Burke Millrite DRO installation

[Ischgl99]

I got a Sino DRO a number of years ago and installed the X axis on my Burke Millrite, but never got around to the Y axis due to the complexity of the angled castings, then discovered the scale was broken in the middle and could not be salvaged. So, I was using 1 DRO axis and dials on the other for a number of years. I finally got around to ordering a Y axis scale and trying to figure out how best to mount it.

I decided to install the X axis scale on the front of the table since it has a T slot already there, and I can mount the reader head in the spot for the table stop. I don't have a power feed installed, so that hasn't been a problem, but I may install a power feed at some point and will need to figure out a work around. I decided against mounting on the back of the table since that would have taken up too much of the Y axis travel, and since this is a smaller mill to be begin with, I did not want to take up any additional travel.

There is not much info out there to use as ideas, and what I found was people making brackets at the required angles. I didn't want to do that, so I came up with an adjustable bracket instead. Luckily the casting near the knee ways looked to be straight, so I only needed one adjustable bracket. I decided on an angle bracket mounted to the machine with slots to allow in and out as well as horizontal twist adjustment. To allow for vertical adjustment, I used a steel rod in the horizontal adjustment block with a mounting block on the other end that could twist in the vertical direction. I forgot to get pictures of this before the scale was mounted.

Once this was installed, I needed a way to attached the reader to the Y axis. There is a bracket driven by the Y axis leadscrew that is in a good location to use, but it is a rough casting.


To use this, I would need to machine the casting flat, and then drill and tap two holes for the reader bracket. That sounded like too much work, so I decided to use a method that was even more work! I made a mounting block that I was going to attach to the leadscrew bracket with JB Weld. I have the DRO unit mounted to the mill by using a piece of angle aluminum attached using JB Weld and it has held for several years, so I was confident this would work as well.


That sounds easy, but then I needed a way to hold it in position while the epoxy cured. I made a contraption the sits flush against the Y axis saddle with an adjustable piece holding the mounting block in place. One of my woodworking clamps was the right size to use to hold while the epoxy cured. At this point, removing the leadscrew bracket and machining it was sounding like a better idea. After curing overnight, the block was firmly in place and it was time to fabricate the brackets to drive the reader.

I had some brackets from the Sino scales, but they have a different hole spacing than the Ditron scale I bought as a replacement. So I needed to modify one of the Sino brackets to work with the Ditron angled bracket, and fabricate a piece from the mounting piece I just installed to the other bracket pieces. Finally success! Everything is dialed in the vertical and horizontal directions and the reader head moves nice and smoothly. Finally I can use the DRO as intended. Well, not so fast. My father-in-law bought me this DRO on one of our trips to China and the store gave him a lathe unit when I asked for a mill unit. When he tried to exchange it, they told him it was no different and they would not take it back. So, I have a unit with lathe features and none of the mill features I wanted. That will be corrected this week when the new DRO unit arrives and this DRO gets moved to the lathe.

 

[neonguy]

Thank you for posting this, lots of good pictures and ideas. I am planning on installing a DRO on my Wells-Index mill one of these days and your post was a lot of inspiration. I tend to think about things a long time before doing them, hopefully with better results than if I just jumped in.

 

[Ischgl99]

Thank you for posting this, lots of good pictures and ideas. I am planning on installing a DRO on my Wells-Index mill one of these days and your post was a lot of inspiration. I tend to think about things a long time before doing them, hopefully with better results than if I just jumped in.

You’re welcome, I was hoping my post might help someone with their installation. I tend to spend a lot of time planning how to do something, and in my searches there was very little on how to mount brackets on angled surfaces, so I kept putting it off. The a-ha moment came when I saw the linear scales from Newell that use articulating brackets, that might help you as well if you have some odd surfaces to mount to.

 

[Tim9]

Very nice installation. I did mine a while back. And I only did the X and Y axis. I’m such a procrastinator and have a bad case of ADD disorder. But hey, I get by.

 

[Ischgl99]

Thank you. I’m not sure if I will do the Z axis, but I did get the 3 axis unit in case I do decide to do that at some point. Using the dial for the knee is not that big a deal since it’s not adjusted while cutting, but I use mostly metric dimensions, so having the right units would help. The new DRO also has a tachometer feature, so will be installing a sensor for that at some point.

I have never been diagnosed, but I do have a lot of ADD symptoms that frustrates my wife to no end, but as they say, opposites attract. My daughter is not happy that is a trait she inherited from me…

 

[Ischgl99]

I decided not to wait as long to install the speed sensor as I did for the Y axis scale, so I got that finished yesterday. I spent some time trying to figure out the best location for the speed sensor and there is enough space between the belt cover and the motor mounting bracket to fit the sensor. You can see it to the left of the flag at the underside of the belt cover.

I needed to install target magnets on the underside of the spindle sheave for the sensor to detect, I wanted multiple magnets so that there was good speed resolution at lower speeds and added 3 magnets. The DRO has a menu item for the number of targets, it defaults to 1, but you can increase that if you want to have more. To avoid any potential unbalance issues, I put the sheave in my lathe and evenly marked out the places for the magnets by using the camlock studs on the spindle as a reference to the bearing cover bolt on the headstock.

Since the mill was taken apart to do this, I needed to do my drilling on the drill press. I center drilled each location and then drilled to the required depth. I wanted the holes flat since I was concerned drilling deep enough to fully seat the magnets might drill into the V groove for the bottom belt, so after drilling the point deep enough, I switched to an end mill. That was an interesting experience. It worked, but I don't want to do that again.

The magnets are held in with JB Weld, I used my woodworking clamps to seat them fully in the holes while it cured.

Next step was to mark out the location for the bracket. I used a Sharpie on my indicator articulating arm to draw a straight line by moving the table. I marked off two locations for threaded holes. I first made them 1" apart, but after tapping them, realized that was too close to a protrusion on the underside and needed to do another one at 5/8" from the front one.

The bracket to hold the sensor is fairly simple, a hole for the sensor and two slots for the mounting screws to hold the bracket on the machine.

Here is a picture of it installed. I fired it up and it works great! I verified the speed by using a handheld tach I have and they are within a couple RPM of each other. No more guessing what my spindle speed is now. Pictured also is the Ditron D80 DRO unit. It feels like a toy compared to the Sino I had on it, but should be a big improvement now with actually having mill features on the DRO on my mill.