PETG advice
Posted by racitup
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Re: PETG advice July 07, 2023 12:49PM |
I think because it's not a full metal hot end, the heatsink needs the fan permanently on so the main PLA head part doesn't melt
For anyone else looking for PETG advice:
* I don't recommend removing the fan ducts, they don't seem to make a difference to the print other than they may prevent/cool plastic that is stuck to the outside of the nozzle meaning it doesn't oxidise and fall off into the print leaving ugly brown streaks
* It's very important to reduce the first layer speed a lot. On very small parts I needed 20%. I probably wouldn't go above 50% at all
* I did eventually get 80degC bed temperature working with a 250degC nozzle temperature. I was using 230degC before and I think the hotter filament compensates for the cooler bed. I read an article saying 250degC is best for PETG in terms of strength. The manufacturer recommended 230degC
* I'm now trying a glue on the bed. It is covered with kapton tape, and on top of that I'm painting on a 50:50 mix of PVA glue and water, that I read works instead of all these expensive glues around. It certainly hasn't made things worse and I think just gives the bed a bit of a matt surface finish that helps. Before that I tried a 600 grit sandpaper on the tape surface which I think probably helped
* I haven't tried the external heater again but am trying to prevent draughts
* Drying the filament certainly hasn't made things worse either
* Good quality filament will help. I inherited a reel of PLA that is awful. It literally has lumps of brown plastic moulded into the filament randomly which would cause a jam and block the nozzle, which obviously doesn't help with print anxiety!
* Obviously getting the print height consistent across the whole bed is vital, so make sure you do the mesh grid compensation and calibration with the nozzle hot. I have a raised spot opposite a tower which I don't really understand
Initial results are promising, and it's not that much harder to print than PLA
For anyone else looking for PETG advice:
* I don't recommend removing the fan ducts, they don't seem to make a difference to the print other than they may prevent/cool plastic that is stuck to the outside of the nozzle meaning it doesn't oxidise and fall off into the print leaving ugly brown streaks
* It's very important to reduce the first layer speed a lot. On very small parts I needed 20%. I probably wouldn't go above 50% at all
* I did eventually get 80degC bed temperature working with a 250degC nozzle temperature. I was using 230degC before and I think the hotter filament compensates for the cooler bed. I read an article saying 250degC is best for PETG in terms of strength. The manufacturer recommended 230degC
* I'm now trying a glue on the bed. It is covered with kapton tape, and on top of that I'm painting on a 50:50 mix of PVA glue and water, that I read works instead of all these expensive glues around. It certainly hasn't made things worse and I think just gives the bed a bit of a matt surface finish that helps. Before that I tried a 600 grit sandpaper on the tape surface which I think probably helped
* I haven't tried the external heater again but am trying to prevent draughts
* Drying the filament certainly hasn't made things worse either
* Good quality filament will help. I inherited a reel of PLA that is awful. It literally has lumps of brown plastic moulded into the filament randomly which would cause a jam and block the nozzle, which obviously doesn't help with print anxiety!
* Obviously getting the print height consistent across the whole bed is vital, so make sure you do the mesh grid compensation and calibration with the nozzle hot. I have a raised spot opposite a tower which I don't really understand
Initial results are promising, and it's not that much harder to print than PLA
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