My Precision Mathews PM935TV Arrival/Setup

[GA Gyro]

Keep in mind a 2/3 or 3/4 size BP will be a clone as I believe the smallest vertical mill that Bridgeport made was a 9x42, I think I heard of a 9x36 but cannot confirm.

When you get into the 2/3 or 3/4 size BP clones most will not have nod, only tilt and their y-axis travel with be in the 8.75"-9" range. Jet JVM-830 and JVM-836 seem to be the most popular in that 2/3 or 3/4 size criteria. I believe Enco had a Taiwanese model a few years ago, model 100-1525 that I hear was a nice machine but again, did not have the nod feature and was only available in step pulley design. Nothing wrong with step pulley design but that particular model was limited on low and high RPM compared to the full-size mills.

I was actually looking for one for nearly a year before purchasing the PM-935TV but living in a machinery desert doesn't offer much. Good luck in your search, I know those smaller vertical mills are out there as I know a few people who have them, but then again when I tried buying them they wouldn't part with them. I guess that means they are happy with them at least.

THX Mike.

Having a mill, even if it is 'just' an RF45 clone... gives me the time to shop for a Bridgie. If a plan I am working on turns out... a warehouse arrangement... then the space issue is resolved... and a full sized Bridgeport would be really cool.

That is down the road though...

BTW: Matt has a VS version of the 932PDF... one of them has my name on it already.
It is the head from the PM45CNC... on the 932 body. Same VS range... the rest is a 932.

I think I found a SWEET deal today... looking through a bunch of stuff at a warehouse, lots of odd stuff. There was a table with about 5 SQ/FT of small boxes... ranging from 4x4" to 6x6".. each had some tools in it: end mills, drills with MT taper shanks, chuck on a taper shank, center drills, tool blanks, carbide inserts, just all kinds of stuff. There was not time to really get into it... however I asked if I could come back and pick through it and work out a price... was told yes. Now here is the good part... A lot of the mills and drills, still have the shipping coatings on them...
Guy said he had another bunch of boxes of 'that stuff' (sounds like he may not know much about it), if I wanted to look at it... well YE-AH...

 

[szenieh]

My PM935TV knee mill finally arrived last Tuesday and I have spent a few days last week getting it set up and personalized a bit.

First off, I must say that now after having it for nearly a week it is everything I had hoped for. The quality is extremely high end and compliments my PM1340GT very nicely.

I will admit that when the driver backed up to my shop and opened the door, my stomach jumped into my throat and I wanted to strangle the driver. The mill had tipped over onto its' side, broken through the pallet and was leaning against the inside of the truck box. It didn't go all the way over onto its' side but more horizontal than vertical. Evidently the driver was a bit aggressive at driving and the mill had pulled the four large lag bolts right up and out of the pallet it was sitting on. I jumped all over the driver and asked if he didn't see the large "TOP HEAVY" lettering on each of the four sides of the crate. Needless to say I did NOT tip the driver on this delivery.

He wanted to close up the truck and bring it back to their dock and get it stood upright with a forklift. Although a forklift would have been the best alternative, I didn't think it would make it another 30 miles back to Salt Lake City without going the rest of the way over and for sure creating more damage. I also didn't want to wait another 5-months to get another one. I wanted to get it upright and inspect prior to making any definitive decision.

Here is how it showed up at my home/shop.
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After removing three sides of the pallet/crate to get a better look.
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Luckily my son had just gotten home and was able to help me because the driver was absolutely worthless as far as helping. All he wanted to do was bring it back to their Salt Lake City transportation hub and really didn't want me messing with it. My son and I got the engine hoist up into the back of the truck and strapped the top of the column. We raised it about as far as we could with the hoist and got the weight up off of the head and away from the side of the truck so I could get a better visual of it. All I could see at this point was the small handle for the RPM that was broken. I was able to push it the last few degrees to get it vertical and standing back on the pallet flat on its' base. We shifted/jockied it around so I could drive the lag bolts back into the pallet and then we used a 10k pound ratchet strap to secure it to the pallet.

Once we got it out of the truck, on the ground and somewhat in place in my shop we removed the remainder of the plastic wrapping and did a thorough inspection. Unbelievably there was NO damage with the exception of the small handle for the dial. I called QMT and Matt was busy but I informed Nicole about what had transpired and she was awesome. After speaking with Matt she called back to ask a few more questions and I forwarded the pictures that I had taken to Matt.

