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  1. #1
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    Clear path servos

    I have looked around and haven't seen anyone talking about this, has anyone ever looked into upgrading their tormach with clearpath servos? I was just curious, it could be done for $1500ish and it would seem that they are quite a bit faster.

  2. #2
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    Re: Clear path servos

    First thought was 'Again? So soon? Doesn't this usually only come up once a month not back to back weeks?' j/k

    Looked through a lot of the info on their site and if I'm understanding it all... Very interesting! STEPPER KILLER drop in replacement that takes the signals and interprets the data into a self contained closed loop AC servo. WOW. Freakin smart.

    I like the 'so what's the catch' section: nothing they left out would be a loss really. Feedback isn't present now so these would just be a faster and stronger 'stepper' that happens to be a servo and able to actually HANDLE the increased speed.

    Mind you I ran my 1100 at 160ipm rapids and had them up to 300 to see what would happen. Answer: loss of positioning. I think the steppers couldn't quite manage the resistance from a dovetail system at gnarly speeds. I often though the Tormach steppers would probably toss my HAAS table around like it was nothing since I can turn the ball screw with the tips of 2 fingers.

    Looking forward to the machine and electronics gurus to weigh in. For $1500 I'd have ordered those in 2 seconds flat if they work out. Heck, if they work I might be putting more weight on picking up a 770. Need a 10K spindle, but need accuracy that exceeds Tormach range unfortunately (0.0001 steps 3D the backlash alone may ruin those parts). Then again these wouldn't account for the backlash. Perhaps since it's practically zero-force cutting I could leave the gibs on the looser end of adjustment where there's no backlash. Thinking out loud sorry.

    Cool find. Looking forward to some thoughts. :cough:ray:cough):

    Sent from my SM-G935V using Tapatalk

  3. #3
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    Re: Clear path servos

    Quote Originally Posted by Gravelleknives View Post
    ...it could be done for $1500ish...
    I think that's highly optimistic. It appears to me the most suitable motors are more in the $650-700 price range per axis. Pretty sure you'd have to add DC power supplies(I'm pretty sure the Tormach stepper drives are powered directly from the AC line, while the Clear Path drivers require external 75DC power, probably ~500W per axis), which would add another ~$200 per axis. Then you'd have to machine motor mount adaptors, most likely also swap out the ballscrew couplers, and definitely do a bunch of re-wiring. It appears to me you'd also have to enclose the motors, as the motor connectors do not appear to be even remotely water-proof. That enclosure could prove problematic for motor cooling. By the time you're done, you'd be up around $2500, which is roughly the going rate for any similar AC servo system, so there's nothing really unique about the ClearPath's.

    Properly done, it would absolutely make the machine faster. Rapids of 200-300IPM should be quite do-able. It would absolutely be much quieter, as AC servos are virtually silent. Having done a stepper to AC servo conversion on one of my machines, I can tell you it will make no discernable difference whatsoever in accuracy, repeatibility, or surface finish. So, is $2500 and several days work for faster rapids and less noise worth it? If you're doing a lot of 3D surfacing, or doing a lot of production work, it could well be (though for production work, an ATC will likely be much more valuable, as it frees up your time to do other things while the machine is grinding out parts). But, it's a significant project, and not a fast and simple bolt-on.

    Regards,
    Ray L.

  4. #4
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    Re: Clear path servos

    Maybe one of y'all with a very active YouTube channel could get them to 'sponsor' a build then manufacturer a kit with the mounts and housings (if required). Donating a couple motors for thousands of targeted demographic viewers is a no brainer.

    I've 'donated' over 100 of my cruise controls at even the remotest possibility of that exact scenario.



    Sent from my SM-G935V using Tapatalk

  5. #5
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    Re: Clear path servos

    Quote Originally Posted by SCzEngrgGroup View Post
    Pretty sure you'd have to add DC power supplies(I'm pretty sure the Tormach stepper drives are powered directly from the AC line, while the Clear Path drivers require external 75DC power, probably ~500W per axis), which would add another ~$200 per axis.
    Tormach powers the stepper from a 48VDC power supply. But that would have to be upgraded, since it probably doesn't have a high enough current rating.

    The upgrade wouldn't be quite so expensive if you just did it to the X&Y axis.

