Changing from PETG to PLA  

RE: Changing from PETG to PLA

You have to do it manually. Simply load the PLA but select PETG as filament type on the LCD menu. Then run a couple of extra purge cycles (simply answer no when it asks you if the correct color is extruding). Finally upload it and reload it with the correct temperature. 

RE: Changing from PETG to PLA

I usually go like this:

Preheat to current filamenttype.

Unload filament.

Load new filament - purge 3 times (the same when changing colors).

Manually raise temp to last filamenttype +5c.

Wait 1min to allow it to fully soften up and melt inside

Manually extrude about 100mm.

Then print as usual.

I do this for every filamenttype change. Even PLA to PETG etc.

RE: Changing from PETG to PLA

When I change from one species of filament to another, unless there's a specific reason to do otherwise, I'll use the nozzle temperature of the higher temperature filament.

As soon as the purge is complete, I'll back down to the lower temperature if applicable.

One issue I did have was when I did a PC Blend print in the evening and just shut down the machine for the night without removing and purging.  I had a devil of a time getting a lower temp filament to flow freely the next morning.

I'm now in the habit of when I do a PC Blend print I will, as soon as the print is finished, eject it and purge with a scrap piece of some lower temperature filament.

RE: Changing from PETG to PLA

On my Mini I can just issue the Change Filament command. The printer remembers what it has loaded and heats up to the appropriate temperature. Then I tell it what type I'm loading in. I have gotten a good purge each time. Now, that said, both of my jams so far have been changing back to PLA from either PETG or ABS. So perhaps a bit of additional manual purging is needed.

RE: Changing from PETG to PLA

Now, that said, both of my jams so far have been changing back to PLA from either PETG or ABS.

That's exactly the point. When you go from higher temperature to lower temperature filament, you may not be able to purge everything out. So I first load with the higher temperature, then after a purge reload with the target temperature. PETG to PLA may not require it but try running PC blend and then loading PLA at PLA temperature.  Not pretty. 

RE: Changing from PETG to PLA

Yeah, I think I've learned a manual purge at the higher temp filament needs should be done. So unload, purge, then load instead of change.

RE: Changing from PETG to PLA

So unload, purge, then load instead of change.

Actually, my procedure on the Mini to load PLA after say PC Blend  doesn't involve unload/purge/load, instead it's two Changes.

* Change Filament to unload the PC but then select PC instead of PLA as the filament type to load the PLA  

* When prompted if proper color is extruding say  no to get one or two more squirts of filament (which is essentially a purge)

* Change filament again but this time reload with PLA selected as filament type 

So I "purge" by running the lower temperature filament through a couple of times at higher temperature. A purge after an unload is not going to get every residual filament out of the hotend. 

RE: Changing from PETG to PLA

OK, I'll keep that in mind.

RE: Changing from PETG to PLA

Of course having said all that, I have to admit that I usually don't bother with this procedure when loading PLA after PETG.… I don't use super cheap filament, and good PETG is cleared just fine at 210 degrees with a couple of "no" when prompted if it has loaded okay. But I do it after ABS, TPU, or PC.