x axis slips part way through some prints

x axis slips part way through some prints

Postby jonyo » 2013-Sep-Fri-09-Sep

I have this problem, with certain print jobs, where the print will look like the x axis slipped part way through the print job, sometimes multiple times. See what I mean in the attached image (One with "Liam"), which is a print of the attached STL (which is NOT tapered like that, should be letters strait up and down). The first one on the left was the "first attempt", it seemed to have slipped twice, first time pretty early, about half way through the first layer.. You can see part of the "first layer" is filled in, part of it is just the perimeter... Then slipped again about half way through the print.

On on the right is the second attempt after I read something about speed of small gaps, I adjusted it down... That seems to have reduced the slippage (but it may just be random when it happens), but for some reason resulted in holes going from top to bottom like the top and bottom layers didn't get filled in all the way, so I changed it back.

This also happened on a test print I used for calibration early on, this one: [oops, it says my post looks "too spammy" because of off-site links, it is thing 4203 on thingiverse] and result is attachment #2, it slipped part way into the middle "block". At the time I was focusing on calibrating the scale, wanted to focus on one thing at a time... Anyways as you can see, it skips over and the infill is partly exposed, then a little further up it "skips back" but not quite as much. So it's not always skipping in one direction, seems to go both ways.

I've printed other models just fine, it seems to consistently happen on models with small rectangles. Actually I printed thing 62826 from thingiverse with no shifting at all... From what I've read, think it might be all the jarring from it going back and forth over a small sections. But just not sure how to fix or if that is even the real problem.

I've searched and searched, and found many posts that sound "similar" to my problem, but they all talk about skewing on the X axis "over time", basically where you have a "leaning" print. And, all of the ones I read, seem to be on older versions where the fishing line was directly on the rod, mine is starting out with the new instructions (just got my printer about 2 weeks ago), with the tubing, sand paper, and zip tie. Also I wasn't quite sure what to "search for", anyways all that was just to lead up to me saying sorry if this is a FAQ or something, but I wasn't able to find the answer...

Any help is appreciated! :mrgreen:
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x axis slips part way through some prints

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Re: x axis slips part way through some prints

Postby Tdeagan » 2013-Sep-Fri-14-Sep

This could be caused by the x-axis motor not getting sufficient amperage and missing steps. The Printrboard has trim pots (one per motor,) which can be adjusted to provide more power. Turn them incrementally clockwise to get more power (don't go so far that the motor starts running hot.)

There may be other PB Simple-specific problems that I'm not familiar with relating to the string, but the motor amperage could be one thing to check.

Good luck!
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Re: x axis slips part way through some prints

Postby bradleyc » 2013-Sep-Sun-11-Sep

If your calibration cube is slipping, then your prints will slip as well. The motor is not skipping the steps, it is either motor's shaft slipping on the tube or the tube slipping on the string. Once you have the tube into the shaft exactly where you want it, put a few drops of super glue between the tube and shaft. Do this as well as securing the zip tie over it. This will help the tube grip tighter to the shaft. Sometimes you can't see the slippage, but there's microslippage that will cause your prints to screw little by little. It adds up. So after doing that, wrap two or three loops of string around your tube. Do this as tight as you can. Do this for both the X and Y axis.

If you have already done this, then the problem is a software problem and I will give you further help if it is. But try the above method first.
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Re: x axis slips part way through some prints

Postby jonyo » 2013-Sep-Mon-16-Sep

Tdeagan wrote:This could be caused by the x-axis motor not getting sufficient amperage and missing steps. The Printrboard has trim pots (one per motor,) which can be adjusted to provide more power. Turn them incrementally clockwise to get more power (don't go so far that the motor starts running hot.)

There may be other PB Simple-specific problems that I'm not familiar with relating to the string, but the motor amperage could be one thing to check.

Good luck!


