Printing misaligns each new layer

[MauricioCb 0]

After the first layer of a print, the extruder has some kind of offset and prints the next one displaced a few centimeters from where it should. Every new layer is displaced the same distance as I show you on this photo.

 

 

After searching about this I tried to fix it by tightening the belts of the ultimaker and updating the firmware, but nothing works, why is this happening and how can I solve it?

Thanks.

[gr5 2,224]

Looks like it's the X axis that is losing steps.  Had you noticed the Y axis is fine.

 

So 3% of the time this is caused because you never oiled the gantry.  Put no more than one drop of oil on the 6 rods in the gantry (count them to be sure you got all 6).  Push the head around before and after to see if there is a huge difference.

 

But 95% of the time this is caused by a pulley where the set screw isn't tight enough.  There are 5 or 6 set screws and pulleys for the X axis.  Push the head left and right and see which ones move.  It's almost always the one on the motor - the hardest to get.  I think UM2 printers were mostly shipped with a black and green hex driver - this is a critical tool to have as you can tighten the motor pulley set screw without taking a single thing apart.  If you don't have a long hex driver you'll have to remove that corner cover - it's held on by only 2 screws.  Remember you can push the head around until the set screw is in the best possible position.

 

Tighten all 5/6 set screws but the one or two on the short belt are usually the ones that slip.

 

If you don't believe me you can mark the shaft and the pulley with a sharpie and you'll see that it slipped part way through a print.

[MauricioCb 0]

Hello again!

 

I did everything as you said, first with a complete clean up of the printer, then tightened the set of screws and finally dropped some oil on the 6 rods in the gantry. Also the firmware has been updated.

 

 I've done some printing and the problem now seems to be completely random, some of the prints turn out perfectly while others present the same issue, I've noticed that the problem happens with the brim, which are the first layers. So I'm starting to think that it's due to a software of firmware problem.

 

What else can be done?

Edited June 8, 2020 by MauricioCb

[Ian_Tranter 0]

Hey There Friend.

Have you seen a solution to your issue, I'm experiencing the same issues and have done almost everything you have apart from checking the firmware.

I also print with a brim and have only seen this happen on software version 4.2.1., see images attached

Please advise of any solution you may have? 

Does anyone know of a phone line for support? 

[MauricioCb 0]

I haven't found a solution yet, but this is how is printing at the moment:

It's a small piece so the issue is not as visible as with bigger prints, with the bigger ones is the same as the first post... so as bigger the print is, greater the offset turns out to be.

 

Can you notice the offset at the firsts layers? I've checked the software version and it is 4.6.

 

[MauricioCb 0]

Here's another example of what is happening:

[Ian_Tranter 0]

That's awful, we can't print a good part no matter what... Do you know if there is a contact number as I think there is a compatibility issue with the software?

 

If admin see this post please advice?

[geert_2 558]

Is this also present Cura's layer view?

 

If yes, it is most likely a Cura software-issue.

 

If no, it is most likely a printer hardware-issue (which I think it is): or the motor is missing steps due to too much friction, or some pulley is sliding over its shaft instead of gripping it, as gr5 said.

 

The "too much friction" can be identified by moving the head with your hands: this should go smoothly and evenly in both directions. If you almost can't move it by hand in one direction, then the motors can't either. I had this once when a new oil I used for lubricating the rods, dried into a sticky, thick gum in a couple of days.

 

For a pulley sliding over its drive shaft: also check the ones on the stepper motor: they see twice as much load as the others.

 

Further, I have no idea how likely a dying stepper motor or printed circuit board are?

 

[IRobertI 521]

1 hour ago, geert_2 said:

Further, I have no idea how likely a dying stepper motor or printed circuit board are?

 

I've been working with Ultimaker technical support for six years and I don't think I've ever had that be the root cause of layer shifts/leaning prints. Not saying it's impossible and I might have forgotten such a case, just that it's not something I can remember seeing.

