R8 collet problem

ChipsAlloy!

ChipsAlloy!

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Hello all,

I have cleaned up my PM932 tonight and started checking out the stuff I had ordered with the machine.

I assembled the drill chuck on the arbor and all went well. Runout seems good although I am not a pro at indicating, just trying to get it right.

After that, I found out I cannot insert my R8 collets in the spindle. The alignment pin inside the spindle seems to make contact with the bottom of the slot in the collet.

On the picture below: R8 collet to the left and R8 to MT(?) arbor and chuck to the right.
I measured both shanks are same diameter (24mm)
R8 collet slot is 4mm wide while chuck arbor is 5mm


Milling 013.jpg

On the picture below you can see the slots depths
R8 collet slot is 1,5mm deep while chuck arbor is 3mm deep
Milling 016.jpg

I may have attempted to modify these to fit but since I dont have working collets I cannot really hold my endmills (except in the chuck but doesnt seem to be wise)

These are advertised as having a 10 year warranty so I could just return them to PM

Is there an quick way to fix this or am I better off returning these?

Milling 013.jpg Milling 016.jpg
 
I had exactly the same problem with the collets I ordered with my PM32. The groove width is not the problem, the depth is too shallow. Might not be a bad idea to send Matt an email so they know about this issue. When I commented on it, they had never heard of the problem before.

Cheers,

John
 
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The keyway is supposed to be .156 wide x .094 deep. If they don't meet the specs. I would return them. I would also make sure that the replacements they send are checked before they go out the door. I don't know where you got them but obviously the qc guy must have been on break when those were packaged. That would be a real bummer if you don't have any other collets to use.

Chuck
 
I would call Matt, he was very responsive and helpful with the problems I had. My stuff is only a month old so I am going to check all of the collets, so far though, the five or six I have used have been fine. The slot is definitely deeper on the ones I am looking at.
 
John, i just sent an email to PM about the issue. I will return the set.
 
FWIW, I didn't have this problem with my R8 collets but did have problems with other collets I've purchased over the years. I never had a whole set have the same issue but sometimews one or two in a bunch. In more recent times, I've learned a quick pass with a roto-dremel tool is a good fix if it's just a single unit. This is pretty much akin to getting a new QCTP holder that's too tight and a couple minutes with a file fixes the problem.


Ray
 
Matt responded earlier and told me the pin inside the spindle was sticking out too much and that I should tap the pin a little. I will have to check that out tonight.

The thing that bugs me is looking at R8 specs, the slots in the collets are not deep enough. If I move the pin, will I have problems with other tools that are built to spec in the future?

I would not want to make these collets work just to realize other tools wont work anymore.
 
Do you have nay R8 tooling to try? If an R8 fixure of some sort fits, I'd leave the pin alone. The collets I've had over the years were either too narrow or not deep enough or both.


Ray

ChipsAlloy! said:
Matt responded earlier and told me the pin inside the spindle was sticking out too much and that I should tap the pin a little. I will have to check that out tonight.

The thing that bugs me is looking at R8 specs, the slots in the collets are not deep enough. If I move the pin, will I have problems with other tools that are built to spec in the future?

I would not want to make these collets work just to realize other tools wont work anymore.
Click to expand...
 
Well I have that R8 drill chuck arbor that came with the machine. This one fitted in nicely after I filed the keyway's burs.
This arbor has the right keyway depth but has a larger width (according to R8 specs).
 
Sadly, with accessories like this, you'll find variances. I just bought a couple sets of drill bits ($80 each) and found that most are not even sharpened properly. The collets and T-slot kits packed with the PM equipment come from 2nd party sources and in this case, some or perhaps all the collets are not slotted properly. You'll find similar discrepancies with Morse tapers as there are two standards for overall length (one with and one without tangs) but I've got a handful of them that are everything outside and in-between the "specs" -and it is annoying because it interferes with the ejectors in the various taper blocks. On all those tapers, I had to shorten the long ones and tack a short extension on the short ones...

FWIW, on some of the 5C collets I had to adjust, they were not low end and were about $35 per collet (Hex type). They were from Travers tool. On the up-side, all of them were concentric and otherwise well made.

In any event, I'll mention it to Matt and I suspect he'll contact you.

Ray
 
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