Short update:

No progress for the last 2 weeks on the router design. I have been really busy with other projects and commitments. I had already bough 180W servos but those I already returned for some 400W servos with integrated drives. Those servos are now fitted on a Hitachi Seiki lathe (huge lathe with 400mm 4-jaw chuck) with a 1:1 ratio on the X-axis and a 2:1 ratio on the Z-axis. Ballscrews are 2005. WOW, I can now run the lathe at 10m/min without any problems. Ballscrew whip is no problem. I am very happy with that upgrade.

Anyway back to the router. Since I will be using servo motors with a 3000rpm rated speed, I thought I could take full advantage of that. I plan to do the following:
  • Swap the 2010 ballscrews to 2020 on the Y-axis and X-axis.
  • Swap the 1605 ballsrew to 1610 on the Z-axis
  • Change gearing ratio from 2:1 to 3:1 on all axis. This will give me more torque, with lower ballsrew rpm while increasing the ballscrew pitch.
  • Add belt tensioners to get more teeth engaged because of the 3:1 gearing.

This will limit the ballscrew speed to 1000rpm, and increase the Y- and X-axis maximum feed rate to 20m/min. Z-axis feed rate will stay at 10m/min. I feel like this is a better idea than trying to spin the ballscrews at 1500rpm with the 2:1 ratio. I want to take full advantage of the servo motors RPM.

On another note I was planning to use 400W (maybe even 750W) Delta servo motors, with dual motors on the Y-axis. I need to do some calculations if it would be a good idea to go for 750W. Anyway I saw on YouTube that there is a auto tuning function available in the software but I am not sure how to tune the dual motors on the Y-axis.

  1. What do you guys think about the increased ballscrew pitch, 3:1 gearing and belt tensioners?
  2. Is it possible to auto tune 2 motors at the same time?
  3. Perhaps I could change the design and use only 1 servo motor on the Y-axis with belt drive connected to both sides. This in turn will not allow for squaring the gantry with motion controller but I think i can get it square any way.
  4. How wide can the gantry be without having to use dual slaved Y-axis motors?