Prints getting squished at the left edge of the print bed
Recently I printed a model which barely fit onto the print bed and I noticed that parts going right up to the left edge of the print area (rear left corner) were sort of cut off. So I printed four 45° rotated squares touching the very edges of the print area, one in the middle of each side. All came out fine except the left one, which looks kinda squished (unlike the original model which looked clean cut about 5mm from the edge).
Any idea what could be causing this and how to fix it?
RE: Prints getting squished at the left edge of the print bed
Bed level correction ... set Left down a bit.
RE: Prints getting squished at the left edge of the print bed
Bed level correction ... set Left down a bit.
I don't see how that could cause what I'm describing. Just to be extra clear, my problem isn't that part of the square is thinner, my problem is that the square isn't square.
BTW you're not the first person to make that suggestion. darcshadow suggested the same thing, but deleted his post before I could reply.
RE: Prints getting squished at the left edge of the print bed
lol, yeah, I reread your post and realized you were only talking about the very edge and started to post saying never mind when I realized I could actually delete it. 🙂
RE: Prints getting squished at the left edge of the print bed
What does the bottom of the parts look like? It could still be a leveling issue if (and it kinda looks like it) if that part of the bed is lower and thus the Live Z is off in that area and paths aren't properly merging. Before using the nyloc bed leveling approach I basically had to write off about 25-50mm from each edge because my bed was so unlevel and it would produce bad results (collisions, adhesion issues, squished, separated layers, etc..). If you take your calipers to all 4 squares, how do they compare to each other for the height? Is that left square a bit thicker? If so you definitely have a level issue (that may or not be the cause of this issue). If not, probably not.
As you say it was touching the edge of the print area, take a look at the X axis on that side. Maybe something is going on with the assembly that isn't letting it really get to true 0. Make sure there aren't any small print artifacts on the parts that could be colliding and preventing proper travel. Also check the wrapping on the extruder cables. If that is too tight it could be causing a spring effect when pulled the the extreme left side and causing a "bounce" effect of drawing the extruder away from the true 0 position. On one of my rebuilds I had the wrap tight enough that it actually caused it to fail to calibrate due to too much tension that prevented the carriage from moving smoothly.
RE: Prints getting squished at the left edge of the print bed
Non-linear is not normally possible with the printer by itself. Almost always a secondary issue is creeping in.
ZIP and post your STL. And we can start there.
RE: Prints getting squished at the left edge of the print bed
I misunderstood what you were say and the squares are commonly used for Z calibration. My brain farted that direction.
To rule out the obvious, starting with your STL, or better, your 3MF - zeroing in on the issue will be easier.
Also - how old is the printer?
RE: Prints getting squished at the left edge of the print bed
As for what? I'm going to guess ahead of time it's a damaged belt; or an interference problem as the extruder slides up to the left X-Axis support and something is riding the belt. You don't by chance used belt tensioner springs, do you?
RE: Prints getting squished at the left edge of the print bed
What does the bottom of the parts look like? It could still be a leveling issue if (and it kinda looks like it) if that part of the bed is lower and thus the Live Z is off in that area and paths aren't properly merging.
I printed the squares on a textured sheet, so you won't be able to see much on the first layer, but here goes: 
Before using the nyloc bed leveling approach I basically had to write off about 25-50mm from each edge because my bed was so unlevel and it would produce bad results (collisions, adhesion issues, squished, separated layers, etc..).
I actually regularly place prints all the way up to the edge (I try not to print everything in the middle as a crude attempt at wear leveling of the sheets) and I have no issues except for the leftmost ~1cm.
If you take your calipers to all 4 squares, how do they compare to each other for the height? Is that left square a bit thicker? If so you definitely have a level issue (that may or not be the cause of this issue).
The leftmost corner of the square is indeed 150 microns thicker, but I think that could be overextrusion (as in the printer thinks it's printing a square and ends up stuffing the same amount of material into a smaller area).
As you say it was touching the edge of the print area, take a look at the X axis on that side. Maybe something is going on with the assembly that isn't letting it really get to true 0. Make sure there aren't any small print artifacts on the parts that could be colliding and preventing proper travel. Also check the wrapping on the extruder cables. If that is too tight it could be causing a spring effect when pulled the the extreme left side and causing a "bounce" effect of drawing the extruder away from the true 0 position. On one of my rebuilds I had the wrap tight enough that it actually caused it to fail to calibrate due to too much tension that prevented the carriage from moving smoothly.
The X axis seems clear all the way, but if I push the extruder all the way to the left, there's a bit of springiness (but I can't see what's causing it). Is that normal? This is my first and only printer and it was a kit, so I have no reference.
I misunderstood what you were say and the squares are commonly used for Z calibration. My brain farted that direction.
To rule out the obvious, starting with your STL, or better, your 3MF - zeroing in on the issue will be easier.
Also - how old is the printer?
3MF attached. The printer is 3 months old.