Here it is close to its' new home in my shop.
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This was the only damage. No big deal and Matt was great to get a new one in the mail immediately.
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I got the pallet cut down so I could lift the mill off of the pallet and get it sitting on the floor. I then commenced on taking measurements for a base. I needed to get the mill a few inches up to make it more comfortable. After exchanging information with a few members of the forum who already own this machine I had originally decided I was going to build a base that was 4" in height combined with leveling feet which were 2" for a total of 6" overall height gain. I really liked the height in which it was sitting on the pallet which was closer to 8" overall height. That did it for me, so I embarked on fabricating a base that would raise the milling machine a total of 8". The base would bolt directly to the bottom of the mill yet be slightly wider at the footprint and employ leveling feet.

I started with some 2"x4"x.125" rectangular tubing and some 2"square tube x .125" wall.
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I machined some threaded bungs and welded them to the rectangular tubing to anchor the mill to the base.
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I then welded the 2" square tubing to the 2"x4" rectangular tubing as well as gusseted it for strength.
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Base completed, painted and sitting in front of the milling machine ready for installation.
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And there she is, sitting on her new base in her new home.
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So far this all took place on Tuesday. The truck backed up to my shop door just before 2:00PM and by 7:30PM it was sitting in its' final resting spot.

Now on to Wednesday morning. I took a couple of days off work to get it all set up and put my shop back together so I wanted to get right after it. I installed my 220VAC/30amp plug and she purred like a kitten. So nice and smooth running. I noticed immediately that none of the collets fit in the spindle and I kind of was expecting that due to other threads that I have read.

Here is how to remedy that. There is a small set screw on the back side of the quill that must be loosened to remove the collar.
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Next use a spanner wrench to remove the collar.
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Once the collar is broken loose it should spin out freely by hand.
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Collar removed.
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Once the collar is removed there is a set screw with another one under it. The top one is a locking set screw, remove it. Then back the inner one out just enough so that the collets, drill chucks and other tooling will fit into the spindle/quill freely. Once you are happy with the fit, install the outer set screw and tighten. Then reassemble everything in reverse order.

Now on to tramming the head. Got her dead on in both axis.
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I also installed the Eason ES-8A onto the machine and got it all hooked up and operational.

More to follow.

Mike.

Hello Mike,
The pin sizes for that collar seems 3/16". The only pin spanner wrench on McMaster Carr with that pin size has 2" maximum range. The holes seem more than 2" apart. Can you confirm that? McMaster also has a 4.8mm pin size that opens up to 100 mm which should work but pin might be hard to get into that hole. It is also twice as expensive. Any help would be appreciated.

Salah

 

[petertha]

I removed mine with a dedicated homebrew wrench contraption that you will laugh at but it worked. I will post pictures tonight. I used 3/16" dia drill rod pins & can upload PDF. I heard that some of the commercial pin wrenches which satisfy the span criteria still may need to be modified with respect to the hubs ground or pins remachined/extended in order to function properly. I've also heard of people putting in a brass pin & doing the hammer tap-tap in a radial fashion, but mine refused.

A proper dedicated wrench would be a useful & relatively inexpensive tool to be included in the toolbox IMO. I'll donate my CAD diagram if someone wants to do the laser/water cutting from 1/8" plate. I also have a feeling it will be a similar lack of tool episode to re-clock the spring tension on the quill, but haven't gotten that far yet.

Also before I forget, realize that there is a set screw which acts against the threads. I suppose its intent is to prevent rotation but its a bit of fromage engineering IMO. Its very important that this is first loosened before unscrewing the nose, otherwise strong probability of buggering up the threads &requiring excessive torque. So glad PM shows some pics of this in their spruced up user document.
https://www.hobby-machinist.com/threads/935-spindle-nose-piece-removal.74301/#post-623063

 

[szenieh]

I removed mine with a dedicated homebrew wrench contraption that you will laugh at but it worked. I will post pictures tonight. I used 3/16" dia drill rod pins & can upload PDF. I heard that some of the commercial pin wrenches which satisfy the span criteria still may need to be modified with respect to the hubs ground or pins remachined/extended in order to function properly. I've also heard of people putting in a brass pin & doing the hammer tap-tap in a radial fashion, but mine refused.

A proper dedicated wrench would be a useful & relatively inexpensive tool to be included in the toolbox IMO. I'll donate my CAD diagram if someone wants to do the laser/water cutting from 1/8" plate. I also have a feeling it will be a similar lack of tool episode to re-clock the spring tension on the quill, but haven't gotten that far yet.

