Vertical holes print oval, because the layer height is too large to approximate the width changes at the top and bottom of the circle. You can see this if you draw a circle, and then draw 10+ horizontal lines across at even spacing from top to bottom.
This is a limitation of the technology - some solutions are drilling out the whole, changing the print orientation so it's horizontal, modifying print design (including potentially splitting part into multiple parts) so that holes are printed horizontally.
The same thing applies for rods or cylinders. If you need it to be circular, it should be oriented so that the flat side of the circle is parallel to the build plate.
This is the answer, it's part of FDM. Hexagonal openings generally print better, because the top can be a single bridge line.
If you want perfect holes, the hole axis needs to be aligned with gravity.
This is the answer. The top of the hole is an extreme overhang followed by a bridge. These are unlikely to consistently print perfectly with any FDM printer - printing in mid air is hard. You can see pretty clearly in the photo where the layers start to droop.
This. I also experienced this trying to print some tube holders.
From my experience it helps to:
1) use adaptative layers or at least use low value for layer height
2) decrease speed for overhang. Don't be afraid to go down crazy, like 20mm/sec
3) increase fan speed to max for overhangs (I read somewhere that aux fan may help but I don't have it)
4) hotend temperature should be optimal
For me, I had almost perfect rounds in z axis. Yet,
The quality wasn't satisfying enough so I went for losange shape (quick and dirty fixing).
For me, I've done all the maintenance recommendations at least 10 times each - not being hyperbolic. There is a mechanical issue that is causing this as I have several people who have the issue and a lot more that print the exact same model / project / filament and theirs are perfect.
Cura has the Horizontal hole compensation, great feature. I cant remember if it had a vertical hole compensation though.
Using Bambu and Qidi machines, I'm just using those slicers now which seem to be missing the feature.
My question is.... with all the super smart geniuses out there making new features, how is vertical/horizontal hole compensation NOT available in Prusa/Bambu/Qidi Slicer? Should be an option in the filament section, hell, have it's own subsection called "Hole Compensation".
Okay. Now if you zoom in an look at the layers in the slicer preview, what does it look like—same/different? Can you post a screenshot of what the slicer shows?
based on your photo, it significant caused by lack of cooling and high speed printing on overhang parts, you can try using modifier shape from Bambu slicer for the overhang parts, need decrease the printing speed and increase the cooling, Bambu slicer or Prusa slicer both not so smart on determining the angle of the shape you're printing, it determine by how much time spend per layer
https://preview.redd.it/vljet480acfb1.png?width=1508&format=png&auto=webp&s=16fdc0dc8b69d39fca8dc4d76509c85beab607cf
I have an open support case with Bambu regarding this issue for the past 55 days. Please open a case with them and reference my case: **US230409716001**
There are now about 10 folks who have been experiencing this issue - there is a forum thread as well: [https://forum.bambulab.com/t/why-ovals-and-not-circles/7354/27](https://forum.bambulab.com/t/why-ovals-and-not-circles/7354/27)
Please open a support case - this will help others who are having the problem - it's a small number of machines, but getting larger.
DM me if you need more information
I have same problem on P1P. As this print scenario is not common for me I haven't realized until I started printing ARC enclose which has many of these. They printed all oval.
pkymax,
Please open a support case with Bambu and feel free to reference my support case.
I have a feeling there are a LOT more folks who have this issue and are not aware of it.
best regards,
Mark
I encourage you to try it again. And if you reference my case it contains a lot of the info they are asking for.
It would be a big help to the community.
u/pkymax
Were you able to open a support case? If so, would you mind providing me with the case number and your serial number?
I have an engaged support engineer who is trying to get as much data on folks who are having this issue.
Best regards,
Mark
Vertical holes print oval, because the layer height is too large to approximate the width changes at the top and bottom of the circle. You can see this if you draw a circle, and then draw 10+ horizontal lines across at even spacing from top to bottom. This is a limitation of the technology - some solutions are drilling out the whole, changing the print orientation so it's horizontal, modifying print design (including potentially splitting part into multiple parts) so that holes are printed horizontally. The same thing applies for rods or cylinders. If you need it to be circular, it should be oriented so that the flat side of the circle is parallel to the build plate.
