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ClearPath Servo Motors

Discussion in 'Concepts and Ideas' started by Metalguru, Dec 8, 2016.

  1. Metalguru

    Metalguru Master
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  2. Darathy

    Darathy Journeyman
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    Yes they are awsome ,i've seen them in action on NY CNC() they are great since they will not loose any stepps and will have constant torque throughought their speed!! But yes they are way too expensive for me :( i'd buy them over the normal steppers if they were 100$ per motor.
     
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  3. Joe Santarsiero

    Joe Santarsiero OB addict
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    They'll be that cheap someday Darathy. Someday.
     
  4. Florian Bauereisen

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    Hi,
    i have a set of three of them on my diy-cnc ( pictured in my avatar). These are simply fantastic is all i can say about them...
    And soo quiet... don┬┤t hear them move at all if going slow (faster you hear the square wagons on their rails)
    Apart from that price is relative:
    3 quality steppers of equal strength and 3 good drivers cost aprox 50% of these... going Closed loop would have cost me (Germany) just about 200 Euro less..
    I recon i will move them a couple of times if i ever decide to build another cnc ;)
    Other than that... tools, measuring devices, small parts, computer, ps, bob,... all ads up so much that actually 2-300 Euro is not going to make me stop buing quality, you spend it just once (hopefully) While other things like bits being a constant drain on the wallet without even getting noticed.
    Greets
    and a happy new year

    Flo
     
  5. PhotoSgt85

    PhotoSgt85 Veteran
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    I haven't used these although I have spec'd them for a project design at work. Everything I could find says that these offer a great alternative to steppers and I can assure you from getting other quotes on servo systems that these are much cheaper than any other system I've found. These are on my list for future upgrades to my C-Beam Machine XL.
     
  6. Metalguru

    Metalguru Master
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    Still, cheap is relative. When the motors cost more than the rest of the machine put together, that's a big hit.
    It's a long stretch from a $20 stepper motor to a $300 servo motor.

    I agree that they do look really good, however. I'm dying to try them out too.

    MG
     
  7. PhotoSgt85

    PhotoSgt85 Veteran
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    I agree that the cost could be prohibitive for some applications, however these are not only motors.

    High-Torque Stepper Motor, Stepper Motor, Driver, Stepper Motor kit, DC Servo Motor, DC Servo Motor kit, Stepper Motor Power Supply, CNC Router, Spindle, and other Components. Stepper Motor | Stepper Motor Driver | CNC Router | Laser Machine | 3D Printers For Sale

    The link I have put on here is the first google result for closed loop steppers. The clear path motors have encoders as well as controllers built in. Basically to equal what the clear path is you would need a closed loop stepper with a driver, at a NEMA 23 those could be from 200 and up depending on where you go for the Driver. You could make this a lot cheaper with some ebay specials but integrating it all together is sometimes not worth the hassle. Basically if the functionality you need is met with a stepper that is definitely go that way. I don't know that I would get them to only use them as quiet steppers, but if you are going to use some of the other functionality then the stepper equivalent is just as much and probably more when you factor the time you need to take to set it up.

    One thing I'm thinking of is that the Clear Path motors run a routine when you set them up to determine the inertial load so that they accurate move without under or overpowering the load. They also track the torque on the shaft by tracking the encoder vs the position it is going to.

    Not trying to shill for them or anything but I did a lot of digging and Clear Path is where I ended up. Take it for what its worth and when I get them in at work Ill post a video of them operating on the sample changer. :)
     
  8. Metalguru

    Metalguru Master
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    Don't get me wrong, they are really cool, and If I had an unlimited budget they'd be at the top of the list.

    They would certainly make machining easier, faster, and more accurate, and you would be able to get rid of a bunch of limitations of the stepper driven machine.

    MG
     
  9. Marcus1

    Marcus1 Journeyman
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    Any Results yet?

