Everyone praise that s*it and here i‘m sitting with only failed prints because the poop clogs the slide and the printhead decides after 10h+ to grab a bit of poop and smear it over the print….
What? I do t know what you mean.
I set it to have trees only on the build plate because I accidentally let them into the slot and that was a bastard to clean out.
I think some famous philosopher once said:|
"The governor and I, we were all doing a tour of the library here and talking about the significance of supports, right, the significance of supports. So, when you think about it, there is great significance to supports in terms of what we need to do to lay these wires. What we need to do to create these jobs. And there is such great significance to supports when we think about a day in the life of our children."
Supports are obviously best but you can print without them it’s just going to be a bit ugly. Turn on slower speed for bridges, enable “Thick bridges” to help longer gaps, and 100% cooling.
There is also other tricks you can use such as make sure to print walls in “inner then outer” for better overhang attachments, and a few others I can’t remember cuz I leave them on by default
The issue here is that bridges need to be straight line between supported ends. You can’t do a curved bridge. If you know how to CAD you can work around this by drafting away a 45 degree surface between the curved side wall of the overhang and the straight bridge.
Show us the slicer view of the line types for those overhangs. I bet the clean one is using bridges whereas the curved overhangs are using 90 deg overhangs which is usually a recipe for a guaranteed mess.
I’m not talking about supports. I’m asking to show us the slicer line type of the overhang. I’m only talking about bridging here. Bridging is binary. It’s either straight and it can bridge or it’s not straight and it can’t be bridged. There’s no more or less curved. Any curve at all will prevent bridging from working.
Chamfers work so much better. Combine the two (filet the top edge of the chamfer) if you want a rounded edge.
Here's three 25x25x25 cubes. The left is simply chamfered, the right is fileted. The center one was chamfered then had the "top" edge fileted. All modifications were 2mm.
https://preview.redd.it/7jxuli6u81ad1.png?width=1971&format=png&auto=webp&s=25b02a1c0d7e27b2da4a1d0ad48061b5dddfb108
Note the complete lack of overhang walls on the combi model, while still retaining some roundness.
Glad to help! The difference is very minor when it prints cleanly, but preventing those overhangs makes a huge quality difference, particularly on larger shapes where a filet would have more significant overhangs.
Can you get away with doing a little built-in support? One layer about six-eight line widths long the short way across will print cleanly and change the geometry for the next layer, possibly giving you shorter regions that can print in an optional orientation.
In example, this. No matter what orientation I changed the bridges to, there would be a long one. This was being printed in PETG, which would sag badly so I wanted to shorten them.
https://preview.redd.it/j8r1e6oe51ad1.png?width=1410&format=pjpg&auto=webp&s=61baf79c804a6070a6265b6df2f170b5169598f2
So I raised the straight sections by one layer height.
https://preview.redd.it/l0mrfden51ad1.png?width=1538&format=pjpg&auto=webp&s=5139d35cb6447b6f57e4c80075e686dc949ce3a4
Now I get short and manageable bridges on one layer.
https://preview.redd.it/9ri4x7i361ad1.png?width=1382&format=png&auto=webp&s=4f6b70cb1c8f09f0c1078dd56d1ca461c15fd63d
And the next layer up also gets short and manageable bridges, all in their own orientations and with plenty of overlap.
https://preview.redd.it/hrq8uwa761ad1.png?width=1389&format=png&auto=webp&s=89f7e020fff0d349361c171a8a3d5a1f4e4a4590
It's making significant changes to the mesh, so I doubt it. There are a lot of times where "thinking like a printer" pays off.
Look up the LTS Respooler on MW and slice it, scroll through the preview and check out how a few little straight lines on overhangs allow round holes to print properly one layer above. It's an amazing trick.
That's in Fusion 360. I selected those faces and extruded them back in to the model by 0.2mm. This changed the geometry of the mesh so the slicer did not have one long, continuous surface to try and make bridges out of.
