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  • DRO Advice

    I have a Harrison 14" lathe, and I want to mount a DRO. The problem is the design of the cross slide, doesn't make it easy to mount a scale. I prety well have to mount it off the back of the cross slide. I need to find something that is compact, and cost effective. Also if the scale can be cut, so I can keep it as compact as posstible, that would be great. I like Mitutoyo, but you can't cut the scale - Same with Newell - great system - the microsphere might work, but you can't cut down the scales. Suggestions greatly appreciated.

    Thanks

    Pat

  • #2
    Avoid putting the scale off the back. Flex and vibration will give you false readings.

    You should be able to order the scales in custom lengths from Newall. And there is a thread where someone talks about cutting down a Newall scale, can't remember if it was here or over on PM.

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    • #3
      Which Mitutoyu are you thinking about? I cut a scale down to fit a older round column mill, Y axis. Took about 6 in. off as I recall. the scales are what appears to be printed circuit boards. Cut it with a Jewelers saw as I recall, and shortened the housing in the band saw and mill.You need to be careful which end to cut, If you need more info ,PM me and I will try to remember more of the details.Bob.

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      • #4
        I just checked, and it is a Mitutoyo Digi matic scale. I shortened the end opposite the label. That should be the end with the ground screw. i was able to use the short scale as is for the Y, contrary to my first post, sorry 'bout that.You should be able to peek into and see what type of scale you are dealing with. Again, if I can help more PM me. Bob

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        • #5
          I had to mount mine off the rear also, no problems yet. I also cut down the glass scales I had.

          Here are two posts on the H-M forum:
          http://hobby-machinist.com/index.php...19713#msg19713

          http://hobby-machinist.com/index.php...20428#msg20428

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          • #6
            I had a failure of the reader on the 600mm Z axis (longitudinal) scale on my dad's lathe. It was a Mitutoyo series AT-102, long out of production. I found a 150mm long unit on Ebay, pulled the reader off of it and put it in place of the broken one.

            After looking things over, I don't think it would be all that difficult to shorten one, but I wouldn't try it myself when I was able find a new one on Ebay for under $100. In the case of an AT-102, it's a glass scale and would require a deft touch with a diamond cutoff wheel along with careful dust control.

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            • #7
              Why not go for a magnetic scale, slimline and only need around 2" extra on length for reader.
              http://i1140.photobucket.com/albums/...CABLING006.jpg
              When tailstock shoved up to cross slide only lost less than 1/4", now measure the smallest glass jobbies.

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              • #8
                Newall Microsyn scales are the smallest that I know of. I won't say it's 100% but Mitutoyo have a magnetic scale set up much like Newalls as well as the glass scales. I don't know anything about any of their scales tho. Mitutoyos display units are probably the equal to any out there and better than a lot as far as programed in functions. Easy enough to check Mitutoyos web site, Their good about drawings and specifications.

                Pete
                Last edited by uncle pete; 09-13-2011, 09:05 AM.

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                • #9
                  I've just ordered DROs for my BP clone and Harrison L5.

                  Installation on the L5 is even harder because I have the taper turning attatchment. My plan at the moment is to mount the scale under the bed, with a 'U' bracket transferring the motion. There's an example of such an installation here; http://mtechdro.blogspot.com/search/...showcase-lathe

                  If that doesn't work out, I'll look at a couple of alternative scales. I upgraded to a 1um scale, so it could be used on my cylindrical grinder if it didn't work out on the lathe.

                  The first is a magnetic strip type; http://www.machine-dro.co.uk/digital...-encoders.html Their printed litrature also lists a 1um reader head, but for some reason it never appears on their website.

                  Many years ago, I recommended a DRO system for an mill here at work. They didn't have the budget for any of the industrial systems, but a 'hobby' level system was good enough. Made by BW Electronics, it used fine steel cables running around drums attatched to rotary encoders. http://www.bwelectronics.co.uk/ I thought the company had faded away (I don't think the website has been updated since the 90's), but a recent article in Model Engineers Workshop said otherwise.
                  Paul Compton
                  www.morini-mania.co.uk
                  http://www.youtube.com/user/EVguru

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                  • #10
                    Pat,

                    Just a thought - with a bit of milling,would it be possible to mount the scale between the saddle and the cross slide? Somewhere near the feed screw maybe. Wouldn't be easy, but the end result would be a totally hidden, protected scale that never gets in your way.

                    Ian
                    All of the gear, no idea...

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