July 8, 2016 at 5:36 am #14599
I saw this on a recent hackaday article. Would we benefit from doing something similar on both of our doubled up drivers?
I am just about to adding electronics to my build and would rather do it now vs later if it is a better route to go.
Anyone, done this with their build yet?
NeilJuly 8, 2016 at 6:45 am #14603
I saw that the other day too. I think it looks like a great idea.
My RAMPS board has a total of 5 driver sockets.
I had been considering using 2 drivers each for the X & Y axis and then figuring out all of the modifications to the firmware to make it work.
This solution seems to be better by far
…it still leaves me with 2 driver sockets on the RAMPS board in case I need them for extruders, while providing an individual driver for each motor.
I’m also still considering maybe using the Mechaduino closed loop controllers that mount directly on the NEMA17 motor.
But first of all, I intend to ensure that my existing drivers are tuned properly!!
Lots of great choices.July 8, 2016 at 7:43 am #14609
I knew this would come up and I have been trying to decide how to word it. If you have large steppers this will/can help squeeze more power out of them. Do you need more power?
The kit I sell seems to be fine on the power side of things so I undervolt the steppers because the X and Y have enough power and then active cooling of the ramps is not needed. I need to tune the z axis, I ship it at about .46V but I think I need to start turning them up as people seem to be demanding more speed.
As is the drv8825 drivers with a tiny heatsink usually work at .7V just fine. If you put a small fan on them you can turn them up to a tiny bit over 1V without over heating.
That stacking way will make pot tuning harder to deal with. There is a $3 board on a few of the electronics sites that is a better option, it lays the drivers side by side, no soldering required, and I think you can use an external power supply, win win. If you do start to crank up the power watch the stepper temps they will quickly get hot enough to soften the PLA mounts. I prefer not to run my steppers much past “warm to the touch”July 8, 2016 at 8:09 am #14611
@vicious1, your approach is the most sensible…tune the existing drivers properly and there should be plenty of torque for this machine.
By the way, thank you again for sharing the MPCNC with us…I have quite a bit of fun with mineJuly 8, 2016 at 12:49 pm #14637
@vicious1, Do you remember where you saw the $3 boards? I have another project using ramps that could utilize the stacking but would rather go with the second solution you detailed as this will free up my second extruder port on the printer I built.July 8, 2016 at 5:48 pm #14652
Oh man I spent hours looking for that expansion board, I can’t find it anywhere, there was even a board to mount the drivers sideways on the ramps sheild for better cooling I can’t find that either. I know it was a link from the reprap wiki that got me to the product but I can’t find it to save my life.
I did find a few other things. I will drop the links here so I don’t lose them again.
This one is an expansion that makes it easy to add as many as you want daisy chained.
Easy series plug, gotta try this out should be the best option actually. or I could just stop being lazy and hand wire one up.
http://rigidtalk.com/wiki/index.php?title=Z-Axis_Stepper_Motor_-_Series_Connected_Splitter_BoardJuly 8, 2016 at 7:41 pm #14654
Thanks A ton for finding that I wasn’t having much luck finding anything other than expansion boards but they were around $20 and only added 1 stepper which was way to expensive for my taste. I was able to find this based off the one you found on aliexpress, it seems a bit cheaper and there are some better shipping options to the states. I am going to order a couple and see if I can slave one of these to my existing on board driver somehow, hopefully without too much customizing. Will try and let you all know how it went in a couple of weeks when all the parts show up.
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