Made an RT on/off from a classic on/off

[Spider-TW]

It didn't come out as straight as I had hoped. I think I hit the limit on my cheap drill press.

I was making some ends for my jeweling setup and had a thought. I wanted an RT on/off for a parts mag I was upgrading. I had a left over RT 0.750 on/off pin from my pneumag experiments, a nibbled oring from the on/off in my maxflo inline reg, and a left over classic on/off. I thought I would try to put the RT pin in the classic on/off, since that is where the benefit from the Rt is anyway. I decided to make a brass insert for the classic on/off, kind of like a fiber optic connector setup.

After mounting the old classic on/off the best I could, a .120 bit would float through the on/off without any noticeable rubbing or deflection. I drilled out the body to .125, which turned out very easy.



I cut a "long" piece of .125 brass rod and after cleaning the cutting fluid off the on/off and sanding the finish on the brass, I used the overnight version of JB weld to mount it in the body. That let me clean up the overfill and use the left overs on other stuff.




After letting it set, I drilled "a little more" than 1/16 of an inch into the body with a #5 bit (0.205 diameter) to make a pocket for the RT oring (the pocket has a coned bottom)

I followed that with a bit for the pin (drill index was 0.076, but I need to check the number).



I then took the assembly out and used a razor saw to cut the end of the brass that was sticking out and sanded the end down on a flat surface (kitchen counter )

[Spider-TW]

The blue on the oring is marker to let me know it was a bad oring, but the nibble is facing up. You can see that the holes are off center, and the oring is sitting a little lower than normal, but I tried it out and it works. No leaks, light pull. The trigger pull is noticeably shorter than the classic on/off in the same setup, which is odd since the pins are the same length. It may be some extra oring compression from the extra teflon oring I left in the base.

I was thinking that it would be easy to put shims in it under the top, but right now it doesn't need any.

I'll have to run a few tanks of CO2 through it to test my brass insert durability (temperature changes), but it seems like it works and it is at least a use for an old classic on/off.

[Newt]

Nice work. You need to get yourself a lathe. That'll solve your centering problems nicely.

That brass should be durable enough. Might be even better since brass is a very good anti-friction surface.

[Spider-TW]

Nice work. You need to get yourself a lathe. That'll solve your centering problems nicely.

That brass should be durable enough. Might be even better since brass is a very good anti-friction surface.

I'm only a little worried about the different metal expansions cracking the JB weld. That's why I want to run a bunch of CO2 through it.

With a lathe, I could make flat pockets too.
A lot of the junk in the garage is my way of reserving space for later. I surf craigslist for one every now and then, but I need to learn more in order to identify a good deal that matches my 'wants'.