[neomagik]

Please help,

I've just finished building my first cnc machine and I'm testing the motors before I attach them.

Using Mach3 motor tuning, I can't get them to turn above 135 mm per min without stalling.

Other values are:-
steps per = 1800
acceleration = 2mm/sec/sec
step pulse and dir pulse = 0

Kernel Speed is 25000Hz

Motors are NEMA 23 Stepper Motor MY103H702

Controller is 3 Axis TB6560 CNC Stepper Motor Driver Board Controller

Power supply is 24VDC 10A

DIP settings are:

Current setting - 75% (turning this down/up stills stalls motor)
Decay mode - don't really know what this is and can't remember setting
Microstep setting - 1/2

Any help would be greatly received.

Rob

[irving2008]

Please help,

I've just finished building my first cnc machine and I'm testing the motors before I attach them.

Using Mach3 motor tuning, I can't get them to turn above 135 mm per min without stalling.

Other values are:-
steps per = 1800
acceleration = 2mm/sec/sec
step pulse and dir pulse = 0

Kernel Speed is 25000Hz

Motors are NEMA 23 Stepper Motor MY103H702

Controller is 3 Axis TB6560 CNC Stepper Motor Driver Board Controller

Power supply is 24VDC 10A

DIP settings are:

Current setting - 75% (turning this down/up stills stalls motor)
Decay mode - don't really know what this is and can't remember setting
Microstep setting - 1/2

Any help would be greatly received.

Rob

Hi Rob,

Those motors are very high inductance for their current...10mH and 1.4A. I have the same motors and they stall out in free air, no load at 300rpm with my driver, half stepping I can't coax them above 2000stesp/sec. You say 135mm/min, but you don't say what pitch leadscrew... 1800 steps per ?

75% setting on those boards is roughly 1.2 or 1.5A depending on which supplier you got it from (.33 or .22ohm sense resistors). The decay setting will make little difference, but fast decay is the better one, however the diodes they use are not best suited for the job so there is a lot of residual energy in the motor coils even on fast decay and this gooes towards limiting limiting the maximum step rate.

At 24v the corner speed on the motor is about 330rpm and torque drops off really fast above that...

[cleansurf2]

Newbie question:

I have been reading these forums regarding supply voltages, beware stepper motor impedance (back EMF), etc... But still haven't been able to clarify some details.

1) a) The TB6560 has a 5V and 12V regulator, so regardless of what voltage you supply the board, the motors will run off the onboard regulated rail yes?
b) The motors use the TB6560 12V or 5V rail???

2) Many motors seem to be rated below 4V, is the motor voltage rating somewhat irrelavant. ie. will motors rated anywhere between 3.7V-12V be OK to use with the TB6560?

3) My application is a 4 axis hotwire foam cutter (threaded rod drive). I shouldn't need a lot of torque. Decent speed would be good. I am thinking stepper motors Nema17, 0.5 Amp/phase would suffice. Am I on the right track. What resistance per/phase, inductance/phase should I be looking at for use with the TB6550?

Specsheet for various Nema17 motors
http://www.alltronics.com/mas_assets/acrobat/28M039.pdf

4) Love to get some advice on my best option motor from this chart please?

------------------------

Some Altronics motor specs I've been considering for this application.
5) Anyone know a better supplier for Australia (Altronics shipping is a killer)?



Small (8.4V 0.56A, 15 ohm, 24.00mH / phase)
http://www.alltronics.com/cgi-bin/it...-stepper-motor

medium (1.0A)
http://www.alltronics.com/cgi-bin/it...-stepper-motor

Real small (note: 0.9 degree step, slower?????)
http://www.alltronics.com/cgi-bin/it...-stepper-motor

thanks for any advice
Rick (Australia)

[irving2008]

Newbie question:

I have been reading these forums regarding supply voltages, beware stepper motor impedance (back EMF), etc... But still haven't been able to clarify some details.

1) a) The TB6560 has a 5V and 12V regulator, so regardless of what voltage you supply the board, the motors will run off the onboard regulated rail yes?
b) The motors use the TB6560 12V or 5V rail???

No, the regulated rails are for the onboard electronics only, the motors run off the main supply rail which should be limited to 30v

2) Many motors seem to be rated below 4V, is the motor voltage rating somewhat irrelavant. ie. will motors rated anywhere between 3.7V-12V be OK to use with the TB6560?

The motor voltage is only relevant with non-current limited unipolar drivers, for any decent current-limiting/chopping/pwn drive its of no interest. More important are phase current and phase inductance as they determine motor performance.

3) My application is a 4 axis hotwire foam cutter (threaded rod drive). I shouldn't need a lot of torque. Decent speed would be good. I am thinking stepper motors Nema17, 0.5 Amp/phase would suffice. Am I on the right track. What resistance per/phase, inductance/phase should I be looking at for use with the TB6550?

decent speed implies good acceleration and low friction. acceleration of the screw and gantry = torque... With low pitch threaded rod you need high motor speed assuming direct drive therefore low inductance. Don't touch anything >10mH/phase and <5 is prefered.

Thos 1A motors 2.26mH/Phase run bipolar on 30V should be good for 40ips on 1/2x10 rod up to a meter long

[cleansurf2]

irving2008,

Very much appreciate the feedback.
Thank you!

Rick (Newbie)

[cleansurf2]

I have received my TB6560 control board, yehaa!

I am using in a 4-axis hotwire configuration and would like to use software more specifically designed for hotwire cutters, in particular RC foam wings.

The TB6560 is advertised for Mach3 use. I would like to use either:
Foam works. http://www.foamwork.net/ and/or
Profili 2. http://www.profili2.com/eng/default.htm

Any advise on where to look for configuration details. I am guessing the DB25 wiring from the PC may be a factor here and I may have to build a custom DB25 PC cable?

Appreciate any advise
Thanks
Rick (Newbie)