# Dro On G0755 Mill



## Happycamper (Oct 28, 2015)

I'm fixin' to (Texas term for getting ready to) install a 3 axis DRO on my mill and I have a few questions directed toward anyone that has done this. Looking at the back of the table, there are gib adjustment screws, and as I recall as I write this, oil ports. How/where was the x axis scale/reader installed? And for the z axis, I want to install it on the quill. Should the scale be mounted stationary, or to the quill with the reader stationary? Pics would be appreciated. Y axis looks to be a fairly straiforward install. Did you wire it into the machine's electrical panel? Any special problems I should be aware of?

Jerry


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## Cobra (Oct 28, 2015)

Hello Happy.
I installed a two axis system from DRO Pros (magnetic scales) on my G0755 last year.
I did place the X axis scale on the back of the table.  It does not interfere with the gib adjustments and will clear the oil port but it certainly makes use of the port more of a challenge.
I now have to take the cover off the scale to get at the port.  The hardest part was having to buy a new 90 degree drill to mount the reader.  There is not enough room for even one of the small drills.
But hey, I got a new drill out of it.
The Y axis is not as space challenged but I did need to fabricate a bracket to hold the supplied bracket for the reader.
This bracket is in the way when you need to adjust the lash on the X axis feedscrew but that is not a regular event so I was not fussed with it.
I did not get the three axis set from DRO Pros because of the space in and around the quill.  I have gotten by without it for the last year but I think I will get one of the stand alone Mitutoyo quill gauges eventually.
It has not been a big deal to use the wheel dial.
If you want some photos, I can probably dig them up for you.
Jim


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## Eddyde (Oct 28, 2015)

Hell, even us "Damned Yankees" know "Fixin' to" at least those of us that attended the John Ford school of western culture 
Kidding aside, I just ordered a 3 Axis DRO for my Mill, so I'll be watching this thread closely. Curious, which DRO did you get?


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## RJSakowski (Oct 28, 2015)

I did a three axis install on the G0755 in 2011 at work.  I used the Grizzly DRO which is the same as the DRO Pros DRO.  The x axis was mounted on a bar of ground O1 which was mounted on standoffs at the front of the table. The standoffs permitted the use of the power feed limit switch. The y axis was mounted below and to the left of thwe table.  A tapered adapter plate allowed mounting the pickup head vertical..  The scale was mounted on a machined piece of 3/4 aluminum stock.  The z axis was mounted to the left of the feed indicator with the pickup mounted on a ring fastened to the bottom of the spindle quill.  I did the drawings for the parts at work and have since retired so I don't know if I still have them.  If I can rustle them up, I will post them.

Bob

Edit:  Here are some pics of the y axis pickup mount and scale that I found.  I'll look for others.


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## RJSakowski (Oct 28, 2015)

OK, I located the SolidWorks files for the G0755 DRO install.  The folder is quite large, about 17 MB.  It will need to be sorted through and cleaned up which will take some time if anyone is interested.

In the meantime, here are some pics of the three axes assemblies.

Bob


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## Happycamper (Oct 28, 2015)

Thanks guys. I ordered from the dro store in Singapore. Ordered last Thursday, shipped Friday and I got them today(Wednesday). Can't beat that. Bob, I appreciate your drawings. The z scale, the head was stationary and the scale was attached to the quill? And thanks Jim for the pics. I had been looking at the back and thinking on how to drill and tap it. Now I'll look at Bob's idea. 

Jerry


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## Happycamper (Oct 28, 2015)

Also, looking at the back of the table, there are two holes that appear to have been for table locks. They are in about the same position as the front locks and the same size. Anyone know what they are there for?


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## RJSakowski (Oct 28, 2015)

Happycamper said:


> Thanks guys. I ordered from the dro store in Singapore. Ordered last Thursday, shipped Friday and I got them today(Wednesday). Can't beat that. Bob, I appreciate your drawings. The z scale, the head was stationary and the scale was attached to the quill? And thanks Jim for the pics. I had been looking at the back and thinking on how to drill and tap it. Now I'll look at Bob's idea.
> 
> Jerry


Jerry, yes the readout is fixed on the z axis.  The G0755 presents  a problem with finding a convenient mounting for the z axis because of the boxy character of the gear drive and the control box on the left.  The mounting chosen seemed like the best solution.  Having the readout fixed also minimizes flexing of the pickup wires which should improve service life.

I would have preferred to have the scale mounted from both ends but there wasn't any practical way to do that.  That said, there wasn't any problem with flexing or erratic readings.

Bob


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## Happycamper (Oct 31, 2015)

I've been looking at the stop/depth gage. Maybe changing out the threaded rod for a solid rod mounted in bushings to keep it plumb. Then attaching the reader head to the rod with the scales fixed.


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## RJSakowski (Oct 31, 2015)

My recollection is that there was some rotational play in the spindle and that I used an additional stop to limit that rotation as it affected the alignment of the pickup to the scale.  You would have to modify the hole in the bottom of the head to control that play.  You will also have to modify the front plate on the head to accommodate a bracket for mounting the pickup.  Maybe the head casting as well.

It's been over four years and I'm a bit fuzzy on it. I can see if I can get some photos of the actual setup.

Bob


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## Happycamper (Nov 1, 2015)

Thanks Bob.

