Giant 20' x 3' x 2' router build

[charlieuk]

There's nothing between the motors. I would definately go with the digital drives thou in My experience I'd go with EM806 rather than the DM856 as they are worth the extra. They have better resonance handling and stall detection and just seem to run motors that bit smoother than the DM856.

With the rack I'd go with sprung loaded as it keeps backlash to a minium and lowers rack wear. Problem with fixed is you need to be very precise with rack alignment and pinion tension/engagement otherwise it wears quickly and can stick or bind causing motor stalls.
Sprung loaded is more work but more forgiving and if done correctly gives better backlash and longer life.

Cheers thanks for that, are the digital drivers cnc4you good alternatives to the em806 only that they have been super helpfully through my build and
offer great backup and support from them so far.

I will do a little more searching to see what I can find for the rack and pinnion and come up with some sort of design unless zany one knows of something avalable for mod 1 rack? Many thanks