Chinese stepper motor drive problems

[Dale gribble]

Hi, I've bought one of these Chinese stepper motor drives to run my rotary axis, I just asking if i have everything wired properly. I 've upload the PDF and Jpeg. I've checked I'm getting a signal from the BOB. What is happening is when I turn it on, the green led lights up and the motor locks which is correct. but I get no movement when try and move the motor in the software ( Mach3 ) DRO is moving. I've wired as follows 49v to dc - and dc + / connected phase A and B to motor / Connected pin 17 on BOB to puls+ and pin 16 dir+ / left the enable unconnected. Also played with dip switches and checked internal jumpers for single clock mode. Have i done something stupid or is the drive a dud?

Any information would be gratefully received

Kind regards

Dale gribble

P.S. everthing was working with a gecko 251 until i needed it for my mill as a spare and thought i'd give this drive a go would of bought another gecko but we do get hit with import tax's and admin from the courier in the UK.

[Al_The_Man]

Just a shot in the dark, are you supplying 5vdc for the Opto's?
edit: I see that is pin 17 on the BOB you mention, it might be an idea to confirm you are getting +5 to common?
Al.

[doorknob]

If I understand correctly, you have connected the Step output from your BOB to PULS+ and the Dir output from your BOB to DIR+.

That conflicts with the information in the driver manual. The driver documentation says, "Control Inputs 5v logic from current sinking (NPN) interface, 15mA typical". The wiring diagram indicates the same thing.

In other words, this driver should be wired as follows (according to the typical wiring diagram):

Connect the Step output from your BOB to PULS- through a small-value resistor* (perhaps 100 ohms or less).

Connect the Dir output from your BOB to DIR- through a small-value resistor* (perhaps 100 ohms or less)

Connect the PULS+ terminal to +5 volts.

Connect the DIR+ terminal to +5 volts.

Depending on the design of your BOB (and any jumpers that you may have set), you may need to change the Mach3 "active low" setting to correspond with the way that the driver is hooked up to the BOB.

* It is not clear from the ratings shown in the manual, but it may be OK to use a direct connection instead of using the small-value resistors mentioned above. The LEDs in the optoisolator inputs of the driver are looking for 15 mA of current. There is already a 200 ohm series resistor in place, so depending on what the forward voltage drop of the LED is (and the "on" state collector-emitter voltage drop for the output transistors in your BOB circuit), you should be able to figure out a suitable resistor value to add, however the LED may be able to handle the driving current using the 200 ohm resistor alone. You could do a test with a resistor and a multimeter if you wanted to trim it to exactly 15 mA (but that should not be a critical measurement to make).

There may be an alternate way to wire up the driver, but it depends on the specifics of your BOB's internal circuit - if you wanted to leave the wiring as it is currently set up, and if your BOB is able to source sufficient current, then you might be able to simply connect the PULS- and DIR- terminals to the BOB ground terminal, but you would need more info about your BOB before deciding whether to do that.

[Dale gribble]

Hi, thanks for the replies

Al I have checked the volts to the BOB and it's 5v

Doorknob i for got to mention what BOB I'm using its a c10 for cnc4pc I've uploaded the PDF. I'll follow your instructions tomorrow. I'm use to just connecting a step and dir form the BOB on all the other drivers I've used. but as you have probably guessed i weak when it come to electronics

Kind regards

Dale

[doorknob]

OK, if you want to leave the wiring the way that you currently have it set up, the C10 should have the output buffer capability to directly drive the optoisolator LED inputs of your driver, (but I don't remember whether you would need to set a particular jumper on the C10 in order to enable that mode).

Do you currently have the PULS- and DIR- terminals of your driver connected to the C10's ground terminals?

[Dale gribble]

Hi,

Do you currently have the PULS- and DIR- terminals of your driver connected to the C10's ground terminals?

I have nothing connected to either of minus terminals. just the Step output from my BOB to PULS+ and the Dir output from my BOB to DIR+.

What do you recomend?


Regards

Dale

[doorknob]

I would connect the PULS- and DIR- terminals of the driver to the GND terminals of the C10. For example, the terminal strip for pins 16 and 17 looks like it has extra GND terminals adjacent to those pins specifically for that kind of hookup.

[Dale gribble]

Ok, will give that a try tomorrow

Many thanks

Regards

Dale

[Dale gribble]

Hi Doorknob,

I connected the PULS- and DIR- terminals of the driver to the GND terminals of the C10 and the motor now spins.

Many thanks for your help much appreciated

Kind regards

Dale

[doorknob]

Glad to hear that... Glad that I could be of help...