Internal combustion linear actuator

[lemontree]

I am kind of interested in powering a linear actuator using internal combustion. I haven't found much on the internet about that.  Sometimes if you don't know the right keywords you don't get any worthwhile results.  I once went looking for blank pcb material, and found next to nothing.  If you search using copper laminate you'll find plenty. Any ideas?

[definitionofis]

I would attach a model airplane internal combustion engine to a gear box
and the gear shaft to a long threaded rod with a matching nut soldered at the end
of a copper plumbing pipe with a slightly larger internal diameter to fit over the threaded rod.

Reverse would be a problem, unless the gear box had an electro-mechanical gear swap for reverse.

On the other, a long piston, slow, Stirling engine could do push-pull. That is not internal combustion.
It is external.

Maybe the egg suction technique could be used: That is internal combustion.

Egg Suction Into Bottle Experiment

[waltr]

Your idea reminded me of a Myth Buster's episode where they tried to reproduce engines that ran on blackpower.

[lemontree]

My idea was to use an electric solenoid to compress a mixture of air and butane up to its auto ignition point.  Then let the combustion products expand against a piston (ie the solenoid core) and extract work from the linear motion.  Maybe for a jumping robot or you can generate electricity from linear motion.
I guess it not possible to do that in a very simple way, or at least you would need some electrically actuated valves and things.

[waltr]

Look up SPUD guns, Potato Guns and Pumpkin guns. These all operate under the principle of expanding gas (burning butane or propane and air) to  push a piston (spud).

Just be careful with your experiments as we do want you to be able to report back.