Jerry


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## Happycamper (Nov 11, 2015)

Well I finally got the x and y axis scales mounted. Bob, I looked at mounting the x scale to the front but with the stop switch for the drive, it looked like I would have had to stick it out quite a bit. So, I mounted it on the back. There was an oiler for the gibs in the middle and I made an L mount there to bring the ball oiler up to the top of the scale cover. On the Y, I followed your drawings(loosely since I was using stuff out of my scrap bin for the mounts). It came out OK and I'm happy with the results. Now to do the z. Thanks for all y'all's input.

Jerry








And here is the relocated ball oiler.


And the y:
	

		
			
		

		
	




And the end of the y:


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## RJSakowski (Nov 11, 2015)

Jerry, 
A nice neat install.  How much y axis travel did you have to give up by mounting the x axis scale on the rear of the table?

Bob


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## Happycamper (Nov 11, 2015)

Not much. The bellows over the gibs took up some anyways. Plus, one of the things about the 755 is when the table was at the back, the spindle was over/past the front edge of the table.

Jerry


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## Happycamper (Dec 6, 2015)

RJSakowski said:


> My recollection is that there was some rotational play in the spindle and that I used an additional stop to limit that rotation as it affected the alignment of the pickup to the scale.  You would have to modify the hole in the bottom of the head to control that play.  You will also have to modify the front plate on the head to accommodate a bracket for mounting the pickup.  Maybe the head casting as well.
> 
> It's been over four years and I'm a bit fuzzy on it. I can see if I can get some photos of the actual setup.
> 
> Bob



Bob, thank you for your posts and pics. They really helped. I've been traveling and haven't had time to work on my mill but I have the x and y installed and have made the brackets for the z. I am in the process of installing the z brackets and getting them parallel and plumb. The problem I'm working on is the rotational torque and overcoming that. You mention an additional stop and modifying the hole in the bottom of the head to control the play. Would you be so kind to explain that? Thanks,

Jerry


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## RJSakowski (Dec 6, 2015)

Happycamper said:


> Bob, thank you for your posts and pics. They really helped. I've been traveling and haven't had time to work on my mill but I have the x and y installed and have made the brackets for the z. I am in the process of installing the z brackets and getting them parallel and plumb. The problem I'm working on is the rotational torque and overcoming that. You mention an additional stop and modifying the hole in the bottom of the head to control the play. Would you be so kind to explain that? Thanks,
> 
> Jerry


Rotational movement to the  left is limited by the mounting bracket for the DRO.  As I recall, I added a second piece to the right which limited the rotational movement to the right to a few thousandths.   It was a fairly small piece, on the order of 1/4" x 1/2" x 1" and mounted directly to the mill head housing.  I made a couple of screen shots of the the bottom and front view of the SolidWorks model but I seem to have a problem uploading files right now.  I will post them when things are working again.

It has been several years since I last saw the mill.  It happens to be in the possession of a friend and I had asked him the take some photos of the setup.  I will re-ping him.


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## Happycamper (Dec 6, 2015)

Thanks Bob. I would appreciate that.

Jerry


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## RJSakowski (Dec 6, 2015)

Happycamper said:


> Bob, thank you for your posts and pics. They really helped. I've been traveling and haven't had time to work on my mill but I have the x and y installed and have made the brackets for the z. I am in the process of installing the z brackets and getting them parallel and plumb. The problem I'm working on is the rotational torque and overcoming that. You mention an additional stop and modifying the hole in the bottom of the head to control the play. Would you be so kind to explain that? Thanks,
> 
> Jerry


  Still trying to upload file with no joy.  I will try again later.

Bob


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## RJSakowski (Dec 6, 2015)

RJSakowski said:


> Rotational movement to the  left is limited by the mounting bracket for the DRO.  As I recall, I added a second piece to the right which limited the rotational movement to the right to a few thousandths.   It was a fairly small piece, on the order of 1/4" x 1/2" x 1" and mounted directly to the mill head housing.  I made a couple of screen shots of the the bottom and front view of the SolidWorks model but I seem to have a problem uploading files right now.  I will post them when things are working again.
> 
> It has been several years since I last saw the mill.  It happens to be in the possession of a friend and I had asked him the take some photos of the setup.  I will re-ping him.


Jerry, It appears that I can now upload files.  Here the bottom and front views.  The block limit rotation to the right was in the location shown in red.  You can also see some of the detail as to how I mounted to the existing bracket for the quill stop.

Bob


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## Happycamper (Dec 6, 2015)

Ok!I see how you did it. I was looking at a very similar setup with a "U" shaped piece of 1/4" stock on the bottom of the head and the base of the scale riding in the U. But your set up is a lot easier to make.


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## fixit (Sep 8, 2016)

Happycamper said:


> I've been looking at the stop/depth gage. Maybe changing out the threaded rod for a solid rod mounted in bushings to keep it plumb. Then attaching the reader head to the rod with the scales fixed.


that is how I did it


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## astroracer (Sep 8, 2016)

Here is the build thread for the Tpac Tools DRO I installed on my Frankenmill. Around 400 or so for the kit and it works perfectly. 
http://www.hobby-machinist.com/threads/a-tpac-tools-dro-for-the-frankenmill.35333/
Mark


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