Supports REALLY bad
Hi all,
I am a bit of a noob with this whole 3d printing thing but still seem to be getting some really good prints that I am more than happy with. However, although I am aware that I can not really expect what is in contact with supports to be really great, I notice that its really bad at times and it seems to affect layers above the supports too. What I am really asking, I think is, is this normal and if not, can I correct it.
The fist picture shows what I have before I even remove the supports. You can see that the print is badly affected above the line of the supports. This needs to be filled with some kind of filler. The second picture shows it after and it looks pretty bad too though I can sand that down at least.
Re: Supports REALLY bad
supports are much, much, much less effective for sloped surfaces like that and really only as a last resort for a feature that is otherwise completely unsupported. surfaces resting on supports are likewise guaranteed to be ugly - no way around it.
hard to tell from the pic but if that surface is angled more than 45-50 degrees then part cooling, layer height and wall thickness can all affect surface quality on overhangs.
Re: Supports REALLY bad
That area also looks like it suffered from heat warping, where the print nozzle spent a lot of time over that spot making small movements to ensure that the "vertical shell thickness" is at least the same as your the rest of your perimeters.
You may try increasing the number of perimeters to 3, and turn off "Ensure vertical shell thickness". Use the Preview tab in Slic3r PE to cut down to that area, and toggle "Ensure vertical shell thickness" on and off to see the difference.
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Re: Supports REALLY bad
Thank you both for your reply. This makes interesting reading. I have looked at the "Ensure vertical shell thickness" option in Slic3r and it certainly seems to make a difference. I hesitate to print that again as it was an 18 hour print and I might get by with sand paper but I have seen this issue on a number of prints so will certainly play around with perimeters and that setting.
The idea of the hot end hanging around for a long time warping the print sounds interesting to me as I do prefer slow and accurate to fast. Just in case anyone has some additional suggestions, I should mention that the area you see with the supports was lying with the support side on the bed. The surface of the part is uneven and big which is why it needed support.
Thanks again
Re: Supports REALLY bad
The idea of the hot end hanging around for a long time warping the print sounds interesting to me as I do prefer slow and accurate to fast
you'll see it with smaller features and very, very slow speeds such as the chimney on a benchy model OR something like sharp overhangs in the first few layers where the heated bed prevents you from cooling as quickly.
using a silicone sock is recommended.
Re: Supports REALLY bad
I think you are on to something. This was close to the heated bed and it is better with parts further away.
Thanks again for the post, I hadn't considered the incidental heat as being a factor!
I love this printer 🙂 Had it about two months now and between my girlfriend and I, we now need scheduling software to book printer time 🙂
Re: Supports REALLY bad
I think you are on to something. This was close to the heated bed and it is better with parts further away.
Thanks again for the post, I hadn't considered the incidental heat as being a factor!
I love this printer 🙂 Had it about two months now and between my girlfriend and I, we now need scheduling software to book printer time 🙂
lots of people like to design parts with chamfers on the bottom to "aid" printing and reduce elephant's foot. so, thats something else to watch out for since if you're printing very hot that overhang will not print properly.