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  1. #11
    The 48V PSU will make a difference. Try with 4.5A but check the motors temperature, if they'll get too warm or hot, reduce the current. Higher current increases only the low speed torque.

    Hiwin rails need to be very carefully aligned to have a smooth movement.

    https://www.youtube.com/watch?v=AGT5gXpcmBA#t=1m58s

  2. #12
    hi paul photo of laser, still some bits to do, like airline laser pointer, and the cabinet is half done, kev
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  3. #13
    Quote Originally Posted by paulus.v View Post
    It is not that simple to get the pulley tooth size. You have the pitch line, which corresponds to the belt insertion, where the belt bends. From there you calculate the gap between the teeth to correspond to the belt teeth dimension.

    But it looks like it might go, a small change in radius gives you 6 times as much off the circumference...

    Click image for larger version. 

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  4. #14
    Quote Originally Posted by Robin Hewitt View Post
    But it looks like it might go, a small change in radius gives you 6 times as much off the circumference...

    Click image for larger version. 

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    got my belt and pulley from cnc4you they match perfect, kev

  5. #15
    Quote Originally Posted by paulus.v View Post
    The 48V PSU will make a difference. Try with 4.5A but check the motors temperature, if they'll get too warm or hot, reduce the current. Higher current increases only the low speed torque.

    Hiwin rails need to be very carefully aligned to have a smooth movement.

    https://www.youtube.com/watch?v=AGT5gXpcmBA#t=1m58s
    that video is good info, learnt a lot about hirwi rails, best way line 1 side and slide car to each bolt both sides as you tighten rail up, moves super smooth then, as there is drag on them before fitting as they are preloaded, kev

  6. #16
    Quote Originally Posted by kev20009 View Post
    got my belt and pulley from cnc4you they match perfect, kev
    Momentary hope, but they have nothing to fit my 15mm wide belt.

    I think I might try 3D printing a pulley. Well, why not?

  7. #17
    Quote Originally Posted by paulus.v View Post
    The 48V PSU will make a difference. Try with 4.5A but check the motors temperature, if they'll get too warm or hot, reduce the current. Higher current increases only the low speed torque.
    Yes it will make a difference it will blow the bloody drives up.!!! . . . . Why do you people give advise without looking and knowing exactly what your telling people to do.? These drives are 50V Max and 48vdc is far too close to limit and when traveling at high feeds the back EMF will fry the drives.

    Kev stick with your current supply for now. I suspect your problem comes from lack of pulses due to high micro stepping with low pulse rate.
    Setting lower micro stepping won't cause stalling and should allow higher tuning of velocity because less pulses are needed.
    3200 is too high and pointless really because most steppers can't resolve higher than this. What it does help with is smoothness but this comes at the cost of high number of pulses which can lower your velocity if can't provide them. If using parallel port with 25Khz then this will most likely be your problem.

    I've seen you mention 10mm but is that width or pitch.? T5 is 5mm pitch not 10mm. So with 20T your linear Pitch will be 100mm per rev.
    Now given your using 3200 pulses per rev and using frequency of 25Khz which is standard frequency for parallel port the max RPM you'll get from your motors is 468.75Rpm.
    This is calculated by taking frequency and dividing by pulses per rev or micro stepping in your case. This will then give Revs per Sec which you times by 60 to give RPM.
    Now take the pitch and times by RPM to get max velocity. So 100 x 468.75 = 46,875mm/min or 781.25 mm/sec .

    So you see if using 25khz with 3200 MS and 5mm pitch with 20T you can't possibly be reaching 800mm/sec.

    Drop the Micro stepping to 1600Ms and your RPM doubles and so does your Max velocity. Lowering Ms won't or shouldn't cause stalling motors. Unless your trying to spin them too fast.?
    By this I mean say if you used same parameters as above but with 400Ms then you could possibly tune the velocity so that the RPM is higher than the motors can handle so get saturated. Above 1500Rpm then steppers motors will struggle depending on load voltage etc.
    Last edited by JAZZCNC; 29-01-2017 at 10:29 PM.

  8. #18
    Quote Originally Posted by Robin Hewitt View Post
    Momentary hope, but they have nothing to fit my 15mm wide belt.

    I think I might try 3D printing a pulley. Well, why not?
    Is there a reason you bought pulleys and belts from different suppliers?
    You think that's too expensive? You're not a Model Engineer are you? :D

  9. #19
    Quote Originally Posted by magicniner View Post
    Is there a reason you bought pulleys and belts from different suppliers?
    I don't think it matters where you buy them, the spec for the T5 pulley has 0.6mm of slop. I presume there is a good reason for this and it was not done simply to piss me off

  10. #20
    Quote Originally Posted by JAZZCNC View Post
    Yes it will make a difference it will blow the bloody drives up.!!! . . . . Why do you people give advise without looking and knowing exactly what your telling people to do.? These drives are 50V Max and 48vdc is far too close to limit and when traveling at high feeds the back EMF will fry the drives.
    I only advised 45V I said that I have no experience with these crappy drives. The Chinese say that the drives have over-voltage protection. I couldn't find any information about what chip is inside.

    My THB6064AH based drives, rated at 50V max, were happy at 46V with my 150kg gantry. At 48V they tripped an error (from back-EMF) with no damage.

    If they'll fry, he will be advised to get the AM882 and see how nice his machine will move at 100mtr/min.

    I was impressed by these DSP drives. They more than doubled the speed, with the same voltage and current setting.

    Quote Originally Posted by JAZZCNC View Post
    If using parallel port with 25Khz then this will most likely be your problem.
    He is using an AWC-608 Controller. I couldn't find any information about the step output frequency. Found somewhere "150MH". Could it be they spelled wrong 150kHz?

    Quote Originally Posted by kev20009 View Post
    Now I can only set steps to 3200 any lower stalls and can only move at about 4mm second
    What should I understand from the above sentence? What means 'lower' and 'only'?

    I googled these drives and found them popular on 3D printers not a 50mtr/min laser...

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