- March 18, 2018 at 8:07 pm #55613
I’m currently thinking of redesigning my MPCNC in order to improve the Z axis rigidity. My plan would be make the table move up and down instead of the gantry.
But for that, I would need to plug one stepper motor in each corner of the table (I could probably be fine with just 2 of them, but I’d prefer to use 4 to get a better rigidity).
So I was wondering: can I hook up 4 motors in parallel to a single motor driver?
Won’t it overheat? Is there an actual recommendation on how to know how much is too much?
Thanks in advance !March 19, 2018 at 8:16 am #55633
Well I did 4 in parallel for the 4 headed printer, but now that I learned some things you should try them in series if your power supply can handle it. Or 2 in series paralleled, you have options. Can’t wait to see it.
1 user thanked author for this post.March 19, 2018 at 7:52 pm #55700
BarryParticipanthow to know how much is too much?
Smoke tells you there was too much… 😀
1 user thanked author for this post.March 20, 2018 at 8:02 am #55723March 20, 2018 at 11:15 am #55737
I think it completely depends on the driver and the motor… My drivers are limited to 3 amps per driver, but I could run 2 1.5 amp motors or probably even 3 1 amp motors on them. My motors are 2 amps though, so I use 1 motor per driver.
You could get a dedicated driver board (or make one) that can drive 4 motors I’d bet.March 20, 2018 at 11:07 pm #55814
Yeah, kind of something like this but if possible way more rigid than this looks.
I could be ok with only 2 steppers but that would imply using ball screws, which are a bit expensive and bulky.
I’ve not started the design yet, still looking for a good way to make things as accurate and rigid as possible. My concern would be table tilt if I limit the design to two motors only.March 20, 2018 at 11:13 pm #55817
If you did 3 in a triangle there would be no tilt. It would be easier to square it to your X/Y as you’d be able to adjust to their plane simply.
March 20, 2018 at 11:48 pm #55825If you did 3 in a triangle there would be no tilt. It would be easier to square it to your X/Y as you’d be able to adjust to their plane simply.
- This reply was modified 1 month ago by Geoffrey.
That doesn’t sound like a bad Idea, but I’m not really sure how I could do that.March 21, 2018 at 3:49 am #55828
There are lots of examples of folks using 3 motors/lead screws for the z-axis. Here’s a couple of examples:March 21, 2018 at 6:42 am #55831
Geoffrey, BT, that’s related to a 3D printer, but as far as I iunderstand, Dui is interested in using it for CNC applications, with different efforts. the lower the number of motors, the lower the stability/rigidity.
Or perhaps have a way to forward on motor’s moves to the other vertical supports, belts/pulleys for example ? (perhaps a way to motorize 2 screws with one motor, for a total of 4 screw with two steppers ?March 21, 2018 at 2:33 pm #55882
If you search around on the OpenBuilds forums for the C-Bot and D-Bot 3D printers (can’t look up the links atm) there are various plans and builds using 2 motors along with belts to drive 3-4 lead screws and 3 motor/3 screw designs. All seem to work quite well Also consider using more akin to the threaded rod over standard lead screws for the mechanical advantage, as I’m sure the bed will be heavy in comparison to a 12″12″ 3D printer bed.March 21, 2018 at 6:44 pm #55907If you search around on the OpenBuilds forums for the C-Bot and D-Bot 3D printers (can’t look up the links atm) there are various plans and builds using 2 motors along with belts to drive 3-4 lead screws and 3 motor/3 screw designs. All seem to work quite well Also consider using more akin to the threaded rod over standard lead screws for the mechanical advantage, as I’m sure the bed will be heavy in comparison to a 12″12″ 3D printer bed.
That’s true, but it is kind of a hassle to design the belt/pulleys system. Plus any belt will introduce a slight backlash, which means that one side will not move exactly as much as the other, varying the tilt of the table continuously.
In my opinion it is just easier to add 4 motors directly, and probably not that much expensive considering the price of a stepper is only 3 or 4 dollars.April 2, 2018 at 9:01 am #56848
I would use 4 steppers and leadscrews wired in series. Then I would also want to come up with a way to run each of them independently for leveling. What best way to lock the rest while I engage only one stepper in the series?
In turn, so I only need an extra driver for the procedure.April 2, 2018 at 9:12 am #56849
If they’re wired in series, you can’t lock one, they’ll all turn together. You’d need one driver per stepper if you want individual stepper control.
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