Stepper motors - problem

[dudz]

I have had no problems with my 3 Stepper motors until now. The Z axis motor still goes good.
The X and Y axis motors are on ballscrews via belts an pulleys and have began to act strangely.
I had two fuses blow in my controller, then found the problem to be two fried IC drivers. So I have replaced these. Now the X axis motor hisses plus it moves only very slightly and judders alot when jogged. And the Y motor sounds rough although it does turn properly but vibrates the machine. I have changed no settings. I have played around with "motor Tuning" in Mach3 but I can find no better setting than what it was set at originally.

[JAZZCNC]

Need more info.?

What drives. Give settings.
What BOB.
What you Changed from before.?

[wilfy]

if the IC's have fried could they possibly have told the motors to put out more power than they can handle and as such you have burnt the steppers out?

[dudz]

Need more info.?

What drives. Give settings.
What BOB.
What you Changed from before.?

BOB ; www.easy-cnc.com * Your best option in driver boards for CNC machines (http://www.easy-cnc.com)
Drivers ; A3977

Things that have changed from before. X axis Nothing except new cutting table. Y axis longer belt same pitch. motors act the same without belts mounted.

Motor tuning settings in Mach3 that have worked fine for all 3 motors until now ;

Steps Per 535
Velocity 199.98
Acceleration 10
Step pulse/Dir Pulse 0

8181

[Web Goblin]

Did you swap the good original IC to the positions of the faulty ones to see if the drives ran ok one at a time? You could also have faulty driver chips. Or you could stick one of the new ics in the known good axis position to check it out.

[JAZZCNC]

Did you swap the good original IC to the positions of the faulty ones to see if the drives ran ok one at a time? You could also have faulty driver chips. Or you could stick one of the new ics in the known good axis position to check it out.

Agree with Web Goblin swap things around to eliminate things.! . . . .After that then don't waste any more time on them Crappy Allegro A3977 chips and All-in-one boards.
You'll have this problem all the time unless you run them well below there rated currents/volts.
You can get decent 50V lead shine copies for not lot of money and while not the best drives in world they are still miles better and far more reliable. So cut your loses and save your self the frustration.!!

[Jonathan]

I agree with Jazz - if you can't get the current drivers to work without buying anything, get some better drivers like m542 or 80V drivers if the motors can withstand that.

It does sound like you might have a problem with one or more of the motors. Disconnect each motor and measure the resistance between each of the 4 wires (i.e. 6 combinations) and compare it to the Z motor which is working. One of the phases may have burnt out, which would cause the motor to only move very slightly. If you've not got a meter to do this, then you can disconnect the motor from the driver, try turning the motor with each of the two coils/phases short circuited and if it gets harder to turn when short circuited then the motor is probably fine.

[dudz]

I agree with Jazz - if you can't get the current drivers to work without buying anything, get some better drivers like m542 or 80V drivers if the motors can withstand

Like this one ; ?? CNC Kit 5 Axis CNC Breakout Board +Cables+ 3 Axis M542 Stepper Driver Controller | eBay (http://www.ebay.co.uk/itm/CNC-Kit-5-Axis-CNC-Breakout-Board-Cables-3-Axis-M542-Stepper-Driver-Controller-/181075447833?pt=UK_BOI_Industrial_Automation_Contr ol_ET&hash=item2a28f01019)

I swapped the driver chips around.... same problem.

One thing I now remember doing before all this went wrong, is turning the motors via their pulleys while no power to the bob was on. Perhaps this could have sent a higher current to the bob and killed it ?

If I change the motors also, which ones would I need ?