I got the tubing from McMaster already. McMaster is amazing. I ordered it at about 1:30pm yesterday and it was delivered the same day! i am about 15 miles from the warehouse.
I thought a great way to attach this would be to thread the tubing into each end. It did an experiment on both the HDPE and PTFE, which are both 1/8" ID 1/4" O.D. I think it turned out great. That is a 1/4-20 thread.
The trick is holding onto the slippery tubing. I used a 1/4" lathe
collet. I put a 1/8" brass rod inside first to keep it straight and keep it from collapsing. The thread hold strong (about 40lb pull) on a standard thickness nut. The thread is very slippery so it will easily loosen. I think I might use a long coupling nut to get more thread engagement.
This is the PTFE tubing. It has a tighter ID and is more slippery, so that will be my first test.
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