    I don't think you truly get all the real benefits of a system designed with a servo motion controller, but you would get faster rapids and cutting speeds.
    Tim
    Tormach 1100-3, Grizzly G0709 lathe, Clausing 8520 mill, SolidWorks, HSMWorks.

  6. #6
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    Re: Clear path servos

    Does anyone know the torque specs on the Tormach steppers? I know I looked it up in a white page a while back but I can't remember.

    Sent from my SM-G900V using Tapatalk

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    Re: Clear path servos

    Quote Originally Posted by tmarks11 View Post
    Tormach powers the stepper from a 48VDC power supply. But that would have to be upgraded, since it probably doesn't have a high enough current rating.

    The upgrade wouldn't be quite so expensive if you just did it to the X&Y axis.

    I don't think you truly get all the real benefits of a system designed with a servo motion controller, but you would get faster rapids and cutting speeds.
    I'm still pretty new to a lot of this stuff but couldn't you upgrade to a 75vdc power supply pretty easy? Couldn't you speed up your Rapids that way? From what I've read most steppers that size can Handle 75vdc.

    Sent from my SM-G900V using Tapatalk

  8. #8
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    Re: Clear path servos

    Thanks a lot for your input everyone, pardon my ignorance.

    Sent from my SM-G900V using Tapatalk

  9. #9
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    Re: Clear path servos

    Quote Originally Posted by Gravelleknives View Post
    I'm still pretty new to a lot of this stuff but couldn't you upgrade to a 75vdc power supply pretty easy? Couldn't you speed up your Rapids that way? From what I've read most steppers that size can Handle 75vdc.

    Sent from my SM-G900V using Tapatalk
    No, that is completely false. For steppers, optimal voltage is a function of the coil inductance. Arbitrarily increasing voltage will likely result in motor heating, and likely damage to the drivers, unless they are spec'd for the higher voltage. With servos, reduced voltage (i.e. - running the motors at 48V when they're spec'd for 75V) will result in proportionally reduced maximum speed. Even if the voltage were correct, it's not at all likely the stepper power supplies would provide the additional current necessary for the increased torque that is required to be able to increase the performance.

    Also, torque ratings between steppers and servos are not remotely the same - the specs have completely different meanings. And, steppers and servos have completely different torque/speed characteristics. So, selecting a servo motor based on the corresponding stepper torque rating will surely result in disappointment, unless the differences are well understood, and factored into the decision. The ONLY way to properly size any drive system is by measuring the actual machine requirements, and doing the math, based on the targeted performance. Guessing rarely turns out well, and is exactly why so many home-build machines turn out to be such disappointments.

    As for the idea of "upgrading" only X/Y, that would be foolish. First, many Mach3 version simply do no work correctly when the X axis torque/acceleration performance differs significantly from the X/Y performance. I'm sure this is not a problem with PathPilot. However, on any move involving the Z axis, ALL axes will be slowed down to the performance of the Z axis. For 3D profiling, this would mean almost no improvement in performance on most operations.

    Regards,
    Ray L.

  10. #10
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    Re: Clear path servos

    Quote Originally Posted by SCzEngrgGroup View Post
    First, many Mach3 version simply do no work correctly when the X axis torque/acceleration performance differs significantly from the X/Y performance. I'm sure this is not a problem with PathPilot. However, on any move involving the Z axis, ALL axes will be slowed down to the performance of the Z axis. For 3D profiling, this would mean almost no improvement in performance on most operations..
    Well we are talking about Tormachs with path pilot.

    Since z axis movement is largely nonexistent during most cutting, having it slower will not significantly reduce overall cutting time. Most CAM strategies (unless maybe you are mold making) do the cuts on the same Z plane, and only step up or down in z-axis at the beginning of running the next path.

    During most cnc cutting (except maybe mold making), the X &Y axis move tens of inches for every 1" of movement of the z-axis.
    Tim
    Tormach 1100-3, Grizzly G0709 lathe, Clausing 8520 mill, SolidWorks, HSMWorks.

  11. #11
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    Re: Clear path servos

    Quote Originally Posted by tmarks11 View Post
    Well we are talking about Tormachs with path pilot.

