Heloo! So I built a Prusa MK2 clone from scratch. I have 8mm Acme threaded rods on my Z-axis. Both motors connect to a single DRV8825 driver on Ramps 1.4. Latest Marlin Firmware. The left motor nearest the Ramps seems to work fine, But the right motor, farthest from the Ramps some times hesitates and throws the level off. But not always. I tuned the drivers per a video I saw. So any thoughts on how to fix this? Could it be my wiring, Would increasing the driver current work? Thanks Max https://reprap.org/forum/read.php?1,799854,799854#msg-799854 Sun, 16 Aug 2026 13:05:12 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,799854,799906#msg-799906 https://reprap.org/forum/read.php?1,799854,799906#msg-799906
Using a single motor with a looped belt guarantees that the screws stay in sync, and the X axis perpendicular to Z, whether the machine is powered up or down or cycled. Of course, both setups have failure modes. If the pulleys let go of the screws or motor, or the belt breaks or comes off the pulleys, all bets are off. Think about how often you've seen any of those failures, then think about the dual motor failure modes. With dual motors if a cable/connector fails, or a driver fails (if you're using two), or a screw comes loose from its motor shaft, or you simply cycle power to the machine (like each time you turn it on), or a curious child with nothing but bare fingers decides he wants to see what happens when he/she turns a screw, you're out of luck.

You can take all sorts of preventive measures to ensure that these failures don't occur. In either setup, you can put lock-tite on the grub screws of the pulleys and motor couplers, motor mounts, etc. (a good habit to get into), and use good construction practices (a good habit to develop) to ensure that belts don't come off pulleys, you can enclose the machine to make it difficult for curious fingers to go places they shouldn't. In the dual motor set-up you can inspect the cables and connectors, use a single driver (not without its own risks). The newer Prusa machines get around the power cyclingproblem by lifting the X axis to the top of the frame until hard stops are hit at the top of the Z axis. That forces the X axis to tilt back to perpendicular to the Z axis (assuming the frame is square), and should only have to be done at each power-up.

Either machine setup can be used with or without autoleveling.]]> the_digital_dentist General Thu, 07 Dec 2017 21:22:13 -0500 https://reprap.org/forum/read.php?1,799854,799902#msg-799902 https://reprap.org/forum/read.php?1,799854,799902#msg-799902
Thanks]]> disneytoy General Thu, 07 Dec 2017 20:07:11 -0500 https://reprap.org/forum/read.php?1,799854,799901#msg-799901 https://reprap.org/forum/read.php?1,799854,799901#msg-799901
Increasing the current wont help?

Thanks]]> disneytoy General Thu, 07 Dec 2017 20:03:30 -0500 https://reprap.org/forum/read.php?1,799854,799883#msg-799883 https://reprap.org/forum/read.php?1,799854,799883#msg-799883 www.thingiverse.com]
It is one of the common design error seen in the Prusa and many other 3D printers.]]> MKSA General Thu, 07 Dec 2017 16:10:45 -0500 https://reprap.org/forum/read.php?1,799854,799873#msg-799873 https://reprap.org/forum/read.php?1,799854,799873#msg-799873
DRV8825 drivers have problems skipping steps at low speeds. It won't be the cause of this particular problem, but it may be the cause of others. See: www.engineerination.com/2015/02/drv8825-missing-steps.html#!]]> the_digital_dentist General Thu, 07 Dec 2017 14:33:01 -0500 https://reprap.org/forum/read.php?1,799854,799854#msg-799854 https://reprap.org/forum/read.php?1,799854,799854#msg-799854
So I built a Prusa MK2 clone from scratch. I have 8mm Acme threaded rods on my Z-axis. Both motors connect to a single DRV8825 driver on Ramps 1.4. Latest Marlin Firmware.

The left motor nearest the Ramps seems to work fine, But the right motor, farthest from the Ramps some times hesitates and throws the level off. But not always.

I tuned the drivers per a video I saw.

So any thoughts on how to fix this?

Could it be my wiring,

Would increasing the driver current work?

Thanks

Max]]> disneytoy General Thu, 07 Dec 2017 12:10:43 -0500