Using PLA for support PETG prints  

RE: Using PLA for support PETG prints

Yeah I think there's some community knowledge that could definitely be shared.  I also had the same problem with the PLA support layer peeling away from the PETG support at a few critical places, leading to failure to print in those areas.

My observation is that the toolhead was moving too quickly, changing direction before the PLA had a chance to cool and remain where it is.   I also chatted with another XL user who suggested eliminating any layer gap.

So i'm going to try a new print over the weekend with creating a copy of the SOLUBLE INTERFACE settings then applying the following modifications

support material > interface pattern spacing (default 0.1mm) changed to 0.0

speed > support material interface (default 50%) changed to 20%

then see how that goes.

RE: Using PLA for support PETG prints

Let me know ... I have no success at all 🙁

RE:

So support distance should be 0 or “soluable”. Snug. Sometimes your best bet is to paint the supports on since ps doesn’t do a good job with auto support placement. Learn to do it BEFORE you do it on complex prints. Find a simple object with a simple flat overhang. Check in the preview that the support tops are all flat and solid and that they are at the layer before the object starts. It works best on cad made files since they are usually clean undersides Vs more organic statues or scans. See the pics in my post in the upper thread. When the undersides are complex it will still work, but you may have to snip sections of the supports to get around a mechanical bond.

ALWAYS have lift on Retraction aka z hopping set to at least 1.5 mm. All MMs printing requires z hopping! Cooling must be high enough to prevent curling on tongues with pla.

You may be able to use a prime tower so long as it’s no more than three materials but you have to check to ensure that the support material is all on its own in the tower… Otherwise ps’s prime tower does not as of yet properly support mms. See my other posts.

I do NOT use a prime tower.

I Set retraction on tool disable for each extruder to 11.7mm which draws the material out of the melt zone when the tool is parked. This cuts way back on strings and drool.

also…

all the default material presets are way too hot. PLA-200c, PETG 215c.

RE: Using PLA for support PETG prints

So I had great success, but I needed like eight tries to tune it, but now it works every time. The Filament needs to be pretty hot and it really needs to be squished onto the support. Also I am printing with an enclosure, but I am not sure that is necessary. I attached an example for you guys, so you can check out the settings.

RE: Using PLA for support PETG prints

I've heard of this (using a hostile plastic filament for support material) but never tried it.  I've had good luck using soluble support material, but of course there's the time and mess of soaking to dissolve it.

I may just give this a shot, as it seems that you got it to work as expected and it may just give the appearance of the soluble supports with the convenience of break-away supports.

In some cases, with some prints only, I have been able to actually break away the soluble support material, thus eliminating the need to soak.

RE: Using PLA for support PETG prints

I can't find your attached example for the settings!

Posted by: @acht

So I had great success, but I needed like eight tries to tune it, but now it works every time. The Filament needs to be pretty hot and it really needs to be squished onto the support. Also I am printing with an enclosure, but I am not sure that is necessary. I attached an example for you guys, so you can check out the settings.

RE:

Thanks for the reply and I agree on most of the things you say but my issue was PLA for support material on PETG prints. Using “soluable” and Snug is not enough for it to work. 

BTW I don't use primetower either.

Posted by: @tobycwood

So support distance should be 0 or “soluable”. Snug. Sometimes your best bet is to paint the supports on since ps doesn’t do a good job with auto support placement. Learn to do it BEFORE you do it on complex prints. Find a simple object with a simple flat overhang. Check in the preview that the support tops are all flat and solid and that they are at the layer before the object starts. It works best on cad made files since they are usually clean undersides Vs more organic statues or scans. See the pics in my post in the upper thread. When the undersides are complex it will still work, but you may have to snip sections of the supports to get around a mechanical bond.

ALWAYS have lift on Retraction aka z hopping set to at least 1.5 mm. All MMs printing requires z hopping! Cooling must be high enough to prevent curling on tongues with pla.