    Looking for a good servo solution as I am sick of making scrap
     
  10. Metalguru

    Metalguru Master
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    I think you may be expecting servos to solve a problem that may not even be motor related.

    It may be that you are blaming your motors for making scrap when likely it is some other problem. A LOT of people sucessfully use open loop stepper systems without issues, so it is probably unfair to simply blame the motors. I've probably personally built at least 30 machines, and never had a problem related solely to stepper motors. Out of the more than 100 steppers I've bought, I've never had a bad one or one that didn't perform properly. And they are pretty much all cheap Chinese units.

    Occam's Razor... Servo's will not solve your problem if it is related to other components or software in your system. Just sayin....

    Clearpath is still the way to go. They are much cheaper than a non integrated solution, and even if you were to cobble together some kind of closed loop servo system, you would still have to write all the software to run it. I'm pretty sure you don't have the millions to spend that Clearpath did... I have a client that installed Clearpaths on his C-Beam XL. That machine is so smooth, quiet, and insanely accurate its hard to believe.

    MG

    12135236_155104221509819_621577010_n.jpg
     
  11. Marcus1

    Marcus1 Journeyman
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    MG

    Not Blaming steppers, Just want to find a good solution.
    Using a small cutter to pierce material. Using a vac table and spiral compression cutter. Pieces can come out and interfere with the cutter causing loss of position, scrap is then made.

    Using Mach 3 ESS with OX
     
  12. Rob Taylor

    Rob Taylor Veteran
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    Seems like the obvious solution would be to either change the geometry of the vac table, or go to tabs and second op cleanup with a pallet system. Unless you mean the chipload is interfering with the cutter, in which case adding coolant or airblast might be an option, or change from peck drilling to straight-through or vice-versa... There are a lot of things to change about the operation before deciding the machine is at fault. Obviously you may have tried some of these things already, but that's all probably for a thread in its own right.

    Speaking of motor selection, anyone know off-hand what a good torque ballpark figure to be looking at is for HSM of mild steel on 16mm ballscrews? I'll be calculating it out anyway, but it would be good to have numbers from experience, if there is any. I know most people cut wood and alu.
     
  13. Metalguru

    Metalguru Master
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    Yeah,
    Yeah, those issues have nothing to do with motors. Perhaps, as Rob said, put tabs on your cuts, another possibility is to cover the back of the piece with masking tape to hold everything together.

    One of the problems with vac tables is that as you make cuts, you lose holding power as holes are uncovered. Vac tables are not really suited to making through cuts. Also, you are damaging your table surface with every through cut and reducing it's holding power.

    MG
     
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  14. Marcus1

    Marcus1 Journeyman
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    MG

    Yep have used tabs and then cut through on the last finishing path, it all helps but there is always one that jumps out and interferes. When you are cutting maybe a 1000 piercings in one sheet **** happens. Just want the machine to stop when it has and give me a chance to sort it out. Vac works well when the cut outs are large, just not small

    Have priced these motors up and is coming to 1468$ inc post. Anybody want to go for a group deal????
     
  15. Rob Taylor

    Rob Taylor Veteran
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    The point of tabs would be to be able to remove the entire sheet and then manually remove the parts- as I said, perhaps a second op cleanup pass with palletisation/custom fit jaws (ie. turn the pieces on their side, exposing just the tab and clamping the rest) could be an option, depending on the exact parts. Cutting through the tabs on the last pass is still going to result in the same problem when you're using a vac table- it's just not the best solution for the task. Plus it seems like you're inherently at risk of using the vac table as a spoiler board, which doesn't seem like the best idea.

    If you're just 2.5D routing out parts from sheet plate and can't go to a fiber laser for whatever reason, I'd go to a custom spoilboard solution, with specific geometry that allows clamping to a minipallet system on the table and supergluing to the work sheet- then you can just heat it up and all your parts fall out, no tabs required. Periodically you'd need new spoilboard though, but you could use the machine to resurface it for a while. But expecting small parts to not get flung around by a high power spinning object no matter what the motive force is doesn't seem sensible.

