# R8 collet problem



## ChipsAlloy! (Sep 23, 2013)

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






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



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?


----------



## johnnyc14 (Sep 23, 2013)

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


----------



## Chuck K (Sep 23, 2013)

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


----------



## Jeephead (Sep 24, 2013)

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.


----------



## ChipsAlloy! (Sep 24, 2013)

John, i just sent an email to PM about the issue. I will return the set.


----------



## Ray C (Sep 24, 2013)

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


----------



## ChipsAlloy! (Sep 24, 2013)

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.


----------



## Ray C (Sep 24, 2013)

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.


----------



## ChipsAlloy! (Sep 24, 2013)

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).


----------



## Ray C (Sep 24, 2013)

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


----------



## Hawkeye (Sep 24, 2013)

I had the same problem with some R8 tooling in my ZX-25 mill/drill. I figured out that the grooves on some of them were, as mentioned, too shallow. I ended up grinding the pin down just enough to fit the worst of the tools. I've never had any trouble since.

Because the outside diameter of all R8 shanks is the same, within tolerances, the top edge of the groove is in the same place. Works fine with a slightly shorter pin - just not _too_ short.


----------



## ChipsAlloy! (Sep 24, 2013)

I finally got some time to get to the mill and the collet issue is no more. Thanks to you guys here and to Matt who responded to me by email. 

After I unscrewed the ''spindle cap'', I realized the pin was in fact some set screw that can be adjusted so no more questions about it: any reasonable keyway depth will fit in there. One would simply have to adjust the setscrew if another tool had a deeper or shallower slot.

After this happy discovery, I had time to clean and install the vise on the table. I think I did a fair job at ''indicating'' the vise but still need some practice. 

Don't know if «indicating» makes sense to you guys I am french and some times I am not sure if I choose the correct words to be understood.

Again thanks guys, hey, I just made my first (home made) chips! :thumbsup:


----------



## johnnyc14 (Sep 24, 2013)

Cool, I didn't know the pin was adjustable. I'm not sure what the spindle cap is though. Can you post a picture? Thanks,

John


----------



## ChipsAlloy! (Sep 24, 2013)

The spindle cap is the round threaded cap that is just below the lower spindle bearing. There are 3 dimples in the cap that can be used to unscrew it. I used a small punch and gently taped in the dimple so the cap would turn counterclockwise. It was easily unscrewed

Here is a pic of the opened cap (Thanks to Matt's email) You dont see the actual cap but you get where it is installed. The set screw is visible.




	

		
			
		

		
	
PS.: Spindle Cap is the name I gave it, it might no be the official name


----------



## johnnyc14 (Sep 24, 2013)

OK, that makes sense. I'll have to adjust mine a little bit too. Some of my collets are still a bit tight going in. Thanks for sharing that information!

John


----------



## qualitymachinetools (Sep 25, 2013)

Hey Guys, glad to see you are all fixed up. 

 Just remember, that pin in there is NOT what keeps the collet from turning when running the machine. I don't even have them in most of my own machines, I take them out. Because the taper of the R8 is what holds it. I've spun R8 tooling in spindles before, and when you go to take it out, its stuck, because it sheared the key off and turned a bit. With the key not in there, you never notice it, and just take the tool out.

 But if the pin is in there, it can shear off, and get stuck, if your collet is a little loose, or you are using a bigger face mill or larger drill something and it twists in the taper.

 So my advice? (Not just for this machine, ANY R8 Taper) Take the pins out completely. It can save you a headache from getting a stuck collet out, and they really serve no purpose for locking, that is what the taper does.


----------



## ChipsAlloy! (Sep 25, 2013)

Thanks, I checked  our two machines here at work and they both miss the pin so I guess its no big deal after all!


----------



## Ray C (Sep 25, 2013)

First thing I did was remove the pin but was reluctant to mention it here fearing a flurry of contrary opinion but, the cat's out of the bag.  As long as you have a double nut arrangement on the top of the drawbar, there's no way it will get stuck with no way to loosen it.  Just unlock one nut against the other and the thread comes loose then, tap it down and the spindle attachment comes out.  Just always make sure you have plenty of thread engagement  in the spindle attachment.

Ray



qualitymachinetools said:


> Hey Guys, glad to see you are all fixed up.
> 
> Just remember, that pin in there is NOT what keeps the collet from turning when running the machine. I don't even have them in most of my own machines, I take them out. Because the taper of the R8 is what holds it. I've spun R8 tooling in spindles before, and when you go to take it out, its stuck, because it sheared the key off and turned a bit. With the key not in there, you never notice it, and just take the tool out.
> 
> ...


----------

