5 ms·

This could be greatly simplified (at higher cost) by using linear motors for the cross-slides. It may even be more rigid than what is there now (though nowhere

This could be greatly simplified (at higher cost) by using linear motors for the cross-slides. It may even be more rigid than what is there now (though nowhere near rigid enough to do anything real) The design is actually not unique at all - you can buy much better versions of it (at higher cost, obviously). Most positioning actuators you can buy are literally built to be attached to each other in a cross-slide configuration, and to have a rotary table attached to it. They also directly sell pre-built cross-slide actuators. If you just google "cross-slide stepper" or "cross-slide servo", you can see this (servo/stepper just gets rid of the manual ones, which also exist). The normal reason the configuration is not used is because it has no meaningful rigidity.

canadian_tired 5y ago
Well said.
dekhn 5y ago
Are you talking about products like this? https://www.amazon.com/Electric-Sliding-Ballscrew-SFU1605-Working/dp/B07BMKQ9C1 https://www.amazon.com/Electric-Sliding-Ballscrew-SFU1605-Wo... I'm not sure what you mean by "linear motor", I think these cross-slides typically use steppers or steppers with feedback.
- abakker 5y ago
  A linear motor is essentially a stepper motor that has been unrolled. The Stator and rotor are flat. Kern uses them in really high end VMCs and the result is better position control and better rigidity.
  - dekhn 5y ago
    do you have a pointer to a reasonably accessible device I can buy? I work with CNC and 3D printers and other motion stuff a lot and always want to find better products than the cheap steppers I'm using.
    - jbay808 5y ago
      What is your budget?
      - dekhn 5y ago
        I'd like to build this: https://www.thorlabs.com/thorproduct.cfm?partnumber=PT3-Z8 https://www.thorlabs.com/thorproduct.cfm?partnumber=PT3-Z8 but for about $500 or less. I don't think those Z8s are linear motors, though. They mean "linear translation", but using DC servos. It doesn't need to be nearly as precise,
    - toss1 5y ago
      Here you go: https://www.kollmorgen.com/en-us/products/motors/direct-drive/direct-drive-linear/?utm_source=bing&utm_medium=cpc&utm_campaign=us-direct-drive-linear-broad&msclkid=43d5349c12fb197ccd6955826f74ad6f https://www.kollmorgen.com/en-us/products/motors/direct-driv... and their page on success in CNC seems fairly impressive. https://www.kollmorgen.com/en-us/service-and-support/knowledge-center/success-stories/3d-cutting-for-large-formats/ https://www.kollmorgen.com/en-us/service-and-support/knowled... Edit: I'm not sure how accessible these are, but they have a life sales rep chat, so they seem to want to get them to you quickly...
      - dekhn 5y ago
        Generally, if a product requires talking to a sales rep, it's not marketed towards my interests (hobbyist automated microscopy and astronomy), and the product will be too expensive.
        toss1 5y ago
        Ah yes, at that level, you've probably found lots of reasonable linear actuators - rotary motors paired with a screw drive - but I don't recall seeing any low-cost ones either. Maybe eBay is the best bet, but it's hit or miss. It does seem there would be a market for some low-cost options.
      - Ductapemaster 5y ago

canadian_tired 5y ago

Well said.

dekhn 5y ago

Are you talking about products like this? https://www.amazon.com/Electric-Sliding-Ballscrew-SFU1605-Working/dp/B07BMKQ9C1 https://www.amazon.com/Electric-Sliding-Ballscrew-SFU1605-Wo... I'm not sure what you mean by "linear motor", I think these cross-slides typically use steppers or steppers with feedback.

abakker 5y ago
A linear motor is essentially a stepper motor that has been unrolled. The Stator and rotor are flat. Kern uses them in really high end VMCs and the result is better position control and better rigidity.
- dekhn 5y ago
  do you have a pointer to a reasonably accessible device I can buy? I work with CNC and 3D printers and other motion stuff a lot and always want to find better products than the cheap steppers I'm using.
  - jbay808 5y ago
    What is your budget?
    - dekhn 5y ago
      I'd like to build this: https://www.thorlabs.com/thorproduct.cfm?partnumber=PT3-Z8 https://www.thorlabs.com/thorproduct.cfm?partnumber=PT3-Z8 but for about $500 or less. I don't think those Z8s are linear motors, though. They mean "linear translation", but using DC servos. It doesn't need to be nearly as precise,
  - toss1 5y ago
    Here you go: https://www.kollmorgen.com/en-us/products/motors/direct-drive/direct-drive-linear/?utm_source=bing&utm_medium=cpc&utm_campaign=us-direct-drive-linear-broad&msclkid=43d5349c12fb197ccd6955826f74ad6f https://www.kollmorgen.com/en-us/products/motors/direct-driv... and their page on success in CNC seems fairly impressive. https://www.kollmorgen.com/en-us/service-and-support/knowledge-center/success-stories/3d-cutting-for-large-formats/ https://www.kollmorgen.com/en-us/service-and-support/knowled... Edit: I'm not sure how accessible these are, but they have a life sales rep chat, so they seem to want to get them to you quickly...
    - dekhn 5y ago
      Generally, if a product requires talking to a sales rep, it's not marketed towards my interests (hobbyist automated microscopy and astronomy), and the product will be too expensive.
      - toss1 5y ago
        Ah yes, at that level, you've probably found lots of reasonable linear actuators - rotary motors paired with a screw drive - but I don't recall seeing any low-cost ones either. Maybe eBay is the best bet, but it's hit or miss. It does seem there would be a market for some low-cost options.
    - Ductapemaster 5y ago