    Maybe, depending on the thickness of the sheet, you could even support it in mid-air, such that the parts drop out away from the cutter as you finish the last pass?

    I wish. $1468 is the region of the total price I'm aiming at for my next-next build. Maybe in a couple years when it's time to start testing upgrades! I think I'd need 6-7 of them, anyway, so closer to $3000 I imagine. I am intrigued by those NEMA 23 stepper/feedback/controller units up there though. $160 is a promising ballpark if 280oz-in is sufficient for me.
     
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  16. Marcus1

    Marcus1 Journeyman
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    Rob

    Fiber Laser seems a very expensive option. I am mainly cutting MDF and not sure what fumes etc will be produced.

    Tabbing and then cutting out would take ages - as I said there may be 1000 cutouts on a 1000mm x 2200 sheet
    Customising is difficult as every job is different

    Where did you see the $160 Nema 23 units?
    Also any experience of Hybrid stepper closed loop systems?
     
  17. Jonathon Duerig

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    I can't speak to using servo motors (they are out of my price range as well).

    But I can talk a bit about how to cut out small pieces consistently without needing to worry about tabs. I use a pressure foot and have very good results. Most pieces are perfect and even when there is the occasional defect, pieces don't pop out and cause me to skip steps. The pressure foot is made of relatively low-friction plastic and moves around with the blade. Springs press the plastic down onto the workpiece creating friction on the underside to hold things in place.

    (1) It works better on thinner pieces than on thicker pieces (I usually cut 1/8" thick stock).
    (2) It works better on smaller bits than larger bits (less cutting pressure).
    (3) It works best if you have a small final pass. On your main pass or passes, cut down to an 'onion skin', then the last pass just cuts away the last 0.25mm or 0.5mm of material.
    (4) It works better when cutting out small pieces than large pieces.
    (5) It doesn't work well at all if there are contours or large pockets. Small pockets and profiles only.
    (6) It works best with a downcut bit that leaves sawdust in the profile

    I'd say that this is worth a try. I would not be using my CNC router at all if I didn't have my pressure foot. But with it, cutting a bunch of small pieces is extremely fast.

    -D
     
  18. Rob Taylor

    Rob Taylor Veteran
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    Oh! For some reason I thought you were cutting aluminum. Hmm, MDF is trickier. I'd probably go with some kind of double sided masking tape idea, then, like Metalguru said. Something along similar lines to the protective paper film on acrylic.

    Of course, a 60-80W CO2 laser would probably be the best thing, but you're right, it would release some nasty stuff- you'd have to have an air channel in your collimator as well as some kind of downdraft and filtration system on the table. But if all you do is 2D MDF parts, that would be worth the conversion.

    Yeah, custom work kinda precludes my palletisation idea- it sounded like you were doing production runs of identical parts.

    I was talking about the Automation Technologies hybrids you saw above. If the feedback plays nice with LinuxCNC, I'd definitely consider it. Depends how tight the budget gets considering it's at least an HGR25/SFU1605/1.5-2.2kW build, which are plenty expensive in their own right. I have a path to profit on it, but I think I'd rather go cheap up front and slowly add servos later than go with a part-way solution if it starts getting out of hand, since my primary concern up front is functionality at any speed.

    Weird, I was just wondering if some kind of push-down ring would work as I was replying. Had no idea what it was called or that it was already a thing. This is definitely worth a try.
     
  19. Marcus1

    Marcus1 Journeyman
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    Thanks Johnathon for trying to help.

