tiny hydro cylinders

[Ben1272]

I saw where someone was using small pneumatic cylinders for the R/c aircraft landing gear door/canopy/speed flap, market. I think they needed some modification, but it did not look beyond reasonable. They had sourced theirs on Aliexpress, but I imagine yo might find them any number of places. Typically much smaller diamter than hydro-cyclinders. Also there is clippard pneumatics. They make all sorts of cylinders that might be re-purposed.