# Question On G0704 Dro Install.



## Transformer (Mar 28, 2015)

I have my glass scales in hand and I am looking at the best location to install the scales.  For the X axis I can put the scales at the front or the rear of the table.  If I put them at the rear the gib screws will be covered by the read head, and if I put them at the front I may not be able to use the lever handled screws that lock the table in place.  I have seen one P-M installation on this site, on a machine I am told is very similar, where they were installed at the back, and one Youtube video on a machine identical to mine where they were installed at the front.  Neither installation gave details on why they choose one location over the other.  I do not have enough machining experience to have a preference.   Which location would you choose and why?

Dennis


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## brav65 (Mar 28, 2015)

I believe you looked at my post regarding the install on the PM-25MV. I chose the back of the table because I was still able to access the gib adjustment screws and that left free access the x axis table locks and no interference with the Y axis handle. 

There are also pictures of the G0759 which is the 704 with factory installed DRO. The scale is installed on the back of the table as well. 

Send me a PM if you have any questions.


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## wnec65 (Mar 29, 2015)

I have a G0704 and originally installed the  X scale on the front of the table but when I upgraded to Grizzly's powerfeed I moved it to the back of the table to make room for the micro switch assy. that mounts on the front of the table.  It shortens the Y travel a bit but haven't found that to be a problem.


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## Transformer (Mar 29, 2015)

Went to recheck that my read head would indeed cover the gib adjustment screws and discovered that what I thought were the gib adjustment screws actually were the screws that held the half nut in place for the y axis lead screw.  What a rookie!  So mounting the scale at the rear should not be a problem.

Brooks: moving on to the Y axis it appears that your P-M machine has a vertical surface that you were able to mount your Y axis scale to, is that correct?  My machine has the base sloped at about 60 degrees.

I have seen magnetic scales mounted on the sloped base of a machine like mine but the glass scales I have are much larger top to bottom, and more sensitive to chips.  To mount the scales vertically will mean they will have to stand off quite a ways from the sloped base, which would mean a long bent arm to go over the scale and down to the moving read head.  Right now I am thinking of machining a long wedge to go on the sloped base which would give a vertical surface to mount the scale to.  Since the wedge would be mounted to the cast base I assume shimming would be necessary.  Or perhaps there is a better or easier way.

Dennis


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## brav65 (Mar 29, 2015)

Hi Denis,

The G0704/G0759 does have a sloped base.  The 759 uses standoffs to mount the scale to the base.  There is in fact a long bracket needed to mount the read head to the base of the table.  I fabricated mine and bolted/screwed the whole assembly together.    The Y axis is definitely the hardest one to figure out, but take a look at the pictures of my install.


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## RJSakowski (Mar 29, 2015)

I had done a Grizzly DRO Install on a Grizzly G0755 mill/drill  at work in 2011.   I believe that I still have SolidWorks models & drawings.  The x axis scale was mounted in front of the table.  Standoffs were used to support a piece of O1 flat stock to permit the continued use of the the power feed.  I didn't mount behind because I did not want to give up any travel.  The y axis scale was mounted on the left side on an aluminum plate that was relieved for clearance for the lead screw.  The z axis scale was mounted to the left of the depth indicator on the head.  Travel was not compromised on any axis.


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## wrmiller (Mar 30, 2015)

You can't see the detail of how I made the 'overarm' to get to the read head, but you can see that I just used some standoffs from the flat part of the base to get me far enough out to mount the backing plate for the scales. Just one way to do it.


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## Transformer (Mar 30, 2015)

Ah ha.  Thanks guys, looks like standoffs are the way to go, much easier than my wedge idea.  Dennis


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## wrmiller (Mar 30, 2015)

The backing plates that came with the DroPros kit has two allen screws at each end. You may or may not be able to see it in the pic, but I used the combination of longer screws in the top and the lower set screws to get the backing plate vertical within a couple thou from front to back.


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## Transformer (Apr 1, 2015)

wrmiller19: Did you have trouble clearing the bolts that bolt the machine down?


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## brav65 (Apr 2, 2015)

Transformer said:


> wrmiller19: Did you have trouble clearing the bolts that bolt the machine down?



I had a clearance issue on my front left bolt, but switched from a cap head to a hex head and the problem was solved.


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## wrmiller (Apr 2, 2015)

Used hex head bolts. Cap screws sat too high.


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## RJSakowski (Apr 2, 2015)

Transformer said:


> Went to recheck that my read head would indeed cover the gib adjustment screws and discovered that what I thought were the gib adjustment screws actually were the screws that held the half nut in place for the y axis lead screw.  What a rookie!  So mounting the scale at the rear should not be a problem.
> 
> Brooks: moving on to the Y axis it appears that your P-M machine has a vertical surface that you were able to mount your Y axis scale to, is that correct?  My machine has the base sloped at about 60 degrees.
> 
> ...


I have do two DRO installs with glass scales.  One was an old mill/drill and the other was a Grizzly G0755mill/drill.  I mounted the Y scale to a 3/4" thick bar attached to the saddle under the table.  I had to provide clearance for the X axis lead screw bearing housing but otherwise not a problem.   The counterbored holes mount to tapped holes in the saddle.  Additional threaded holes were used in the bar for mounting a scale cover.  If needed, an access hole for the gib adjustment can be added.

The pickup is mounted underneath to the base so there is no "long bent arm".  To account for the casting draft on the bases, I used wedges.  On the first install, the wedge was a separate piece.  On the second, it was integral with the pickup mount.   To deal with any surface irregularities, you can  use epoxy with the wedge to make a stable vertical mounting surface for the scale pickup.  I used that technique when mounting an optical homing sensor on my Tomach.   The following pictures are models from the G0755 install.


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## MAlcocer (Apr 5, 2015)

For the X axis you should be able to mount it to the front and have enough clearance with the y axis handle. To solve the table lock bolt issue I got longer m6x1.0x50mm cup point set screws http://www.mcmaster.com/#catalog/121/3038/=wmfubi. 

I had issues with the stock lock out handles getting bent if I was not paying attention to their position while moving the table. Now I use an allen wrench to tighten my lockouts when needed. 

To mount the y axis I made L shaped brackets that attached to the front and rear of the base. For the head I made a .700" spacer that fits right into the notch of the saddle and then used a piece of 1/4" plate to go down to the head (effectively between the head and the base vs outside of the scale like most installs). I have solid works drawings for most of the brackets and can attach some pictures in a couple days (currently stuck at work).


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## CPCaballero (Aug 16, 2016)

hi wrmiller

I see you have mounted your mill on a wheeled tool cabinet.  I'm considering doing the same.  How does that work for you?  How do you stabilize it? Do you lock the wheels?  How do you level the mill?  Is that a metal plate between the base of the machine and the wood top of the tool cabinet?

Thanks


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## Contract_Pilot (Aug 17, 2016)

I did a DRO Install on my G0704 

Photo's Here! 
http://www.stevenrhine.com/?p=603


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## smokey357 (Oct 26, 2016)

Contract_Pilot said:


> I did a DRO Install on my G0704
> 
> Photo's Here!



Hi Contract_Pilot.

What did you do about the way cover for the Y axis with the X axis in the back?

Thanks


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