Also before I forget, realize that there is a set screw which acts against the threads. I suppose its intent is to prevent rotation but its a bit of fromage engineering IMO. Its very important that this is first loosened before unscrewing the nose, otherwise strong probability of buggering up the threads &requiring excessive torque. So glad PM shows some pics of this in their spruced up user document.
https://www.hobby-machinist.com/threads/935-spindle-nose-piece-removal.74301/#post-623063

Thanks a lot for your quick reply. I would love a pdf drawing of what you made. I did see that set screw in the back of the quill to lock the threads. I did back it out. This is a left-hand thread also, I guess.

Thanks for your help.

 

[davidpbest]

Yes, the nose piece is left-hand threads. And you will discover that it is on there quite tight.

For the life of me I do not understand why that set screw is used because it presses directly on the threads of the nose piece (bad practice) and if you tighten that set screw enough to actually do something useful (like preventing the nose piece from unscrewing), you will discover that the quill retract spring isn’t strong enough (even when tightened to the max) to fully retract the quill.

The relationship between that set screw tightness and the quill movement stickiness eludes me completely, but it’s real. I’ve fussed with that endlessly. I also put a copper ball under a shorter set screw so it doesn’t chowder up the threads on the nose piece.

 

[petertha]

As mentioned I thought it might be worth making an inexpensive pin spanner with wood scrap on hand. I figured if I lucked out it didn’t cost me anything. If it broke, well, then I knew what I was up against. It has 2 lamination's of 3/8” ply on the head. Pins are 3/16” drill rod pressed in. I left the head as a round donut for strength in case I measured wrong or if it took a few tries & ripped the pins out I could drill more holes. Turns out it fits pretty well as shown. The proper tool would be something like 1/8" steel plate.

 

[szenieh]

As mentioned I thought it might be worth making an inexpensive pin spanner with wood scrap on hand. I figured if I lucked out it didn’t cost me anything. If it broke, well, then I knew what I was up against. It has 2 lamination's of 3/8” ply on the head. Pins are 3/16” drill rod pressed in. I left the head as a round donut for strength in case I measured wrong or if it took a few tries & ripped the pins out I could drill more holes. Turns out it fits pretty well as shown. The proper tool would be something like 1/8" steel plate.

Thanks a lot for sharing. This would be a very helpful tool to have on hand.

 

[szenieh]

Yes, the nose piece is left-hand threads. And you will discover that it is on there quite tight.

For the life of me I do not understand why that set screw is used because it presses directly on the threads of the nose piece (bad practice) and if you tighten that set screw enough to actually do something useful (like preventing the nose piece from unscrewing), you will discover that the quill retract spring isn’t strong enough (even when tightened to the max) to fully retract the quill.

The relationship between that set screw tightness and the quill movement stickiness eludes me completely, but it’s real. I’ve fussed with that endlessly. I also put a copper ball under a shorter set screw so it doesn’t chowder up the threads on the nose piece.

Thanks for the information and for confirming that it is a left hand thread. That relationship between the set screw tightness and quill movement stickiness is peculiar- got me curious. I will sure look into that in my machine. But first, I have to get that nose nut released. For me, many of my R8 collets fit just fine. My 3/4" collet did not, but, all the other ones I tried do fit. Seems to be set right on the edge of the tolerance on that slot in the collet.

 

[petertha]

Yes check all your R8 tool slot fits while you are tweaking the combo set screws - the inner dog point set screw followed by outer jam nut set screw. Mine were not loose but not exactly tight either. I suspect if they aren't snugged decent, the dog point screw could just thread itself inward unhindered over time & end up rubbing the slot & prevent tool from going in all over again. I was tempted to clean them with thinner & use a dot of blue Loctite to hold position, but chickened out for now & just snugged them together.

 

[szenieh]

Yes check all your R8 tool slot fits while you are tweaking the combo set screws - the inner dog point set screw followed by outer jam nut set screw. Mine were not loose but not exactly tight either. I suspect if they aren't snugged decent, the dog point screw could just thread itself inward unhindered over time & end up rubbing the slot & prevent tool from going in all over again. I was tempted to clean them with thinner & use a dot of blue Loctite to hold position, but chickened out for now & just snugged them together.

Good point. Thanks for the heads-up. I didn't think about that.

I also have another question. The spindle spins CW on the REV setting of the switch which I find odd. Is there a fix for that?

Thank you for all your help.