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Quill DRO for a PM935?

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Alan H

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#1
Tired of not having a DRO on the quill of my PM935TV. I am sure that others have solved this problem.

Can you share what you did and any insights please?
 

bfd

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#2
you can find a separate dro for the quill its like a digital caliper turned sideways. mitutoyo has one but its costly I got mine for about 40 bucks made a quick mount and I just need to remember to turn it off or barrery replacement time they come in 5" and 6" lengths . they are cuttable with no damage. just make sure the cut is in the mount not used. I got mine at a local tool store. this store sold machinist tools. If I knew how to post pictures I would bill
 

Alan H

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#3
Photos of an install would be appreciated.

Anyone pony up for a Mitutoyo and install it on a PM935?
 

Rich V

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#4
ABOM79 did a youtube vid on installing the Mitutoya quill kit. Same basics for doing it on the PM935
 

Alan H

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#5
Thanks Rich, had all I needed to see.

Has anyone put one of these kits on a PM935? I am assuming it would fit but would like confirmation.
 

Alan H

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#6
After studying the options, I installed a Mitutoyo Quill DRO kit on my PM935 mill. I acquired it on sale at Zoro for a decent price. The kit is for a Bridgeport or clone.

The install went reasonably well but did require a few tweaks to get it “right and tight”. I am sharing some of the details with some photos in case it may help someone who decides to go this route.

While the kit comes with instructions and a very good parts list, Adam’s (ABOM79) YouTube on mounting a kit on a Bridgeport was very helpful to familiarize one with the kit and how it mounts.

The kit came with all the hardware needed with the exception of two mounting screws needed for my PM935 install.

Here is a list of the things I did to make it fit and make the install better for my particular mill. This list is not intended to be all inclusive and one should confirm that the dimensions of your mill would require everything I did or perhaps something different.

Tweaks and insights:

I had to chase the small M3 threads in the mounting frame – the powder coat had choked the threads.

I had to countersink the holes on the back of sending unit mounting plate to accommodate the included #5 gun screws. Screws were too short as supplied to get proper thread engagement. I could have ordered proper length screws from McMaster but decided to simply use what I had and milled a step for them to sit in.

countersunk.jpg

I milled off .060”of mounting bar to move the assembly closer to mill and to maximize the insertion of the mounting tube into the stop ring on the mill.

60 thous skinned off.jpg

I bought two new mounting screws to attach the mounting bar (M4 x 12), one had to be ground slightly shorter to not interfere with the power feed mechanism. I did not leave the depth scale on the machine as called for in the instructions. I found this to not be needed for spacing nor add any functionality since the scale was covered if left in place.

skinned bar in place.jpg

I shimmed the mounting tube to the mill’s stop ring joint to take up .010” of slack in the fit. This allowed the set screw to expand the mounting tube to a good firm fit and eliminate any wiggle in the joint. You can see the copper shim wrapped on the split tube in this photo. This shimming avoids the wiggle that ABOM79’s video shows. Thanks to Adam for making the YouTube since it catalyzed me shimming the tube/stop joint in the initial install and making it rock solid.

counter sunk and shimmed.jpg

mounted with shimmed plug in place.jpg

All in all a very good fit and function with just a little adapting and tuning. There's still plenty of room behind the Mitutoyo for the original depth stop function to be adjusted and work well. I can still put my depth stop clamp on the rod as well. Although many folks keep them removed anyway, the front fine feed crank/wheel also still fits without interference.

Hope this may help others if you decide to go this route. Here is the unit installed on my PM935TV.

IMG_20170704_103445.jpg

pretty nice little DRO that dont wiggle.jpg
 
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MonkMan

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#9
Thanks, this just made it to the top of my (very long) list!
 

Alan H

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#10
Looks great Alan!
Rich, thanks for posting Adam's YouTube. I had missed that one somehow. It was helpful and pushed me forward in buying the Mitutoyo kit. As I pointed out above, it also clued me in on the wiggle issue and to be prepared to address it.
 

Alan H

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#11
"WARNING"
Follow-up on the installation I did -

I did not get the mounting screws for the Mitutoyo mounting bar short enough. The mounting bar uses the same holes as the factory depth scale for installation. The factory scale is mounted over the Auto Feed mechanism (see pg 14 of the PM manual). While I did not believe the bottom screw was interfering with the trip push rod that locks the "Quill Auto Feed Lever", turned out that it actually was interfering just enough to cause a problem.

While everything appeared to be fine, the screw was just long enough to bind the "Trip Push Rod" itself and the "Quill Auto Feed Lever" would not lock and hold position. Lesson learned - Make sure that screw is short enough that it will not infringe onto the trip push rod.

As always, Matt at QMT was ready and willing to help but it turns out that I had laid a trap for the both of us and I wasted Matt's time. Sorry Matt!

Trip Push Rod schematic:

plunger.JPG
Here's a photo of the mounting bar in place with the two screws in the original attachment points for the factory depth scale. Size the length of this screw to not interfere with the function of the Trip Push Rod (#5 in schematic above):

screw.jpg
 

[X]Outlaw

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#12
Thanks for posting this! I'm picking up my DRO kit tomorrow and hoping to install it over the weekend. Between Abom79 video and this thread I think all the "gotchas" are well covered.
 
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