Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: Recommend SIMPLE single axis DRO

  1. #1
    Join Date
    Apr 2010
    Location
    Tropical Milwaukee, Wisconsin
    Posts
    478

    Default Recommend SIMPLE single axis DRO

    I figure that will all the people here with small machines that someone has found something that might work.

    Looking for a single axis DRO. Do not need ANY features other than position. Period.

    Quite frankly, an iGaging 12" would be perfect for size of the kit, but it needs to actually be accurate. ( actually only need ~ 8" - 10" ) Accuracy of +/-0.004" is not acceptable. ( +/-0.001" is not really acceptable, either. )

    Accuracy of +/-0.0005" or better is desired. Small form factor is desired. All other extras or features will not be used, nor appreciated. So, is there an accurate version of the iGaging type of kit? Something else that fits the bill?

    Thanks.

  2. #2
    Join Date
    Mar 2015
    Posts
    3,316

    Default

    It's not the answer you want, but for our purposes, glass scales work very well. They have quadrature output, you could make a single axis display with an Arduino, or simply just buy a Ditron DRO head. You want accuracy, get a 1 micron scale. It's what I use for the crosslide on the lathe

    Sent from my SM-G950U1 using Tapatalk

  3. #3
    Join Date
    Dec 2016
    Location
    Helsinki, Finland, Europe
    Posts
    3,394

    Default

    Quote Originally Posted by Zahnrad Kopf View Post
    I figure that will all the people here with small machines that someone has found something that might work.

    Looking for a single axis DRO. Do not need ANY features other than position. Period.

    Quite frankly, an iGaging 12" would be perfect for size of the kit, but it needs to actually be accurate. ( actually only need ~ 8" - 10" ) Accuracy of +/-0.004" is not acceptable. ( +/-0.001" is not really acceptable, either. )

    Accuracy of +/-0.0005" or better is desired. Small form factor is desired. All other extras or features will not be used, nor appreciated. So, is there an accurate version of the iGaging type of kit? Something else that fits the bill?

    Thanks.
    You probably already know this but accuracy of +/-0.0005" or better over 10" is starting to go in the "measure temperature first, worry about dimensions after that" category.

    Typical linear scales have aluminium body and aluminium vs steel CTE is 12ppm/C
    250mm lenght gives you 3um differential expansion per degree so your "accuracy budget" goes haywire if the temperature difference is 4C.
    To keep the effect reasonably small (1/4) compared to desired accuracy you better keep temperature difference within 1C

    52 USD single-axis dro display: ?
    https://www.aliexpress.com/item/Sing...805018888.html

    Unclear if you can set the scale resolution to something else than 5um. (not that it really matters, looks like typically accuracy specification for 1um and 5um scale is almost same)

  4. #4
    Join Date
    Dec 2018
    Posts
    341

  5. #5
    Join Date
    Apr 2010
    Location
    Tropical Milwaukee, Wisconsin
    Posts
    478

    Default

    Quote Originally Posted by RB211 View Post
    It's not the answer you want, but for our purposes, glass scales work very well. They have quadrature output, you could make a single axis display with an Arduino, or simply just buy a Ditron DRO head. You want accuracy, get a 1 micron scale. It's what I use for the crosslide on the lathe
    A. I'm not making anything beyond mounts for the scale. No time for that, and no desire. I need to purchase it and get going.

    B. The Ditron is everything I specifically DO NOT NEED OR WANT. It is at least 3x larger and have less than zero use for the various functions. This is a travel only application.

    I actually have a few scales laying about, too. If I could purchase a readout I would be open to it. However, I figured that as long as I have to purchase something and it is only one axis, I may as well purchase something newer than 20 years old.

  6. #6
    Join Date
    Apr 2010
    Location
    Tropical Milwaukee, Wisconsin
    Posts
    478

    Default

    Quote Originally Posted by MattiJ View Post
    Ooo... I like that... Perfect. I need to find out if that would work with older Mitutoyo scales or a Newall SHG-AG. Would be great if there was a CONUS vendor, too. Beggars, choosers, and all that, though. Thanks.

    Anyone else?

  7. #7
    Join Date
    Dec 2016
    Location
    Helsinki, Finland, Europe
    Posts
    3,394

    Default

    Quote Originally Posted by Zahnrad Kopf View Post
    Ooo... I like that... Perfect. I need to find out if that would work with older Mitutoyo scales or a Newall SHG-AG. Would be great if there was a CONUS vendor, too. Beggars, choosers, and all that, though. Thanks.

    Anyone else?
    You need inches or is millimeters ok?

    Reason I'm asking is that maybe some universal up/down counter could handle the task if you don't need any of the normal DRO functionality.
    1um scale connected to suitable counter might work just as well?
    ie one of these:
    http://www.weschler.com/_mergefiles/...BF6C356630A0A3

    Need a bit of head scratching to check if its feasible and make it work but probably not worse than chinesium DRO without understandable manual.

  8. #8
    Join Date
    Dec 2016
    Location
    Helsinki, Finland, Europe
    Posts
    3,394

    Default

    Another CONUS possibility:
    http://www.newportus.com/ppt/INF8.html

    price probably makes you take another look at the chinesium DRO without manuals or specifications

  9. #9
    Join Date
    Aug 2014
    Posts
    206

    Default

    +/-0.0005" == 0.01 mm.
    0.01 mm over 12" is dead easy and old bridgeports did much better.

    20 times better or 2 microns or 0.002 mm, 0.0001" over 12" is perfectly doable by anyone.

    As was said, buy a glass scale and readout, about 200$.

    Amateurs hand-fit astro lenses to 0.1 microns or better, routinely. Over 6-10", mostly.
    Amateurs do model engine and steam stuff to 2 microns, and similar stirling engines.

    My professional clients making molds, did 2 microns/12" or better than 0.01 mm over 2 metres, routinely, with std cnc machines.
    No aircon.
    The steel molds cost the clients like audi about 200-400k$, each, for auto production stuff.
    Only 2% of clients bought glass scales for cnc machines, in 20+ years over 8000+ machines.

    The 4 degrees C quote has an error.
    Over 2" in D 3 degrees C == 1 microns of error. Not 10 microns.
    And it is error of plus only, not plus/minus.
    And you wont get 4 degrees of C difference in any steel workpiece, after 2 mins in any room-temp liquid like oil/water/coolant.

    I have and use digital 1 micron micrometers (sold these retail) to 6".
    The micrometer is about 2 micron accurate and 1 micron repeatable.
    The error is about the same at 20C or 30C.

    The micrometers use tiny scales like glass scales.

  10. #10
    Join Date
    Apr 2010
    Location
    Tropical Milwaukee, Wisconsin
    Posts
    478

    Default

    Hrmmmmmm.... I found this today, too...

    https://www.sra-measurement.com/mini...isplay-console


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •