E R 40 collet

[just bill]

Having a fun time with my Hornady LNL progressive lock rings. Their diameter is just a little large for the 6 locking lugs to fit inside a 1" or the largest metric collet. Has anybody ground the internal diameter of a collet just a few thousandth.
Thanks,
Bill

[IllinoisCoyoteHunter]

Sure you can. But you ideally need to have it clamped (so it doesn't move around when grinding). So if you can put a piece of precision ground rod towards the back end of the collet, clamp the collet on the rod, then grind the front exposed portion of the collet however far back you need. I assume you will be using some sort of toolpost grinder?

Not sure what you are trying to do but why not just chuck it up in a 4 jaw? You should be able to tap it true for perpendicularity fairly easily.

[just bill]

Sure you can. But you ideally need to have it clamped (so it doesn't move around when grinding). So if you can put a piece of precision ground rod towards the back end of the collet, clamp the collet on the rod, then grind the front exposed portion of the collet however far back you need. I assume you will be using some sort of toolpost grinder?

Not sure what you are trying to do but why not just chuck it up in a 4 jaw? You should be able to tap it true for perpendicularity fairly easily.

I could try the 4 jaw, but this could become a repeatable event, and the collet would be quicker.

Yes I will be using a dremmel in a tool holder with a carbide mini wheel. I may adapt an air grinder if the mood moves me.
Thanks,
Bill

[IllinoisCoyoteHunter]

Can I ask what you are doing?

[just bill]

I'm using my LNL for brass casing trimming and prep, the threads on the dies aren't long enough to fit the holders and lock rings. It's easier to trim the rings than machining the top of the press. I kinda figgered if the big blue guys could use there's I could use the big red, this is the only thing in 9 years that I had to do to the press.
Bill

[IllinoisCoyoteHunter]

So are you trimming the quick change bushings?

[just bill]

I'm using my LNL for brass casing trimming and prep, the threads on the dies aren't long enough to fit the holders and lock rings. It's easier to trim the rings that machining the top of the press. I kinda figgered if the big blue guys could use there's I could use the big red, this is the only thing in 9 years that I had to do to the press.
Bill

[M-Tecs]

Make an expansion arbor. Take a piece of 7/8" or 1" stock and tap the end for a pipe plug. Remove and slot the arbor. Thread for 7/8" x 14. Screw your LNL progressive lock ring on and machine. A bolt or threaded stock will work but it won't be as concentric.

[IllinoisCoyoteHunter]

ER collets don't do well if you are only gripping on a small area (ie, a thin lock ring). You will find that even if you grind the ID of the collet to fit the lock ring, you will still find yourself having to tap it true for perpendicularity (if you grind too far back and don't leave a shoulder for the lock ring to set against) . So if you go this route, be sure to only grind back far enough to leave just the amount you wish to take off sticking out of the collet. You want a nice, clean shoulder the lock rings can seat against. You'd be basically making a bored collet.

[just bill]

ICH, I was thinking similarly to that, put a piece in the back, grind about .2 0r.3 deeper than the collar so the lugs would be inside the collet and the flange rests on the face of the collet.
Bill

[IllinoisCoyoteHunter]

If you are shortening the flange on the quick- change bushing, then just make one of these so the flanged end sticks off the end for machining. This could be either put in a collet or indicated in a 4 jaw.

[IllinoisCoyoteHunter]

In fact if you want this I can send it to you.

[IllinoisCoyoteHunter]

Sorry, I initially thought you were altering the die lock rings. But it sounds like you are making the flange on thr QC bushing thinner.

[just bill]

If you are shortening the flange on the quick- change bushing, then just make one of these so the flanged end sticks off the end for machining. This could be either put in a collet or indicated in a 4 jaw.

How about a bolt, would the turned head be long enough to support the turning?
Bill

[just bill]

Looks like we were posting at the same time, that looks like a winner. I really love this site.
Bill

[IllinoisCoyoteHunter]

If you want it shoot me your address. If you use a bolt the turned head should be plenty rigid, so long as you take lighter cuts.

[just bill]

In fact if you want this I can send it to you.

PM sent

[just bill]

One of the best things about this site is what Red River Rick says " I make the part..............that makes the parts.
Bill

[just bill]

In fact if you want this I can send it to you.

Got it today, thanks for showing me a better way to approach the situation.
Bill

[ProfGAB101]

I had some dies that I had to screw down so far there was no space for a lock ring on my XL650. I just put the lock ring on the underside.