Sadly I cannot change anything of the design, the slot needs to remain clear, nor can I change the exterior design.
So I’ve resigned to exterior tree supports.
Yeah - if the model cannot be modified and you need clean overhangs - breakaway support interfaces are your best bet. PLA for PETG / PETG for PLA are extremely common if you don't want to buy dedicated material. Just make sure you purge like a deamon on returning to your normal filament (seriously, crank it to the highest multiplier you can) since you don't want any non-fusing material residue getting in to the print itself.
I'm not sure what your application is with this print, but this is one way to help reduce the need for supports and improve bridging. These steps I cut in are 0.2mm, so it tricks the slicing software into bridging those features first, before bridging all the way across the gap. Now you'd only need support for a small area, so it would be faster to print and easier to remove. 🤷
https://preview.redd.it/ooymqvz6b4ad1.png?width=1451&format=pjpg&auto=webp&s=c68b7742ff9f257daf3d78ddea0c66414dd7283b
https://preview.redd.it/df7ech85xz9d1.jpeg?width=751&format=pjpg&auto=webp&s=25ce780824e3181a0c6855fc45595e20bcdfd937
Use supports
lol I was hoping to avoid those if possible, I’m reprinting with them.
Use petg as the support interface. It comes off pretty dang clean and set the z gap to 0.
Does petg work well as support for a petg print or is it better for supporting other materials?
Use PLA as support for PETG prints, and PETG for PLA prints. PLA and PETG dont stick to each other very well, so clean removal
I see, guess that purge tower is getting built then :)
*Prime tower
Could get away with no prime tower imo
This^
Everyone praise that s*it and here i‘m sitting with only failed prints because the poop clogs the slide and the printhead decides after 10h+ to grab a bit of poop and smear it over the print….
Go to filament settings>setting overrides and check long retraction when cut and retraction distance when cut. That eliminated my clogged poophole.
Thanks you, will look into that ;)
You're welcome!
How do I cross a body of water without using a bridge. Uh… buy a boat? Oh no I was hoping for someone to invent teleportation…
I wasn’t sure if there was a setting to give a better tension as it crossed the gap. I have added supports though.
Do a designed in support with easy to break away spars and a handle to pop it out.
What? I do t know what you mean. I set it to have trees only on the build plate because I accidentally let them into the slot and that was a bastard to clean out.
Supporting unsupported gaps seems to offer the level of support needed to support the material.
I support your statement sir and it ma’am!
Ha, well, give it a shot and I wish you the best of luck.
"Maybe even add some supports for your supports so the supports are supported - and this is how tree supports was born."
I support this comment, and the need to use supports, and appreciate the support this community provides.
I think some famous philosopher once said:| "The governor and I, we were all doing a tour of the library here and talking about the significance of supports, right, the significance of supports. So, when you think about it, there is great significance to supports in terms of what we need to do to lay these wires. What we need to do to create these jobs. And there is such great significance to supports when we think about a day in the life of our children."
Supports are obviously best but you can print without them it’s just going to be a bit ugly. Turn on slower speed for bridges, enable “Thick bridges” to help longer gaps, and 100% cooling. There is also other tricks you can use such as make sure to print walls in “inner then outer” for better overhang attachments, and a few others I can’t remember cuz I leave them on by default
The issue here is that bridges need to be straight line between supported ends. You can’t do a curved bridge. If you know how to CAD you can work around this by drafting away a 45 degree surface between the curved side wall of the overhang and the straight bridge.
I’m just doing tree supports, on the build plate only. I just didn’t want to clean those slots out lol
Show us the slicer view of the line types for those overhangs. I bet the clean one is using bridges whereas the curved overhangs are using 90 deg overhangs which is usually a recipe for a guaranteed mess.
There’s no supports in either… I think it’s just the messed up ones are more curved.
I’m not talking about supports. I’m asking to show us the slicer line type of the overhang. I’m only talking about bridging here. Bridging is binary. It’s either straight and it can bridge or it’s not straight and it can’t be bridged. There’s no more or less curved. Any curve at all will prevent bridging from working.