You may be able to use a prime tower so long as it’s no more than three materials but you have to check to ensure that the support material is all on its own in the tower… Otherwise ps’s prime tower does not as of yet properly support mms. See my other posts.

I do NOT use a prime tower.

I Set retraction on tool disable for each extruder to 11.7mm which draws the material out of the melt zone when the tool is parked. This cuts way back on strings and drool.

also…

all the default material presets are way too hot. PLA-200c, PETG 215c.

RE:

I am sorry it seems I can not upload the 3mf, but here is a Link:
https://drive.google.com/file/d/13dBf5iWLEfYaLsVq7-hfZwQ6iYeMN6V7/view?usp=sharing

RE:

Always start with a way simpler object so that you can “learn the ooze”. Toolchangers will never be toasters. It is what it is regardless of what Josef may say.

Start with an object where both materials have good surface area on the bed and the overhang is flat and clean. Of course this assumes you already got single material sticking well. The very best results will always happen when you make the supports yourself in CAD. Currently all the slicer sw out there does not do a really good job with the tops of supports. However, if the community makes it known this is a requirement the devs will start considering it. Regardless you can still get awesome results Vs the marring you get otherwise.

Increasing your temps is not a good thing. A toolchanger (unbeknownst to Prusa BTW) has extremely tight tolerances for temps. The material has to just be hot enough to fuse so that it’s not too soft to control when the extruder is parked. So I recommend do not increase your heat. The new hot block and vertical orientation of the heater has made the reference temp different for the Nextruder. IME with my XL-5, PLA is 200c and PETG is 215c. Note these temps do not mean the molten material is actually that temp, they’re  the settings I’ve found which are closest to what I need to get it to do what I want.

Take a pic of what your printing and post it! Lemme see.

RE: Using PLA for support PETG prints

I would never use PLA as the the support interface material.  What I've been is using a soluble support material like Aquasys120(my new goto now) to print the interfaces between the supports and the model and then use something like PLA for the supports, to save on the petg.

This takes some setup but I've gotten it to work with the following combinations.

Model material /  Interface material/ support material

PLA/Aquasys120/120/PLA
PETG/Aquasys120/PLA
TPU/Aquasys120/PLA

The aquasys can do bed temp from 50-120C thus it's compatible with just about anything you'd want to print.  you you just have to create a profile for aquasys with a bed temp that matches your other filaments that would be printed on the same first layer.

See the following post that has a zip of my different .3mf files for setting this up.   it's really a game changer.
https://forum.prusa3d.com/forum/original-prusa-xl-tool-changer-assembly-and-first-prints-troubleshooting/trouble-printing-with-soluble-supports-pva-or-verbatim-bvoh/#post-686006

RE: Using PLA for support PETG prints

I’ve been doing it now for my clients for two years. It works quite well and they love it. I’m willing to bet I get  just as good results as a soluble material. Ive been able to outbid big industrial machine users thanks to this approach. I get the equivalent results. soluble materials are expensive and a real pain to work with. Been there, done that. Waste of time and money. Unless of course you have designed yourself into a corner and soluble is your only solution. I’ve already seen pics of this on this forum.

RE: Using PLA for support PETG prints

You might be right,  but it's going to be depend on what's being printed.   I wanted something general purpose for PLA, PETG, TPU, whatever.   The PETG + PLA supports might work well, but what about TPU, ABS, etc.   I'm just a hobbyist at this stuff(I haven't tried to sell anything I make) and so I'm sure since you sell stuff you make you you're going to have found what works best for the stuff you print.   I'm still early on in the process for getting this figured out but I feel like soluble supports/interfaces give you the widest array of options with regards to multi-material.   

Posted by: @tobycwood

I’ve been doing it now for my clients for two years. It works quite well and they love it. I’m willing to bet I get  just as good results as a soluble material. Ive been able to outbid big industrial machine users thanks to this approach. I get the equivalent results. soluble materials are expensive and a real pain to work with. Been there, done that. Waste of time and money. Unless of course you have designed yourself into a corner and soluble is your only solution. I’ve already seen pics of this on this forum.

