# PM 932M collet help ***Updated***



## Railin93 (Nov 23, 2017)

Got my 932m up onto the stand finally and went to town cleaning it...while doing so i figured i would try to clean a few collets and check the drawbar fit...well i cant seem to get any of the precision collets i bought to slide up into place...the cheap shell endmill jolder and the other cheapo adapter that the mill came with fit no problem...all parts bought thru PM so they should fit, right?...how do i fix the issue?


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## navav2002 (Nov 23, 2017)

There is a pin that you may need to back out a little bit...I did not have that issue but have seen others who have...Remove the spindle end cap and you should see the set screw/pin that will need to be adjusted...

See Page 3 of this manual:
http://www.precisionmatthews.com/wp-content/uploads/2017/01/PM-932M-Manual-2017-v11.pdf

Congrats on your new machine!!


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## Railin93 (Nov 23, 2017)

I see the pin...how do i get the ring off the bottom of the shaft to adjust it?


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## Railin93 (Nov 23, 2017)

Sweet...thank you...ive got the written manual and it sucks (politely of course)...


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## Railin93 (Nov 23, 2017)

Ok soooo...i managed to get the ring off, set screw out but now i see no way to get to the head of the pin to turn it to back it out....am i missing something here???...did not realize this machine was going to be this big a pain in the ass...so far nothing has gone smoothly with it...


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## Railin93 (Nov 23, 2017)

I got it...had to use an eyeglass screwdriver...thanks Navav2002


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## LEM (Nov 23, 2017)

lower the quill.  lock in the lower position.  Back out the set screw just enough to fit the collet.  Probably won't take much.


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## navav2002 (Nov 24, 2017)

So how do you like it?? We need pictures!!


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## RJSakowski (Nov 24, 2017)

A problem with R8 collets is there is no standard as the collet and socket are proprietary to Bridgeport.  As a result it is often hit or miss regarding collet compatibility.
At work, we had purchased a  Grizzly G0755 which also uses a set screw for the pin.  Eveything was fine for the first few months and then it became more and more difficult to insert collets.   The problem was there was no way of fixing the set screw position in place and it slowly workjed its way into the socket.
I removed the OEM set screw and machined a dog point on a socket head cap screw.   I verified the point would fit all the collets and end mill holders we had and the length of the screw was adjusted so when the point was properly positioned, the screw was tightened securely.  As I recall, the final adjustment was done using shim washers.


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## Railin93 (Nov 24, 2017)

Its a work in progress right now...ive had it about three months but 13hr shifts 6 days a week kinda kills time to get it set up...but i love it so far even though its fought me tooth and nail every step of the way...


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## Profkanz (Nov 24, 2017)

RJSakowski said:


> A problem with R8 collets is there is no standard as the collet and socket are proprietary to Bridgeport.  As a result it is often hit or miss regarding collet compatibility.
> At work, we had purchased a  Grizzly G0755 which also uses a set screw for the pin.  Eveything was fine for the first few months and then it became more and more difficult to insert collets.   The problem was there was no way of fixing the set screw position in place and it slowly workjed its way into the socket.
> I removed the OEM set screw and machined a dog point on a socket head cap screw.   I verified the point would fit all the collets and end mill holders we had and the length of the screw was adjusted so when the point was properly positioned, the screw was tightened securely.  As I recall, the final adjustment was done using shim washers.


Bridgeport had a double screw setup. The key was a short dog point set screw which was locked at the correct depth with a shorter though hole set screw. The short locking screw can be made by cutting off the hex socket of a regular set screw. This setup allowed adjusting the dog point screw by a hex key going through the locking screw into the dog point screw. Locking the screws together in place was a tricky operation to say the least. Most shops left the screws out after fiddling with them too often. Since the R8 taper is a self locking taper, the key did not really function as a drive key but more as a collet lock for installing and removing them. At one point there was a three lobe key wrench available that was used by inserting it into the 3 slots in the collet for tightening and removing.


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## benmychree (Nov 24, 2017)

I had an Italian vertical mill, an Induma, 1 -S that used the same dog point screw, when I got it, the screw was sheared off and also the rack gear teeth had been stripped by using it as a arbor press to broach a keyway, so I was able to buy it quite cheaply; a customer who was going to Italy on a equipment buying trip to the same city as the mills were made ordered a new quill and the screw for me and imported it.  I installed the new quill and the screw, which had to be installed in the spindle while it was removed from the quill; very shortly after I got it back to running, the key got sheared off again; that was probably 30 years (or more ago), and the screw is still sheared.  We mostly used set screw type holders, not collets and really never missed the screw at all.


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## RJSakowski (Nov 24, 2017)

Profkanz said:


> ....Since the R8 taper is a self locking taper, ......


The R8 taper is not self locking.  A drawbar is required to provide enough force to prevent R8 tooling from spinning.


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## Railin93 (Nov 24, 2017)

Finally got the beast up to a point i feel like ive accomplished some sort of feat...may not be much to most but this has been a dream of mine for YEARS...and finally (i say this very conservatively) things are coming together...and i do appreciate all of the help and advice ive gotten so far...trying to get a small personal business up and running  ut i wanted decent-good machines and tools before i jumped into the fires...


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## LarsP (Nov 24, 2017)

FYI  If you Google 'R-8 specification' a drawing does come up showing the important dimensions for a R-8 collet.

I too ordered some collets.  When I tried them some fit and some didn't.  I measured the width and depth and the keyway.  The depth was consistent across all of them.  The width of the keyway varied from .156 (the minimum) to .170.  The collets with the wider slots fit and the ones with the narrow slots didn't.

