Ctc shifting during prints can't figure out why

[ebam]

Had some really good prints recently up until a couple of days ago when it appears to start shifting ever so slightly as you can see in the photo. The shifts don’t appear at the same height on any print, it seems quite random. Its also a shift either to the right or the left upon the x axis. I use a glass plate but that is secure, the belts have a regular good tension, the bolts are tight and the z rods are all straight, bed is levelled regularly. I’m not sure what else to try to look at to fix this issue. Any ideas very welcome.

[keebie81]

How tightly wound is the spool of filament?

[ebam]

Not tightly at all, both rolls are no less than 1/4th used

[MadBuggyofDoom]

Are your spools still mounted on the rear? That cause way too much friction with mine even with PTFE guide tubes (our extruder stepper motors are fairly underdriven current-wise), I made mountings that put the spools above the printer feeding straight down and got rid of issues like that (and jumped up to happily printing at 120mm/s instead of 60)

[ebam]

Haven’t had this issue before and spool is on the side (centre of the holder is attached to the top). Spool is where its pretty much always been, partly why I don’t understand this new issue.

[ClickNPrint3D]

Have you changed anything in your slicer settings between when you had good results to now? Eg print speed, travel speed etc?

[Perry_1]

OK, the number one reason this happens is a failure in the stepper motor cable. These go bad because the cable moves back and forth in the same way over and over, and eventually gets tiny breaks. You don’t say how long you’ve been printing, but this is a common failure, and needs replaced from time to time. This is almost always on the x axis where you are getting the shift.

It could be rail binding, or something else, but almost certainly it is this cable.

[Asuder]

I had this problem! All of my prints kept shifting after I replaced the wires and cleaned out the connector it was fixed.

[ClickNPrint3D]

Check the grub screws on all of your steppers to ensure they are tight.

They can come slightly loose and cause minor misalignments with layers.

[kissfan4]

Also check your speed, i was having an issue with shifted layers on my “y” axis and it ended up being the speed was set too high and would cause the stepper to skip steps.

[arsh0r]

I had a problem problem like this, for me it was a continuous shift to the left of the x axis. Sometimes it was better and sometimes worse, printing speed had a small influence (slow speed = less leaning to the left), but I couldn’t get rid of the shift totally. I checked everything with the machanics, disassembled and reassembled everything. I switched the x/y steppers and even the stepper drivers boards. I replaced the x stepper wires and used a cable chain. I searched the Internet for a solution but sadly found only some posts like this with no answer in the end.

Then I found this post: Redirecting to Google Groups

The problem occurs because of an EMC problem with the stepper wires and the endstop wires laying in parallel.

I would not recommend the approach discussed here: Redirecting to Google Groups

additional filtering can only work in same cases and even a change in cable length can make this not working. I would suggest to switching the cables for shielded ones, but where should the shield be connected to?

For me the following solution worked: reroute the stepper cable inside a cable chain coming from the back of the case. And route the endstop cable from the front (where LCD is sitting).