Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Builds, Repairs, Show Your Machines! => Technical Tips, Builds, and Help => Topic started by: SeeSteam on November 09, 2019, 09:11:57 am

Title: Re: Double Acting piston designs
Post by: Stoker on November 09, 2019, 11:48:50 am

There must be at least a hundred ways, some better some not, depending on situation.

Bored and soldered is about as simple as it gets, or with a wrist pin, at the other end of the spectrum, with various threaded strategies found in between. As long as you hit a reasonable mean for length, adjustability really shouldn't be too critical on our toy engines, and should be unnecessary by dimension and design on a truly engineered model.

Title: Double Acting piston designs
Post by: SeeSteam on November 09, 2019, 09:11:57 am

I've seen several methods to secure the piston to the piston rod:
1. Have the piston be threaded as nut. Bing Gen Set.
2. Have the piston simply be drilled so it can rotate. Early 1900s Bing
3. Have the piston be mounted so it can wobble a bit. One could have o-rings it rides on. Mamod Loco Pistons
4. Have the piston firmly mounted. Mamod TE


For the piston rod end, I see a couple of options: simply drill a hole in the rod shaft. Thread the end of the shaft to allow adjustment. (I have a Big that allows that adjustment.)

[attachimg=1]

Thoughts?