Layers are not alligned in y direction

[charlotte 0]

Hi all,

I have been struggling with this for a while:

after a while of printing correctly, my printhead starts to change its y position (steps of ~2mm each layer), causing the layers not to be neat on each other and forcing me to stop the print... I have been trying to change the potmeter settings, but with no result. My y potmeter looks different than the others, but i guess a missing housing shouldn't be the problem.Any ideas how to solve this?

Charlotte

[Daid 304]

I sometimes have the same problem, but always on the first few layers. For me, I'm guessing that one of the motors is giving off interference to one of the end stops, causing a movement to be skipped.

Another posibility is that the head gets stuck and doesn't move, OR (and I had this happen to me yesterday) that you bed is moving off the screws. Slower print speed can help in this case.

[greenarrow 0]

What speed are you printing at?

When I've had missed steps adding more grease to the four outside rods has normally fixed it.

[charlotte 0]

Hi Daid and Greenarrow,

thanks for you suggestions. About the speed, I use the standard settings and am not printing faster than 150%. The bed is still in the right position. It doesn't look like skipping layers, since the layers are not on a position where the might have to be...

I've been greasing allover with no succes... :( Any other suggestions?

[Daid 304]

Because it was printing ok before, I almost has to be mechanical or electrical.

It could still be interference on the endstops. If you are confortable with trying you could disconnect both the X/Y endstops, and the lower Z endstop. Remove the X/Y homing code, and see if it still jumps layers. (You still want the top Z endstop to get the start height correct)

I'm also seeing 1st or 2nd generation electronics. I'm not sure if there are any known problems with it. But I guess you are on the stock 5D firmware with RepG 25?

And you're using 0.4mm layers? I've been printing at 0.2mm layers and that looks much better, the layers also stick to each other better then.

[cyclone 0]

I've noticed on my UM that the screws holding the X and Y motors slip and the belt(s) loosen. Just enough to make it lose steps. Might put a finger on the belts coming from the motors just to make sure they are still tight.

-b

[ddurant 0]

I've noticed on my UM that the screws holding the X and Y motors slip and the belt(s) loosen. Just enough to make it lose steps. Might put a finger on the belts coming from the motors just to make sure they are still tight.

-b

I added a couple washers to the bolts holding the steppers on - the bolts are just a hair too long and washers will make sure they can be tightened correctly and give things a bit more grip on the wood.

[charlotte 0]

Ok, I disconnected the endswitches and it still happened.

What I actually never noticed before is that I could see the motor 'slipping' or stopping when I just moved the printhead around (not by hand, but from replicator using the manual control). I started experimenting adjusting the stepper motor driver potmeter, which indeed changed the behaviour, but also resulted in a burned driver, haha, I guess I was becoming a little impatient...

Then I thought, ok, will it be the driver or not? Inserting the driver from the X motor, actually resulted in the same slipping way of moving.

So here I am, 1 driver down and still a slipping y axis.. Anybody?

[owen 19]

I could see the motor 'slipping' or stopping when I just moved the printhead around (not by hand, but from replicator using the manual control). I started experimenting adjusting the stepper motor driver potmeter, which indeed changed the behaviour, but also resulted in a burned driver, haha, I guess I was becoming a little impatient...

Then I thought, ok, will it be the driver or not? Inserting the driver from the X motor, actually resulted in the same slipping way of moving.

You need to determine whether it is a weak motor or power to it or something mechanical that is stopping it. So you could swap motors or try moving the extruder around by hand with the motors disabled and see if there are spots where it sticks.

[gremmic 0]

I am having the same problem. When moving the head around by hand (with UM off of course,) mine has always had inconsistent resistance in the Y direction, while X is smooth. The resistance seems to be enough to stop the motor for a few steps.

Today it occurred to me that this could be due to several of my Y-axis pulleys being out of round (they sure look it anyway,) including the motor pulley. The heavy resistance is not reliably cyclical, so maybe it's when 2 or more pulleys are "in sync." That's all I've come up with so far anyway.

[owen 19]

I am having the same problem. When moving the head around by hand (with UM off of course,) mine has always had inconsistent resistance in the Y direction, while X is smooth. The resistance seems to be enough to stop the motor for a few steps.

Today it occurred to me that this could be due to several of my Y-axis pulleys being out of round (they sure look it anyway,) including the motor pulley. The heavy resistance is not reliably cyclical, so maybe it's when 2 or more pulleys are "in sync." That's all I've come up with so far anyway.

I had this happen after I replaced the Y motor and fixed it when I slid the pulley on the Y motor shaft a bit.