Trevithick

[gbritnell]

Brian,
What you have to understand is that if you took any locomotive off of the tracks and ran the engines they would do the same thing, run fast! The flywheel affect is the motion of the locomotive moving on the rails. Steam/air is applied, the piston/wheels start to move and the inertia of the machine takes it past dead center. When we think of flywheels on a steam engine we are generally associating that with stationary engines. I'm not saying that a heavier flywheel wouldn't assist the inertia but I don't think it's truly needed for this application.
gbritnell

[Brian Rupnow]

George-I agree with you.---But--this locomotive is never going to run on a track. It will ultimately be a "shelf queen" like my other engines. It may set on a short pedestal so that it can be ran with the wheels slightly "in the air" for demonstrations, just to see all the neat gears meshing.-So for that, it really does require the flywheel. I like my engines to run slowly when I demo them. ---Brian

[Art K]

Brian,
Your Trevithick looks really good, the flywheel's extra mass does seem to help slow it down. Great work!
Art

[Charles Lamont]

Good to see you finally have something running.

[Brian Rupnow]

Making progress here, one gear at a time. This morning I  reassembled the engine inside the boiler, and added the large gear on the side. Nothing is ever quite the same when you move an engine like this, so all of the battles I fought to get the engine running on my desk were repeated to get it running inside the boiler. I have the heavy flywheel on there for set-up but will eventually put the smaller water-jet cut flywheel back on. I just hung the big gear on there to see if the engine noticed any difference in the load, but the engine didn't seem to care whether the gear was there or not.----Brian
<a href="https://www.youtube.com/watch?v=BtyPYOiTpGw" target="_blank">http://www.youtube.com/watch?v=BtyPYOiTpGw</a>

[Brian Rupnow]

So, here we are!!! Everything goes round and round and up and down like I had planned. I still have to make proper wheels for this thing, and connect the gears to the wheels so the axles will be driven in the finished version. I have a nice color scheme in mind for it. I am really pleased with the results at this stage of the game.---Brian
<a href="https://www.youtube.com/watch?v=AG3fBiSYUPo" target="_blank">http://www.youtube.com/watch?v=AG3fBiSYUPo</a>

[crueby]

Terrific motion, great!

[Brian Rupnow]

Had a visit from three ghostly characters this afternoon. My grandchildren are all getting older. I'm glad they still come across town to Grandpa's house for a visit.

[Brian Rupnow]

Not really a lot left on the "build" of this engine, but I still had to contend with the hole in the top of the boiler that the actuator arm for the 4 way valve (that I couldn't make work) stuck up through.  I decided that the perfect answer to that hole would be a "steam dome". Steam domes are marvelous things. They can be anything that your fertile imagination wants them to be---a safety valve, a pressure indicator, a speedometer. Most living people under 60 years of age have never actually seen a steam engine. I've been fighting a mild flue all week so I think I'll spend the rest of the day on my couch with a good science fiction book.---Brian

[Craig DeShong]

So, here we are!!! Everything goes round and round and up and down like I had planned. I still have to make proper wheels for this thing, and connect the gears to the wheels so the axles will be driven in the finished version. I have a nice color scheme in mind for it. I am really pleased with the results at this stage of the game.---Brian
<a href="https://www.youtube.com/watch?v=AG3fBiSYUPo" target="_blank">http://www.youtube.com/watch?v=AG3fBiSYUPo</a>

         congratulations!  Nothing like seeing all your effort pay off in a well running model.

[Brian Rupnow]

Thanks Craig--I'm really chuffed!!!---Brian

[Art K]

Brian,
Your Trevethick engine runs really well. That is something to be chuffed about!
Art

[Brian Rupnow]

Today I'm doing much the same as Crueby---Making wheels with cut-outs in the face. My approach is a bit different, but worth posting a shot of. I have to make four wheels that are identical in the cut out areas, bores, and outer diameters.  I used a caliper and compass to lay out the diameter of the wheels on a sheet of 1/2" thick aluminum, cut out four rectangles, drilled and reamed on center and pushed a size on size rod thru  the holes to keep everything centered, then ran bolts thru two opposing corners (which will become scrap), then stacked all four plates together in my machine vice to drill all of the holes in at once. That way I only have to do the set-up once. Next trick will be to separate all of the plates and cut the corners off, then turn to size in my lathe.

[Brian Rupnow]

This shows the material that will be cut out of the four wheels. The material is 1/2" thick aluminum. Two of the wheels are only going to be 5/16" thick. The two wheels which have gears mounted on them will be 0.408" thick. My next step will be to cut off all of the outer corners and then turn the wheels to be round. Then I will grip them by the round outer rim with my 3 jaw lathe chuck and thin them down to finished thickness and open the center hole out to a finished diameter of 1/4". The windows will be cut out after the wheels are thinned down.

[crueby]

Nice setup!  Unusual to have a 3-spoke wheel - were the originals like that?