Slave not synchronized

[Træstøv]

Hello everyone

I have build a gantry style router, and i'm using the X- and A-stepper to drive the gantry. The X-stepper is master and the A is slave. Some of the time the steppers move perfectly in sync, but then suddenly one of the steppers loses steps, and drives the gantry out of square. I'm using shielded cabels, and have connected the sheild-wire to the stepper housing at one end, and to the controlbox at the other end.

In "motor tuning" i have tried to set the "step pulse" to 4, which seems to help a little, but it is not good. I will be very greatful to anyone with some advice, on how i get the master and slave to drive in sync.

Regards
Jens from Denmark

[Master of nun]

Hi Jens

I had similar results at one time, I think you may need to drop the velosity down a bit in the motor tuning.

Start off low and increase until it starts occur, then back it off a little bit. If it is still happening no matter how low you set the velosity and accel then we need to look at something else.

You must restart mach3 when setting slave axis, but you are probably aware of this!
also I've found that if I power up motor drives before the PC, I have had slave driving oposite to what it is supposed to.

Regards


Liam

[Træstøv]

Hi Liam

Thanks for your reply! I still loose steps if I put the velosity and accel way down.

I discovered a few things that hopefully can help solve the problem. Until now I haven't hat a grounded cabel for my computers power supply. Yesterday I changed it to a grounded one, and I found, that if I put it into the same power outlet as the controller, the steppers gets a lot more noisy.

If I use different power outlets for the controller and the computer, the steppers noise level stays normal. -by the way, is it normal that the steppers makes at buzzing sound, when they are not moving?

Another thing I found was, that if i use the Mach3 auto axis calibration function "set steps per unit", the stepper will only move, if I've just moved it in the same direction, as the calibration function is going to move the stepper. If I just moved the stepper in the opposite direction, the callibration function will not move the stepper. Instead the stepper stalls, like when you set the velosity way to high.

Has anyone got an idea what could be the problem?

Thanks in forhand
Jens

[Master of nun]

Jens

I'm a little out of my depth here, but I will try to help as much as I can. Please anyone out there with some advice?

I think you need to start over and test your output pins with a multimeter to make sure you are getting the voltages you are supposed to.

also check any settings on your motor drives are correct for your setup.

Perhaps you can post some more details of the BOB, drivers etc. you are using.

I don't know if it will help, but try copying and pasting the velosity and accel numbers from the master to slave axis so they are the same.

When you say it will go a little way before loosing steps...how far and how much time roughly?


are the other axis working ok?



Liam

[Master of nun]

Any progress Jens?

[Træstøv]

Hi Liam

Sorry it took some time for me to reply! I have working a lot lately...

Someone from the Mach3 forum suggested that I should try turning on the "Shirline mode", because it helped to set a wider pulse. Shirline mode apperently makes the pulses even wider.

A lot of thanks to you Liam, -it really means a lot to get help!!

Jens

[Master of nun]

Post your results with the sherline mode, it may help someone else later.



Liam

[Træstøv]

I'm not sure that I know what you mean, -should I make a new thred and post it in that one as well?

[Frederic Gagnon]

Hello Jens,

What stepper driver board are you using ? I have a similar problem and am using a TB6560 all-in-one driver/breakout board bought from ebay.

[Træstøv]

Hi Frederic

I use the 4 axis kit from HobbyCNC:

HobbyCNC PRO Driver Board Packages | HobbyCNC

Jens