Ok, I'm stumped. Question for Gary (ZAPP)

[Gary]

Yes we can make them, but to get zero backlash they will need to be made at the factory, and will be a long delivery.
Also how come you dont have a floating end? you have the lower screw fixed at both ends?

Took a while but here it is, can you make 'em?

16mmx5 screws with your anti backlash double nuts.

Threads are your usual M12x1, flats are 1mm deep.

I'd like 12mm ball races to slide on by hand, not tight. Other tolearances are fairly slack, shall we say .25mm

best regards

Robin

[Gary]

Out of interest what are the flats for? Are you fixing the ball screw and turning the nut?
Also 0.25mm is going to be very sloppy on the bearing and may cause you problems?

[Robin Hewitt]

Out of interest what are the flats for? Are you fixing the ball screw and turning the nut?
Also 0.25mm is going to be very sloppy on the bearing and may cause you problems?

The flats are for the grub screws that lock the pulleys and handles in place. The nuts hold tension against belleville washers I wouldn't want to rely on them to grip anything.

The tolerance does not apply to the shaft diameter, that wants to be a nice sliding fit. I'm sure you can do better than .25mm anyway.

[Gary]

Ok good, i will get the drawing made up asap.

The flats are for the grub screws that lock the pulleys and handles in place. The nuts hold tension against belleville washers I wouldn't want to rely on them to grip anything.

The tolerance does not apply to the shaft diameter, that wants to be a nice sliding fit. I'm sure you can do better than .25mm anyway.