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  1. #1
    Join Date
    Jun 2005
    Posts
    1015

    speed of mill/drill with mach 3?

    how fast can i get my mill drill to go? i've got gecko 320s and i want to run on mach3. i'm running a p4 1.8 GHz computer. i have the standard 5/8 ball screw with 5 threads per inch. also i'm gearing down the servos 3:1. the encoder on the minertia servo puts out 2000 pulses per rev. i think i probably should have bought the gecko 340s but i'm stuck with the 320s right now. what can i expect in terms of speed from all the axes? also can some post the equation on how to figure this out? i'm not an electronics wiz so this encoder stuff kinda throws me for a loop.

    http://www.yaskawa.com/site/dmservo.nsf/aa8198da5462fcbe86256c59004e4bcb/86256ec30065f21886256de2005b9645/$FILE/TSE-C253-20G.pdf

    here is the pdf for the motor and the motor part number is R02MAKOE-UTOPI-200SE.

    i'd appreciate all the help as well as tips on what i can do to make this perform to its potential.

  2. #2
    Join Date
    May 2006
    Posts
    102
    Hi

    It doesn't have much to do with the computer, more to do with Mach3


    5 tpi times 3 (reduction) = 15 servo revs per inch times 2000ppr = 30,000 pulses per inch

    Mach as standard will put out 25,000 pulses per sec so.... 25k div by 30k =).0.833 ish inch second times 60 = 50inches a minute - not very fast!

    Mach can be set to output 45K but thats only recomended if you really have to... and a fast computer - yours don't sound to bad so maybe... (45k only works on registered versions)

    you need to change the encoders me thinks...

    asuming my calcs are correct! I think they are

  3. #3
    Join Date
    Jun 2005
    Posts
    1015
    is that 45kHz per axis or is it total? i believe your calculations are correct as i got the same answers. i just needed to double check. i will buy the registered software so thats not a problem. i was thinking of mounting secondary encoders directly on the axis. what encoder count should be used? i'm thinking the 250 encoders directly mounted to the ball screws.

  4. #4
    Join Date
    Mar 2003
    Posts
    35538
    per axis
    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

  5. #5
    Join Date
    Nov 2004
    Posts
    1
    Hi, i have the same motors you have, and two Geckos 340 for my lathe. There are two issues i don't like:

    1.- There is always some dithering, even with the anti-dither option and low inertia enabled. that makes motors sound whe commanded to remain stopped. You can reduce this sound adjusting the gecko parameters, but in my case, with the parameters adjusted to minimise dithering I get a very bad servo trnsient response. I prefer to have some dithering and have the servos behaving better.
    2: This may be due to the 2000 cpr encoder being too much, but I often find that the 256 error limit is very low, and the system becomes very sensible and goes into error mode with very small disturbances.
    3: I have tested Geckos and a PID controller that I designed for a final career project, and although I love the G340 design for its simplicity and efectiveness, I have never been able to get a decent servo response. While with the other controller (the PID loop ran inside a microcontroller) I always had an almost ideal transient response.

    Well, I don't know if this helps much, but its my experience, maybe someone can suggest something to me.

    Regards,
    Pedro

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