Star hycar washer size

I recently purchased my first star sizer here. I decided to add an air cylinder after much reading here. I found a piece of 1" brass round stock kicking around & decided this would be my piston. I cut 2 grooves in it for "O" rings to seal against the tube wall. My question is how much resistance should I have when moving the piston in the tube. The tube ID measures 1.082", my "O" ring mounted on the piston measures 1.100". I can insert it by hand but it is fairly snug. It takes 10psi to get the piston to move on a completely clean & empty tube. I figure I can always put it back on the lathe & cut another .005". I thought I could use the hycar washer outside diameter as a rough guide. Thanks in advance.

I don't know how the 0-rings will work.
the regular ones just use the plunger end from the screw down types, and they have that little scraper type washer on them.
but they can be very tight in the cylinder.
so tight that sometimes I'm pretty sure I'd knock myself out if my hands slipped or it popped loose while I was pulling it free.

Grease the Hycar washer when you put it in and it will come out easier the next time. I use a little STOS lubricant, which is a gun grease I've had around for years. It keeps you from poking your eye out when pulling the lube piston out of the reservoir. I would imagine the same thing would work for the O-rings.

Hope this helps.

Fred

Well I received my die from lathesmith & proceeded to size boolits faster than I could before. My homemade piston worked just fine with 6661 lube. Now I need to buy more dies. Add me to the list of Star enthusiasts. :grin:

Sig
I have been thinking about putting a air cylinder on my star sizer. Would you mind sharing the info on the cylinder you used?

Thanks!

Jim

Jim, This is the cylinder I'm using.
https://www.zoro.com/parker-round-ai...00/i/G6128281/
Hope this helps.

That helps a lot. I was sure I needed 5 to 6 inches of stroke just wasn't sure what bore size to go with.

I just ordered that cylinder and have a guy looking for some 1"ø Aluminum bar stock to make a plunger and will use my existing hycar washer.

Northern tool has aregulator for about $15. so I figure for about $50 total I should be upad running.

Thanks guys.

The saga continues. Finally got the air system working. The 1"ø aluminum bar stock about 6" long was given to me by a guy at work. It was
given to him by a former coworker. That part will cost me some tamales but it is a small price to pay.

I work for a steel fabricator and have every imaginable CNC machine known to man for steel fabrication but for something made of aluminum
I was basically SOL. A guy that helps me with stuff like that got the thing cut sq. on each end but the hole was slightly off center but with a bit of
sanding I got it to work.

All in all I think I have about $55 fittings and everything else to get it up and going..

Thanks for the help guys.

Quote:

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Originally Posted by runfiverun

[snip] but they can be very tight in the cylinder.
so tight that sometimes I'm pretty sure I'd knock myself out if my hands slipped or it popped loose while I was pulling it free.

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If ya look real close at my forehead, R5, you might find a little crescent-shaped scar from me beaning myself pulling out the plunger to put more TAC-1 into the Star. I was more grateful than embarassed. . . coulda been my teeth.