    Since z axis movement is largely nonexistent during most cutting, having it slower will not significantly reduce overall cutting time. Most CAM strategies (unless maybe you are mold making) do the cuts on the same Z plane, and only step up or down in z-axis at the beginning of running the next path.

    During most cnc cutting (except maybe mold making), the X &Y axis move tens of inches for every 1" of movement of the z-axis.
    I was largely just looking to speed up the rapids, Unfortunately you can't really speed up the cut feed because of the spindle limitations, for plastics you might be able to go 150ipm but much more than that and the RPM's will be a big problem.

  12. #12
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    Re: Clear path servos

    Quote Originally Posted by tmarks11 View Post
    Well we are talking about Tormachs with path pilot..
    The OP has said nothing about Path Pilot, and Tormach has used several different versions of Mach3, some of which may well have the bug I referred to.

    Regards,
    Ray L.

  13. #13
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    Re: Clear path servos

    Quote Originally Posted by Gravelleknives View Post
    I was largely just looking to speed up the rapids, Unfortunately you can't really speed up the cut feed because of the spindle limitations, for plastics you might be able to go 150ipm but much more than that and the RPM's will be a big problem.
    Spending $2500 to do nothing more than speed up rapids makes no sense to me, unless you're doing a lot of HSM toolpaths, especially 3D, where the repositioning moves can significantly increase program run times if rapids are slow.

    Regards,
    Ray L.

  14. #14
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    Re: Clear path servos

    A couple of months ago I had a Clearpath motor (CPM-SDSK-3432S-RLN) in the shop waiting to be installed in another project. Just out of curiosity I replaced the PCNC1100 (series 2) X-axis stepper with the Clearpath and controlled it through the USB interface.

    The servo moved the X-axis very well. I don't remember the top speed, but recall it being "pretty fast". The acceleration had to be limited to keep the Tormach from shaking significantly. The low acceleration would reduce some of the benefits of the faster rapids.

    Both motors are NEMA34 so it fit directly without changes. I would upgrade the Tormach motor coupler to a type that allows a bit of misalignment. I wouldn't use flood coolant without additional protection. You would need a brake for the Z axis.

  15. #15
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    Re: Clear path servos

    Quote Originally Posted by wvines View Post

    Both motors are NEMA34 so it fit directly without changes. I would upgrade the Tormach motor coupler to a type that allows a bit of misalignment. I wouldn't use flood coolant without additional protection. You would need a brake for the Z axis.
    Thanks, Thats what I was thinking. I know someone mentioned a special bracket but I thought It should go right together. When you say pretty fast, you mean significantly faster than normal?

  16. #16
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    Re: Clear path servos

    Quote Originally Posted by SCzEngrgGroup View Post
    The OP has said nothing about Path Pilot,
    He has PathPilot. He shows it is a couple of his videos.
    Tim
    Tormach 1100-3, Grizzly G0709 lathe, Clausing 8520 mill, SolidWorks, HSMWorks.

  17. #17
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    Re: Clear path servos

    Quote Originally Posted by tmarks11 View Post
    He has PathPilot. He shows it is a couple of his videos.
    I didn't specify, but I do use PP.

    Sent from my SM-G900V using Tapatalk

  18. #18
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    Re: Clear path servos

    I don't remember but you can calculate it. What's the lead on the Tormach ballscrew? 0.20 inches?

    I was using the 3432S motor which has higher torque and lower top RPM -- only 1000 rpm. I could hit the max rpm, so the speed would have been 1000 x lead. So 200 IPM if the lead is 0.2.

  19. #19
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    Re: Clear path servos

    Quote Originally Posted by wvines View Post
    I don't remember but you can calculate it. What's the lead on the Tormach ballscrew? 0.20 inches?

    I was using the 3432S motor which has higher torque and lower top RPM -- only 1000 rpm. I could hit the max rpm, so the speed would have been 1000 x lead. So 200 IPM if the lead is 0.2.
    Just checked, the lead is .2. Thanks for the info. Was it getting to 1k rpms pretty quick? Good acceleration?

    This all started because I was researching clear path servos for a cnc router and wondered how they would perform on the Tormach.

    Sent from my SM-G900V using Tapatalk

  20. #20
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    Re: Clear path servos

    Yes, it accelerated very well. The motor would shake the Tormach excessively before I dialed it down.

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