Dual motor and belt on Z

Any comments on the idea of using dual motors for Z and connecting them with a belt ?
Is this like begging for problems in case of 1 motor missing a step or could this help
kepping the bed in level even if 1 motor skips a step or 2 ?

Good solutions are:

A. A single Z motor, driving 2 or 3 screws through pulleys.

B. 2 or 3 Z motors driven from separate stepper drivers, and use firmware and a Z probe to perform automatic levelling after homing (the firmware adjusts the Z motors individually to get the bed level).

Both of these solutions avoid the problem of multiple Z stepper motors getting out of sync.

Regarding your suggestion of dual Z motors connected by a belt, that should be viable. Motors slip 4 full steps at a time, not 1 full step, so the pulleys need only be large enough to constrain the relative movement to within +/-2 full steps. Using 1.8deg motors, this is +/- 3.6 degrees. The tooth width of a 20-tooth pulley is 9 degrees; so 20-tooth pulleys should be sufficient if the belt is tight.

However, if you will be using a belt and pulleys, why not use just one motor?

Edited 3 time(s). Last edit at 11/28/2017 08:25AM by dc42.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Got plenty of steppers/leadscrews/pullys/belts and probe solutions laying around, building a corexy just for fun and to try out diffrent solutions atm and this just got me thinking that 2 should give some extra torque for those Heavy lifting/holding jobbs

So it is possible and should not be a problem, will try this to see how it goes. Worst case I´ll just use the good old 1 motor/pulleys/belt solution.

Thanks.

Quote
Blackgnome
Got plenty of steppers/leadscrews/pullys/belts and probe solutions laying around, building a corexy just for fun and to try out diffrent solutions atm and this just got me thinking that 2 should give some extra torque for those Heavy lifting/holding jobbs

So it is possible and should not be a problem, will try this to see how it goes. Worst case I´ll just use the good old 1 motor/pulleys/belt solution.

Thanks.

This solution is old because it is good ! Like the round wheel is still with us while all the inventors of the square wheel have been quickly forgotten. It is why they keep popping up regularly

---

"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

If you need more power, using 1 motor give you the opportunity to gear up. Use a small pulley on the motor, and larger ones on the screws. It lowers maximum speed but this isn't important on Z. Also still cheaper then 2 motors.

Quote
MKSA

Quote
Blackgnome
Got plenty of steppers/leadscrews/pullys/belts and probe solutions laying around, building a corexy just for fun and to try out diffrent solutions atm and this just got me thinking that 2 should give some extra torque for those Heavy lifting/holding jobbs

So it is possible and should not be a problem, will try this to see how it goes. Worst case I´ll just use the good old 1 motor/pulleys/belt solution.

Thanks.

This solution is old because it is good ! Like the round wheel is still with us while all the inventors of the square wheel have been quickly forgotten. It is why they keep popping up regularly

Skateboarders that have tried them swear by them! (Truth is often stranger than fiction: wheels that are both square AND round!)
I have no connection to the sellers or creators or any financial ties, I just couldn’t resist responding

[www.amazon.com]

Quote
Blackgnome
Got plenty of steppers/leadscrews/pullys/belts and probe solutions laying around, building a corexy just for fun and to try out diffrent solutions atm and this just got me thinking that 2 should give some extra torque for those Heavy lifting/holding jobbs

Have you considered a belt-lifted Z axis?

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Instead of two motors you should use a single one with sufficient power. There simply is no need for a second one since the leadscrews will lock anyway (except if you use the wrong ones) and the power required for lift should usually does not exceed what a 1.7A NEMA 17 can deliver.

---

[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Quote
JonathanThompson

Quote
MKSA

Quote
Blackgnome
Got plenty of steppers/leadscrews/pullys/belts and probe solutions laying around, building a corexy just for fun and to try out diffrent solutions atm and this just got me thinking that 2 should give some extra torque for those Heavy lifting/holding jobbs

So it is possible and should not be a problem, will try this to see how it goes. Worst case I´ll just use the good old 1 motor/pulleys/belt solution.

Thanks.

This solution is old because it is good ! Like the round wheel is still with us while all the inventors of the square wheel have been quickly forgotten. It is why they keep popping up regularly

Skateboarders that have tried them swear by them! (Truth is often stranger than fiction: wheels that are both square AND round!)
I have no connection to the sellers or creators or any financial ties, I just couldn’t resist responding

[www.amazon.com]

Yet an hybrid but anyway, fame at last, after more than 5000 years of trying

Edited 1 time(s). Last edit at 12/03/2017 09:29AM by MKSA.

---

"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

Quote
Srek
Instead of two motors you should use a single one with sufficient power. There simply is no need for a second one since the leadscrews will lock anyway (except if you use the wrong ones) and the power required for lift should usually does not exceed what a 1.7A NEMA 17 can deliver.

Ordered a extra Nema 17 with almost twice the Power just in case. This is at the moment a build for testing ideas on, considered a beltdriven Z but will be a later test.