1. Home
  2. ⏣ General Metalworking
  3. How to choose between using collets and endmill holders for mill?

How to choose between using collets and endmill holders for mill?

I'm pretty much a newbie to milling (last fall I took a manual machine tools class at the local vo-tech and we did turning projects on 13x40 lathes, milling on Bridgeports, and surface grinding on 6x12 and 6x18 machines).

I found a nice small mill (Schaffner vertical/horizontal, 2hp motor, a 7x30 table on a knee, but no quill) in February and brought it home. It's now awaiting installation of a VFD to make it go. The mill takes NMTB 30 toolholders, and I've got a few endmill holders in very good visual condition (I'll check each one with an indicator one of these days). My plan is to be able to futz around the shop, and build up my machining skills with small projects including robots and tools.

My first question is when would I choose to use a collet chuck, say an ER or DA, over an endmill holder. Clearly the collets have the potential to give lower run-out, but I'm a little worried about the tool pulling out (OK, it didn't pull out of the R8 collet in the Bridgeport, but that seems like it had a much larger contact area - maybe I'm wrong).

There doesn't seem to be much of a cost advantage to going with collets vs EMHs and I'm at the decision point of which type to use as a primary toolset. Any suggestions?

Thanks, Pete Bergstrom St. Paul, MN

Reply to
Pete Bergstrom
Loading thread data ...

A rule of thumb that has served me well is: Ok to use collets for holding endmills under 3/4 inch. Above that, endmill holders are required.

Reply to
Robert Swinney

Thanks, that helps. I also found a note from Forest Addy on

formatting link
describing how toolholders wear.

I ended up buying a collet holder so I'll use that for the smaller size tools.

Thanks, Pete

Reply to
Pete Bergstrom

Ive spun more than a few endmills in my 30 taper milling collets. The engagement surface is pretty short. Some have longer "bores" than others, so when looking for a collet holder...be advised.

Gunner

That rifle hanging on the wall of the working-class flat or labourer's cottage is the symbol of democracy. It is our job to see that it stays there. - George Orwell

Reply to
Gunner

That was one thing I thought of. The collets are ER40, the biggest I thought I could find for a 30 taper holder and still be able to buy them for a few years. It's a bigger chuck, but the engagement area was important.

Thanks! Pete

Reply to
Pete Bergstrom

And the double angle will be a good tight fit. I like how the collet is held into the 'Nut' and then the whole of it is screwed in.

I have that set in MT4 and R8. (holder in R8 anyway :-) ) Martin

Reply to
Martin H. Eastburn

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.