 

99% of the time it's the pulleys on the motor shafts when it comes to layer shifts.

 

https://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#shifted

 

https://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#leaning

[Torgeir 262]

Hi,

 

Did you ever check the coil current setting for X and Y axis. 

If the current is set to lo, it might loose step esp. in the beginning of print as there is some added friction during this part of printing.

 

Thanks

 

Torgeir

[Ian_Tranter 0]

@Torgeir No I haven't, I'm just running through the two help files above, will check that also,.

Regards

Ian

[Esteban511 0]

Hi everyone, I am experimenting the same problem, there is a kind of offset in the first layers when I am printing. Also, the extruder is crushing against the printer because of this offset when something is bigger. Another thing is that when I am going to calibrate the bed, the extruder doesn't start in the usual place (middle back of the bed) for calibration in the first point, this is happening at the left corner, then when is going to the second point for calibrate, this is crashing (is like if the extruder is thinking that there's more space but there's not)

 

@Torgeir, I was thinking that maybe is something with the current too ... what should be the current for X/Y, is in this moment 1200 mA

 

Thanks any help you can give me, in the gift you can't hear, but is crashing trying to go more to the left. seems that extruder is confusing the center.

 

 

[gr5 2,224]

It's hard to tell what is going on without sound.  It looks like the X axis goes left but never right.  Does it make a horrible sound when it homes in the back rear corner?  If so, check your limit switch - push the head around and try to hear it hit the X limit switch (on the top panel in the rear left corner.  There are 2 screws that you can loosen and adjust it a bit or sometimes you can bend the switch arm.

 

If it does *not* make a horrible noise then for some reason it seems like it only goes left.

 

If you fight the print head with your hand (don't worry - you can't hurt the printer that easily) and you notice the X axis is much weaker then one of the 4 wires is probably open (not working).  It could be that one of the 4 wires is broken at some point.

 

Or it could be the stepper driver.  It's pretty much never the stepper itself - always the driver.

[Torgeir 262]

I've to agree much with gr5 that's probably a faulty driver circuit.. 

There's 4 DMOS (power MOSFET) for each of the four wires going to the steppers, if just one of them fail, this kind of behavior is typical. If it was the other side failing like this, the extruder head would hit the wall directly.

 

As you have another "spare" driver E2 (you have an old UM2 right?), it is possible to redefine the firmware to use the extra stepper driver serving the X stepper motor.

 

You could always try to increase the current to 1400 mA, just to confirm this is not a friction problem. Running the printer with this high setting for long time can destroy the drivers, as there is no additional cooling to prevent overheating those integrated circuit.

 

In a previous version of S3D I've had, the gcode files from this slicer always increased E1 to 1400 mA!  

 

Good luck.

 

Torgeir

 

 

Edited June 19, 2020 by Torgeir

[geert_2 558]

On 6/18/2020 at 11:25 PM, Torgeir said:

...

You could always try to increase the current to 1400 mA, just to confirm this is not a friction problem. Running the printer with this high setting for long time can destroy the drivers, as there is no additional cooling to prevent overheating those integrated circuit.

...

 

 

Or maybe try the opposite, reduce the current to let's say 900mA? Then the problem should get way worse if friction is the cause. But I think this would give less risk of damaging the electronics? But anyway, if it is friction, you should be able to feel it by hand, by moving around the head manually with the printer off.

 

Further, if I remember well, there was an old UM2-series that had wrong resistors, causing a too high current, which in turn caused the drivers to get too hot, and temporarily shutting the chip down? I had this effect a couple of times on the Z-axis of one of my UM2: the driver would shut down, the bed would drop about 5mm, but it would keep printing. After the Z-chip cooling down the bed would continue moving down normally as if nothing had happened. Except for the 5mm-gap in the print, of course. After reducing the current to 900mA this never occured again. I am still not totally sure this was the cause, and if reducing the current did solve it, or if there was something else going on in parallel.