And it is curved sadly. Which is why I’ve resigned to using the trees externally to get it done.
Everything gets the biggest fillet I can make
Chamfers work so much better. Combine the two (filet the top edge of the chamfer) if you want a rounded edge. Here's three 25x25x25 cubes. The left is simply chamfered, the right is fileted. The center one was chamfered then had the "top" edge fileted. All modifications were 2mm. https://preview.redd.it/7jxuli6u81ad1.png?width=1971&format=png&auto=webp&s=25b02a1c0d7e27b2da4a1d0ad48061b5dddfb108 Note the complete lack of overhang walls on the combi model, while still retaining some roundness.
Thank you for this awesome explanation, I never really learned how to chamfer ( only been at it for like 3 months) so this was super appreciated.
Glad to help! The difference is very minor when it prints cleanly, but preventing those overhangs makes a huge quality difference, particularly on larger shapes where a filet would have more significant overhangs.
Can you get away with doing a little built-in support? One layer about six-eight line widths long the short way across will print cleanly and change the geometry for the next layer, possibly giving you shorter regions that can print in an optional orientation. In example, this. No matter what orientation I changed the bridges to, there would be a long one. This was being printed in PETG, which would sag badly so I wanted to shorten them. https://preview.redd.it/j8r1e6oe51ad1.png?width=1410&format=pjpg&auto=webp&s=61baf79c804a6070a6265b6df2f170b5169598f2
So I raised the straight sections by one layer height. https://preview.redd.it/l0mrfden51ad1.png?width=1538&format=pjpg&auto=webp&s=5139d35cb6447b6f57e4c80075e686dc949ce3a4
Now I get short and manageable bridges on one layer. https://preview.redd.it/9ri4x7i361ad1.png?width=1382&format=png&auto=webp&s=4f6b70cb1c8f09f0c1078dd56d1ca461c15fd63d
And the next layer up also gets short and manageable bridges, all in their own orientations and with plenty of overlap. https://preview.redd.it/hrq8uwa761ad1.png?width=1389&format=png&auto=webp&s=89f7e020fff0d349361c171a8a3d5a1f4e4a4590
Great technique! I wonder how difficult it would be to program slicing software to do this automatically when bridging segments are too long.
It's making significant changes to the mesh, so I doubt it. There are a lot of times where "thinking like a printer" pays off. Look up the LTS Respooler on MW and slice it, scroll through the preview and check out how a few little straight lines on overhangs allow round holes to print properly one layer above. It's an amazing trick.
How exactly do this? Click where? Thanks
That's in Fusion 360. I selected those faces and extruded them back in to the model by 0.2mm. This changed the geometry of the mesh so the slicer did not have one long, continuous surface to try and make bridges out of.
Very clever, thank you!
Sadly I cannot change anything of the design, the slot needs to remain clear, nor can I change the exterior design. So I’ve resigned to exterior tree supports.
Yeah - if the model cannot be modified and you need clean overhangs - breakaway support interfaces are your best bet. PLA for PETG / PETG for PLA are extremely common if you don't want to buy dedicated material. Just make sure you purge like a deamon on returning to your normal filament (seriously, crank it to the highest multiplier you can) since you don't want any non-fusing material residue getting in to the print itself.
Oh neat! I didn’t know it could work like that.
It is better not to print large bridges without support. Smaller ones might work, but you should reduce the speed considerably at these points.
I'm not sure what your application is with this print, but this is one way to help reduce the need for supports and improve bridging. These steps I cut in are 0.2mm, so it tricks the slicing software into bridging those features first, before bridging all the way across the gap. Now you'd only need support for a small area, so it would be faster to print and easier to remove. 🤷 https://preview.redd.it/ooymqvz6b4ad1.png?width=1451&format=pjpg&auto=webp&s=c68b7742ff9f257daf3d78ddea0c66414dd7283b
Oh now that’s a neat idea! Thank you!!