King Midas mill conversion

**Gary** · 15-03-2012

Looking at the drawing is seems over complicated.
If you want zero backlash and don't want any movement on the support bearing just go for a good quality FK12, the gten R1605 ballscrew and the R1605T3-FDID-P1

This is the link to the datasheet for the FDI and FDU type ballnuts and it is 34mm between the flats, so it is actually 6mm difference.
http://www.zappautomation.co.uk%2Fpd...%2FFDU-FDI.pdf

The ballnut is already pre loaded for zero backlash and has been tested on the screw.

you will need ti install chinese fonts in acrobat.

**Robin Hewitt** · 15-03-2012

Originally Posted by Gary

The ballnut is already pre loaded for zero backlash and has been tested on the screw.

That looks interesting, is it shimmed or does it have springs? The data sheet is vague.

**Gary** · 15-03-2012

No its a spacer between the two nuts.
I dont know of any commercial double ballnuts that use a spring.
All the manufactures i have worked with use a spacer to pre load the double ballnut, and there are reasons for this.

Originally Posted by Robin Hewitt

That looks interesting, is it shimmed or does it have springs? The data sheet is vague.

**Robin Hewitt** · 15-03-2012

Originally Posted by Gary

All the manufactures i have worked with use a spacer to pre load the double ballnut, and there are reasons for this.

Good point, I forgot to mention that John will need to leave room to fit an oil pipe to the nut. I use 4mm OD nylon tube and standard push fittings which are a bit sticky out and it will drip