Some types of motor drives don't have backlash. Timing belts, cycloidal, and harmonic drives don't have enough backlash to worry about. The linked harmonic drive is as good as the leadscrew on the other axis.
On Fri, May 15, 2020 at 10:53 PM Roland Jollivet <roland.jolli...@gmail.com> wrote: > > I've been thinking about 4th axes; > While motorised reduction drives are readily available, the issue is > obviously backlash. > > One way to make a zero backlash drive is to use two identical > gearbox/drives. Place them at opposite ends of the axis, and pit them > against each other by a few encoder counts. > So they will track and retain the zero-backlash. > > Of course, the total power available is now less than one drive motor, but > it is an option to use almost any pair of reduction drives that can be got. > But there is also the cost of the second servo amp. > > > On Fri, 15 May 2020 at 14:11, andy pugh <bodge...@gmail.com> wrote: > > > The normally appear on eBay at up to 6x this price. > > https://www.ebay.co.uk/itm/233587431605 > > > > The B versions have conventional incremental encoders and hall > > sensors, so are easy to integrate. Lots of torque, zero backlash and a > > very strong and fancy big crossed-roller bearing make them an > > almost-complete 4th or 5th axis just needing a bracket and a drive. > > > > I have no connection with the vendor, if you order one and receive > > dolls-house furniture instead don't blame me. > > > > -- > > atp > > "A motorcycle is a bicycle with a pandemonium attachment and is > > designed for the especial use of mechanical geniuses, daredevils and > > lunatics." > > — George Fitch, Atlanta Constitution Newspaper, 1912 > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
