Motor won't move in single microsteps - problem, or normal? - Page 2


Page 2 of 2 FirstFirst 12
Results 13 to 14 of 14

Thread: Motor won't move in single microsteps - problem, or normal?

  1. #13
    Registered
    Join Date
    Dec 2006
    Location
    USA
    Posts
    79
    Downloads
    0
    Uploads
    0

    Default Re: Motor won't move in single microsteps - problem, or normal?

    @109jb - you're right - a large RC servo could potentially work. I've been a little reluctant to go down that path, as the output shafts on even the large servos are surprisingly small, so I worry a bit about strength and stability. In order to work with the cable arrangement, I'd need to add a spool/spindle to it, and given the small/short output shaft, I suspect I'd need to add a bearing and support above the spool/spindle to adequately support side loading on that small output shaft joint - its just seemed like more trouble than I wanted to get into, but if the stepper approach continues to be problematic, I'm going to have to broaden my horizons, and a big RC servo will definitely be near the top on the list of options. (The good news is, something like the Hitec HS-5765MH can be had for under $100 - that is a beast of a servo, and should definitely have the needed strength - just a question of mating it up to the cable in a strong enough manner.)



  2. #14
    Registered
    Join Date
    Dec 2006
    Location
    USA
    Posts
    79
    Downloads
    0
    Uploads
    0

    Default Re: Motor won't move in single microsteps - problem, or normal?

    Sigh... Its with much deflation and disappointment that I report that while the stepper is definitely running better/stronger on 48v, I still can't get it to work in full-step mode, and its still missing occasional steps when making full-step moves in 1/2 step mode. (I also found the same thing in 1/4 step mode.) It will make full steps in 1/2 step mode, by moving 2 steps at a time. (And via 4 steps in 1/4 step mode.) At this point, I'd be happy to just have a reliable full-step - if I have to do that via 2 half-step moves, I'm Ok w/ that. There is still also a very narrow range of speeds that it will move reliably in 1/2 step mode.

    The missing steps, ironically, seem to be occurring mostly when I'm letting cable out (ie less load on the stepper), than when pulling cable in (more load on the stepper). I need to perhaps try experimenting with different speeds for pulling cable vs releasing cable, I dunno. The missing steps also seem to be associated with changing direction a bunch of times. (So, if I home it, move it out a bit, jog it back and forth a bit, then return to what should be the step zero position, and its either not quite all the way there, or it has bottomed out a few steps before reaching the home position.)

    I'm thinking the giant-honking RC servo might be the next logical step. I just can't help but feel that I must be doing something wrong w/ the stepper - steppers are used all the time w/o these problems. I don't know if its my driver, my wiring, the stepper, itself. (I have another stepper I will pull from something tomorrow, and try it out, just to be sure these problems are not specific to the motor I'm using.)

    Much confusion and dejection here...



Page 2 of 2 FirstFirst 12

Tags for this Thread

Posting Permissions

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


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Motor won't move in single microsteps - problem, or normal?

Motor won't move in single microsteps - problem, or normal?