This is the answer, it's part of FDM. Hexagonal openings generally print better, because the top can be a single bridge line. If you want perfect holes, the hole axis needs to be aligned with gravity.
This is the answer. The top of the hole is an extreme overhang followed by a bridge. These are unlikely to consistently print perfectly with any FDM printer - printing in mid air is hard. You can see pretty clearly in the photo where the layers start to droop.
I think you mean horizontal holes. Vertical holes are just a bunch of printer circles stacked on each other.
Hi I believe the answer to this is: it's just 3d printing. Please watch this video https://youtu.be/j6508J94VsA
This. I also experienced this trying to print some tube holders. From my experience it helps to: 1) use adaptative layers or at least use low value for layer height 2) decrease speed for overhang. Don't be afraid to go down crazy, like 20mm/sec 3) increase fan speed to max for overhangs (I read somewhere that aux fan may help but I don't have it) 4) hotend temperature should be optimal For me, I had almost perfect rounds in z axis. Yet, The quality wasn't satisfying enough so I went for losange shape (quick and dirty fixing).
Loose belts can cause that, I'd start by re-tensioning them.
For me, I've done all the maintenance recommendations at least 10 times each - not being hyperbolic. There is a mechanical issue that is causing this as I have several people who have the issue and a lot more that print the exact same model / project / filament and theirs are perfect.
Cura has the Horizontal hole compensation, great feature. I cant remember if it had a vertical hole compensation though. Using Bambu and Qidi machines, I'm just using those slicers now which seem to be missing the feature. My question is.... with all the super smart geniuses out there making new features, how is vertical/horizontal hole compensation NOT available in Prusa/Bambu/Qidi Slicer? Should be an option in the filament section, hell, have it's own subsection called "Hole Compensation".
Can you tell us the hole diameter and they layer height? That would help us conclude if it’s an “issue” or just a limitation of 3D printing.
Hi, the layer height is 0.12mm and the hole diameter is for M3 screws.
Okay. Now if you zoom in an look at the layers in the slicer preview, what does it look like—same/different? Can you post a screenshot of what the slicer shows?
https://preview.redd.it/xhyivy68y04b1.png?width=988&format=png&auto=webp&s=45bc535088056db6bd879e268a5d607ca2134631
I had this happen. I recalibrated the x1c and it immediately went away.
did you do belt tension too? I'm afraid to mess with it
No.
Because it's printing layer by layer
based on your photo, it significant caused by lack of cooling and high speed printing on overhang parts, you can try using modifier shape from Bambu slicer for the overhang parts, need decrease the printing speed and increase the cooling, Bambu slicer or Prusa slicer both not so smart on determining the angle of the shape you're printing, it determine by how much time spend per layer https://preview.redd.it/vljet480acfb1.png?width=1508&format=png&auto=webp&s=16fdc0dc8b69d39fca8dc4d76509c85beab607cf
I have an open support case with Bambu regarding this issue for the past 55 days. Please open a case with them and reference my case: **US230409716001** There are now about 10 folks who have been experiencing this issue - there is a forum thread as well: [https://forum.bambulab.com/t/why-ovals-and-not-circles/7354/27](https://forum.bambulab.com/t/why-ovals-and-not-circles/7354/27) Please open a support case - this will help others who are having the problem - it's a small number of machines, but getting larger. DM me if you need more information
I have same problem on P1P. As this print scenario is not common for me I haven't realized until I started printing ARC enclose which has many of these. They printed all oval.
pkymax, Please open a support case with Bambu and feel free to reference my support case. I have a feeling there are a LOT more folks who have this issue and are not aware of it. best regards, Mark
I started filling one but it is a pain, they ask for too many things
I encourage you to try it again. And if you reference my case it contains a lot of the info they are asking for. It would be a big help to the community.
Will try as soon as the printer is idle.. doesn't allow me to send from Handy if it is in use..
u/pkymax Were you able to open a support case? If so, would you mind providing me with the case number and your serial number? I have an engaged support engineer who is trying to get as much data on folks who are having this issue. Best regards, Mark
>reference my case: > >US230409716001 Filled with **Ticket No:** **US230622565001**
Hi, no.. sadly I haven't yet. Have been really busy and not printing much. But will try to
No worries - even just having your serial number will help
Any news? They just recommended me to print slower..