Settings for a detailed PETG print?
I have been printing very fine models in PLA with success using largely derivatives of 0.05 Ultradetail, generic PLA and MK3S+ with 0.25 nozzle settings, e.g. an 8 hour print with sub 1mm detail.
I am now trying to print some of the same parts (though not as long as the 8hr print above) in PETG. After about an hour, the PETG does not feed and the Bondtech feeder starts giving the dreaded clicks with sticking filament. The nozzle ceases to extrude the very fine filament melt. I have tried the successful PLA settings modified for PETG temperatures and also the standard 0.05 Ultradetail, generic PETG and MK3S+ with 0.25 nozzle settings but the problem persists. I have tried adjusting the nozzle temperature to 245 for first layer (from 230) but that doesn't help. Incidentally I noted that the second and onward temperature (245) is higher than the first layer (230) and the bed temperature rises from 85 for first layer to 90 for subsequent layers. Is this correct for PETG?
Plainly there is something wrong with my feedrate and flowrate which is causing the sticking of the filament and therefore grinding of the filament. I just can't seem to get this right. I'm not sure if the nozzle size (0.2mm) is causing back pressure and thus jamming or there is too little filament being fed to the hotend which causes the nozzle to 'dry up' (stop extruding).
I would be grateful if someone with experience of printing very fine detail PETG objects can indicate settings?
Tony
NB. I have attached my custom PETG config bundle if that helps!
Try printing 5 at a time
The temps are higher for PETG and what you are seeing is normal - the nozzle is too close to the small part for too long ... and it doesn't get a chance to cool. Eventually the heat build up spreads and your extruder stops being able to grab the now softened filament strand at the bondtech gears. This is to be expected for small highly detailed parts that have the print head hovering on the same tiny layer for too long. With PLA, the temps are so low you don't experience this.
The fix is to bed 4 or 5 of the same small part to print at the same time. This approach makes the head move to another part of the bed to work on that layer and the layer just printed has a chance to cool down.
RE: Settings for a detailed PETG print?
@dan-rogers Thanks for the tip about nozzle height. This I will certainly try out though the first level calibration routine looks good. Your reasoning sounds sensible.
I was printing 4 units of which there are 3 separate parts and even these have gaps at lower levels making some of the lowest bits about 1.5mm square(ish)!
And a slicer setting
There is an advanced slicer setting that lets you tell the slicer not to let the print head spend too much time in a small area. In practice, it just moves the head away from the print if it spends too much time in a definable small area.
Something to consider
@apemberton
Another thing to consider, with a 0.25 nozzle less material is moving through the hot end in a longer period of time, this allows for heat creep, and can cause jamming. You might want to look more at the temps you are printing with, it's ok to use very low layer height with tiny nozzles such as 0.25.
Good Luck
Swiss_Cheese
The Filament Whisperer
RE: Settings for a detailed PETG print?
There is an advanced slicer setting that lets you tell the slicer not to let the print head spend too much time in a small area. In practice, it just moves the head away from the print if it spends too much time in a definable small area.
@dan-rogers, Thanks for your advice. Which slicer setting are you referring to? (I assume via exprt mode.)
Another thing to consider, with a 0.25 nozzle less material is moving through the hot end in a longer period of time, this allows for heat creep, and can cause jamming. You might want to look more at the temps you are printing with, it's ok to use very low layer height with tiny nozzles such as 0.25.
@swiss_cheese, Thanks but what temperatures (first layer vs the rest) would you suggest? I have tried some temperatures between 230 and 245 for first layer reducing by 10 degrees for subsequent layers (but never below 230). I also note the recommended temperatures on the PETG reel label.
RE: Settings for a detailed PETG print?
Filament settings, cooling page, cooling thresholds section - setting is named slow down if layer print time is below...