Problem with R8 collets tightening properly

Those lips are suppose to be there. They stop the collet from deforming and collapse. I have some like that and some that are not. I will try and get a picture after work. I have Bridgeport’s and imports.
 
They are there for manufacturing purposes. The web supports the grinding process then are removed afterwards. Apparently they didn't finish the job, it's cheaper that way. Better collets manufactures grind out the web. Soap box time "we buy inexpensive tools expecting every thing to be as advertised" only to be disappointed afterwards are spending a good deal of time making them work. And yes I am guilty of the same. Don't know about you but I would rather spend a little more on quality and spend more time making chips.
 
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Canus said:
Found a picture on Ebay of a set similar to mine. Notice the 1/8", 1/4" & 3/8" collets. Will probably have to use a dremel with a cutoff disk to clean mine up.
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Those are substantial lips! A diamond credit card would not handle that job... The collets will still work, just less range toward smaller sizes being held. Those are so obvious that I really do wonder if they are intentional.
 
You will find that almost all collets (both my 5C and R8) have additional webbing in all smaller collets 1/4" and under. If you are only seeing this in the smaller sized collets then it is intentional. These type of collets that collapse only at the tip have a very limited clamping range something on the order of +/- 0.002" for R8's. On the smaller clamping sizes the additional webbing prevents you from over clamping the collets and damaging them. If you use a 1/4" collet and it can only be used with a 1/4" shank end mill/drill. The web should not collapse at all, then end mill or 1/4" pin should just slide into the collet with light pressure. Typically I just use a few R8 collet sizes such as 1/4, 3/8, 1/2, 5/8, 3/4", so it pays to buy some higher quality ones for these sizes.

These are Lyndex and Royal R8 collets.
20180620_065527.jpg
 
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mksj said:
You will find that almost all collets (both my 5C and R8) have additional webbing in all smaller collets 1/4" and under. If you are only seeing this in the smaller sized collets then it is intentional. These type of collets that collapse only at the tip have a very limited clamping range something on the order of +/- 0.002" for R8's. On the smaller clamping sizes the additional webbing prevents you from over clamping the collets and damaging them. If you use a 1/4" collet and it can only be used with a 1/4" shank end mill/drill. The web should not collapse at all, then end mill or 1/4" pin should just slide into the collet with light pressure. Typically I just use a few R8 collet sizes such as 1/4, 3/8, 1/2, 5/8, 3/4", so it pays to buy some higher quality ones for these sizes.
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Makes sense, Mark. None of my collets have that feature, but they are inexpensive Interstate branded ones bought from Enco many years ago...
 
That is a manufacturing process. And I do not think it is to limit chucking size. Rather it’s to maximize the chucking surface on the smaller hole sizes. Ie: if you slotted a 1/8” hole with (3) 1/6” wide slots, you would have nothing left of the hole. And to speed up the slotting process, they hog out with a wider cutter, then go in with a thin one…Dave
 
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Problem is my 3/8" collet will not tighten on a 3/8" end mill. Chucked up two different end mills and neither were secured after tightening. Guess I will have to remove some of the lip/web. Will head to the shop in a few and install the 3/8" collet with no tool and measure the id with the collet tightened. Will also check the OD of my 3/8" end mills. If this checks out I will try installing an additional washer under the head of the draw bolt in case the threads of the draw bolt are bottoming out in the collet before completely tightening it.
 
Canus said:
Problem is my 3/8" collet will not tighten on a 3/8" end mill. Chucked up two different end mills and neither were secured after tightening. Guess I will have to remove some of the lip/web. Will head to the shop in a few and install the 3/8" collet with no tool and measure the id with the collet tightened. Will also check the OD of my 3/8" end mills. If this checks out I will try installing an additional washer under the head of the draw bolt in case the threads of the draw bolt are bottoming out in the collet before completely tightening it.
Click to expand...
Please, before you go and modify anything. Check it all out first. Make absolutely sure what the problem is. If you change the slots configuration, you can’t put it back…Dave.
 
Did you run a tap through the collet to clean the threads?
 
All collet threads have been chased. Will not perform any material removal until everything else has been checked out. Temps are in th high 90s today so shop environment is not conducive to long stays.
 
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