Thread: Can't get motor spinning w/Mach3 & g540

Originally Posted by Woodlake

Cool - Thanks Chris.
So it should read 3K3 not 3R3!
What about the fact its 1/2 w and not a 1/4 and 1% not 5%?

Yea you can use a 1/2 Watt resistor with a 1% tolerance with no dramas.

3K3 is right.

I'll grab some from Jaycar then!.
Thanks very much Chris.

Paul

Originally Posted by Woodlake

Success - I have motor movement!
I unsoldered the resistor I put across pins 1 - 5 of the DB9 plug. Once I did that, the motors turned!?.
So what did I do wrong? I'm guessing I used the wrong resistor?
I have attached a pic of the pack I used.
Can someone point me to the correct one I should use please?

Regards,
Paul

Hi Paul,

I've just tested the profile and it is fine. The resistors you have are 3.3 ohm (3R3). You need 3500 ohm.(3K5)

The resistors you have limits the current to 3.3mA. Not enough to drive much at all.

If you remove the resistor, the current will be set at 3.5A but the G540 will not reduce the current when in idle.

You will find it very hard to find 3K5 resistors. Grab some 3K3 ones from Jaycar, they will work fine and I doubt you will notice any difference if you used 3K5 ones.

I have a reel of 3K48resistors that is near as damn it to 3K5. If you like I can put a few in the mail.

Cheers,

Peter

Thanks Peter.
If the jaycar ones will work, it'll be just as easy to grab some of those.

Paul