Collets

[foamcutter]

I am in the process of designing and building a CNC router/mill to work on aluminum, stone and mild steel. I am trying to design a spindle that I can use collets in. My question is what ready made collets are going to be the easyest to build a spindle and closer around? I have little experience with collets so this is why the question. There are many differnt ones offered on ebay some are less expensive than others. What should I look for in collets? Thanks Ron

[ARB]

DA collets would be the most straight forward to make if you are planning to make all the parts yourself and buy the collets. If It was me I would figure out how I could adapt a ER32 collet chuck into the design as I prefer the ER series collets to all others.

Good Luck

[cadman]

If you want to use existing collets, use ER or TG collets. DA collets are designed for low precision drilling, no milling or tapping.

TG collets more suitable for heavier milling than ER collets but their main drawback is that the collet chuck nuts only come in one size, usually about 2.5" diameter, something to think about when using small cutters.

ER collets come in different sizes (8,11,16,20,25,32,40 & 50) and the collet chuck nuts are sized correspondingly from about .5" for an ER8 to 2.5" for an ER40/50.

I use ER collets and milling chucks.

[Sinnister]

I find the ER series of collets to be quite adequate for milling at speeds of up to 10,000 rpm's. They also have the advantage of closing on a range of dia's. In the ER16 series 10 collets will work for any dia between .019 to .393".

[foamcutter]

Thanks for the replies guys. I have been lurking on ebay. There seems to be a number of auctions for R8 collets. Are these the same as you are refering to above as ER collets? Thanks Ron

[Sinnister]

No, The R8 is for a Bridgeport type mill and would probobly be to large for what you want to use them for. Check this out, it should give you the specs for a number of ER series collets.
http://www.mscdirect.com/IWCatSectio...85&View.x.y=4a

[HuFlungDung]

For what I do, ER16 collets are very handy.

Another approach might be to look at Kennametal's KM tooling. This is a modular approach which has a great selection of tooling designed to fit a standard series of 4 base configurations (adapted to different horsepower machinery).

Then, you can purchase different styles of collet adapters to fit the same Kennametal master. You might find that the ER16 is not large enough, so eventually you could buy the ER25 or ER 32 series adapter and reuse the same base shank.

The KM tooling is not an automatic quickchange setup in itself though. However, the different modular ends are quick to change over manually for a different job setup.