# Limited Quill Travel - Pm-932m



## Bray D (May 14, 2015)

Gunrunner you need to order a set of these for the Z axis hand crank. Bill did you just spit coffee on your monitor? :rofl:

View attachment 253356


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## Rex Walters (May 15, 2015)

I've got a Grizzly G0762, not a PM, but I'm totally stealing your idea for a bushing to keep the drawbar concentric. Thanks for the tip to keep the bushing OD smaller than the inner races of the splines. 

FWIW, unlike the PM, the top nut on the grizzly drawbar just had a roll pin to keep it from turning (not welded or part of the drawbar). That roll pin sheared off within about a half day of use (its possible I like drawing collets tighter than they need to be). I bored the hole a little larger and replaced the roll pin with a small hardened dowel pin and it's worked fine since.


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## Bray D (May 15, 2015)

I can't claim the idea for the spacer - I stole it from Darkzero. However, I believe he made his on a lathe. Mine was made with my boring head on the mill.

My top nut came with a roll pin from PM as well. I decided to just weld on the replacement. So far so good!


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## coolidge (May 15, 2015)

You could use some grade 8 jam nuts which are a lot thinner or order up some threaded rod and make your own drawbar slightly longer.


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## Bray D (May 15, 2015)

I don't think that would solve the issue. Regardless of the drawbar length, something needs to react off of the top of the spindle. There will always be something against the top - either a nut or a longer spacer that you would make. Apparently the very top of the spindle passes into the female splines approx. 1" at max travel, so the drawbar nuts/spacer absolutely need to be a smaller diameter than the minor of the male spindle spline.

I went ahead and massaged the flange on the nut and OD on my spacer the other night to bring them down in size. Everything works great again!


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## coolidge (May 15, 2015)

Bingo.


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## GarageWrench (May 24, 2015)

Rex Walters said:


> I've got a Grizzly G0762, not a PM, but I'm totally stealing your idea for a bushing to keep the drawbar concentric. Thanks for the tip to keep the bushing OD smaller than the inner races of the splines.
> 
> FWIW, unlike the PM, the top nut on the grizzly drawbar just had a roll pin to keep it from turning (not welded or part of the drawbar). That roll pin sheared off within about a half day of use (its possible I like drawing collets tighter than they need to be). I bored the hole a little larger and replaced the roll pin with a small hardened dowel pin and it's worked fine since.



Rex, on yer G0762 there is no motor for the head up n down, has that been an issue or an inconvenience?

Buck


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## Bray D (May 24, 2015)

I can't speak for Rex, but having a lift motor on the head is a blessing. I move my head frequently and I could see the temptation to take shortcuts (longer quill extension rather than just dropping the head) if I didn't have a motor.


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## Andre (May 24, 2015)

Just a thought, a lot of quill movement should be avoided when setting up parts if possible. Using a large endmill with the quill down can cause chatter, or if counterboring near a thin wall....break through the wall. Been there, done that, got the T-shirt! 

Plan out your steps before you start. 

On knee mills you can avoid that by using the knee, just remember to not touch the knee lock, as that will move the table. Don't forget to remove backlash, if the knee lock is tight.


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## Bray D (May 26, 2015)

Indeed. The quill extension is kept as short as possible during milling operations.


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## GarageWrench (May 26, 2015)

Bray D said:


> Indeed. The quill extension is kept as short as possible during milling operations.



Just wondering, on a mill like a Grizzly G0730, how much movement of the knee is there in say one revolution of the knee hand wheel? Also can you feed a piece into the cutter with the knee, just like using a quill?


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## wrmiller (May 26, 2015)

On my friend's BP clone (the one in my avatar) I always used the knee for plunge/pocket cuts. More precise. I don't remember the numbers though, sorry.

But on a bench mill we have no choice but to use the quill for plunge/pocket cuts. Fortunately for me I very seldom need to do them and when I do they are pretty shallow.


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## tmarks11 (May 27, 2015)

GarageWrench said:


> Just wondering, on a mill like a Grizzly G0730, how much movement of the knee is there in say one revolution of the knee hand wheel? Also can you feed a piece into the cutter with the knee, just like using a quill?


