View Full Version : That crazy Canadian steam engine guy is at it again---

brian Rupnow
06-25-2009, 06:50 PM
I just finished a very quick build of another small steam engine. This engine was originally designed by a clever man named Chuck Fellows over on "Home Model Engine Machinist" website. I modelled it in 3D Solidworks and then created a full set of detail drawings. Of course, I couldn't leave well enough alone, so then I had to build it. It will eventually be built as a "hit and miss" version, with a set of flywheel mounted governors which control the steam inlet valve. The exhaust valve is a slave mechanism, that is actually operated by the incoming steam when the inlet valve opens. When the inlet valve is closed, the exhaust port is open to atmosphere, allowing the engine to freewheel with no backpressure in the cylinder. This valve set-up also gives the engine a very distinctive "popping" sound as it fires. If anyone is interested, I will provide a link to a download site so you can use my plans to build your own.---Brian

brian Rupnow
06-25-2009, 07:09 PM
This is the download link. All the drawings are saved as .pdf files. If you use them to build the engine, I want to know how successfull you were, and you owe me a beer!!!
http://www.mediafire.com/file/ghmqmclvdzm/UPDATED HIT AND MISS STEAM ENGINE PLANS.zip

06-25-2009, 08:27 PM
Very nice looking and running engine. JIM

Rookie machinist
06-25-2009, 08:40 PM
Brian do you have the flow simulation software for solidworks? If so have you ever used it to check the efficeny of a steam engine and its operation. I am thinking of purchasing it for testing my own steam models before I build them. I would like some feed back as to how well it actually works.

06-26-2009, 12:27 AM
Cool engine!

The problem w/ that sort of valve is that you don't get any benefit from the expansive power of the steam - a lot like a duplex pump. This is why you get that "pop"....

- Bart

06-26-2009, 02:51 AM

What does it mean to "log in or use a supported browser"? I use FF3.XX



Cute little thing, regardless.

brian Rupnow
06-26-2009, 08:27 AM
Brian do you have the flow simulation software for solidworks? If so have you ever used it to check the efficeny of a steam engine and its operation. I am thinking of purchasing it for testing my own steam models before I build them. I would like some feed back as to how well it actually works.
I do not have that add on package.--sorry!!

06-26-2009, 09:09 AM
Neat engine and sound. Can't wait to hear what it sounds like once you get it to "hit and miss". That will be different for sure.

06-26-2009, 10:53 AM
I'm speechless! Great job, thanks for sharing!

Thomas Staubo
06-26-2009, 02:55 PM

What does it mean to "log in or use a supported browser"? I use FF3.XX ...
It seems the link is broken because of the spaces in the link.
This works better: :)

http://www.mediafire.com/file/ghmqmclvdzm/UPDATED%20HIT%20AND%20MISS%20STEAM%20ENGINE%20PLAN S.zip


06-27-2009, 02:34 AM


Even with your aid it took a couple stabs to get a download.



David Powell
06-27-2009, 07:38 AM
Brian, A joint group of Model Engineers and Live Steamers is holding an International meet for all those interested on the weekend of July 11 and 12 at the Richmond Hill Live Steamers site. Attendance is open to all enthuiasts,Compressed air will be supplied to give stationary models a run on picnic benches outdoors. Please see the RHLS site for more details. Probably Saturday will see more attending than Sunday, come along and make yourself known. Regards David Powell

brian Rupnow
06-27-2009, 08:45 AM
David--Unfortunately, on that weekend I will be engaged in my OTHER hobby. A group of 80 hotrods from Ontario is leaving whitby on the 03-July to cruise to the East Coast Hotrod Nationals in Moncton, New Brunswick. I will be driving my 1931 model A Ford Roadster Pickup. We will be gone for 14 days. However, I will be exhibiting at the Cookstown Steam show put on by the Georgian Bay steam Club on the long weekend at the beginning of August---Brian

David Powell
06-27-2009, 12:51 PM
One problem up here is that the really good weather season is too short, so those of us who have several hobbies which use the outdoors have many possible events each weekend and we just have to make choices we would rather not. Maybe Global warming would be a temporary answer? Regards David Powell.

brian Rupnow
06-27-2009, 05:36 PM
My plan was to have hotrods as a summertime hobby, and steam engines as a wintertime hobby. This year however, the #$%@ economy being what it is, I have no engineering work (my real job) and the hotrod is finished, so I have ended up doing my wintertime hobby in the summertime just to have something to do.---Brian

brian Rupnow
06-30-2009, 01:24 PM
I have had numerous people emailing me and asking about the flywheels, and if they can build the engine as a conventional engine without the hit and miss function and the governors. The answer is---#1--The flywheels CAN be made from aluminum, and they CAN be made to 1/2" thick. ---and the non governor flywheel does NOT have to have the long extended hub as shown on my drawing.---I only made the extended hub that long so that both flywheels would be spaced out the same distance from the crankcase, and I wanted the extended hub to drive an o-ring drive pulley to power some secondary equipment.
----#2-You can build the engine with 2 identical flywheels and skip the governors. You will need to build a cam-hub similar to the one in the attached picture.--Please note that I built this from a "scrap" peice of brass and 3/32" steel rod---there is a bit of machining at the extreme outer diameter of the peice in the picture which serves no purpose and doesn't have to be there----And the one in the drawing will not be as thick as the one I show in the picture.

brian Rupnow
06-30-2009, 08:39 PM
Well boys---Here ya go!!! Its running in hit and miss mode. After 2 hours of messing about with tiny, tiny, tiny #0-80 socket head capscrews and adjusting the timing, it runs. This video was made in the first 5 minutes of operation, so its a bit choppy. Its been setting on the corner of my desk running now for half an hour, and its getting much smoother. I am happy as a pig in mud!!!
http://i307.photobucket.com/albums/nn294/BrianRupnow/th_HITANDMISSWORKING.jpg (http://s307.photobucket.com/albums/nn294/BrianRupnow/?action=view&current=HITANDMISSWORKING.flv)

06-30-2009, 08:45 PM
Congrats Brian!

06-30-2009, 09:33 PM
Another mighty fine engine Brian,congrats!

brian Rupnow
07-01-2009, 08:36 AM
I may have shot myself in the foot a little by making the flywheels from steel. My theory was that if the flywheels were uber heavy, they would let the engine "coast" longer between firing cycles. What I overlooked was the fact that since they are so heavy, it takes considerably more kinetic energy to overcome their "resting inertia", so the engine has to fire 5 or 6 times to get the engine spinning fast enough to actuate the governors. If the flywheels had been made of aluminum, which is 1/3 the weight of steel, the firing profile would probably have been quite different. When I get back from the Canadian Rod Tour, I am going to build a small scale varying load machine to demonstrate how applied load affects the hit and miss cycle as the engine runs.