After running a print, the motors are hot to the touch.. The x motor I can even feel heat coming through the wood it is enclosed in. Could it be a problem in the opposite direction, too much amps? It seems to only slip on really short movements in the x direction, where there is a lot of going back and forth...

bradleyc wrote:If your calibration cube is slipping, then your prints will slip as well. The motor is not skipping the steps, it is either motor's shaft slipping on the tube or the tube slipping on the string. Once you have the tube into the shaft exactly where you want it, put a few drops of super glue between the tube and shaft. Do this as well as securing the zip tie over it. This will help the tube grip tighter to the shaft. Sometimes you can't see the slippage, but there's microslippage that will cause your prints to screw little by little. It adds up. So after doing that, wrap two or three loops of string around your tube. Do this as tight as you can. Do this for both the X and Y axis.

If you have already done this, then the problem is a software problem and I will give you further help if it is. But try the above method first.


Hmm, this might be difficult, right now the tubing is pretty much butted up against the motor (the motor has a little recess at the base where the shaft meets, and the tubing actually goes into that slightly). Should I undo the entire thing, zip ties and all, then do a little super glue on it as I'm pushing the tubing on? right now there just isn't any room to get super glue in there... I think first I'll take a sharpie and make a mark from the tubing to the shaft, print something that causes the slippage, and see if the lines still meet up afterward. I'll post the results (might take me a while before I can find the free time to work on this).

I've noticed, the tension on the x/y strings are not so loose that it allows "give" in either direction, but when you touch them they are not "tight"... I've read some people have it tight enough to pluck like a guitar, it's no where near that tight. I tried printing this tensioner (thing 127498) but it seems to be the ideal type of 3d object to cause the slippage LOL... would be sad, in a funny way, if it was indeed the tension on the X belt, and the thing I could print to help me get better tension, won't print because of the problem...

If it makes a difference, the printer handles "larger" objects just fine, in fact it printed this part (thing 97263) perfectly the other day for my kid's train track.... If you notice the orientation is such that it is "long" in the x axis.
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Re: x axis slips part way through some prints

Postby jonyo » 2013-Sep-Tue-08-Sep

Update: I scaled the speeds in slic3r down, all the 60mm/s down to 40 with exception of support material and bridges.. also changed gap fill down to 15mm/s (from 20). And now prints are turning out AWESOME, like you see in the movies and commercials lol :D

I have to say, I love all the tweaking and learning about how things work but it can be frustrating... Now that I have it printing perfectly I'm hesitant to change anything (at least for a while), even if it means slower prints. I was able to print out the x tension doodad (actually printed 4 of them on the plate, all 4 came out great), probably after a while I'll mess with it. But for now I'm "tweaked out" lol, will live with my slightly slower printer till I get in the mood to tweak it some more. Then I'll try the super glue thing and also stick the tension things on there so I can get it properly tightened, and see how it does again back at full speed...

Curious though, since it now works with the speeds scaled back, does that point to one problem or another? Or would that happen no matter what the "cause" was for the random slippage, whether it be missing steps in the motor or actual slipping?

And thanks for the suggestions and help so far, love that there is such an active community here!!! :mrgreen:
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Re: x axis slips part way through some prints

Postby Mooselake » 2013-Sep-Tue-18-Sep

You might want to check your acceleration, which might help the slipping. Search the forum for "simple acceleration", no quotes.

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Re: x axis slips part way through some prints

Postby mdfast1 » 2013-Sep-Tue-19-Sep

I wouldn't think missed steps would be so consistent. I would lean toward loose belts or slipping on the motor shaft.
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Re: x axis slips part way through some prints

Postby thawkins » 2013-Sep-Fri-02-Sep

IAfter running a print, the motors are hot to the touch.. The x motor I can even feel heat coming through the wood it is enclosed in. Could it be a problem in the opposite direction, too much amps? It seems to only slip on really short movements in the x direction, where there is a lot of going back and forth...


Hot motor == hot shaft
Hot shaft == hot vinyl
Hot vinyl == soft vinyl
Soft vinyl == slippage
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