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Hi there

Is there a 3000mm or longer length ball screw available in 20 or 25x05 or should a rack and pinion system be considered for a Y-Axis setup in a CNC machine with a typical configuration as this one in photo?

Hi Sven, welcome to CNC Zone.uk. Its nice to see our products assembled into a machine....

Y axis Ballscrew: For production purposes, to make the application cost effective you will need to use a 25x25 or 32x32 Ballscrew with a rotating Ballnut, cost £2500gbp lead-time 18 weeks.

Therefore I suggest a cheaper option: Rack and pinion; the pinion will require assembly to bespoke bearing block, as the stepper motor bearings are not designed to carry the extra load of the pinion.

Hi Kevin,

You are right, the most practical solution would be a rack and pinion setup. Regarding the stepper motor bearings, I am playing with a design idea with pinions on both sides underneath the machine bridge assembly connected to a common pinion drive shaft. I then connect the stepper motor via a belt drive to this pinion drive shaft. This gives me the opportunity to gear the setup for in the region of 6000mm/min and everything is neatly tucked away underneath the machine. What I also achieve is a very stiff bridge assembly in yaw. I will later, time permitting, post sketches of this design idea.

Regards

svenh:

Is there a 3000mm or longer length ball screw available in 20 or 25x05 or should a rack and pinion system be considered.

Have you considered a toothed-belt? Bolt the carriage to the belt, and motorise one pulley. (rather like a souped-up flat-bed plotter). We used such a setup sucessfully for a semi-circular axis on an x-ray microscope. (a much bigger machine than it sounds)

Hi there,

I did not consider a toothed belt but it seems like an excellent idea. I will definitely do some research in that direction.

Regards

I have just checked our database of bespoke machines….We recently manufactured a hot wire machine. Designed predominantly as a foam block cutter with the option of adding a Z Axis, this was driven by one of our new linear slide systems with a toothed belt; this offers a repeatability of 0.075mm (0.003”)

The Z Axis was added later for the roughing of the surf board profile….