Thread 2949617

I mostly tinker with air guns. I have some designs for valves I'd like to try out. Would it be better to try to have cnc services make them for me, or get a $500 mini lathe and learn how to use it?

1. Have you had any success with online cnc services?

2. Are those mini lathes any good? Valves are mostly made from aluminum or brass and delrin, but steel seems like a wiser choice for anything that would be bearing pressure.

>>2949617 (OP)
thats cool
mind to share your designs ?

im dabbling in airguns also, ive used column drills and mini lathe
avoid the crappy toy jewelers lathe, but i think a small tabletop lathe (the one i used was maybe 70cm long)
while it was slow to cut steel, going slowly was alright
i'd suggest getting the lathe with some carbide cutting tools, this way when/if you fuck up with your dimension, you can just cut a bit more instead of drawing and ordering another one (waiting 2 weeks)

>>2949876
In a regular valve, the stopper is held in place by the air pressure and a return spring. When the stopper is depressed via the pin, air pressure slips around the stopper and flows out through the transfer port.

In this design, the high pressure air is kept off of the back of the stopper by a separate chamber. The stopper has a hole drilled through the back and is vented through the transfer port, so the only force normally holding the stopper closed is the return spring. When the stopper's pin is depressed, high pressure air flows out through the transfer port and also through the hole in the pin, flowing backwards into the second chamber and pushing the valve back closed. The goal is to have the valve be very easy to open (like the valve on an unpressurized tank), but to close again very quickly under the force of the pressurized air as it is released.

This image is simplified a bit, but I hope it illustrates the concept. I don't have a prototype yet.