Prints have a tapered edge
I built my Mini over the weekend and have a couple of problems, but the print quality is fine, atleast I thought it was.
I started printing some of hte demo pieces (Sheep, Nut/Bolt and Benchy) and they look amazing.. Perhaps better than my MK3.. But then I tried one of my regular prints.. Something that I have literally printed 1000s of on my Mk3 and don't like what I saw.
The object in question is around aprox 40mm wide 5mm thick and 12mm tall... And I print them in 2 rows of 12.. The print looked good, but when I took them off the bed and looked closely they are aweful
Here are some pictures.. This is what it should look like:
RE: Prints have a tapered edge
Prusa site is having troubles today and its making it impossible to post.. Such that this post didn't come out as I wanted. (How do I insert pictures???)
So THIS is what it should have looked like
And this is what they turned out like (Mini is top and bottom, MK3 middle)
You can see that the vertical edge is skewed/tapered on the Mini, but perfectly straight on the Mk3.
This makes the Mini unusable for me in its current form as I need it for this kind of part....
I am stabbing in the dark, but could this have anyhting to do with the 4.0.2 problem where they are using "Junction Deviation" where as in 4.0.3 "Classic Jerk".. I write this with no idea what either do, but just wonder if this could explain the problem I am seeing.
The complication here is that not all parts came out like this... Some of them were OK and others taped.. I need to repeat the print to see if its got anything to do with their location on the bed.....
Does anyone have any thoughts.
Jon
RE: Prints have a tapered edge
Have you tried simply slowing down? Drop speed to 50% and see if the problem goes away. If so, you know it's something you can fix with slicer settings. If you'd care to zip up and upload a copy of your 3MF project settings, more ideas might be forthcoming.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Prints have a tapered edge
Mine doesn't have this problem.
Maybe loose belts or the Z-axis isn't really fixed to the Y-axis/bed. Check the screws.
RE: Prints have a tapered edge
I am not 100% sure whether it will do this if I just print one.. So when I get home from work, i am going to print 4 in each corner of the bed, just to see.. If its easily reproduced, its easily fixed..
I will update a 3MF file later too...
RE: Prints have a tapered edge
I am not 100% sure whether it will do this if I just print one.. So when I get home from work, i am going to print 4 in each corner of the bed, just to see.. If its easily reproduced, its easily fixed..
I will update a 3MF file later too...
I see in an other thread you are reporting clicking sounds ( https://forum.prusa3d.com/forum/general-discussion-announcements-and-releases/retracting-and-clicking/#post-193111 ) are these resolved? that could also be the reason of your troubles...
Mini with FW:4.4.1 + SuperPINDA + Bondtech Heatbreak + PC4-M8 couplers + 1 piece boden
RE: Prints have a tapered edge
I am not 100% sure whether it will do this if I just print one.. So when I get home from work, i am going to print 4 in each corner of the bed, just to see.. If its easily reproduced, its easily fixed..
The part appears to have a step on the outside curve of the wall that is missing on all 3 samples. If that step is on the inside where we can't see it in the pictures, I suspect you'll find it corresponds to the distortion on the outer wall. Speed and extrusion can contribute to internal features causing bulging on outer surfaces. Post up your zipped 3MF file so we can all see the same thing, but I've found that a combination of reduced external perimeter speeds, sometimes adding an extra perimeter and tuning filament extrusion multiplier can help with these issues.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Prints have a tapered edge
I am not 100% sure whether it will do this if I just print one.. So when I get home from work, i am going to print 4 in each corner of the bed, just to see.. If its easily reproduced, its easily fixed..
The part appears to have a step on the outside curve of the wall that is missing on all 3 samples. If that step is on the inside where we can't see it in the pictures, I suspect you'll find it corresponds to the distortion on the outer wall. Speed and extrusion can contribute to internal features causing bulging on outer surfaces. Post up your zipped 3MF file so we can all see the same thing, but I've found that a combination of reduced external perimeter speeds, sometimes adding an extra perimeter and tuning filament extrusion multiplier can help with these issues.
The step is there.. Its just hard to see in the photo.. Interesting you should mention that as on the opposite side (the convex face) there is an artifact which looks like a tiny layer shift.
Whats troubling is that I print these all day long on my MK3 with a similar layer (in 2 rows of 12) and default settings.. Its not a particularly complex object...
I am going to do some more playing/testing tonight.. And will upload some examples
RE: Prints have a tapered edge
I am not 100% sure whether it will do this if I just print one.. So when I get home from work, i am going to print 4 in each corner of the bed, just to see.. If its easily reproduced, its easily fixed..
I will update a 3MF file later too...
I see in an other thread you are reporting clicking sounds ( https://forum.prusa3d.com/forum/general-discussion-announcements-and-releases/retracting-and-clicking/#post-193111 ) are these resolved? that could also be the reason of your troubles...
Nope.. not fixed yet... Working with Prusa on that one.. But I don't think its related as the print quality is good in general.. But it might be linked so for now, i am reserving judgment until I get the clicking fixed.
