A5S -Layer shifting

gripnack

Hey guys,

I am a bit out of my depth as to what could be wrong. I have searched on the forum for more cases of layer shift and read the wiki. I recently replaced the Bowden tube and after that it seems like my printer isn’t printing the last few layers of every print straight. Now I noticed two things that seem unrelated but I wanted to ask you guys.

1. My power switch doesn’t seem to turn off, like it won’t click off.
2. The heating block has leaked filament through the block and it got rather globbed. 

And the nozzle isn’t hitting the print. 

Samuel Pinches

Ok, as boring as it is, we need to narrow down the possible causes. Can you start with some simple test cubes, to see that everything else is printing ok. You can take a print test cube, and stretch it in the Z direction to make a tall tower, at least as tall as this print. Print it with zero infill first, and if that is successful, try with 20% infill.

I don't think the bowden tube would cause this issue though. Not sure that is related or coincidence.

1. Power switch sounds like it is faulty. A few A5S seem to have this fault unfortunately.

2. Can you show some more photos? This may need to be cleaned off first -- heat the block up to temp, and carefully try to wipe away the globs? Have you changed the nozzle before?

michalko99

Hi. Point 2 might be correct clue. If burned filament drops from nozzle block to printed part, according to size of printed part, it has enough time to cool down. Another pass of nozzle will hit it hard. I see that it happens on Y axis-the weaker one, because of big mass caused by heated bed.

check your tightening. Nozzle should not be screwed in into heater block completely. Your overburned filament is visible in red marks.

Kasey

I'm having the same problem. Have had the nozzle replaced by a technician. All prints fine until near the end then the layer shifts >5mm to the left and ruins the job, even tho' the actual printing it still ok. The nozzle does appear to be scraping in spots by then. Could that slowly push the model across to the left? Or could I be setting the level with the nozzle too close to the plate?

Kasey

Also, what does M-off do and how does one tell if it's on. or off ?

Samuel Pinches

@Kasey if filament accumulates on the nozzle and then a blob drops, it can harden/solidify and then when the nozzle tries to pass over it, it may collide and cause a motor to skip steps. Try reslicing the part in a different orientation.

M-off disables power to all the motors. If the motors move freely by hand the motor power is off.

Kasey

I seem to have solved most problems now. Found by leaving the nozzle in the centre of the plate after levelling, it reminds the printer where centre is, before stating to print. So far, no more final drift of the job to "off centre". Also, the use of a "glue stick" over the area I know the item will get printed on, makes for a perfect attachment of the first layer, allowing for a perfect foundation for the item to be printed. It's amazing how effecting the use of the glue stick really is.