I used to use the spare wheel of my car – pump it up at the garage, make an adaptor with a tap on it  to go on the tyre valve, and use a bit of hose to connect the adaptor to the model. Not sure if it would give enough pressure to run your model for a reasonable time, but it worked for me before I got a compressor.

Pro-tip – don't get a puncture on your way back to the garage to refill your tyre…

Edited By Bob Unitt 1 on 06/03/2022 12:25:06

Hi Roy and welcome to the forum.

There's a bit of an awkward gap in the world of air pumps. Engines need a good volume of medium pressure air. Unfortunately car pumps produce low volumes of high-pressure air, and fans produce large volumes of low volume air. Aquarium pumps are a bit low on pressure and volume.

Bob recommends using a car tyre as a reservoir. The pressure is a bit high and unregulated, but there's a reasonable amount air available. I've used a plastic lemonade bottle and car foot-pump to prove an engine will turn: not ideal!

These days I use a small electric workshop air compressor similar to this one:

These have a largish reservoir tank and a pressure regulated output that can be set to suit the engine. Start at about 5psi and work up for reasonable running. Note a car tyre starts at about 30psi and comes down, unregulated.

The downside of workshop compressors is cost, noise and space! Quiet domestic demonstrations of an engine really need something quieter. A spray paint compressor might do the job, but I've never tried one. Perhaps someone else has a suitable recommendation.

Dave

I run my Stuart Beam engine, and all my other little engines, from a Revell air brush compressor (quite running with a reservoir tank). Can get it going nice and slow at about 5 psi.

Barry