You use the knee for precise movements of the cutter against the workpiece, with the quill fully raised and locked. Like Bill said, this gives you very precise control of how deep you plunge the end mill, etc. 

You generally don't use the quill except for drilling and boring.

Most bridgeport mills have 0.100" movement of the knee per revolution of the hand wheel. I think the G0730 is actually 0.125" per revolution.


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## Rex Walters (Jun 10, 2015)

GarageWrench said:


> Rex, on yer G0762 there is no motor for the head up n down, has that been an issue or an inconvenience?
> 
> Buck



Sorry, I've been traveling and just noticed the question. The manual crank for the head on the G0762 is definitely an inconvenience (I use other words in the shop ;-). Especially since unlike a full sized mill, the crank is on the left of the column in the rear, not in front on the knee, and you've got to lean over your bench to get at it. I've got an old motor I may repurpose someday as an automatic cranker.

On a bridgeport or full size mill, I agree with Tim that you would usually only use the quill for drilling/boring. On a bench top mill, though, there is no dial on the Z axis *except *on the quill, so you're forced to use the quill while milling (unless you have a DRO in Z). Basically, when milling I try to minimize the quill extension: crank the head down until the cutter is almost touching, then use the dial on the quill to touch off (or touch a feeler gauge/cigarette paper), then zero the dial on the quill and keep extending the quill until you're at depth. For anything but very light cuts I have to use the quill lock to ensure the depth doesn't creep up.

Overall, I'm quite happy with the mill, but in addition to the manual crank in the back, other annoyances include: 

max spindle speed of about 2500 RPM, 
no spindle lock (need two wrenches to tighten the drawbar), 
"inconvenient" to tram in the nod axis (shims), 
the levers on the gib locks are too long and interfere with way travel in both X and Y (had to grind them shorter), 
the gib locking knobs are made of some soft pot metal (I've already stripped the one to lock the Y axis), 
and the zero locking knob on the Y axis interferes with way travel (I just removed it since I use a DRO).
surprisingly few good places to mount holders for lighting


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## GarageWrench (Jun 10, 2015)

Rex Walters said:


> Sorry, I've been traveling and just noticed the question. The manual crank for the head on the G0762 is definitely an inconvenience (I use other words in the shop ;-). Especially since unlike a full sized mill, the crank is on the left of the column in the rear, not in front on the knee, and you've got to lean over your bench to get at it. I've got an old motor I may repurpose someday as an automatic cranker.
> 
> On a bridgeport or full size mill, I agree with Tim that you would usually only use the quill for drilling/boring. On a bench top mill, though, there is no dial on the Z axis *except *on the quill, so you're forced to use the quill while milling (unless you have a DRO in Z). Basically, when milling I try to minimize the quill extension: crank the head down until the cutter is almost touching, then use the dial on the quill to touch off (or touch a feeler gauge/cigarette paper), then zero the dial on the quill and keep extending the quill until you're at depth. For anything but very light cuts I have to use the quill lock to ensure the depth doesn't creep up.
> 
> ...



Thanks Rex, great info indeed. I was wondering how much movement in the head up/down do you get with one revolution of the crank?

On your G0762 with a max of  2500RPM, it looks like that machine has one of the highest rated speeds of any machine its its category, being a square column mill.

Im taking a road trip to Grizzly in a couple weeks to look at the selection of mills, hope it s solves my issue of trying to decide witch mill to order. 

Thanks for your time sir, please keep posting and add some pic's!

Buck


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## Rex Walters (Jun 11, 2015)

I'll measure the travel tomorrow and create a new thread in a more appropriate forum (with pictures). Without a dial on the crank, I've never used the crank for anything more precise than about +/- 0.500".

If I measure the travel, I'll pretty much be obligated to jury rig a dial of some sort.... ;-)
-- 
Rex


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## Rex Walters (Jun 11, 2015)

To answer the question, it appears to move 3mm (0.118") per revolution of the crank. So much for an easy job of making an inch dial...

I've stopped hijacking this thread. Any further comments/questions regarding my G0762 should go to my thread on the Grizzly forum.
-- 
Rex


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## Bray D (Jun 12, 2015)

No worries on the thread jack. I said everything I wanted to say in my original post, haha. This thread is simply for awareness - if it happens to get peppered with some other useful information then that's all the better!


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