[fanwary]

Hi,
Finally after two months of trying and frying a BOB I got my motors running but they're slow and gets heated.
I use stepper motors that I bought from Probotix and here's the link for it's specs
280 OzIn 8-Wire Stepper Motor -

My drivers are wantai DQ542MA
Stepper Motor Driver DQ542MA:Stepper Motor Driver DQ542MA wholesaler

the winding between motors and drivers are as follows:
RED+BLUE ==> A+
YELLOW+BLACK ==> A-
WHITE+BROWN ==> B+
GREEN+ORANGE ==> B-

I asked Probotix support and they told me that It's better to connect them this way..... but I really doubt the connection.

And for the driver DIP switch I don't really know what to select so I left them all at OFFs which gives 25000 pulse/rev with PEAK output current 4.2A
I tried playing with motor tuning in MACH3 but that doesn't help.

Please help me run these motors faster.
Thanks

[Mzones]

Being set at 25,000 pulses a rev. it won't be fast!
If it's getting hot, amp setting is too high!

[WoodSpinner]

your running 3 amp steppers at 4.2 amps, no wonder they get hot, cut it back to 3 amps, that should at least help with the heating(keep you from frying the motors).

John
oh, and cut the microstepping back to something reasonable like 1/8th

[jfong]

Looks like your running the steppers in bipolar parallel mode. Running them at 4.2 amps is fine per the stepper motor datasheet. If you find that the axis have plenty of torque, you can dial down the current a bit. Also make sure idle current reduction is turned on the driver. This will reduce stepper heat when the motor isn't turning. Switch setting 4 is idle current, it should be off.

Set the drive to 8 or 10 microsteps. I use geckodrives which are default 10 microstep drives. They run my steppers just fine. Try 10 microstep mode. Switch 5,6,7,8. Off,on,on,off

Good luck
Jim

[109jb]

Wrong. His motors are rated for 3 amps UNIPOLAR, but he is running them in BIPOLAR parallel. The spec sheet says they are good for 4.2 amps wired that way, so his current setting is good.

The motors WILL get hot, but that doesn't necessarily mean too hot. If you can hold your hand on them they are not too hot. Switch #4 is for idle current. If the switch if off, the idle current cuts back to 1/2 of the set current after 500 ms.

Like was said, the microstepping is way too high to get any speed out of it. I would set the switch settings as follows:

1: off
2: off
3: off
4: off
5: off
6: off
7: on
8: on

This will set it for 4.2 amps, idle current at 50%, and 1600 steps per rev (1/8 microstepping).

[jfong]

Also to add I use similar 8 wire 276oz stepper motors but made by kieling. Wired up bipolar parallel mode at 4.2 amps with gecko drivers. They do get HOT! With a 36volt power supply, they easily spin over 1000rpm using mach3 parallel port, 10 microstep.

From what I've read, steppers are fine if they run hot. I don't have a good temperature meter so I don't know how hot they get. My cnc is in a cool basement. You can still touch them and not get a burn. I wouldn't hold them for any length of time though. It's been running like this for a long time so the steppers seem to be ok with it.

[109jb]

As an indicator, Oriental motors, who make the Vexta steppers say that the maximum allowable case temperature of their steppers is 100 deg C (212 degF). Pretty darn hot and will definitely burn you. I would not count on all motors being able to handle that much, but you get the point.

Oriental Motor Product Forum ? View topic - Maximum temperature of a step motor

[fanwary]

Ok got it up and running smoothly. .. The problem was with pulse/rev selection. ... at 4000 pulse/rev speed is perfect and smooth and the steppers don't get so heated.
Thanks everyone for your help.. really appreciate it

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