CW-5045 Stepper drive and G3 Controller

[shaun]

Hi Guys,

I'm having some issues getting my stepper drivers working with my G3.

I have CW-5045 drivers (not v2). They take differential inputs for Pulse, direction, and enable.



I've wired them up as per the directions for the similar leadshine driver in the online docs.

I've also tried connecting the - side of pulse and direction of the driver to ground on the Masso, and the + side to the coresponding S+ and D+ terminals on Masso - as you see done in the online docs for the A/B axis on the Masso G2.



With the driver connected up as per the leadshine example in the docs, I scoped the outputs of the S+ and S- referenced to ground to check the differential signals out of Masso.

Without the driver connected I see 3.64V peak.

With the driver connected I see 2.95V/2.55V peak. -so about 0.65V DC drop. With the load of the driver.

I've attached pictures from the scope.



The stepper looks to be connected correctly - it locks up solid when I apply power to the driver.

Has anyone successfully used these drivers? Perhaps they won't trigger with less than 5V on their inputs?

 

[masso-support]

have you tried another drive? and do you get the same voltage drop?

 

[shaun]

Yes, I've tried another driver and I see the same voltage drop, and the same problem.

I've also tried another stepper motor too and see the exact same behaviour.

Are the voltage levels I'm seeing normal? I thought the outputs would be 5V?

 

[masso-support]

now that your controller has the resistors removed, the drivers are giving the maximum current, if the drive is not working then as a last resort you can try to connect the negative side of the drive input to MASSO GND and the positive side to the S+ signal.

before you do the above can you please share the new signals with scope, this will show us how much difference it made after increasing the current.

 

[shaun]

Hi,

Without the resistors, the voltage drop is better ~0.4v drop instead of ~.65V.

The first two pictures show open circuit/connected voltage measured between ground and S+/S- with both probes.

The third picture shows the scope trace on the S+ pin only when the corresponding negative side of the drive is connected to the Masso GND as you describe.

Unfortunately, the stepper driver still does not move.



Given the documentation for all stepper motor drivers i've read seem to say they want 5V level signal on their step/dir/en pins, why is Masso only designed to do ~3.8V?

 

[masso-support]

that is the driver voltage we have always been using even with Gen 2 units. Do you know how much input voltage and current the drives need?

 

[shaun]

Not sure on the current, but it worked with 5V supply on the Step+ pin and the ground switched via an LPT port adapter board with LinuxCNC.

I never measured the current because it just worked.

 

[masso-support]

@shaun the current limiting resistors were the only thing we added to G3 and never had any issues reported on G2, not sure why these drives won't work.

Do you have 5v available in your setup somewhere?

 

[shaun]

Yes, I have a 5V psu in the cabinet.



I tried using the 5v supply to manually trigger the step input on the driver and i goes nowhere... im guessing i might have dead drivers?

 

[masso-support]

1. please wire the negative side of the 5v PSU to the negative of the power supply connected to MASSO.
   
2. Connect the positive of the 5v PSU to the positive input of the stepper driver step/pulses input.
   
3. Connect the S+ signal from MASSO axis connector to the -ve of the stepper driver step/pulses input.
   

hopefully this will have enough voltage difference to drive the inputs on the driver.

 

[shaun]

Hi,

Ive connected and tested as you suggest.

Scope was connected to the Step channel of the stepper driver: GND to PUL-, probe tip to PUL+. Second scope channel was not connected.

Voltage was definitely higher, but the waveform was nothing like before - this is perhaps why the driver was unable to trigger this time?

I've just ordered another set of stepper drivers to replace these. - Lichuan MC542s. Manual attached.

 

[masso-support]

you mentioned that the drives were working earlier with 5v signals. There is a 20 pin IDC header on the bottom right side of MASSO-G3 which gives 5v TTL output signals. Will you be able to get a IDC cable as shown below and we can provide you the pin numbers, then cut the other end of the cable and screw step and direction wires to the drives:

 

[shaun]

Sounds good... I ll get a cable/connector and can do this.



please send me the pin out.



cheers!

Shaun

 

[shaun]

I ve got a cable... can you send me the pin out?

 

[masso-support]

IDC 20 pin connector gives 5v TTL output signals as below:

• Pin 1: Ground (Common for Stepper drive Inputs)
  
• Pin 2: Do Not Connect.
  
• Pin 3: B Axis - Direction Signal.
  
• Pin 4: B Axis - Step Signal.
  
• Pin 5: A Axis - Direction Signal.
  
• Pin 6: A Axis - Step Signal.
  
• Pin 7: Z Axis - Direction Signal.
  
• Pin 8: Z Axis - Step Signal.
  
• Pin 9: Y Axis - Direction Signal.
  
• Pin 10: Y Axis - Step Signal.
  
• Pin 11: X Axis - Direction Signal.
  
• Pin 12: X Axis - Step Signal.
  
• Pin 13: Do Not Connect.
  
• Pin 14: Do Not Connect.
  
• Pin 15: Do Not Connect.
  
• Pin 16: Do Not Connect.
  
• Pin 17: Do Not Connect.
  
• Pin 18: Do Not Connect.
  
• Pin 19: Do Not Connect.
  
• Pin 20: Do Not Connect.
  

 

[shaun]

Hi,

I gave it a go, and still not working. I suspect my drivers are busted. Seems odd all 3 are dead, but they've been stored in the same place for the same duration.

Once my new drivers arrive, I'll give them a go and let you know the outcome.



I've attached the scope trace and photos anyway. The peak voltage when connected was 2.64V.

One scope trace is the Masso output measured but not connected to the stepper driver. Other trace is with it connected.

I notice there is some decay without it being loaded. I'm guessing you have a RC filter on the output for these pins.



I adjusted the volts/div for the direction - I was seeing some noise. Its probably just being induced in the direction line from the adjacent step line. The cable I used is about 75cm long.

Cheers!

-Shaun

 

[masso-support]

@shaun, there is something else wrong because firstly after removing the resistors the controller worked with other drives that other clients pointed out, next after connecting the signals to the TTL outputs if the drive is not working then probably need to look at the drives because at this voltage the drives should have worked.



please keep us updated and if you want, you can also send us the drive and we can have a look.

 

[shaun]

Hi @masso-support

New drivers are working.

They are wired up as you'd expect (S+ to Step+, S- to Step- etc).

I can confirm Lichuan MC542 (available on alibaba relatively cheap) work with the G3 without the resistors. Given the G2 and G3 are the same on the outputs with G3 just having additional resistors, it should work on a G2 as well.

What value were the resistors on the G3? I can wire some in series with the driver and test so hopefully you can add another low cost driver to your list of what works. These seem to be a modern design digital open-loop stepper driver. The build quality internally looks good too. These were $19USD each plus shipping direct from the manufacturer.



Cheers!

Shaun