figuring out how to make it in a 3 jaw chuck, don't have a four, but thats half the fun. For me it's a lot of trial and error to get comfortable with turning something. Some day I will get a kit and give it a try, but before I cut into the $100 casting I'll keep working on scrap till it's comfortable. Would love to build my son a working engine some day. There's no reason you can't practice on your own design of a crank, piston or cylinder even if there's no chance it would actually work, as in my case. The principle is there.

                            Sounds like you already have the "skills" won't know for sure till you try.

                            Best of luck,
                            Cheers, Bob


                            • #15
                              You can Do It!!! That is the whole reason I got into this hobby was to build steam engines. If I can do it Youy Can!!! I started with oscilators and have progressed to bigger and better and more complicated. Each one has taught me new techniques, new tools and new challenges that I never thought I could overcome. Get to work!!! Don't put it off! It is like the potatoe chip, bet you can't do just one!!!! I have 14 done and running and as soon as you are done with one you are tackling the next one. I try to stick with the plans from bar stock because if you screw up a're done and lost the whole ball of wax. Dive in, The water is fine (frustrating but fine). Fred