# Alignment Pin Issue?



## HighWall (Jun 26, 2015)

I have a new PM935TV mill and it accepts my R8 keyless chuck just fine, but my MT-3 quick change collet adapter won't go into the spindle.  The chuck's keyway is a little bit deeper cut than the MT-3, so I think I need to shorten the alignment pin.  Any tips on getting to that screw?  I don't have a wrench to get the nosecap off the quill and I don't want to bugger anything up.  Been there, done that.  Sorry if it's a basic question, but the instructions with this tool assume a lot.


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## jds (Jun 26, 2015)

Highwall,
Check back a few threads, last october Mike...Zmotorsports had a video and a write up on the 935 and I believe smudgeo had something on here also. 
There is a set screw on the nose cap on the back side.  The pin also has a set screw.


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## tmarks11 (Jun 26, 2015)

Buy or make a pin wrench.  Trying to take that nut off without one will be an exercise in frustration.  As mentioned above, this seems to be one of the first thing many news owners of the 935 get to deal with.  Matt needs to feed this back to the factory.


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## T Bredehoft (Jun 26, 2015)

Whoa, forget the pin wrench. Its easier than that.   Crank the spindle down three inches, lock it vertically.  Rotate the spindle until a slot appears in the outer casing. In you will see the back of the pin, its a flat head screw. (Maybe you have to rotate something else, not sure, don't have my mill at hand. ).  Anyway, back that screw out a turn and try the MT3 adapter.


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## RJSakowski (Jun 26, 2015)

+1 on Tom's suggestion.  I had the same problem with a Grizzly G0755. As I recall they used a set screw which worked its way deeper.  I replaced the OEM screw with a modified socket head cap screw which ended the problem.


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## T Bredehoft (Jun 26, 2015)

Thanks, RJ, I may be suffering from teh same malignant set screw. I'll check into it. 

Tom


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## HighWall (Jun 27, 2015)

Well, I had another look at the mill.  There is no access to the interior on the housing for the quill.  The only feature is a set screw towards the bottom.  The ring at the bottom of the housing has two holes for a spanner.  I believe that's the way I'll have to go.  I have a collet set coming Monday.  I'll see if they fit.  Don't know exactly the best way to obtain the appropriate spanner wrench, but I'll keep looking.

Thanks for your attention.


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## Duker (Jun 27, 2015)

HighWall,  Smudgemo aka Ryan built one that I copied out of simple angle iron. Check it out in my or Ryan's 935 threads. It took me about 10-15 minutes to make.


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## HighWall (Jun 28, 2015)

Well, I took an alternate approach.  Since my Glacern keyless chuck fit perfectly, I decided to deepen the keyway on the MT3 adapter.  No problem, really.  I used the (accursed) Dremel with a reinforced cutoff disc and gently deepened the keyway.  Worked great.  Now it's a perfect fit.  We'll see how the rest of the R8 collets fit when they get here.  I may well adjust the alignment pin anyway.  I figured the depth of the keyway isn't mission critical, as long as it goes up into the quill.  At least, that's the misapprehension under which I'm currently laboring.


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## T Bredehoft (Jun 28, 2015)

As long as the pin clears the slot you are good to go.


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## Smudgemo (Jun 28, 2015)

I think you're still going to need to take it apart.  Too many of us had this issue.

You need to first back out the set screw you can see (on the backside.)  Then turn the collar (it has reverse threads), and the spindle drops out.  A simply pin wrench is easy to make.  Before you can back out the actual locating pin, you have to remove a set screw.  You can remove the alignment screw entirely, but if you don't, back out until your collets will slide in and replace the setscrew.  Then slide it all back in and tighten up the collar so things spin properly.  Tighten the collar setscrew, but not too tight.  I noticed it's fairly easy to foul the quill's retracting into the head if the collar's setscrew is too tight.
-Ryan


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## turnitupper (Jun 29, 2015)

HighWall said:


> Well, I took an alternate approach.  Since my Glacern keyless chuck fit perfectly, I decided to deepen the keyway on the MT3 adapter.  No problem, really.  I used the (accursed) Dremel with a reinforced cutoff disc and gently deepened the keyway.  Worked great.  Now it's a perfect fit.  We'll see how the rest of the R8 collets fit when they get here.  I may well adjust the alignment pin anyway.  I figured the depth of the keyway isn't mission critical, as long as it goes up into the quill.  At least, that's the misapprehension under which I'm currently laboring.


Misapprehension!, I work for him. He certainly fills the scrap bucket. Ditch the pin.
John.


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## T Bredehoft (Jun 29, 2015)

I've seen other recommendations to scrap the pin, but I can't understand then what keeps the collet from turning when the draw bar is tightened. Do you depend on the friction in the taper? I'd leave the pin in and work out a way to keep it the right depth. 
This is a hobby, projects are what keep it going.


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## wrmiller (Jun 29, 2015)

No way I'd completely remove that pin. Fortunately it isn't an issue for me though. Good luck.


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## RJSakowski (Jun 29, 2015)

There have been instances where the drawbar seized up and, once loosened slightly, the collet rotated in the spindle making removal very difficult.  Additionally, an R8 adapter was not meant to provide torque by virtue of the friction on the tapered surface.  Any slippage could result in galling the surface of the R8 taper and/or spindle.  A Morse taper is smaller providing greater frictional forces but even they have a tang to prevent rotation when torque is required.

You might get away with removing the pin for light duty work  but, in the end, you will find that you are over-tightening the drawbar to prevent slippage, shortening the life of the drawbar and quite possibly leading up to the problem initially described.

I would not defeat the design of of the R8 system by removing the anti-rotation pin.


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## qualitymachinetools (Jun 29, 2015)

Hey guys, Yes on the 935TV, and the 25, they are both just set screws. The 25 has easy access by lowering the quill as mentioned, and with the 935, you have to unscrew the end cap on the spindle, and then you can get to it.
  I have been seeing a lot of the R8 tooling where the key slot is not very deep, I've told the people at the factory about it, and they have a standard that they tighten it to, and say it perfectly meets that when they put it in. But either way, its easy to fix.

   I actually prefer not to have the pin in though. I've had thing slip and get jammed in there, not the easiest thing to get out. (Usually face mills or drill chucks)    Yes probably was pushing the machine a little bit too far, but it has happened. Almost daily at the one shop I worked in (Not daily to me, just in the shop)   But either way is fine, really. I've seen plenty of it both ways.


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## catoctin (Jun 29, 2015)

Yes, I guess everyone with a PM935 hit the pin issue.  I didn't have a spanner when mine arrived so I used a plumbers strap wrench (Lowes variety).  Enco carries spanner wrenches and they are just a day away in the Bay Area via UPS.  Also, check a variety of your R8 tooling.  I hit a Glacern chuck that was bought new and appeared to have been dropped in the factory on the nose of the slot.  A quick touch-up with a jewelers file removed the bur created by the drop and it went right in.

-Joe


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