Does Prime Blob adjust for Nozzle Size?
I started to experiment with a .8mm nozzle; never used one that large before. One thing I noticed is that the Prime Blob does not seem to be as large as when using a .4mm nozzle and as such is not as effective in removing "strings" from the nozzle tip. Does anyone know if the nozzle size has an impact on extrusion rate or amount?
7 Replies
I don't believe the blob is adjusted based on the nozzle size. So you might want to adjust it yourself
I believe you are correct. I looked more into this and found the prime_blob macro and the code looks like this:
Extrude a blob
G1 F60 E20
# 40% fan
M106 S{fan_speed}
# Move the extruder up by 5mm while extruding, breaks away from blob
G1 Z5 F100 E5
# Move to wipe position, but keep extruding so the wipe is attached to blob G1 F200 Y{y_start + (25 * y_factor)} E1 Question now is how to adjust for nozzle diameter. I know we set this in printer.cfg but I am not sure how to reference this or adjust in the macro. Another question is should the adjustment be linear to 0.4 or some squared or cubed factor to account for area or volume. Any suggestions?
# Move to wipe position, but keep extruding so the wipe is attached to blob G1 F200 Y{y_start + (25 * y_factor)} E1 Question now is how to adjust for nozzle diameter. I know we set this in printer.cfg but I am not sure how to reference this or adjust in the macro. Another question is should the adjustment be linear to 0.4 or some squared or cubed factor to account for area or volume. Any suggestions?
I would ask @elco he made that macro originally
G1 F60 E20
That's the blob. The extrusion distance is fixed
so the amount of filament is fixed
and I don't see how a larger nozzle would make the blob smaller
the only reason I can think of is that it oozed more before the blob was started
It will adjust for nozzle size in 2.1
GitHub
RatOS-configuration/macros/priming.cfg at development · Rat-OS/RatO...
The RatOS modular klipper configuration. Contribute to Rat-OS/RatOS-configuration development by creating an account on GitHub.
Oh Boy! lots of changes coming. I see that you are taking the ratio of the .4mm nozzle to the new nozzle and then squaring that number to account for the need to adjust for the area of the new nozzle. Thanks for letting me know. In the meantime I can make a local fix to make it work.