# Collet Won't Fit In A New Machine - Keyway Is Too Shallow



## catsh16 (Nov 14, 2015)

Just setting up our new PM 727. and the stock R8 collets that come with it (and other R8 collets I have lying around) won't make it past the keyway. (I do have R8 chucks that will fit.)  what the heck!
After additional measuring: It appears that the depth of the keyway is ~0.02" shallow on the collets that won't fit(or conversely that the key-pin is too long inside the spindle)
(keyway is measuring 0.63" depth vs. 0.94" ie. 3/32" per the R8 spec.) 

Has anyone run into this problem? any good solutions (other than cutting deeper keyways on a machine which won't receive a collet!)?


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## TOOLMASTER (Nov 14, 2015)

screw the pin out a bit..or just remove completely


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## catsh16 (Nov 14, 2015)

yep, just figured that out. the keyway pin is a long nose setscrew. It can be accessed by lowering the spindle and manually rotating it until the setscrew is accessible through one of the machined access slots.  
The setscrew was super loose - I re-installed it with some locktite.


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## RJSakowski (Nov 14, 2015)

I had the same problem with the set screw on a Grizzly G0755.  I replaced the setscrew with a socket head cap screw.  I cut the thread to length and turned a dog point on the end to fit the R8 collet slit width .  Now it can't work its way further in and it can be easily removed if necessary.

Bob


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## coolidge (Nov 14, 2015)

You might run a grub screw up behind the set screw to lock it in place if you have the thread depth, that's how my PM935 came. As we were discussing in a thread on my PM935 the mill is in spec its the tooling that's out of spec with the R8 standard, the keyway is supposed to be .094 deep on R8 tooling. So far the only R8 tooling I have that's in spec is my made in Germany Albrecht chuck. Even my made in Japan higher end Lyndex collets are out of spec (too shallow) on the keyway. I removed my set screw altogether. I have busted one off before and jammed it between the spindle and tool then had to beat the tool out. If you do some research this issue is not uncommon, there's a camp out there that remove these set screws for this very reason. The set screw is just for alignment its not a key that can take the torque if the tool slips in the spindle. Typically something like a face mill that has lots of grab and the diameter/leverage to grab the work piece strong enough to jam and spin the tool in the spindle and snap off the set screw.


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## catsh16 (Nov 15, 2015)

Thanks for the advice everyone. 
FYI to anyone else planning to set up this machine: read below and save yourself some time
Yes... very happy so far (cut metal for the first time on it yesterday, finished my first piece today).   Here are a few set up challenges I've had to overcome:
1) The draw bar was also too long (Collets not in spec?) and wasn't drawing the collets tight. I put a few washers between the draw bar top and top of the spindle to fix this.  Easy fix... but it took an hour to figure out what was wrong and get the right washers (7/16"?). 
2) The table locks for the X axis (on the front of the machine) clash with the Y axis bottom bed... if you arn't careful you'll bend, or break one/both of these levers... watch out! (I'm think I'll cut the levers shorter so they don't cause additional problems in the future). 
3) get some sticky pad-zip tie holders to guide the power cable away from the Z axis handle.
4) The base (pedestal) bolt pattern does not match that of the machine. having 2 pieces of 2x10 16-20" long, qty4 1/2-20 x 2.5" carriage bolts, nuts, washers, lock washers, and qty4  3/8" x 5" wood/lag bolts (and assorted spade bits up to 1")  will speed this along.
5) yes - the pedastal base is too short... even with the 2x10 (1.5") spacer addition. I imagine I'll want to raise it an addtional 3".
6) a 'come-along' & overhead mount + 10-15" of rope to tie around the head of the machine got the machine onto the base quite easily. I would NOT plan on inviting over all your friends and trying to lift it with brute strength- many fingers would be at risk.


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## kf4zht (Nov 16, 2015)

I just setup my 727 and had issues 1, 2, 3 and 5. I plan on replacing those table lock handles with a SHCS, It will need an allen wrench but that isnt a huge deal. Also the Z axis ones on mine are all in the height adjust crank.


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## lpeedin (Nov 16, 2015)

Catsh16, I had every one of the same experiences as you with the exception of the base and stand bolt patterns on mine did match.  Matt told me that the stand is actually made by a sub-contract factory and not in the same factory that makes the machines.   I have a couple of solutions for what I did to overcome the issues. 

1) Draw bar:  I too found out that the draw bar was too long.  I used washers at first, but then I ended up turning a bushing on the lathe that kept the draw bar centered at the top as well as providing the necessary length adjustment.  

2) I quickly realized the front x-axis locks were not going to cut it.  I found black plastic knobs with long M8 threads at Ace Hardware (not sure if that is a national chain or not) for about $5 each.  They don't get in the way and offer a large comfortable knob to grip and turn.  

3) I used zip ties also to keep the power cable out of the way.  But, have since removed them.  Since the head travels up and down, I just let the power cable rest on the hand crank shaft and then by default the hand crank becomes the cord keeper-out-of-the-wayer.

4) Didn't have this problem.  I thought I did at first, but since the bolts are so long, mine worked out just fine.  I did make sure to chase the holes in the front of the stand with a tap to clean out the paint so that the bolts would actually thread in.  

5) My base has been raised approx. 5" by means of 4 x 4's and 2 x4's.  I have ever intention of building a large base / table just like I did for my PM1127-VFLB lathe.  Just need to quit finding little machining projects to work on and then I will have time to build it.  

6)  I built a gantry type crane out of 2 x 8's with casters when I got my lathe.  Since the mill is the same weight, I was able to use the crane for that as well.  I added a cross bar with rubber coated hooks to the crane and use it to hold my compound bow's when it is not being used as a crane.


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