Since the tolerances for width and depth aren't terribly critical I decided that, since in I had the tools and equipment to fix the collets, that would be easier than shipping them back to the dealer and waiting for replacements.  Running an 1/8' endmill down one side to make it .010 wider  +/-cured the problem.

Ergo, the moral of the story is check to width too.

L


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## Railin93 (Nov 26, 2017)

So... got the collet issue worked out

I got the DRO back on and i think i may have damaged the Y axis scale so ill have to power it up to check it...pray i didnt but ill eat it if i did due to lack of paging attention when i ran the table back too far and the bracket caught the edge of the reader mount and shoved it backwards and twisted the reader pretty good...and lemme tell ya, i dont envy they guys that install these on a regular basis...the bolt holes for half the brackets are drilled uneven, half crooked, barely usable...the X axis scale can barely be trammed because of the way they mounted it...the way cover actually mounts over the reader head and sandwiches it on the back of the table and the cover wont fully seat because of the bolts on the cover...i expect some corner cutting but man, some of the things ive seen are really half-assed...10mins would have made the whole mounting of the scales 100x better...and more professional


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## Railin93 (Nov 26, 2017)

Well not gonna let one mishap slow me down or deter me from finishing this beast and seeing her come to life...go the head trammed and man what a bear...the three bolts act nothing alike in reference to each other...rhyme or reason to their seq or tightening pattern...BUT i did manage to get it within .002 over a 14" span so im pretty stoked about that...


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## Railin93 (Nov 28, 2017)

Gonna aim this question at Matt and hope he sees this...how much is a new Y axis scale if i did break this one?...still have to get a plug for the mill before i can power it up but how would i know if it is damaged or broken?...


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## T Bredehoft (Nov 28, 2017)

Re: Tramming the head. I have your machine's little brother, the PM25. I made two blocks that screwed to the head and had screws that pushed on the column mount. They would lock the head in position, and allow tweaking the tramming. I checked it the other day when I had the vice off, it was out .003 in 18 inches. tweaking with the screws got it down to less that the width of the needle on 0 both ends.

Granted, if I were to want to tip the head I'd have to remove one of these, but I don't plan to do that. I have a sine plate for tipped work.


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## wrmiller (Nov 28, 2017)

Did the tramming mod to my PM25 shortly after getting it. Worked really well.


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## qualitymachinetools (Nov 30, 2017)

Just answered your message, if it works, you should be fine. They are pretty durable. Not 100%, but they arent as fragile as one might think.


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## Railin93 (Dec 2, 2017)

T Bredehoft said:


> Re: Tramming the head. I have your machine's little brother, the PM25. I made two blocks that screwed to the head and had screws that pushed on the column mount. They would lock the head in position, and allow tweaking the tramming. I checked it the other day when I had the vice off, it was out .003 in 18 inches. tweaking with the screws got it down to less that the width of the needle on 0 both ends.
> 
> Granted, if I were to want to tip the head I'd have to remove one of these, but I don't plan to do that. I have a sine plate for tipped work.


By chance you got any pics of said device?


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## T Bredehoft (Dec 2, 2017)

I took a picture of one of them a couple of  years ago, you couldn't see anything. I made two blocks, 1/2 wide, 3/8 thick and an inch long from half hard 4140. I cut a flat about .090 deep on one end (undercut), drilled a quarter inch hole through the other end. tapped a 1/4 20 hole in the thin end for set screws, and tapped holes in the dovetail side of the head near the top. with the set screws just flush with the bottom surface I screwed the blocks to the dovetail side with 1/4 20 socket head cap screws. Tight. I then ran the set screws up against the surface of the head. When I tram the head I place a test indicator on a .100 jo block as far from the quill as I can, with another .100 Jo block on the  other end of the bed. I swing the TI back and forth, just touching the Jo blocks, set zero on one and compare the other one. By tweaking the set screws I can correct the head to a true zero.  Here's a crude sketch.


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## Railin93 (Dec 3, 2017)

Hmmmm...i like the idea...

So i got the mill powered up and checked all misc functions and such before doing the initial startup...low 1 was going good for about 2min when it started screaching and squealing...at first it was intermittent but then it got more and more frequent...checked what i knew and all seems good...sight bubble shows me 1/3 way full of oil in the gearbox which is a bit low, i know...could this be the reason for the squeal??...sounds like its coming for the spindle shaft or the quill itself...dont wanna run it anymore just in case it might become a huge issue without some hints or possibilities as to what might be causing it.....


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## umahunter (Dec 5, 2017)

Well I got my mill today  and I have the same problem I can't even get a collet in there


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## Railin93 (Dec 5, 2017)

The manual is an invaluable download...the printed manual sucks...you can use a decent punch to drift the ring off around the quill and then use a very small flathead screwdriver to back the set screw out and remove or adjust the pin...some remove, i just brought mine out so the collets would go in...i am having an issue with the drill chuck adapter...it is much longer than the rest of the R8 stuff i have and the drawbar bottoms out before it even gets close to pulling it all the way up...and i was really hoping to use that a good bit too...may have to see about locating a nicer one that might be more "in-spec" than the chinese one it came with...jus sayin


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## fradish (Dec 6, 2017)

http://www.hobby-machinist.com/threads/pm-727m-new-mill-has-arrived.57473/post-488308

Here is a post about the sort of trimming aids I think you're interested in.


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