guys, I've looked at the "how to" and can't seem to find an answer.

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(Chuck Comito) #1

guys, I’ve looked at the “how to” and can’t seem to find an answer. I have my y axis running from 2 steppers and 2 drivers. I’ve been looking at this: http://smoothieware.org/general-appendixes#doubling-stepper-motor-drivers.
So I connected both drives and both motors to their respective drivers and then daisy chained the signal from one driver to the other (I did this on the drivers themselves). I’m pretty sure this is wrong because one motor works and the other doesn’t. Perhaps I missed something, any ideas?

(Sébastien Plante) #2

did you update the config?

(Chuck Comito) #3

@Sebastien_Plante what would I need to update? I’m only using one port for the 2 drives.

(Sébastien Plante) #4

@Chuck_Comito Oh, no config then. So I guess they are in series?

Just watch to make sure you don’t go over the Amp for the driver !

You might also want to try in parallel ?

(Sébastien Plante) #5

Look at this wiring
http://rigidtalk.com/wiki/images/thumb/8/82/Series_Connected_Stepper_Motor_Wiring_Diagram.JPG/350px-Series_Connected_Stepper_Motor_Wiring_Diagram.JPG

(j.r. Ewing) #6

Did you turn on power in the config file for the second driver

(Sébastien Plante) #7

@j.r_Ewing is using the same port for both :slight_smile:

(Chuck Comito) #8

I’m using 2 drivers from one port. Tb6600 cheapie. In parallel.

(Sébastien Plante) #9

@Chuck_Comito Oh… external drivers…

look here then : http://smoothieware.org/general-appendixes#external-stepper-drivers

You need to solder new pin on the board, did you do that ?

Tell exactly what you did, cause it’s a little confusing right now !
http://smoothieware.org/general-appendixes#external-stepper-drivers

(Chuck Comito) #10

I wired both external drivers to their own power (36vdc supply) I then wired each driver to their respective stepper motor. Then, I wired the EN, DIR, STP, and ground to the the first driver and then added jumpers from the first driver to the second driver with for each of those signals. All my wiring has continuity and power. I may need to scope the second driver or even swap it out. Perhaps it’s a dud…

(Sébastien Plante) #11

Hum yeah… look good. Try swaping the stepper, if it dosent work, try swaping the driver and see if it’s still working/not working… you might be able to isolate the problem! Good luck !

(Chuck Comito) #12

So after some testing it was a faulty driver. The good thing is I figured it out. Bad thing is I gotta buy a new one. Thanks for your help all!!

(Sébastien Plante) #13

you might be able to drive both motor from the same driver if it’s powerful enough :slight_smile:

(Chuck Comito) #14

I thought about that but my drivers are slightly underrated to begin with. Ideally my motors want 60vdc. I was originally powering them all with a 24vdc supply but have since upgraded to a 36vdc. I can’t find 60 volt stepper drivers that don’t cost an arm and a leg. The drivers I have are capable of 42vdc max. I built most of this prior to fully understanding all the requirements so now I’m just trying to put a bandage on to get me by until I can afford a proper setup.

(Sébastien Plante) #15

oh… hope they will work well if you under-volt them that much. I feel like you will have a lot of step skipping under load :frowning:

Maybe it will cost less to find some 12V or 24V stepper and use full power !

(Thibaut Robin) #16

Hi Chuck I’m having the same problem except both motors do run but with one over heating. For what I think, the ideal solution would have been a simple software “mirror or duplicate” function that would allow duplicating signal from one output to an other using the config file. I’ll take a look at the firmware ASAP to see if this is possible to implement it. Take a look at my queue; Antonio Hernandez has a few suggestions worth trying.
https://plus.google.com/u/1/113509964356441672141/posts/GUwM94NWzcj
I’ll keep you informed if I find a solution.
Cheers.

(Sébastien Plante) #17

@Thibaut_Robin http://smoothieware.org/general-appendixes#doubling-stepper-motor-drivers
http://smoothieware.org/general-appendixes#doubling-stepper-motor-drivers

(Chuck Comito) #18

@Thibaut_Robin that would be nice. I did get my new driver and got it to move properly. The problem now is that the y axis (the one with the dual motors and drivers) shut down after a short period of use. I’m trying to figure out if its an over heating problem or something else. Let me know if you find a solution and I’ll do the same.

(Thibaut Robin) #19

@Chuck_Comito Ok Chuck, I will keep you informed as soon as I have time to work on it. What is your actual setup? is it open-drain or with level shifters? Have you checked the micro switches setup on the drivers (max power setup, current reduction on hold, stepping)? Do the motors stay on hold if you disconnect the drivers from the SmoothieBoard?
I haven’t got then time to work on it but chances are my problem comes from an unbalanced resistivity between both motors due to different cable lengths. have a look at the end of my message queue. I’ll keep you informed, maybe tooday…

(Chuck Comito) #20

@Thibaut_Robin it is open drain. My setup is exactly like yours based on your photos. I have checked all the switches. I have not tried checking the motor hold when disconnected. I’m going to measure the current draw while running and see if that gets me anywhere. I was also thinking of making some changes internal to the drivers to share the load more equally. Maybe a breakout with a resistive load to equalize them. I’ll let you know in more detail what I mean by that later today. I’ll also post my wiring diagram for comparison.