home built laser engraver : what type of linear drive ?

[rkovvur]

For the laser engraver i am planning to build, I am now stuck on the issue of the type of linear drive for the X and Y axis.

I'd like to know what others are using.

I initially planned on using lead screw type (ACME with delrin nut). Then thought of changing to ballscrew. Now i see that commercial lasers use the belt type(this gives no backlash, but the motor needs to be handle the inertia of the gantry).

If you guys are successfully using a drive mechanism, plase share it

[zax15uk]

rkovvur,

For a laser application the gantry and head (optics housing) is low mass, and higher speed so a belt drive is typically used.

A CNC machine has a heavier gantry with more mass for the spindle etc so a ball screw would be optimum and a lead screw acceptable.

I would recommend the belt drive if it is a pure laser system.

Zax.

[rkovvur]

Thanks!

My worry about the belt drive is its resolution. And the belt tension and i believe that the stepper would need to have higher torque.

In a screw drive, i guess a lower torque motor can be used, right?

[zax15uk]

Resolution should not be a problem with the correct pitch belt and pulley. If you are concerned about belt tension you could add a spring loaded automatic tensioner.

You won't need much torque, so it shouldn't be a problem. I would always use a belt drive for laser applications.

Zax.

[wktina]

belt and stepper should be your ideal and economical choice

[pixpop]

What about belt drive with a servo instead of a stepper? Any reason not to do that?

[zax15uk]

Servo and belt would be optimal, but higher cost compared to a small stepper.

Zax.

[wktina]

Originally Posted by pixpop What about belt drive with a servo instead of a stepper? Any reason not to do that?

if you want to use a servo instead of stepper,then belt is not a wise choice,precision can't be satisfied.
so you should choose servo motor with ball screw
stepper with belt is optimal partner

[pixpop]

Originally Posted by wktina if you want to use a servo instead of stepper,then belt is not a wise choice,precision can't be satisfied. so you should choose servo motor with ball screw stepper with belt is optimal partner

I think you're probably right, but I'm not sure I understand. Can you not improve precision by increasing encoder resolution?

[wktina]

Originally Posted by pixpop I think you're probably right, but I'm not sure I understand. Can you not improve precision by increasing encoder resolution?

increase encoder resolution will not change much.this is rigid problem,but belt is too flexible.if you want to know details,pls write me email
tina@wklaser.com

[zax15uk]

Servo and belt drive is an ideal solution for high speed applications. You can achieve much quicker acceleration and faster rapids compared to a stepper.

It may not provide any better resolution when coupled with a belt (although this isn't necessarily true) but it will be quieter and smoother.

With the low loadings of a laser system the belt drive is the way to go, and if cost isn't the major factor I would use servos.

Zax.