Collet vs. End Mill Holder

[rwm]

When would you want to use and end mill holder vs a collet in a mill? What are the advantages?
Robert

 

[benmychree]

Use an end mill holder when you can't get close in enough with a collet, use a collet when concentricity is most important.

 

[Grandpop]

I use end mill holders whenever an end milling pulling down in the collet will wreck something. Every time you are roughing or milling to depth. I only use collets when end mill holder will not fit, or the cutting diameter is the primary important feature necessary.

I allways have my quill jammed in position when using end mill holder for bottom cuts with solid u-shaped block above the adjustable stop, the quill up against the stop, and the adjustable stop tight against the stop. Nothing can pull down to wreck your piece that way. Especially important when using indexable cutters or fly cutters.

 

[mmcmdl]

Use an end mill holder when your end mill shanks are over 7/8" . And personally even though they make them , I wouldn't use a 7/8 collet milling .

This is in reference to R8s only .

 

[rwm]

I take it that end mill holders hold tighter than collets? Yes, I am talkin' R8 (not the car)
R

 

[darkzero]

I take it that end mill holders hold tighter than collets? Yes, I am talkin' R8 (not the car)
R

Not necessarily hold tighter but yes in a sense. End mill holders are for weldon shank end mills. They use a set screw to tighten down on a recess & flat on the end mill. You must use an end mill with a weldon shank. The weldon shank won't slip (spin) like it could in a collet.

So you can use a weldon shank end mill in a collet but you can't use a straight shank end mill in an end mill holder. Also if you have a poor quality end mill holder (loose tolerance), that can introduce run out since the set screw would be pushing the end mill shank against the bore of the end mill holder.

 

[rwm]

Got it. Couldn't you just grind a flat on the end mill? Sounds like I may want to get an end mill holder for some of my larger end mills.
Robert

 

[mikey]

Might be just me but the only time I've had an end mill come loose and dig into a part was when I used an end mill holder. And yes, I had the set screw tight on the Weldon shank. Now I don't use end mill holders at all. I use ER collets and have never had an end mill slip, although I admit I don't use honking big end mills.

 

[darkzero]

I've never had an end mill come loose in an end mill holder but that cause I don't use them. I only own one end mill holder but I'm using it as an extension for a slitting saw arbor. I also use ER collets & haven't ever had an end mill slip but I too do not use big end mills.

 

[Chewy]

Mikey & Darkzero, how big are you going with the ER32? I only use endmill holders, 3/8, 1/2 & 5/8. I use the ER32 for some really small endmills. I have others and I broke out the 7/8" the other day for a ball mill. First time in 2 years. Would you recommend getting the R8 collets? I have a lot of double ended mills.