Cutting Pivots To Length?

Michael J. Spangler

Michael J. Spangler

Joined
Oct 8, 2003
Messages
2,181
alright guys what is the best way or any way to do this with a mill??
i'm talking normal pivot barrels

i don't wanna put the thing in the vise or in the chuck and put tension on it and squish the pivot egg shaped. (i've done that already)

is there an easy way to do this??? or should i find a lathe somewhere?

i know there are a number of jigs i can make to get the pivots cut or ground down etc. but there must be a good way with the mill right?? please tell me there is. thanks again
 
Well, here's the low-tech solution a lot of guys use ...
Take a piece of bar stock that's the same thickness as the finished pivot-barrel length you desire. Drill some holes in the bar so the pivots fit nice and smooth, then, pushing the pivot into the hole from behind, grind flat on the belt grinder. Some guys bolt a plate on on side so once the pivots are in the holes, you put the plate on and it holds them all in. That's a must if you're doing more than one at a time.
This method is quick and easy, and since a few thousandths + or - usually isn't a factor, it's accurate enough.
 
You can do that or the opposite and use a dowel on the inside clamp the whole piece in a vice and use an endmill and shave off what you need.
 
I can cut 1/8 SS pivots in half with a jewelers saw. I cut heat treated 3/16 pivots with my bandsaw.

The hard part is to keep them from turning while cutting. Once you cut into it there's no problem.

If you grab the pivot in a chuck or in a tap handle your holding it from at least 3 sides and are less likely to "sqiush the pivot egg shaped" :rolleyes:
 
thanks guys good advice. keep em coming

chuck: "less likely" doesn't sound like good practice to me. i guess i better get in the shop and make a jig
 
You should be able to mount it in a drill chuck or collet chuck in your mill spindle and put a lathe tool in your vice. Or even an end mill cutter being held in the vice to work like a lathe tool.

If the part is so fragile you can't hold it this way, that doesn't sound right to me.

My lathe is manual. When I have a turned part that needs CNC, or a bunch of identical turned parts where I really need a CNC lathe, I put them in the spindle of my mill and use the mill as a lathe.

BTW, you will probably get a better, more square end turning it lathe style, than face milling it or grinding it.
 
ahhh a collet... the perfect answer. i wasent thinking of that.... damn now i need a collet. ahh well easy enough. but i think for the future i'm going to make a jig up. much easier. untill then a collet it is.

now i need more pivot pins:grumpy:
thanks again guys
 
The problem with grinding them down is that you are wasting money!

If I make a folder with a blade that is .105, the backbar is .125, the liners are .050 each so my pivot needs to be .225. So if I cut a .500 (1/2 in) pivot in half I get 2 making a $2.50 pivot cost $1.25.

Over a year it all adds up!

Mike, use a small "V" block, grab it in your vise on your mill and use a slitting saw or thin cutoff wheel and cut them down.
 
If you are mass producing get yourself a collet for sure, imho the best way to grap thin walled pieces, or you can use round stock cut to length and drill out.
 
65535 said:
If you are mass producing get yourself a collet for sure, imho the best way to grap thin walled pieces, or you can use round stock cut to length and drill out.
Click to expand...

:confused: If you're mass producing, you'd just specify the correct length when the screw-machine guy is turning out your parts...:D
 
good point all of you. i like that idea chuck. i'm going with a 125 back bar and 40 thousandths liners so i can easily get 2 out of a 1/2" long pivot with room to spare.

thanks again guys.
 
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