Repetier Firmware v0.91 Rumba y-axis skipping problem

Very simply, at random layer heights, my Y-axis will skip and the print will shift. There is no sound like with a normal stepper skip, the axis is very smooth and it happens regardless of the speed. I have replaced my stepper drivers on the Rumba board with DRV8825, no difference. Played with acceleration, jerk, speed to no avail. It still skips, and when it does, it seems like it is always the same amount.... about 3mm.

I have now moved to Marlin v1.0.2 firmware, and the skipping problem disappeared immediately.

Any ideas? I really like Repetier and want to stay with it, but I also want to be able to print stuff

That is a known problem with the hardware. No idea why marlin doe snot have it. Simply put your stepper driver for y on E2 and configure y axis to use that instead and you will see it is gone.

Strangely it is always y axis on rumba if it happens.

---

Repetier-Software - the home of Repetier-Host (Windows, Linux and Mac OS X) and Repetier-Firmware.
Repetier-Server - the solution to control your printer from everywhere.
Visit us on Facebook and Twitter!

Quote
Kalus
Very simply, at random layer heights, my Y-axis will skip and the print will shift. There is no sound like with a normal stepper skip, the axis is very smooth and it happens regardless of the speed. I have replaced my stepper drivers on the Rumba board with DRV8825, no difference. Played with acceleration, jerk, speed to no avail. It still skips, and when it does, it seems like it is always the same amount.... about 3mm.

Any ideas? I really like Repetier and want to stay with it, but I also want to be able to print stuff

I had the same problem - used one of the other drivers for the y-axis - problem solved.

---

You only learn when you change your mind.
[www.deltaprinter.co.za]

Hey Kalus,

Did you ever find a solution to this other than switching to Marlin? Have you seen the problem reoccur after switching to Marlin?

I'm also a big Repetier fan, so I'd like to resolve this issue once and for all. I've been using Repetier with RUMBA boards, all purchased from different suppliers, slightly different versions, but they all have the same problem. I'm trying to figure out if it is a hardware problem or a firmware problem.

I have been using the E2 socket in the meantime, however, it's not a great permanent solution since I want to eventually use all of the sockets for different purposes. Let's try to find the problem to this and fix it.

You can still use y axis socket for E2 instead. Loosing a step every now and then is not so critical for extruders.

---

Repetier-Software - the home of Repetier-Host (Windows, Linux and Mac OS X) and Repetier-Firmware.
Repetier-Server - the solution to control your printer from everywhere.
Visit us on Facebook and Twitter!

What version of the RUMBA board do you have? (when did you purchase it?)

I'm running a RUMBA on my delta. I remember reading about this problem in a couple of forums before I assembled everything. So far, I haven't had any problems, so I'm wondering if only certain batches had this issue?

I've purchased various; from Reprapdiscount when they were still operating (the originators of the RUMBA board), from Geetech, from Robotdigg, and now from another random supplier in China. All are flawed on the Y axis, not a single one of them works properly.

Of course, all of them are also using the same design and the traces haven't changed. I've got a small batch in production where I've changed the traces for the Y stepper motor on the RUMBA. In 2 weeks I'll let you know if the problem persists.

How long does it take before one notices the y-axis skipping issue? Is it an immediate thing?

It depends on a few things. I noticed the problem is worse with less microstepping (1/2 or 1/4 steps) as opposed to more (1/8 or 1/16). You usually have to run a print for a few hours before noticing anything.

At 1/8 steps nothing appeared until the last 20min of my 3 hour print.