Here is some more information about Rudy's tractor that I built.
Mine was completed about 30 years ago, and has run lots and lots.
Some of the changes and suggestions were based off of information from a friend who had built one of these too.
The gear ratio was changed to slow down the speed of the tractor. This seems to be a more realistic speed and allows more power. It will easily pull itself though grass or along a gravel road at the local engine / tractor show. It always draws attention.
I found notes on the gears i used:
the crankshaft pinion is 20 teeth, 0.417 " Pitch dia. 1 required.
the idler gear is 72 teeth, 1.5" PD 1 required
the counter shaft gear is 100 teeth, 2.080" dia. 1 req.
the counter shaft pinions are 16 teeth, 0.335" PD. 2 required.
the bull gears are 120 teeth, 2.5" PD. 2 required.
The crosshead design was changed to match a more prototypical design.
It is close to what Case used and is a more sturdy design.
It is made of brass, and photos will follow soon.
We also made small fans to put on top of the stack while building pressire.
We found that the alcohol burners had flame going everywhere, so the fan keeps the fire going the right direction. It also allows the steam pressure to build much quicker.
once pressure is built8 up, and the engine is running, the engine exhaust provides sufficient draft.
This fan is made with a simple bent blade impeller and a small 1.5 volt. motor.
Since there is no water level gauge glass on the boiler, you can't tell how much water is there.
To Begin, I unhook the pressure gauge compression fitting and take a plastic squirt bottle and a short length of tubing to fill the boiler through the 2nd fitting and valve. I stop when the water comes out of the pressure gauge pipe fitting.
You will need to learn how much alcohol needs to be put in the burner to time it running out about the same time as the water. When pressure drops, after about 20 minutes, the boiler may be dry. Be sure to check to see if the fire is out too. You may need to pick the tractor up and flow the fire out from under the fire box.
I also put a "T" pipe fitting under the safety valve and made a small whistle to connect to that.
More fun.'
Photos to follow
Doug