Page 2 of 2 FirstFirst 12
  1. #11
    Ross77's Avatar
    Lives in Devon, United Kingdom. Last Activity: 2 Hours Ago Has been a member for 8-9 years. Has a total post count of 689. Received thanks 25 times, giving thanks to others 40 times.
    Clearly, yes some people have strong opinions.



    I am using Delrin anti backlash nuts on my converted Chinese mill but then it is only a toy for learning and occasional use in model engineering. I have 1 thou backlash on both X and Y axes and it gives very little friction at that setting.
    Delrin will have reduced friction But I found that it just acted as a damper and masked the backlash. measuring low backlash only under a no-load condition. Once the load is applied it compresses until the the other edge of the screw is in contact( ie play in the screw/nut). The amount of compression is dependant on the load so you end up with varying amounts of error on the work piece.

  2. The Following User Says Thank You to Ross77 For This Useful Post:


  3. #12
    Quote Originally Posted by Ross77 View Post
    Delrin will have reduced friction But I found that it just acted as a damper and masked the backlash. measuring low backlash only under a no-load condition. Once the load is applied it compresses until the the other edge of the screw is in contact( ie play in the screw/nut). The amount of compression is dependant on the load so you end up with varying amounts of error on the work piece.
    Agreed, this can be a problem but like everything it depends on the design. Some use springs to compress the split nut and of course these flex under load. I am just using screws to adjust it with no flexibility. My first attempt did have a flexibility problem which I traced to the flange on the nut flexing. It was cured by backing it with a substantial steel washer.

    Again, horses for courses.

    Russell.

  4. The Following User Says Thank You to russell For This Useful Post:


  5. #13
    i2i's Avatar
    Lives in Cardiff, United Kingdom. Last Activity: 23-12-2016 Has been a member for 7-8 years. Has a total post count of 693. Received thanks 30 times, giving thanks to others 0 times.
    at the end of the day, you're going to cnc a manual mill for what reason. You want an accurate computer controlled milling machine that will cut metals from ally to probably steel.

    The first need is accuracy, which means ballscrews.

    You don't need to go any further.

  6. The Following User Says Thank You to i2i For This Useful Post:


  7. #14
    Hi John

    I agree, i have used Oldham couplings for many years, i just thought things may have moved on a little, they seem so expensive these days.

    Regards
    Ray

  8. #15
    Unless I'm out of touch with other couplings, not that I'd use them, I thought they were about the same price.
    I get mine from ARC, used to buy off RS but they have cut their range right down.
    John S -

  9. Not sure if you have looked at buying your ballscrews from China? There is a massive cost difference between China and the UK. Check out Linearmotionbearings2008 on ebay.

  10. The Following User Says Thank You to JoeHarris For This Useful Post:


  11. #17
    Many thanks i2i.

    Yes commonsense must prevail, i am converting to CNC for greater control and accuracy, so i will go down the ball screw route, if i can find screws and nuts that will fit under my slides. My Lead screws are 14 mm diameter, what would be the smallest diameter ball screw i could use i wonder?

    Regards

    Ray

  12. #18
    You could go down to 12mm dia ball screw.
    The biggest problem will be finding enough room for the ball nut!
    On my Sieg X1 conversion I used RSW ball nuts which have the smallest dia, when I did mine I thought you could not get them with wipers fitted but you can.
    RSW Ballnut

    Just an idea to think about
    Peter

  13. The Following User Says Thank You to ptjw7uk For This Useful Post:


  14. #19
    You can get 12mm (RM1204) ballscrews from linearmotionbearings2008 on eBay. The steel the ballnuts is made from is just about soft enough to mill, so if you need to make them a bit smaller that's a cheap option. It's probably easier to grind it and glean the nut thoroughly afterwards. Clearly the stiffness and critical speed of the screw are both reduced if it's smaller, however in this instance neither is significant since it's a small machine.
    Old router build log here. New router build log here. Lathe build log here.
    Electric motorbike project here.

  15. The Following User Says Thank You to Jonathan For This Useful Post:


  16. #20
    Ross77's Avatar
    Lives in Devon, United Kingdom. Last Activity: 2 Hours Ago Has been a member for 8-9 years. Has a total post count of 689. Received thanks 25 times, giving thanks to others 40 times.
    Have you got any space between the base and end plate on the bottom axis (Y- I think on a mill)? I'm just looking to put ballscrews on my mill and want the biggest diameter possible as it is only supported on one end. The channel between the ways is too small for 20mm dia. ball nut but I have space to move it forward and mount the nut flange on the face of the base.

    Any way just a thought.

  17. The Following User Says Thank You to Ross77 For This Useful Post:


Page 2 of 2 FirstFirst 12

Similar Threads

  1. Looking into a ballscrew, not sure if I should buy. Help
    By oldmam4m80s in forum Lead Screws, Nuts & Supports
    Replies: 21
    Last Post: 28-07-2017, 10:15 PM
  2. WANTED: Ballscrew and nut
    By D-man in forum Items Wanted
    Replies: 8
    Last Post: 30-08-2013, 04:25 AM
  3. Ballscrew Woes, help please!
    By jonbabbz in forum Lead Screws, Nuts & Supports
    Replies: 9
    Last Post: 21-04-2012, 12:16 AM
  4. Where to get C3 & C5 Ballscrew
    By AdCNC in forum General Discussion
    Replies: 10
    Last Post: 10-08-2011, 06:56 PM
  5. FOR SALE: Looking for a ballscrew (eBay)?
    By Smiler in forum Items For Sale
    Replies: 13
    Last Post: 16-05-2009, 03:22 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •