Hi mate, watching from Australia. I have some rivet guns which I bought, and some are missing pistons, one old gun I have is a Broomwade (UK made). I was thinking to machine some up from suitable steel and harden them. Is the length of the piston critical to the force of the hammer blow, and can the lengths be longer to increase force? Interested to hear your comment. Thanks.
That a great question. I don’t know the answer. I would imagine that a longer piston could work. If it was too long, there would be less throw. (Less space to build momentum) On the other hand, the piston would be heavier, so maybe it would hit harder. I’d be interested to see. It you make a larger piston for it, could you post a video? Good luck, I hope you get them working!
Late to this, It is probably handled by now. But still..you need the piston to be a suitable steel to harden properly yet resist the impact forces. S7 (50CrMoV13-1) is a more than adequate tool steel, there are other options available. Talk to an knoweldgeable machinist. As far as the dimension of the piston, the length is not super critical. As long as it will funtion the best, as far as hitting harder, a heavier piston will generate less kinetic energy than a lighter piston. There is a trade off at a point however the velocity of the piston is much more important than just the weight.
Awesome video. Thank you! Air blowing by and piston freezing up is exactly the problem I have on 2 different guns. The only question I have is why does it happen? Am I not using a thick enough oil? Or is it just bound to happen sooner or later? Either way thanks for the info.
Thanks! Sorry for the delayed response. I haven’t checked in for a while. In my experience, it has always been moisture related. Having an air dryer helps. Even being stored for to long can cause them so seize up.