clamping of solid carbide drills

[dhiruj]

hi

we want to use solid carbide drills for blind hole drills...

I am not very confidant of the ER collets as in a few operations my tools slipped through them.. the dia of the drill shall be from 5mm to 14mm..

can anybody please suggest a good clamping method for drills.. my machine has coolent through spindle.

dhiruj

[dertsap]

a good er collet should work
if you have DA holders you can get collets that have rubber in the slits to allow for thru spindle coolant ,you can probably get er's the same.

best performance and tool life will be gained by dialing in the drill dead nuts,carb drills don t like to be offset

[DareBee]

You will smash those drills long before they will "push" in an ER collet (assuming you tighten the nut).
ER's are availaible with rubber seals.

Like Derstap says, indicate and true-up the runout (<.001 max) with it all mounted in the spindle.

[M-man]

A hydralic chuck would be the best for tool life, but they are expensive. I uses collets myself and it works OK,

[Geof]

I am not sure I totally agree with Darebee, which is a bit unusual.

I have pushed drills back in ER collets but only when I did not make sure the drill was firmly in contact with the stop screw inside the collet body.

When the screw is adjusted so the drill cannot push back I have never rotated one in a correctly tightened collet; the machine will stall or the drill breaks first.

[Eurisko]

Use the proper size collet for the drill.
Don't chuck on the flutes.
Make sure that the collet, taper and locking nut are clean.

We routinely use solid carbide drills in collets with no positive stops.

Test for collet fit by putting the drill in the collet and squeezing the collet by hand. If the drill can be pulled out under pressure, it's probably the wrong collet.

[Mitsui Seiki]

A hydralic chuck is of course best but a Regofix with a sealed collet works too.And they are a lot cheaper.We use Regofix all the way up to 12mm drills.
And the good thing about Regofix open collets is that you can use coolant through spindel on any drill,tap,reamer or what ever you put in them.Prolongs life of the tool.

[big_mak]

Collets should be fine, for larger drills you may want to move to TG100 collets, as you get more shank contact with them as these collets are longer overall than the equivalent ER collets I believe.

[DareBee]

That's OK Geof
I do mostly one-offs and likely run wussy chiploads.

Although I have never slipped a drill and don't use my stop screws.

[big_mak]

I read once somewhere, that using the stop screw in the back can actually afect the run out of your tool. Saying double angle collets are designed to have contact on both faces, as you tighten the nut. I will try to find the article and post the link.

edit: the link gent's http://www.mmsonline.com/articles/020404.html

[Geof]

I read once somewhere, that using the stop screw in the back can actually afect the run out of your tool. Saying double angle collets are designed to have contact on both faces, as you tighten the nut. I will try to find the article and post the link.

edit: the link gent's http://www.mmsonline.com/articles/020404.html

Thank you for the link. I can quite see the backup screw would reduce the clamping forces. I only ever use it on drills, it doesn't help much on mills which tend to pull out not push in.

[big_mak]

I think in your case, Run-Out would be the biggest detriment, when running drills on your 15K machines. Tool life will improve vastly if you can eliminate run out, and have the tool cut equally with all flutes.

I'm sure you know this. I've been cutting lots of stainless lately, and speeds maybe slower, but run out has an ever more severe impact on tool life when cutting these types of materials.