How feasible is printing PETG for PLA supports?  

RE: How feasible is printing PETG for PLA supports?

I tried it on my Mk2.5 and it seemed to work fine. Just print a block, pause mid-print and swap PETG for PLA. For me it stuck just enough to not produce spaghetti, but popped apart easily.

RE: How feasible is printing PETG for PLA supports?

When i get my 2 head XL i am going to try this. I will post my results.

RE: How feasible is printing PETG for PLA supports?

A good article that gives the rundown on how to use PLA and PETG as support for each other:
https://help.prusa3d.com/article/combining-materials-xl_498103

Selecting the "Soluable FULL" print setting defaults to extruder 1 as main material, and extruder 2 as the supports with "Snug" fit.

RE: How feasible is printing PETG for PLA supports?

I have been printing PETG with PLA for support and it works well as long as your printer is not one of the ones that seems to be impacted by extrusion issues.

I have set the bed temp to 70c which is a little high for PLA and a little low for PETG but it seems to work.

RE: How feasible is printing PETG for PLA supports?

Also, there is no problem doing that. This ist ne nice think about the XL, you can not only combine different colors, but different materials with different Temperature.

RE: How feasible is printing PETG for PLA supports?

So I just tried exactly this on my 2 Head XL with 0.3 Nozzles. Wanted to Print this huge amazing Rocinante Model.

The good:

• XL handles it perfekt
• Bed Temp 70c-80c on textured sheet with 3dlack results in great Adhesion
• The supports come off very very easy - no hassle at all

The Bad:

• The supports come off very very easy - while printing 😭 

RE: How feasible is printing PETG for PLA supports?

What material combination did you do?

RE: How feasible is printing PETG for PLA supports?

PETG for Supports and PLA for the Model.

Posted by: @georg-4

What material combination did you do?

RE: How feasible is printing PETG for PLA supports?

Thank you for clarification. 
Vise versa would be interessting.

RE: How feasible is printing PETG for PLA supports?

Altough it should be working, i hadnt had success. But im also mixxing different manufacturers

RE: How feasible is printing PETG for PLA supports?

Anyone have any more advice on how to get multi material printing to work reliably? I've been dealing with two issues, printing PLA with PETG supports.

First is bed adhesion. I've tried both sheets, tried a few temps in the 70 - 80 range. PLA seems happiest on the satin sheet, PETG on textured, but I can never get both.

Secondly, I'm trying a complex shape that requires supports on the Model itself. I cannot reliably get the PETG to deposit on the PLA model surface. I have a feeling maybe I'm being too optimistic with that, but if anyone has had success there, I'd love to hear about it.

Appreciate any guidance!

RE: How feasible is printing PETG for PLA supports?

I didn't find that PETG and PLA worked at all. Maybe it was the brands? I've tried Amazon Basic PLA with CR-PETG and they didn't stick.

My best success is with nylon. I've printed Essentium HTN with Amazon Basic PETG supports. It worked so incredibly well! When hot, the two materials stick together very well but when cold, they pop apart easily. So easily that the PETG stuck better to the bed than the HTN.

RE: How feasible is printing PETG for PLA supports?

I have had success printing Prusament PETG supports for a Prusament Galaxy PLA part as long as the supports are from the bed and not on the part. Setting the bed temperature is a bit tricky, particularly for large parts. If the bed temperature is left at the default high value, then a large part will tend to warp (and dimensional stability is one of the reasons to use PLA). I had better luck running a bit high for the first layer or two and then reducing back to ~65 thereafter. The wipe tower has been a bit of a mess but the support surface was nice and smooth and the separation very easy. However, I have not found any way to use PETG if it is on top of the PLA - there is just not enough bonding.

I specified Galaxy PLA, since I have found that Galaxy Black prints noticeably better than the straight Jet Black, even though they are both supposedly the same PLA material. I do all experimental PLA builds now with Galaxy Black or Galaxy Silver and then move to the other filaments after success with those filaments.

RE: How feasible is printing PETG for PLA supports?

Printing PLA onto PETG can have issues but overall seems fine.

Please ignore the infill-perimeter separation, that's a separate multi-nozzlesize side-effect.

PETG onto PLA is much more of a pain.

And as a counter, this is the result of black PETG snug support with zero x-y separation from the PLA model. Looks like every other layer got squished into the model, like a zipper. I'm guessing one got printed before the other and the order switched each layer? I needed a metal pick and force to remove it. If model and support were same material they would undoubtedly have fused into a single part.

So it seems like you need a more mechanical approach to get PETG to stick onto a PLA surface, maybe have a single raised line of PLA so when the first line of PETG gets extruded it does so into a 'corner' rather than just a flat smooth surface. Also avoid sharp corners and/or/maybe speed on smooth surfaces. Maybe that's why the circle (actually a sphere) test did so well compared to the triangle/square test. There is are couple 'stair steps' as the first few layers of a sphere which provided corners for the PETG to better attach to where as the square and triangle was just PETG onto a flat relatively smooth plane.

But I haven't actually tried supports that start on the model in any real print yet.

For supports from the bed, I created a profile for PETG when used as supports for PLA so the bed stays at 60c, equal to PLA instead of averaging out to avoid warping/curling of the main model. It's sometimes hard to tell if supports fail because of bed adhesion, or if its because of other reasons. If my current print pans out, then the issue is really just beefing up organic settings with things like full double walls, etc. Fingers crossed.

RE: How feasible is printing PETG for PLA supports?

I’ve been using pla and PETG combinations on virtually every print I do now. It has worked quite well, but I am finding the PS’s support generation to be not all the great. For some objects it’s ok, but not all.

Lately I’ve been making separate support structures myself in PS using objects from the gallery and using negative Boolean versions of my object to make a perfect fit full contact support object for optimal surface quality. It’s tricky to do, but it works nice and it saves a lot of material. I was thinking about posting the task flow here. We will be talking about it in detail in our podcast along with how to do it in Fusion360 and in Blender.

RE: How feasible is printing PETG for PLA supports?

Here’s the task flow on my forum:

https://groups.google.com/g/3d-printing-tips--tricks/c/ktltkQQeRa4

RE:

Printing PLA or PETG on the other as supports will not work.

The two materials will not stick to each other. That is exactly why you want to use them as supports for the other. The trick is to only support from the bed.

I run prusament, overture, and a couple of other brands without any issues.

I have filament profiles that have the bed temp at 70C for both materials.

You need to make sure that your top contact z distance is set to 0(soluble) .

RE: How feasible is printing PETG for PLA supports?

Works fine. Yes the supports have to be on the bed…

RE: How feasible is printing PETG for PLA supports?

Another pic before I remove the supports