belts vs screws?


View Poll Results: Belt or screw drive?

Voters
97. You may not vote on this poll
  • Belt drive

    30 30.93%
  • Screw Drive

    67 69.07%
Page 1 of 3 123 LastLast
Results 1 to 12 of 25

Thread: belts vs screws?

  1. #1
    Registered
    Join Date
    Mar 2008
    Location
    USA
    Posts
    33
    Downloads
    0
    Uploads
    0

    Cool belts vs screws?

    Hello to all:

    I starting to plan out my DIY five or six axis wood cnc router. My question for all you experts out there is: Belt drive or screw drive? I have heard that belt drives are faster, more accurate and don't strain motors as much. I'm looking for as much input as I can get, so please give your two cents worth!

    Similar Threads:
    Last edited by neeboy; 04-01-2008 at 03:19 PM. Reason: misspelling


  2. #2
    Registered
    Join Date
    Mar 2008
    Location
    USA
    Posts
    33
    Downloads
    0
    Uploads
    0

    Default

    Geez, I guess I shoula looked at the other posts first! Ooops!



  3. #3
    Registered automizer's Avatar
    Join Date
    Dec 2005
    Location
    Canada
    Posts
    439
    Downloads
    0
    Uploads
    0

    Default

    I have run machines with both and I have to say I do not like belts at all. I found that if the belt got warm ie on a hot day that it would grow and throw your machine out of alignment or running it under high load it would skip a tooth on the belt and really screw you up. Now this was running a belt over 10' long with square teeth, I know there are better belts out there but I say ball screws all the way.

    I'm not lazy..., I'm efficient!


  4. #4
    Registered
    Join Date
    Apr 2008
    Location
    usa
    Posts
    49
    Downloads
    0
    Uploads
    0

    Default

    In my limited experience, I prefer belt drive due to speed and yes it is easier on the motors. with my screw drive, I could only get up to 30" per min(with a 276 oz-in). With the belt drive, I can get to about 1700" per minute(but I also increased the from 276 to 640oz-in.). I would like to play with a nice ball screw, but that is out of my price range.



  5. #5
    Registered
    Join Date
    Aug 2005
    Location
    knoxville,usa
    Posts
    578
    Downloads
    0
    Uploads
    0

    Default

    Many are going to rack and pinion because of speed increase and much less costly than ball screw. Check the posts related to rack and pinion before making a decision. I means you will have to use 2 motors in the x axis but with the price of motors on ebay its a no brainer...I would still use ballscrew or Acme on Z axis

    Bob



  6. #6
    Registered
    Join Date
    Dec 2006
    Location
    usa
    Posts
    775
    Downloads
    0
    Uploads
    0

    Default

    Tell me about resolution accuracy with the belts. With a 200 step motor, and a 2 inch diameter pulley, the resolution is terrible. I assume that you are micro stepping the motor to get it into a reasonable accuracy range. Is that true?



  7. #7
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Location
    United States
    Posts
    32785
    Downloads
    0
    Uploads
    0

    Default

    You can get pretty much the same speed whether you use belts, or screws. Regardless of what you use, you always trade speed for accuracy. If you get 2" per motor revolution with a belt, you can get similar performance (and resolution) with a screw with a 2" lead. Very high lead screws are about 80% efficient, though, so belts will give you a slight edge there. But screws imo are easier to install. The only way to have high speeds and high resolution is to go to servos, where gearing and high encoder counts can give you extremely high speeds and still have high resolution.

    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  8. #8
    Registered
    Join Date
    Dec 2006
    Location
    usa
    Posts
    775
    Downloads
    0
    Uploads
    0

    Default

    Ger,
    How about length of axis in the DIY machines. Do you agree that 4 feet is pretty much the limit for a screw drive? Given a 72 inch screw minus the allowance for the gantry width. But with a belt drive, longer is possible?

    The attached image is my inspiration for joining this thread. The owner posted this machine in the Vectric forum. I hope it's ok with him that I repost it here.

    I can't image buying an acme screw long enough to span that distance pictured.
    Dave

    Attached Thumbnails Attached Thumbnails belts vs screws?-4x8-foot-router-table-jpg  


  9. #9
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Location
    United States
    Posts
    32785
    Downloads
    0
    Uploads
    0

    Default

    Quote Originally Posted by Glidergider View Post
    Ger,
    How about length of axis in the DIY machines. Do you agree that 4 feet is pretty much the limit for a screw drive?
    No, but you'll need to increase screw size and motor size, and cost goes up, sometimes real fast.

    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  10. #10
    Registered
    Join Date
    Apr 2010
    Location
    USA
    Posts
    169
    Downloads
    0
    Uploads
    0

    Default

    Quote Originally Posted by Glidergider View Post
    Ger,
    How about length of axis in the DIY machines. Do you agree that 4 feet is pretty much the limit for a screw drive? Given a 72 inch screw minus the allowance for the gantry width. But with a belt drive, longer is possible?

    The attached image is my inspiration for joining this thread. The owner posted this machine in the Vectric forum. I hope it's ok with him that I repost it here.

    I can't image buying an acme screw long enough to span that distance pictured.
    Dave
    My ball screw has 5' of travel. Of course, it is also 1" in diameter. ;-) There are screws available that are over 2" in diameter. They are heavy...



  11. #11
    Registered Pplug's Avatar
    Join Date
    Jan 2007
    Location
    USA
    Posts
    723
    Downloads
    0
    Uploads
    0

    Default

    You could always use a rotating nut design so the screw stays stationary. Then you would have no whip at all. My techno has a rotating nut on the 11' x axis ballscrew. The screw is about 2" in diameter.

    http://www.glenspeymillworks.com Techno LC4896 - 2.2Kw Water Cooled Spindle | Moving Table Mill from Omis 3 CMM, 500Lb granite base | Epilog Legend 32 Laser Engraver


  12. #12
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Location
    United States
    Posts
    32785
    Downloads
    0
    Uploads
    0

    Default

    I happened to measure the ballscrew on our Morbidelli today. It's 30mm, with a rotating nut, and moves a 1000lb+ head at about 1500ipm. There's about 13ft of travel, as it's a 5x12 machine.

    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


Page 1 of 3 123 LastLast

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

belts vs screws?

belts vs screws?