Hammer Valve Grooves

[clemsonguy1125]

A while ago I made a simple single shot pellet gun which worked well and had a XRV hammer valve. I decided to try an upgrade it to a multishot hamer valve much like sniper heros. Most of its pretty simple and is just threaded fittings. Right now my only problem is the actual bolt with oring grooves that is ground down for better flow. I pulled out a spare bolt and popped it in my hand drill since I dont have a drill press. I held the file against it and was only able to cut shallow grooves into it and couldnt grind down the "stem". Is there a better way to do this with a hand drill?

[jrrdw]

The uneveness makes me think he did it by hand/blood/sweet and tears. A piece of sand paper will work wonders while turning the work piece in your drill, just use a back and forth motion and even pressure with a steady hand/s. Lock your drill in a vise and use the trigger on lock, then you can hold your sand paper on both ends like a belt.

[ramses]

um... a lathe works great

that's about all you can do with a drill. you could clamp the drill to something and use a dremel in your hand. use the grinding wheel or cutting wheel. Harbor freight currently has an angle grinder on sale for $10. Buy the "variety pack" of disks and have at it.

[jor2daje]

Before I got my lathe if I wanted to remove that much material I would hold it in my hands and spin it against a bench grinder, you could used a drill but I prefer holding it.

With a little more patience Im sure you could achieve that with a hand drill and a fairly rough file, unless your using a hardened bolt.

[clemsonguy1125]

I wish I had a lathe but for now I dont I guess my best bet is Jrrdws sandpaper idea. Heres the only progress I made in 10 minutes with a file.

[jor2daje]

I dont know how quick you expected it to be but that doesnt seem much slower than I expected, how fast does your hand drill go? If its not to quick I think its more time efficient to sand by hand.

[clemsonguy1125]

Honestly I have no idea how long it would take, my drills a 800 rpm craftsman with a 6.0 amp motor

[ramses]

Be careful not to over heat the motor. It is most likely designed for a lower duty cycle, typical of what a drill would encounter. I doubt it has good radial bearings, and instead has only thrust bearings, because it shouldn't see radial loads if it were used as a drill. I have heard horror stories about people screwing up their drill presses with those silly x/y tables, because the spindles don't have good radial bearings.

Try a grinder if you have a lot to take off. or outsource it to a member here with a lathe, although I hate cutting mild steel. Surface finish can be challenging, even on a lathe. At least on the tiny parts I do.

[Crna Legija]

i clamped my drill in the vice and put a bolt in it zip tied the trigger down and use my angle grinder to grind it away.

[lemming124]

why not use a smaller diameter bolt, with an o ring between two nuts as a seal?
like the bolt piston here: http://www.spudfiles.com/forums/self-cl ... 17609.html

[Mr.Sandman]

I used a drill press and a bastard file to make my hammer valve grooves, works wonders. Imo files work much better than sandpaper, and they take off more material.