Bicycle air pump project
depends
You certainly can print parts of a bicycle pump, for example, the outer case and maybe the inner piston, maybe even the housing for the connection valves.
However, you cant print the buffer spring or the valves itself. You will have trouble printing the adapters. And you will have to print in ABS to smooth the inside of your pump with acetone vapor, so you have a smooth surface that forms an air seal under operation.
It would be cheaper and more durable to just print just the fittings and use a PVC Pipe as the cylinder itself.
As in all things, if this is a good pump depends a lot on design and your machine.