As for what? I'm going to guess ahead of time it's a damaged belt; or an interference problem as the extruder slides up to the left X-Axis support and something is riding the belt. You don't by chance used belt tensioner springs, do you?
No springs. 100% stock MK3S.
I managed to get pictures of the original print where the problem manifested itself (it was a commission).
This part was in left rear corner. As you can see, it looks clean cut off (like the printer didn't even try to extrude beyond a certain point).
RE: Prints getting squished at the left edge of the print bed
3MF not attached - it needs to be zipped then uploaded.
RE: Prints getting squished at the left edge of the print bed
My bad. Attempt #2.
Also update: I found the source of the springiness. It was a zip tie rotated the wrong way. I turned it around and now the extruder slides freely all the way to the left until the cooling fan hits the Z screw. I immediately tried printing this test again, but the issue remains.
RE: Prints getting squished at the left edge of the print bed
This new forum is a mess - so many defaults set to make it intolerably hard to use.
As suspected, the part is fine.
The printer motion is fixed by microstepping. There is zero chance the microsteps are stalling, or you'd see a layer shift. This leaves something that is adding a non-linear - repeatable - "flex" in the X-Axis motion. The only place that can happen is with the belt itself. Something is pressing on it as the extruder approaches the left stop.
Position the extruder about 1/2" away from the left stop, and take a photo of the belt paths; upper and lower. It wouldn't hurt to take shots from top, front and side (looking through the X-Support above and below the gear). Also, snap a shot of the belt at right side idler at the same time.
It is also possible, but unlikely, the rat tail out the back of the extruder is hitting the EINSY case prematurely. But that would more likely cause a crash/shift than a compression of motion.
RE: Prints getting squished at the left edge of the print bed
An extremely unlikely scenario is the belt is bad; with a pitch change along the length. Very unlikely, but you might be the recipient of a spliced section of a manufacturing run. You might be able to see a change in texture along the belt, or a change in belt thickness; but often this would be a hidden defect discoverable only by measurement, like laying the bad belt next to a good belt.
RE: Prints getting squished at the left edge of the print bed
My bad. Attempt #2.
Also update: I found the source of the springiness. It was a zip tie rotated the wrong way. I turned it around and now the extruder slides freely all the way to the left until the cooling fan hits the Z screw. I immediately tried printing this test again, but the issue remains.
Attachment removed
Yeah definitely shouldn't be anything that causes it to spring back. Glad you got that fixed even if it's not the issue.
How about a pic of the X axis all the way over at the left side so we can see how it lines up. It's a bit hard to find a good measurement point, but from the outside of the left Z rail (smooth bar) to the extruder housing (see pic) my calipers are saying the distance is 34.8mm when I have it pushed all the way to the left while the printer is off. How does yours compare?
If you create a piece that uses most/all of the Y distance and is maybe 5-10mm wide and print it all the way against the left edge, I wonder what that would look like (probably only need to print the perimeters of the first layer). I'm curious if it's consistent for the entire left edge or if it is just a specific area.
Ugh. Sorry for the rotation.
RE: Prints getting squished at the left edge of the print bed
tim-m30: I'm not sure what belt paths are, but here are all the other pictures and then some.
I couldn't really get it in a photo, but I've noticed the top of the belt is closer to the from of the printer than the bottom. As if I pushed it too far into the extruder body. Not sure that could be the cause though. While I can see it causing a bit of non-linearity, I think it would make the extruder move faster towards the end, not slower.
gnat: Here's a picture of the extruder all the way to the left. My calipers read 34.45.
RE: Prints getting squished at the left edge of the print bed
Gnat -this is a head scratcher. There is nothing I can think of in the drive system than can deliver a non-linear feed except a belt that is stretching or is bad from the factory. And it has to be a change in belt tooth pitch. Nothing else I can think of will cause the extruder to move linearly for 200 mm then start compressing over the last 10 mm.
The easiest reason for this belt defect is problematic, and makes it even weirder (belt was over stretched during motor installation). Because the bad length should be shorter, not longer than the rest. Though, if the belt chords were pulled loose from the rubber, the rubber might be compressing the section. lol - a lot of hypotheticals ...
RE: Prints getting squished at the left edge of the print bed
I think I see it: David, roll the extruder right and look at the belt on the gear: do you see this "extruding rubber" anywhere else?
RE: Prints getting squished at the left edge of the print bed
And David, for the next time; when posting images there is a control in the upload page just above the Add to Post button: if you select Link To MEDIA FILE folks can zoom in to your images without any fuss.
RE: Prints getting squished at the left edge of the print bed
In any case, I think the X belt needs to be replaced. Or, you might be able to just swap ends to get by until a new belt is in hand. But the work involved I'd wait for the new belt and avoid printing that last 10 mm..
RE: Prints getting squished at the left edge of the print bed
I looked at the pulley through a magnifying glass (40x) while moving the extruder from end to the other. While I have no idea what I'm looking at (looks more like fibers than squished rubber, but the reflections from the aluminum and the awkward angle make it hard to see clearly), it looks the same over the whole length of the belt.