R8 Tooling Question

[Bill Givens]

I recently converted my mill head to R8 from MT#3. I bought a R8
collet set and now find that they will not fit the R8 slot in the mill
spindle due to the fact that the vertical alignment grove on the
collet is too shallow to fit the pin inside the milling spindle.

Other R8 tooling fits fine because the grove is deeper....

Did I get a bad set of collets, or do I need a R8 collet chuck to
make this work? I thought about just grinding the pin down in the
spindle so that it would fit the collet. Will this be ok... or will I
mess up my regular R8 stuff? I could mill the slot in the collet a
little deeper but I don't want to do it on all 11 of the collects.

Also is an ER R8 collet the same as a regular R8 collet?

Thanks in advance for any light you can shed on this for me!!!

Bill

[James P Crombie]

Bill
There seems to be a lot of variation in the depth of the slot on the
collets or tools, I havve seen this befor and usually the only thing to do
is to back off the screw/pin, there is usually a second set screw behind
it to lock it in place. If it is a solid pin then you may have to file it
down. Check the parts drawing if you have them to see what kind of pin it
is. I had the same problem on a tool grinder with some cheap 5C collets.
Good luck.

Bill Givens wrote:

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James P Crombie
Summerside, Prince Edward Island
Canada
Machinist - Amateur Astronomer - CadCam Guy

http://www3.islandtelecom.com/~jpcrombie My Astronomy website
http://www3.islandtelecom.com/~jpcrombie/rhino/ My DesignWerks web page

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[Bill Givens]

Thanks for the reply...the problem turned out to be a locating pin
that was too long. I ground the pin down to fit the collets and all
is well.