Dro For Mill

joshua43214 said:
@Ed ke6bnl
I have not bothered to do any error correction yet. I just set the hand wheel to 0, and made a full turn. It read spot on +/-1/10th repeatedly. My mill has ground imperial lead screws, so I trust them to be pretty accurate. I will check it eventually with a gauge block. If you use a 1-2-3 block, measure it first as accurately as possible. You should also overtighten or partly lock the gibs so it takes effort to turn the wheels because sag and twist can skew the reading. Keep in mind that the faces of the 1-2-3 block and the backing block must be in the same plane, and even a tiny bit of dust between them can throw off the measurement when using a 1/10ths indicator - I prefer gauge blocks for this because they have smaller faces and can be wrung together. You could maybe use the standard from your micrometer instead. It makes no sense to check a 1um scale against something that has "loose" tolerances like a 1-2-3 block. My 1-2-3 blocks are all off by a few 1/10ths in all dimensions, squareness, and parallelity. Provided you get the scales and read heads parallel to under a thou, it should be pretty accurate out of the box
I had the same unit on my old mill and it did not require adjustment. My new mill has much higher tolerances, so I expect I will fuss with it some to get it consistent with the mill's specs.
I know the display will do both sin error and compression. Sin error is clear enough to me - it compensates for the scales being out of parallel to table movement. I am not sure what the purpose of compression is.
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I have a used Bridgeport that is in the 50's, with a J head, so I am sure I will be ok if I got the results you had. The reason I brought it up was my last mill a Rockwell I put Yuriy's Touch-DRO on and part of the procedure was to set the scales to match the Readout. Thanks again.
 
joshua43214 said:
The x-axis read head is bolted to the casting with a machined spacer. The x-axis scale is spaced away from the table to allow oil from the ways to bleed past.
The y-axis scale is bolted to an aluminum strip. The strip has wedge shaped spacers that have slots milled in them. By moving the spacer up and down, the strip can be aligned parallel to the axis. The base casting itself is not parallel to the y-axis, so one wedge had to be slightly thinner than the other. The read head is screwed from underneath to a piece of angle that is in turn bolted to the arm coming down from the moving part. It was a tight fit, and I had to pre-assemble it.
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I like your approach of putting the Y axis read head mount behind the scale, nice n neat. I have the same problem with my Y and Z axis scales aligning to the castings, I am going to try alignment washers http://www.mcmaster.com/#catalog/121/3244/=zvwaff I've had luck with these in the past aligning linear bearings to shafts. Hopefully, I'll be able to install my DRO soon.
 
Ed ke6bnl said:
same unit I purchased, got it in about a week and it tested ok, but may be a couple of weeks to get started on the install. if you beat me to it lets see some pictures and how dids and how doos.
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My aliexpress is now installed went pretty smooth and working very well, I would like to learn more on doing bolt hole with a start at X axis straight up got it working well with x to the rt. and using start at 0 and end at 360 but other starts I am confused. but works well I am pleased with the price.
 
My DRO arrived yesterday and got the Y axis scale on. Installed X scale and got it all dialed in and hooked up the DRO and the X scale is dead. I can swap Y and X and the readout works, so bad scale. No matter how I move it the position readout doesn't change.

I just emailed the seller but even if he ships tomorrow I won't have it before the end of my vacation. It took 1 week before DHL picked up the original shipment after I ordered it, and 5 days to get here after that.

I need to make mounts for the Z scale and was going to use the new mill to do that instead of the Bridgeport. So now I don't know if I should go ahead and make the Z scale mounts or not, depends on what the seller is going to do.

This sure messes up my plan to get the mill finished and moved into position and put the Bridgeport up for sale :frown:
 
I have a van Norman 22 lu made in 1943 and I want to put a dro on this what would u all go will I have to keep the cost down I will start with a cheap one.that will help me along.then get a better one.latter any help would be noce

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Ebay is a viable option, buy one that will last, that way you only have to drill once. Tim
 
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