PSI Keychain O-ring question

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Dehn0045

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I looked up the bushing diameter on PSI website (PKSECRETC) and turned to those dimensions. I measured with calipers before starting and the diameter seemed a little small, the diameter at the endcap didn't seem important but the importance at the threaded end was less clear. I decided to go with the specified diameter (0.450) with a slight bulge. I'm not disappointed with the look, but the O-ring seems a little wonky. It bulges out unevenly and doesn't look the best. I wonder if it will be fine without the O-ring or if it will tend to unscrew on its own (obviously without an O-ring there will be greater risk of moisture issues). I have a few more of these in-progress, so I am wondering if a larger diameter will work better with the O-ring. Any advice or suggestions?

The wood is spalted Magnolia that I collected from alongside the road on my way home from work (the spalting was unintentional but somehow worked out perfectly)

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BCnabe

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I didn't like the o-ring and left it off of the one I carry every day. I've had it come unscrewed a couple times in the 4-5 years I've used it.
 

Humongous

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The ones that I did didn't have a problem. If I remember right I put the o-ring on the coupler, threaded on the cap then pressed the whole assembly into the tube. Maybe the coupler is too far in? I believe there is a groove where the o-ring sits.

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Dehn0045

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I didn't like the o-ring and left it off of the one I carry every day. I've had it come unscrewed a couple times in the 4-5 years I've used it.

Thanks Dennis! Good to know I shouldn't worry too much. I have a wife and a young daughter, so I haven't had my hands on a $100 bill in years, but I was thinking about putting a $20 in it -- would hate to have it unscrew and lose it.

The ones that I did didn't have a problem. If I remember right I put the o-ring on the coupler, threaded on the cap then pressed the whole assembly into the tube. Maybe the coupler is too far in? I believe there is a groove where the o-ring sits.

I was considering disassembling and giving something like that a try. The "groove" seems really small, not really much bigger than the threads. Maybe leaving a little gap inside of the threads is better.

It looks like you turned the ends to small.

Yeah, I turned it to their specified diameter. I knew that it would look too small on the endcap, but I thought that the diameter was critical for proper function of the o-ring. It seems like the o-ring might function better with a larger diameter instead...

I found this customer photo on PSI's website. It looks a lot like what I have going on. Even with the slightly larger diameter at the ends the o-ring is still visible. I am thinking something like Ken suggests (with a slightly larger diameter) is probably the best. I will give it a try and see what happens.
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More4dan

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You could leave the body slightly longer than the tube and cut a recess for the o ring while holding it in a collet prior to final turning. Then turn the body to the cap OD or bit larger. That way the cap can screw down and contact the wood.


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Humongous

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Another tip for these is to take a large drill bit and ream or countersink the bottom cap before assembling. Creates a V shape in the base and makes it easier to insert money into. It won't catch on that lip at the bottom.
 

Dehn0045

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Another tip for these is to take a large drill bit and ream or countersink the bottom cap before assembling. Creates a V shape in the base and makes it easier to insert money into. It won't catch on that lip at the bottom.

Thanks Ken, I saw a thread where it was suggested to mount in a collet chuck and chamfer the sharp edges. A drill bit sounds even easier. Thanks for the tip
 

Dehn0045

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For this one I turned to 0.495 versus the specified 0.450. on assembly I left a small gap between the threads and the blank. It appears that the threaded couplers that I got do not have a groove for the O-ring. It seems possible that mine came with the wrong coupler (the whistle version doesn't have a groove). I decided use a little blue threadlock during assembly to keep things secure. I also champferred the fittings by mounting in my 4-jaw chuck using pin jaws and my skew, was pretty simple. I like the fit better at this diameter and the O-ring seems to be doing its job.

This time in mesquite with wax finish.
PSX_20200207_175427.jpg
 
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