Dual Lead Screw W/ Indipendant Steppers

[CAMCRASH]

Is it possible to have dual lead screws on a single axis with independent stepper motors
If so what would I use or how would I maintain synchronization between the motors?

[ironDigit]

tuning is the answer to this.
any motor should be tuned before it can optimally perform in any given situation.

Though from what i've read tunign motors can be quite a challenge to a noob like meself.From here on i can only imagine what issues go along with tuning 2 motors and drives to both eachother and a axe.
Your drive/motor supplier should be able to inform you about tuning procedures for your hardware.

I'ld suggest a bigger motor and belting it to both screws wich will result in a synced system even when losing steps etc......

have fun !

[joecnc2006]

Originally Posted by CAMCRASH Is it possible to have dual lead screws on a single axis with independent stepper motors If so what would I use or how would I maintain synchronization between the motors?

Yes works i am doing it on my 4x4 machine.

Joe's CNC 4x4 Hybrid

Joe

[ger21]

If you use mach3 for control, it will keep the motors synced with it's slaving option.

[joecnc2006]

I just jumpered two drivers to the same step and direction pins, i.e. 2 and 3, it works fine. and i also have the two leadscrews with a belt to keep them square as an insurance.

Joe

[Mr.Chips]

Originally Posted by joecnc2006 I just jumpered two drivers to the same step and direction pins, i.e. 2 and 3, it works fine. Joe

Hmmmm I'v seen other articles where they say this is not possible.

Any risks to the drivers in trying this?

This sure would be the best way to go to prevent racking.

[joecnc2006]

Well, i have been running my 4x4 for over 6 months like this, So i would say yes it is possible.

[digits]

Originally Posted by joecnc2006 I just jumpered two drivers to the same step and direction pins, i.e. 2 and 3, it works fine. and i also have the two leadscrews with a belt to keep them square as an insurance. Joe

I think the mechanical connection between the screws might be key here. I had a setup with twin screws and twin servos, with both drivers wired to the same step/direction pins - it was a pain to get square as I had to be able to drive each screw independendly to square it up. This meant re-wiring the screws to be independent axes and then slaving them in Mach 3, but I really need all my axes, so it's not a long term solution for me.

Without a mechanical connection between the screws, everytime I had to hit E-stop, the unbalanced mass of the axis allowed it to skew slightly as it slid to a violent stop. This then required re-alignment which was tedious. Poweroff was also a problem as I had twin screws on my vertical axis!

During running however, I did have two screws running with only electronic syncing (common step/direction pins) at several hundred IPM with no issues.

[joecnc2006]

Yes that is my backup, I have a belt connecting the two lead screws to keep the gantry sq.