better startup custom-gcode slic3r?
since the newest firmware has a very long startup preheating i'm having oozing issues.
I've tried lowering my temp for the first layer startup to as low as possible which helps but i always have a stray filament that causes problems
1) is there a better startup G-code now? i'm using Slic3r 1.36.2
2) is there a retraction Code that can be used before the preheat to try and fight oozing?
3) is there a way to increase the length of the first wipe outside of the print area? a longer wipe could help me.
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Re: better startup custom-gcode slic3r?
You can modify the start code yourself. This is what it says by default:
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line
If you want to make the line longer, just increase the X value (X position) and E value (amount to be extruded).
For instance:
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X140.0 E25 F1000.0 ; intro line
That would make the second, thick part of the start line twice as long.
Re: better startup custom-gcode slic3r?
G1 X140.0 E25 F1000.0 ; intro line
That would make the second, thick part of the start line twice as long.
That would produce a line 3mm wide and probably cause skipping, damage the filament and possibly cause the print to fail...
Each linear mm of extrusion is about 2.4mm^3. At a layer height of 0.25mm drawing a line 80mm long while extruding 60mm^3 is way too much.
The original purge line was intended to load the filament into the nozzle; you cannot simply double up the extrusion to make a longer line. Maybe add 5mm at most.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: better startup custom-gcode slic3r?
It is indeed 'too much', but by design. Since the start line is just a single line, excess filament can flow to either side. It works just fine on my printer, even with a 'preloaded' nozzle:
(thats the stock gcode, but clearly my nozzle isnt empty)
That said, Im not sure a longer line will actually prevent oozing, Im not sure why the stock line wouldnt be plenty.
Re: better startup custom-gcode slic3r?
Personally, I would not design anything that exceeded the specification of my tool.12.5mm^3/sec is greater than the maximum melt volume of the E3D hot end (with increased temperatures).
However, the idea of the purge line is to simply load the nozzle. Increasing the pressure within the nozzle (by over-extruding) will simply create ooze when moving to the part. The idea is to reduce the nozzle pressure by reducing (or even stopping - coasting) the extrusion for the last part of the priming line and then a small retraction at the end before moving to the model.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: better startup custom-gcode slic3r?
ah i didn't realize this wipe was for the pressure in the nozzle.
for me it seemed to act like a nozzle clean and if it was longer then it would wipe my nozzle of some of the extra ooozing going on before it hits the first layer of my part.
maybe it makes sense to install a small wipe block shape, like a 5mmx 75mm x .2 Bar and set the slicer order to hit that first, so it absorbs the ooze and start up boogers, then it goes to the main part and begins the first layer.
“One does not simply use a picture as signature on Prusa forumsâ€
Re: better startup custom-gcode slic3r?
I've started playing around with a wider skirt to try and get the junk to come off then. The problem seems to be the skirt is put down at a fairly fast speed, but the rest of my first layer is only at 70% so it the big goobers seem to wait to come off at the slow speed. If it's a big enough print, and I'm fast, I can usually grab them with a small pliers before they cause an issue. I like the way the rest of the print goes, with very little stringiness, and good bed adhesion, so I don't want to play around with temps too much.