3D Printing for a Hit and Miss style 4 stroke Engine

In the latest edition of Maschinen im Modellbau, 5/2025, there is a four-stroke hit and miss style engine incorporating a lot of 3D printed components. The builder had previously made a flame licker with a printed crankcase and decided to try an internal combustion variant.

The bedplate is printed with PETG and the crankcase and main bearing caps with PA12CF.

Thats pretty cool !
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I look forward to my copy landing on the door mat.

Oh great, I have to go to the newsagent today.

Interesting info - thank you Roger 

I just Googled PA12CF review and saw a short YT video.
Here you could see the Nylon being softer after being soaked in water (it will absorb moisture from the Air too) and grooving in dimensions as a result too ....
So it might not be useful for all our purposes 

Per         

Give it a try!

You can also 3d print material form Igus in different grades depence on performance. A bit harder than petg or pla because it has kind of lubrication include in the filament.

In some machines we now use bearings from Igus that replace bronze bushes with good result. Self lubrication and almost maintance free. And it is more flexible and take more misalignment.

3D printing today if you do not need state of the art machine is not that expensive tool anymore. It depence what you want to print. Alot of information online! just try;)

I have a small gas engine of unknown origin probably turn of the last century. The builder ( in my opinion ) was really ambitious with a 32 mm bore and 60 mm stroke. It’s been in my possession for many years. We tried to get it running but with such large proportions the tiny flywheel had no chance. To the point.

We printed a cylinder liner insert using a Carbon fibre reinforced PLA. this liner was then honed to size ( 24 mm ) and a 24 MM Aluminium piston was used. Everything rotated very smoothly until we turned on the gas, Propane. The piston became stuck almost immediately. For us it was an interesting experience and a shame the plastic reacted in such a way.

  Graham.