Hello.
I would like some help as how to correct this issue I am having with my print. The first 1-3 layers of the PETG supports are not adhering to the previous layer of printed PETG material. Support wall loops are 2, support type is Tree Strong, and the support speed is 60mm/s. Any help is very much appreciated.
It’s not exactly clear, but I’m assuming the support material is the same PETG as the model itself?
I can’t fire up Studio right now to look, but there’s a parameter for the distance between the support and the printed surface. “Interface” distance or something like that. It will probably be the same as your layer height (or close to it). Find it and reduce it slightly.
If you’re using a dedicated support material for PETG (PLA works great, BTW), set that interface distance I’m talking about above to zero.
Make sure the part fan isn’t running when the support is being printed.
Yes that is correct. Both are the same material. Okay I will look at that. I thought about changing the base pattern from default to rectilinear but I didn’t know if that would help.
Just to clarify, what I am printing is a basically a hollow box, so there are supports that will be on the inside of the box to support the top face. What is happening is that the initial layer of the supports are not sticking to the inner face of the box (previous layer of material).
I guess the parameter yor mentioned is “ Bottom Z distance” ?
That is what I was thinking as well.
filament shrinkage. reduce cooling.
I am having this same issue with PETG-CF. Did you get this figured out and if so, how? Many thanks.
If you are intending not to remove the support material anymore because it is a fully enclosed box, you can set the “Bottom Z Distance” to 0.
But my question would be, why are you not designing it as a solid block and play with wall and bottom and top layers for the strength and us a very simple infill pattern.
When I look at the wall thickness it is already huge. You are already using a huge amount of material for this box.
There are some adaptive infills that gradually get denser towards the top.
Can you show a picture of your intended model and describe it’s function?
I was trying to be simple by saying it is a box, but really is it a hollow jug. This jug is supposed to be filled with sand and used as a counterweight to hold down soccer goal posts. With that being said, the supports do have to be removed. I reran the print last night changing the bottom z distance I originally had (.24mm) to .18mm. This improved the bottom layers but not completely as I checked it this morning and some of the intial layers of the supports are peeling up again. I’m attaching a pic my first successful print. I’m not sure why the settings used for that one are not repeatable.
Clear now, so it needs to be filled.
So you need a hollow part. So the high wall count is definitely required.
Glad it worked out.
So the picture I sent was my first successful print which did not have repeatable settings. It causes failures which was my first picture in this topic. So the issue is still at hand. Does this mean that Tree supports are not repeatable for this application?
You could set the distance to 0 so you can be sure it’s connected to the base.
It will be harder to remove the support though. A simple internal open rib structure that supports the top with bridging in between would help enormously in my opinion. The internal structure doesn’t need to be removed.
This might make it harder to put the sand inside though.
If they would be having big chamfered holes in there the geometry could easily be bridged without the need for support.
Take a look at flipping it over so it is printed with the openings face down on the build plate. The supports can grow to reach the “top” from the build plate surface. You won’t have to deal with the issue you have now, printing it right side up.
Okay I will try adding that. What do you suggest in the bridge lengths? I’m always scared that those will cause failures too.
I thought about that, but the load will be in the same direction of the cross section so I’m afraid it will separate after the load is applied. That is why I am printing in the orientation it is in now.
Oh, you’re laying it on its side to print it.
Yeah, I’d go with internal ribbing and bridges. Note though, the first two layers of the bridged top surface will be much weaker than the opposite side printed on the plate. You will want to bump the top surface layer count up to compensate.
You would require dry sand to fill it with
I would be thinking about 30-40mm between the ribs. There are some nice bridging test models that help you to determine and tune the maximum bridging distance for your filament. I have seen bridges up to 100mm on YouTube that looked still acceptable, but that was with PLA I believe.
The ceilings wont look super nice for the 1st couple of layers but adding some extra layers would help.
If you would have 2x2mm ribs on the ceiling and chamber them with the walls, you are building a custom support structure and the distance between the chamfers could be the bridge distance again.
Not at computer now, but will sketch out something for you later.
