Anything I should be concerned about here? (overhangs and stuff)
First post and new to 3D printing. Had my Prusa since Christmas. Assembled it. I'm not familiar with what I should be worried about so here are some prints.
Benchy (stock, I didn't slice it): Ports are not round with flattened tops. Z line on chimney
3D Test Fixture: Very bad overhangs above 60 degrees. Artifacts on edges of degree towers.
Cup holder: Bulge on outside opposite bevel on inside. Some Z bands. Artifacts around handle.
Are these fixable, and if so what should I be looking at?
Rick
RE: Anything I should be concerned about here? (overhangs and stuff)
From looking at the bottom of your benchy, I'd say your z-offset is putting your nozzle a little too high. The picture below will give you a better idea of what you are aiming for. You want your lines of fill to snug up to the perimeters. The overhangs on the benchy will not look perfect, they are deliberately hard to print.
It is essential to get the z-offset dialed in first.
Mk3S+,SL1S
RE: Anything I should be concerned about here? (overhangs and stuff)
Good call, thanks. I actually did lower it from -1.06 to -1.135 after printing that.
RE: Anything I should be concerned about here? (overhangs and stuff)
Looks like you have a similar defect on the tops of your round windows.
RE: Anything I should be concerned about here? (overhangs and stuff)
These pictures show the progression I used to get to the lower Z value. I didn't go lower because I was afraid, I would scratch my new steel plate.
RE: Anything I should be concerned about here? (overhangs and stuff)
If you make you z-offset lower in small increments, there is no danger. When you are getting too low there will be very little extruded on your sheet and that is the warning to stop. I find that there is a range between it looking good and being too low. You can go lower in small increments until it is clearly too low and come back up again a bit to get the cleanest first layer and the maximum adhesion. See https://help.prusa3d.com/en/article/first-layer-calibration-i3_112364
Mk3S+,SL1S
RE: Anything I should be concerned about here? (overhangs and stuff)
Thanks. I will try that.
I would really appreciate is some input on the other artifacts that I have mentioned. Are these normal/expected?
RE:
For the line on your cup-holder, see https://help.prusa3d.com/en/article/the-benchy-hull-line_124745
and also https://help.prusa3d.com/en/article/seam-position_151069
A 60 degree over hang is at about the limit for filament printing. Those overhang test models are not expected to print perfectly, they are to show you the limits on your printer so that you can be aware when you design your models. There might be ways to improve on this for a specific model.
Your prints look pretty clean to me. If you have an issue with a specific print, you can always post the ZIPPED .3mf file (it has to be ZIPPED or it won't get attached) and folks here can look at it and advise you how to improve your print.
Mk3S+,SL1S
RE: Anything I should be concerned about here? (overhangs and stuff)
If you make you z-offset lower in small increments, there is no danger. When you are getting too low there will be very little extruded on your sheet and that is the warning to stop. I find that there is a range between it looking good and being too low. You can go lower in small increments until it is clearly too low and come back up again a bit to get the cleanest first layer and the maximum adhesion. See https://help.prusa3d.com/en/article/first-layer-calibration-i3_112364
You gave me the guts to try it. I went from -1.135 where I have been printing down to -1.26 where I was clearly scraping along rather than laying down a clean line. Looks like it confirms I'm at the best Z with -1.135. Glad I did it though. I had been chicken, lol.
RE: Anything I should be concerned about here? (overhangs and stuff)
For the line on your cup-holder, see https://help.prusa3d.com/en/article/the-benchy-hull-line_124745
and also https://help.prusa3d.com/en/article/seam-position_151069
A 60 degree over hang is at about the limit for filament printing. Those overhang test models are not expected to print perfectly, they are to show you the limits on your printer so that you can be aware when you design your models. There might be ways to improve on this for a specific model.
Your prints look pretty clean to me. If you have an issue with a specific print, you can always post the ZIPPED .3mf file (it has to be ZIPPED or it won't get attached) and folks here can look at it and advise you how to improve your print.
OK, I read all those and they were helpful, THANKS! I think I understand the bulge problem. Not sure it will be easy to fix but I'll keep it in mind as I design. Also learned a bit about seams and how to control them and a hint about adjustment of the extruder idler that I would like to know more about since I never really adjusted mine other than making it level with the wall.
