I read an interesting post by dan_house from 2017 on buttoning a piston using nylon screes threaded into tapped holes on pistons and machining down to size.Another member stated that Delrin would be better than nylon for this application.I have not seen any threaded DelrinCan Delrin rod be threaded with a standard 1/4-20 or 10-32 die??I am up to me ears in a project to convert an Umarex Octane to coil spring and thought I might just as well go whole-hog.....
A small dimple in the piston and super glue in the delrin.Some sanding or turning on a lathe to fit and your good to go.Once they are in the gun? They are not going to pop out.And I MIGHT have some of the ARH glue ons here. I'll check and let you know.
I use JBWeld slow cure for buttons. Clean piston with acetone, dab three match head sized drops of the epoxy equidistant around the end of the trigger side of the piston and allow to cure overnight. Next day, sand to fit, wipe again with acetone and reassemble.Good to go.
Ron. I have the ARH glue on buttons. Just not the NP2 little balls they used.I'm over my 10 PM's per hour so couldn't send a PM about that.
1/4" if my memory serves me well??
My test rifle is the Umarex Octane coil spring conversion.Not exactly a high-end critter.I doubt it has a hardened piston.Dunno if I can plunge an end mill to make a pocket or not.I guess plunging into a circumference would be easier than into a flat surface.I had pondered a dimple with a 135deg. drill bit and machining a Delrin rod to mate....
Quote from: Ronno6 on September 30, 2022, 07:15:03 PMMy test rifle is the Umarex Octane coil spring conversion.Not exactly a high-end critter.I doubt it has a hardened piston.Dunno if I can plunge an end mill to make a pocket or not.I guess plunging into a circumference would be easier than into a flat surface.I had pondered a dimple with a 135deg. drill bit and machining a Delrin rod to mate....Not the entire piston, but I have many springer pistons with obvious heat treating coloration of the piston skirt area. I calculated some pretty high stress in the cutout where the latch grabs the piston so heat treating (hardening) this area makes sense. If you do decide to machine/drill the skirt for buttons, I suggest using a center drill so the bit doesn't flex/wander. similar to these... https://www.harborfreight.com/center-drill-countersink-set-5-piece-60381.htmlEndmill cutter could work IF your drillpress/mill is SOLID. My drillpress flexes enough to make an endmill wander/chatter badly.