Insert a PLA printed part during the print to function as support material for PETG
Hi,
Does anyone has experience in inserting a PLA printed part during a pause of the print so this PLA part functions as a support material for PETG print?
- I need to print mechanical parts (as shown above) from PETG as the parts are to be strong and water resistance. So PLA is not an option.
- Printing in an other orientation is strength wise not wanted.
- Using the normal support option in prusa slicer results in a too thick upper part and thus a wrong "in-between" distance.
See attached 3mf file. - I have a MMU2, but using PVA+ does not work nice with PETG due to the nozzle temperature difference. (An other option I did not try yet is "PrimaSelect PVA HT (High Temp) filament"
So I thought to use an insert, printed on forehand in PLA, to be used a support. Does anyone has experience in using an insert of PLA as support?
Cheers, Bas
Best Answer by Bas:
I did some succesfull tests. The best test including instructions can be found here:
https://www.prusaprinters.org/prints/39647-test-with-preprinted-pla-support-for-petg-models-w
RE: Insert a PLA printed part during the print to function as support material for PETG
I have put multi-colored-by-layer (we need a word for that) PLA cubes inside PLA shells with window holes to make dice with different colored pips or symbols on the top, same color on 4 sides, and different again on the bottom. It was a little fiddly to work out the tolerances and balance, but it works.
- For your example, I’d make the PLA insert 1mm less than size of the void in the X,Y, and Z dimensions between the two mirrored sides. Then make spare inserts .5mm and 1.5mm shorter. Print the PETG parts and pause right before the first layer of the overhang. Try inserting each of the inserts, until you get one that feels just lower than the side walls so far. This is important so the PETG doesn’t fuse to the PLA and you can separate them later. Due to tolerances this is most likely the one 1mm or .5 mm shorter than the void.
RE: Insert a PLA printed part during the print to function as support material for PETG
I did some succesfull tests. The best test including instructions can be found here:
https://www.prusaprinters.org/prints/39647-test-with-preprinted-pla-support-for-petg-models-w
RE: Insert a PLA printed part during the print to function as support material for PETG
Besides the reason stated in bas's instruction, are there other reasons to do this?
RE: Insert a PLA printed part during the print to function as support material for PETG
- The quality of all the surfaces is smooth.
- The height between the overhang is closer to the designed height and at least not less, so:
- no more grinding needed, so less work, but also less change for heat-deformation during grinding.
- Pre printed support can be re-used. So this saves support material and time to print supports in case of a series.
RE: Insert a PLA printed part during the print to function as support material for PETG
I've used a similar method the the one described by Bas, on several parts in the past and had good luck with it.
Another option to try is modeling your own custom supports in your CAD program of choice, you can get some very fine detailed supports in places where the insert method of support simply wont work, or when you can't be there to insert them. If you tune your custom supports just right the results on your finished print can be every bit as nice. and no glue or release is needed. while it does add to the print time, you are freed up to work on other things or be other places.
The Filament Whisperer
RE: Insert a PLA printed part during the print to function as support material for PETG
@dan-p12
Hi Dan, are you willing to share your tuning settings? Do you use the same settings as the first layer on the sheetbed?
RE: Insert a PLA printed part during the print to function as support material for PETG
Looks very good.
I was always thinking why nobody made, metal blocks(or other material), that would be possible to put in the slicer(on the bottom of the bed), so big infills can be filled in with a metal block.
Print till you can put the metal block on the bed, in the model is a hole printed for the metal part.
This could save a lot of print time.
Maybe several different models to put on the bed.
Maybe prusa can make this in the slicer, and sell the blocks to put on the bed.(and of course test this if this works.)
RE: Insert a PLA printed part during the print to function as support material for PETG
A new and bigger example is shown below. See also my first picture in this post. AS you can see I used partly standard support.
RE: Insert a PLA printed part during the print to function as support material for PETG
What is the advantage in using PLA as support for PETG? How about PETG as support for PLA? Custom support using PETG for PETG model or Custom support using PLA for PLA model?
RE: Insert a PLA printed part during the print to function as support material for PETG
@peter-c20
I understood that PETG is not sticking very well on PLA. That is why I use PLA. But when you use glue I think you can use PETG as pre printed support as well, but I have not tested this.