RE: Prints have a tapered edge
I just noticed something about the prints.. Tapered is the wrong word.. Skewed is better as a similar problem exists on the other side (although perhaps not quite as bad)... So the whole print is like a Rhombus.
Here is another photo:
They are positioned on the bed left to right... So it looks like the X axis is slipping during the print...
RE: Prints have a tapered edge
This evening I printed something else and it was equally as horrible.. Check this:
The one on the left is my MK3 and the right the Mini.. They were printed with the wide part on the bed and for some reason the X layer is gradually shifting.
I got a tip off from a colleague to check something and that was the Z height compared to the bed.. And true enough, when I put the hotend down to touching hte bed on the left, it was about 3-4mm off on the right.
So the mesh leveling would be working too hard to correct this and I wonder if this is the cause.
When I assembled the printer I heard that over tightening the screws could cause this so I was quite gentle.. Perhaps too gentle.. I have now tightened them a little more and the bed seems a lot more level.. So I am printing again to see how it looks.
This has to be a weekness in the design.. There is no way to guarantee a totally level bed (relative to the X axis)... I am going to do some work tomorow (using a feeler gauge) to see if I can get it dialled in right across the bed.
Fingers crossed this is the cause of my 'tapered' prints.
RE: Prints have a tapered edge
Nope.. Didn't help.. The bed is now more square.. But I am still getting the shift on the bottom layers.. I am running out of ideas now.. Prusa havn't been much help and simply want the printer back to "service" it.. I have to say that compared to the faultless performance of my MK3 I am not particularly impressed with the Mini at the moment.
Atleast I know the MK3 was built properly as I built it....
Now its clear that I am suffering "layer shift", does anyone have any thoughts.. Why it is just the bottom layers in this print and not all the way up.. Thats got to mean something???
RE: Prints have a tapered edge
This evening I printed something else and it was equally as horrible.. Check this:
The one on the left is my MK3 and the right the Mini.. They were printed with the wide part on the bed and for some reason the X layer is gradually shifting.
I got a tip off from a colleague to check something and that was the Z height compared to the bed.. And true enough, when I put the hotend down to touching hte bed on the left, it was about 3-4mm off on the right.
So the mesh leveling would be working too hard to correct this and I wonder if this is the cause.
When I assembled the printer I heard that over tightening the screws could cause this so I was quite gentle.. Perhaps too gentle.. I have now tightened them a little more and the bed seems a lot more level.. So I am printing again to see how it looks.
This has to be a weekness in the design.. There is no way to guarantee a totally level bed (relative to the X axis)... I am going to do some work tomorow (using a feeler gauge) to see if I can get it dialled in right across the bed.
Fingers crossed this is the cause of my 'tapered' prints.
That extrusion->printed plastic interface is definitely a weak spot in the design. I agree with you 100% there. I'm shimming mine, which is a pain. In my case, not only is the arm not parallel to the bed, but it's also skewed so it's slightly more forward on the far end.
But the issue you're seeing looks more like loose belts or something. Bizarre.
Have you tried printing some straight-up cubes to check the basics?
Also, do make sure you complete calibration again after having gone through any adjustments. Easiest to just reset the printer to defaults and then calibrate.
Pete
RE: Prints have a tapered edge
I believe this issue is fixed.. As i mentioned above the Bed was totally out of level.. I have corrected this and it didn't help.
So I finally got around to checking the grub screws on the motor shaft (I know I should have done this from the start)... As you can't see them its not easy.. But I located the first and nipped it up and it wasn't loose by any means, but not as tight as I would like
So then I moved the X axis a bit fast and lined up a screw in the hole and actually thjought it was the same one... So I didn't really tighten it carefully to see how loose it was and I am SURE that it turned... So I can't be 100% sure, but it looks like one screw was loose and the other 1/2 tight.. And this could easily explain what I was seeing as I guess the gear was 'rocking' on the flat of the motor.
Its a bit of a joke that Prusa built it like this.. If it were a kit and I had built it, I would say that its was my fault.. But when the manufacturer is building this themselves, you would have thought they would know better. So I am far from impressed about this.
But its looking good now and the test prints are as good, if nto better than my MK3.
Just got to fix the clicking problem now!
RE: Prints have a tapered edge
You had some wavy path to get it fixed, all the while you fixed other issues too 😀
RE: Prints have a tapered edge
You had some wavy path to get it fixed, all the while you fixed other issues too 😀
Not all the issues... I still have constant clicking/retractions and I need to strip the Extruder to see whats going on.
I didn't think it was worth the effort as I was convinced that Prusa couldn't have done anything wrong.. But now they have left the grub screws loose, anything is possible...
Whats annoyed me here is that Prusa have offered no Support.. Literally nothing.. As I already knew the basics, they couldn't offer any more suggestions and either wanted the printer back to give a service... Or said they would involve the next level of support, which so far hasnt' happened.
You would think that checking the bed was level and the grub screws tight would be some of the first suggestions they offered?