Mk 3.9 with MK4 Z Axis motors. - Hardware, firmware and software help

RE: Mk 3.9 with MK4 Z Axis motors.

Steffen Hüttner — Sat, 08 Feb 2025 01:00:28 +0000

Many thanks for the quick reply.

RE: Mk 3.9 with MK4 Z Axis motors.

Category 5 — Fri, 07 Feb 2025 20:20:51 +0000

The new Z motors differ only in their connector (you already have an adapter for the new board if you have 3.9s), but they are still 1.8 degree steppers so only the X and Y need to be changed. They are the ones that have been updated to .9 degree.

RE: Mk 3.9 with MK4 Z Axis motors.

3Delight — Fri, 07 Feb 2025 20:17:41 +0000

No, you will need the new z-motors and cables, etc. as they are different. From the 3.9S sales page:

Here is a closer explanation of the difference between the MK3.9 and MK4 upgrade packages: the only difference is in the stepper motors. The MK4 uses higher-precision stepper motors that help eliminate VFA (Vertical Fine Artifacts) – these are tiny surface artifacts that are visible if you closely inspect a printed object. In other words, the motors in the full MK4 upgrade are the cherry on top – if you’re chasing the highest possible level of quality, they will come in handy.

RE:

Steffen Hüttner — Fri, 07 Feb 2025 08:51:14 +0000

Hi all, taking the risk of "reanimating a corpse" I am in a similar situation like the owner of this post but probably a little bit more advanced due to the fact that I have the MK3.9S. After reading the complete discussion I just want to make sure that I understand everything correctly.

If I want to move from the 3.9s to the 4s I need to replace the existing stepper motors for the x and y axis which are basically the same beside different cable length?

I can keep the motors of the Z axis as they are?

The reason why I ask is, when I check the Prusa website, it seams like they change the Z motors as well in the MK4s kit. Is this just because of the different connector?

Many thx in advance for your answer.

Greatings Steffen

RE: Mk 3.9 with MK4 Z Axis motors.

kermit — Sun, 09 Jun 2024 15:34:27 +0000

Yes, I know that, but for a long time both Z-axis engines were unavailable

RE: Mk 3.9 with MK4 Z Axis motors.

WarezMonkey — Sat, 08 Jun 2024 22:34:28 +0000

Never mind, I was dumb. I thought I just needed new Z motors to go from 3.9->4, but I also need new X and Y motors :P

Time to pay for more shipping and duties! :(

RE: Mk 3.9 with MK4 Z Axis motors.

WarezMonkey — Sat, 08 Jun 2024 22:08:24 +0000

Thank you for the tips. This worked! Just a small item on the Y axis left rod in the front allowed the Y axis test to pass.

I "factory reset" the settings of my printer and went through all the tests with my new MK4 z axis motors... it still shows up as 3.9 though. What am I doing wrong?

RE: Mk 3.9 with MK4 Z Axis motors.

konfuzed — Sat, 08 Jun 2024 20:07:50 +0000

Posted by: @kermit-3
I need a new right stepper motor for mk4, can you recommend a replacement??

If you mean the right Z-axis, you can just get one in the Prusa store https://www.prusa3d.com/en/product/stepper-motor-z-axis-right-2/

Also noticed they have the MK4 X and Y axis stepper motors in stock now, so theoretically all the MK3.9s could move on up to MK4s with a motor swap, and no wiring change out required.

https://www.prusa3d.com/en/product/stepper-motor-x-axis-3/

https://www.prusa3d.com/en/product/stepper-motor-y-axis-3/

RE: Mk 3.9 with MK4 Z Axis motors.

kermit — Fri, 03 May 2024 15:23:22 +0000

I need a new right stepper motor for mk4, can you recommend a replacement??

RE: Mk 3.9 with MK4 Z Axis motors.

kermit — Fri, 26 Apr 2024 10:38:19 +0000

I also ordered the same motors as you and I am very satisfied mk3,9 is now mk4 where do you buy the molex click-mate cable connectors and I can't find the pins for them?