RE: Anything I should be concerned about here? (overhangs and stuff)
@rick-lohr
Things to keep in mind:
While Sylvia is correct, a 60 degree over hang is at about the limit for filament printing (on average) this can be pushed as far as 80 with certain design considerations and proper tuning in Slicer. Just something to be aware of.
This bulge thing, all of these issues (they are not the same issue) can be tuned out of your prints with proper application and understanding of the software and the dynamics of the filaments used. the bulk of the folks participating in that thread do not understand what they can do with the software, and this contributes to the problem, as one user that doesn't know conveys to another user that doesn't know, please keep this in mind as you educate yourself. Many of these reported issues aren't actually issues, they are folks that think they should just be able to push a button and get perfect results. It takes education to get great results. the benchy hull line isn't even an issue any more relative to custom G-code, that's a very old bit of info. these things can all be addressed in slicer directly now and they are done on a model by model basis as no to models are the same, they require different tuning to print properly.
As well, while your prints look pretty good for first goes, you will want to start looking at settings like extrusion width and layer heights and start on the journey of learning modifiers to gain control over your prints.
This post was intended to be informative, I'm not chastising anyone, but keep in mind what I have said.
Have fun with it.
Swiss_Cheese
The Filament Whisperer
RE: Anything I should be concerned about here? (overhangs and stuff)
I tried to edit some grammatical errors, but ran out of time, damn you prusa forums!!! 😩
The Filament Whisperer
RE:
Good to know. You are telling me exactly what was expected. You got some great links to start me on that journey? (extrusion width and layer heights)
RE: Anything I should be concerned about here? (overhangs and stuff)
I do but will need to find them, I should mention that Prusa admins have deleted the example files from the posts I'll be referring to. So it will only be the verbiage, Ill try to find the files and re-post them, I deleted many thinking that they would be safe here. I do know better now, and have purchased a domain to host such lessons, however I'm still working on completing the site.
It wasn't just my files they deleted, much of the older posted information that was still pertinent was rendered ineffective by this action.
I'll do my best
Swiss_Cheese
The Filament Whisperer
RE: Anything I should be concerned about here? (overhangs and stuff)
I do but will need to find them, I should mention that Prusa admins have deleted the example files from the posts I'll be referring to. So it will only be the verbiage, Ill try to find the files and re-post them, I deleted many thinking that they would be safe here. I do know better now, and have purchased a domain to host such lessons, however I'm still working on completing the site.
It wasn't just my files they deleted, much of the older posted information that was still pertinent was rendered ineffective by this action.
I'll do my best
Swiss_Cheese
I'm new to this forum so I'm not privy to anything like this going on. I've actually been a mod for an RC Helicopter forum for over 15 years and prior to that I left the previous forum because I was so frustrated that they deleted content. I understand deleting vulger content that is offensive but deleting technical content that was posted in good faith should be community property and left intact IMHO. If it is misinformation, then other posters should dispute it and people should be able to come to their own conclusions. I learn from hearing both sides of a story then make my own decisions. Why exactly was your content deleted?
RE: Anything I should be concerned about here? (overhangs and stuff)
As a learning tool, here is the .3mf for the cup holder. What would I change to address the bulge problem and the artifacts around the handle?
RE: Anything I should be concerned about here? (overhangs and stuff)
My understanding is that older attached files were simply deleted with no other criteria than how old the posts were, I suppose to reduce the amount of storage needed. There was no consideration for the value of the deleted content to the community.
Mk3S+,SL1S
RE: Anything I should be concerned about here? (overhangs and stuff)
I'm aghast!
RE:
As a learning tool, here is the .3mf for the cup holder. What would I change to address the bulge problem and the artifacts around the handle?
The artifacts around the handle are seams. You can preview where the seams will land (any many other useful things) by using the menu at the bottom of the page where you see your sliced item and then compare to the print. You already read the article about seams. You have options for controlling where they land. Depending on the filament you can take them off with sandpaper but test the sandpapering first to see how it affects the finish.
Mk3S+,SL1S
RE: Anything I should be concerned about here? (overhangs and stuff)
It's great that you are so interested in learning all this stuff. I highly recommend you dig into the wealth of information at Bobstro's notes: https://projects.ttlexceeded.com/index.html
Mk3S+,SL1S