RE:

Yes, soluble will give you the widest breadth of solutions. But at a cost: money, your time and the use of one of your tools! Not to mention the mess of the water use. If you're making what you print yourself the very best approach is to make your own supports (see the sample I just uploaded as a separate thread) and simply use a nonbonding material. Honestly I have not tried TPU Vs PETG VS Nylon VS PC, etc. All my use cases for my clients have been objects in PETG and PLA for supports. Perhaps I should put this test on my now very long project queue!

and... BTW... thanks for the tip on the Aquasys120. It's not PVA. I like that. I'll be buying a spool to keep on hand for those client use cases that may need it. Thankfully none have needed it as of yet, but I always like to be prepared.

RE: Using PLA for support PETG prints

Yep,  I get that for sure.   If I were making my livelihood on 3d printing stuff, I'm quite sure I'd doing exactly what you're doing.   If I'm designing something I nearly always try avoid supports at all if possible, but it's nice to have the soluble as a general purpose option though.   I'll leave the fine tuning to you professionals 🙂

Posted by: @tobycwood

Yes, soluble will give you the widest breadth of solutions. But at a cost: money, your time and the use of one of your tools! Not to mention the mess of the water use. If you're making what you print yourself the very best approach is to make your own supports (see the sample I just uploaded as a separate thread) and simply use a nonbonding material. Honestly I have not tried TPU Vs PETG VS Nylon VS PC, etc. All my use cases for my clients have been objects in PETG and PLA for supports. Perhaps I should put this test on my now very long project queue!

RE: Using PLA for support PETG prints

Here’s another example of full contact support. Spyro is printed in 4 colors of PETG and pla support. The pla cost about $12 a spool. Printing this using break away support is unacceptable.

RE: Using PLA for support PETG prints

Yeah I'm still playing with the aquasys120 profile, but basically I just copied bvoh and adjusted temps.  I've actually printed an xyz calibration cube in it using petg settings, it's pretty versatile.   I think I might be able to get the results you're talking about with PETG+PLA but making the support manually and printing that in A120 as a part of the model, then there'd be no interface wonkiness.  I might try that.  My wife is going to be out of town for a couple weeks shortly and then I'll be off the last two weeks of december, so I'll have some time to fiddle some more.    I'm anxious to get my ventilation hooked up so I can try some abs/asa prints with the xl.   I've not tried this yet since upgrading my two MK3s to mk4 and I've not tried it on the xl since I got it either.  It being winter in colorado and my only option for ventilation is a dryer vent hose out the window.... it's been back-burnered.

Posted by: @tobycwood

and... BTW... thanks for the tip on the Aquasys120. It's not PVA. I like that. I'll be buying a spool to keep on hand for those client use cases that may need it. Thankfully none have needed it as of yet, but I always like to be prepared.

RE: Using PLA for support PETG prints

yep, that looks pretty good!  Spools of BVOH and A120 certainly aren't cheap for sure, but if you're only printing the interfaces in soluble, there's really not that much used.   This is why I was looking at using PLA is the primary support structure since you can get spools of it for cheap and then just using the A120 as an interface.   I'm doing some tests with  PLA + A120 interface + PLA support today in preparation for a vader helm print I've been wanting to do but had to wait on the XL to show up lol   I think I might play some custom support stuff like you were talking about but print that custom support in A120 but as part of the model, touching it.

Posted by: @tobycwood

Here’s another example of full contact support. Spyro is printed in 4 colors of PETG and pla support. The pla cost about $12 a spool. Printing this using break away support is unacceptable.

 16016d89-img_0071.jpeg

RE: Using PLA for support PETG prints

Lol xyz calibration cubes out of bvoh(left) and a120(right)

RE:

I just figured out how to keep local minima from getting swept away: "mouse ears"!

10mm mouse ear placed at local minimum where the model geometry would not have enough contact to stick to the underlying PLA