Running a model steam engine from a fish tank air pump

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Junior Member
Jul 19, 2012
Reaction score
I tried to find examples of people running a model steam engine from a diaphragm style fish tank air pump, but could not find a lot of info, so I did some experimenting myself...
I had a very small one many years ago... Of course it ran a tiny (child's toy Mamod) single acting oscillator slowly, only just fast enough so it didn't stall. But too small for an engine the size of yours. It moved and stalled at the end-of-stroke.
So it simply depends on the supply being large enough to make enough speed in 1 stroke to free-wheel over the dead-spot, with enough pressure to push against initial friction and accelerate the first stroke.. (Maybe with the help of the "Hand of Dad").
I use a 'fridge compressor to power my small engines like that as it can develop 25~90psi (90psi when new! - a bit worn now!). but only a very low volume. - Less than 0.5 cu.ft./min. - Yes it will inflate tyres, about as fast as a car-tyre-pump driven from the cigar lighter socket. And it is quiet-ish. - just a purr..... And it can be relaxing to have an engine idling with the compressor purring, while I am doing something on the bench. - Just like your video. I also have a 90dBA 2CFM (paint spray and nail-gun) compressor for doing "proper jobs" and bigger engines. But needs ear defenders!! And I could use a bigger compressor occasionally.