Z axis won't move with both motors connected - squeals and grinds Hello! I am building my first non kit printer. All is moving except the Z axis. Playing around with it tonight; 1: move the Z and it just screams and grinds - will not move. 2: raised (and lowered) the pololu pot voltages. 3: replaced with a brand new pololu (current ones have never been used) 4: unplug one motor and it works flawlessly! Hardware; TAURINO power RAMPS 1.4 PSU seems fine. I use it in my prusa i2. This seems to be my last hurdle. Extruder works (I think), hotbed works and extruder heaters work. Just about working fine except the Z.. Anyone have any idea? I am at a loss. Power does not Seem to be an issue? Blown steppers? Doesn't seem like it if they work alone? Thanks!! https://reprap.org/forum/read.php?1,255815,255815#msg-255815 Mon, 09 Mar 2026 05:18:32 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,255815,811010#msg-811010 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,811010#msg-811010
[www.youtube.com]]]> Roberts_Clif General Mon, 19 Feb 2018 11:31:30 -0500 https://reprap.org/forum/read.php?1,255815,811002#msg-811002 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,811002#msg-811002 tbeaulieu General Mon, 19 Feb 2018 10:48:13 -0500 https://reprap.org/forum/read.php?1,255815,307852#msg-307852 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,307852#msg-307852 or its the wiring]]> nechaus General Fri, 07 Feb 2014 19:35:24 -0500 https://reprap.org/forum/read.php?1,255815,306593#msg-306593 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,306593#msg-306593 new to3Dbob General Wed, 05 Feb 2014 09:37:58 -0500 https://reprap.org/forum/read.php?1,255815,306473#msg-306473 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,306473#msg-306473
I also read that the micro stepping gets messed up when you do this too. At speed they resonate against each other. While running slow things are not too bad. Its possible the original post here had a 0.9 degree and 1.8 degree motor to get such bad performance.


Am I full of it? or can other people qualify this?]]> Robonz General Wed, 05 Feb 2014 06:04:08 -0500 https://reprap.org/forum/read.php?1,255815,256363#msg-256363 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,256363#msg-256363 nophead General Fri, 18 Oct 2013 16:13:00 -0400 https://reprap.org/forum/read.php?1,255815,256343#msg-256343 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,256343#msg-256343
...R]]> Robin2 General Fri, 18 Oct 2013 15:08:32 -0400 https://reprap.org/forum/read.php?1,255815,256160#msg-256160 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,256160#msg-256160
Technically @pnit is correct. Putting 2 motors in parallel, will require the Z stepper driver to deliver twice as much current as for a single motor.

I'd go for a process of elimination to determine the problem. Its possible that one of your Z motors is defective.

Try connecting the X and the Y motors into the Z output and see if you get the same result.

I think you said that you've replaced the Z stepper driver. If not you could try swapping the X and Z stepper drivers and confirm that the driver works for the X motor.


Note. I've blown up 4 stepper drivers in the past, due to a problem with my Arduino, so be very careful not to let the stepper drivers get hot.]]> rogerclark General Fri, 18 Oct 2013 06:15:48 -0400 https://reprap.org/forum/read.php?1,255815,256119#msg-256119 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,256119#msg-256119 Seems like a power issue. Turn 0.1m works. Turn 1m it squeels for about 5 seconds then turns.
If I turn two or three clicks (LCD panel) it just screams until it moves once then screams..

Rods are fine, motors or not stiff or hard to move..

I was fiddling with an option in the controller settings to raise VMax or something which slightly fixes it..

Will wiring in series lower the power required?

I think series could be the solution. So close!]]> kingoddball General Fri, 18 Oct 2013 03:29:34 -0400 https://reprap.org/forum/read.php?1,255815,256081#msg-256081 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,256081#msg-256081
This diagram is from the Mendel90 instructions (thanks Nophead!)



I'm not 100% sure on the technical explanation, but I'm fairly certain that running the motors in parallel decreases the resistance, hence requires more current from your stepper drivers.
]]> pnit General Thu, 17 Oct 2013 21:34:24 -0400 https://reprap.org/forum/read.php?1,255815,256068#msg-256068 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,256068#msg-256068 jamesdanielv General Thu, 17 Oct 2013 20:12:35 -0400 https://reprap.org/forum/read.php?1,255815,256039#msg-256039 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,256039#msg-256039
Motors - Both work when separate.

They turn easily by hand (will double check)

Both motors are turning in the same direction.

Parallel or series?
What is this and how can I tell?
(:D

Thank you all!

Edit: More Info:
I remember - When I try to turn the motors (Printerface or LCD controller), after a few seconds of moving (i.e: 10mm moves) the pololu heat sink is HOT!! Cant keep finger on it...

Which is why I changed it.. New one - Same thing. No other axis does it.


Had a thought...

The power connectors:

4 pins; 2+ and 2-

I have it wired as 2+ / 2- but where it connects to the PSU, I spliced the two together...

The 2 POS lines go into one when connected to PSU (wire guage is fine) (same for NEG).. Could this be an issue?
Only done it this way, as I do it this way for my i2. X(]]> kingoddball General Thu, 17 Oct 2013 17:59:03 -0400 https://reprap.org/forum/read.php?1,255815,256028#msg-256028 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,256028#msg-256028
...R]]> Robin2 General Thu, 17 Oct 2013 17:07:51 -0400 https://reprap.org/forum/read.php?1,255815,255851#msg-255851 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,255851#msg-255851 pnit General Thu, 17 Oct 2013 07:17:49 -0400 https://reprap.org/forum/read.php?1,255815,255840#msg-255840 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,255840#msg-255840
if you turn them by hand is it easy to turn?

when assembling mine, I found the x clamps ( idler and motor ) were really stiff and not the correct width pulling on the threaded rod of the motor making it grind because of the pressure.]]> clack General Thu, 17 Oct 2013 06:35:51 -0400 https://reprap.org/forum/read.php?1,255815,255834#msg-255834 Re: Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,255834#msg-255834 -------------------------------------------------------

> 4: unplug one motor and it works flawlessly!

Is that true of both motors?]]> waitaki General Thu, 17 Oct 2013 06:16:04 -0400 https://reprap.org/forum/read.php?1,255815,255815#msg-255815 Z axis won't move with both motors connected - squeals and grinds https://reprap.org/forum/read.php?1,255815,255815#msg-255815 I am building my first non kit printer.

All is moving except the Z axis.

Playing around with it tonight;

1: move the Z and it just screams and grinds - will not move.

2: raised (and lowered) the pololu pot voltages.

3: replaced with a brand new pololu (current ones have never been used)

4: unplug one motor and it works flawlessly!

Hardware;
TAURINO power
RAMPS 1.4

PSU seems fine. I use it in my prusa i2.

This seems to be my last hurdle.
Extruder works (I think), hotbed works and extruder heaters work.

Just about working fine except the Z..

Anyone have any idea?
I am at a loss. Power does not Seem to be an issue?
Blown steppers?
Doesn't seem like it if they work alone?

Thanks!!]]> kingoddball General Thu, 17 Oct 2013 05:16:58 -0400