    I have tried a pressure foot but with mixed results.
    1. The material cut is between 6mm and 25mm thick - the spring pressure is to great over this range.
    2. The foot causes the cutout to move causing issues

    I do already use an up down spiral compression and rough out witth tabs, final finishing cut 1mm thick
     
  20. Rob Taylor

    Rob Taylor Veteran
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    1) Add a small stepper and leadscrew for altering the spring compression (Hooke's law) and include this as an axis in your gcode processing? Since your g54 z0 absolute position would change based on the thickness of material, you could incorporate that directly into the calculation for the spring axis.

    2) Use an array of captive PTFE balls or micro-swivel-casters instead of a "foot"?

    All else fails... Massively increase the air volume capacity on your vac table setup.
     
  21. Jonathon Duerig

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    For (1), I'd just make a pair of easy-swap feet with different springs (one stronger and one weaker).

    I really like the idea of captive PTFE balls. I had considered trying to use bearings instead of a flat foot for future iterations. But I had discarded the idea as too likely to scratch the surface (steel bearings).

    But I'm actually not sure that this helps Marcus1. When cutting out 6mm, I think a pressure foot is still pretty effective. But it is likely much less effective at 25mm. As I said before, the thicker the material the less effective it is. Because the small area of force from the springs becomes distributed over a much larger area of board and so there is much less friction holding the piece near the cutting head where it needs to be. This is the same basic problem with the vacuum table. It works great for large parts, but not for small ones.

    -D
     
  22. Rob Taylor

    Rob Taylor Veteran
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    Pfft, that doesn't sound like as much fun! :D

    My only concern with captive ball bearings would be that they could drop into your kerf and start pushing the material around from the side. That's probably able to be designed around though.

    If you only need to hold the part in place while you do your final cut-through, it seems like a foot would work just as well on thick material as thin- because it would be hinging directly on the final tab.

    Re. Vac table: holes instead of a grid, and an o-ring around every individual hole. Surface and drill it on the machine itself. Only where the kerf directly overlays a hole would it lose suction. Easier to replace an o-ring if you cut through that instead of re-surfacing the table itself, too. Just a thought.
     
  23. Metalguru

    Metalguru Master
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    Marcus1

    I agree with Rob, tabs are meant to be left in place and the entire sheet removed and manually cut out after routing is done. I have a client that makes 3D letters for signs out of foam board, and he does an entire 4' x 4' sheet at a time, leaving everything connected by tabs. He then pulls them out and manually cuts the tabs to retrieve the letters. A bit more time consuming for sure, but no wasted pieces. He actually uses pin routers to trim off the remaining bits of tabs.

    For the hold down foot idea, use a miniature air cylinder as your "spring". A small regulator could be used to set the applied force. The applied force would be constant and only dependent on air pressure, not the amount of compression of the cylinder. You could set the pressure based on the thickness of the material or whatever factor you want. You could also use a valve to pull the foot up out of the way for fast moves, etc.

    I think we are getting way off topic here, the original topic was Clearpath servo motors. Suggest moving this to a new thread. Where are the Mods when you need them?

    MG
     
  24. Ed Kirk

    Ed Kirk New
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    I installed three of the smallest units that are available on my diy 3d printer several years ago, I have used several control boards (step, direction and enable) to drive them with absolutely no problems. Finally settled on a Smoothieboard, they are fantastic I also use them on my kit build 24x24 inch CNC router with a Flash Cut controller and they are really great. Quiet, smooth and powerful, very simple and clean wiring when using Clearpath wiring (not included, cost extra). I use a 48 volt DC power supply on the 3d printer and the higher voltage Teknic power supply on the router both work with no problems. Great quality, smooth, powerful (overkill for a 3d printer) if you are willing to pay the price they are well worth it. Also, I almost forgot, they are programmable with the Clearpath software (free download). You can set direction, current limit, auto tune to match controller board and equipment and use to monitor parameters when in use via USB. They are no more difficult then stepper motors/drivers if you understand what is going on. The instructions are available as a download, very long and thorough because they include all of the options, Their videos are also good.

    Ed
     

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    #24 Ed Kirk, Aug 23, 2017
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