different speeds depending on direction
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hey community,
Is there an option to define different speeds, jerks etc depending on the direction?
Would be very helpfulThanks
R.G.
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@index4d RRF does not provide that facility. Neither does any other open source firmware AFAIK. Why you would find it useful?
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@dc42
When printing with big nozzles I would like to have different extruder jerks. Prime slow, retract fast. Also pressure advance is not completely solving my under extrusion in the beginning of a line after travel.
R.G. -
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@chrishamm
In this case I need jerk control. The Speeds I can adjust already in cura.Is there any other option?
may a G11 after it?
But I´m not sure how these combination should look like.
R.G.
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@index4d said in different speeds depending on direction:
@dc42
When printing with big nozzles I would like to have different extruder jerks. Prime slow, retract fast. Also pressure advance is not completely solving my under extrusion in the beginning of a line after travel.
R.G.I've done quite a bit of work using large nozzles. Different extruder jerk won't solve your problem, neither will pressure advance. In fact, compensating for pressure build up which likely does not exist with larger nozzles, will likely make matters worse. By "prime" do you mean un-retract? If so, using a slow speed is likely to lead to under extrusion at the start of line, not make it better. The problem with large nozzles is that filament has tendency to ooze during non-print moves due to gravity. Although you are unlikely to completely eliminate this, you can mitigate the under extrusion after a non-print move by using additional length for the un-retract move.
Take a look at M207 https://docs.duet3d.com/User_manual/Reference/Gcodes#m207-set-retract-lengthwhich is what determines the behaviour of G10/G11. The R parameter is the additional length which might help. F is the feed rate (speed) for the retract move and T is the feed rate for the un-retract move.
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@index4d as the other have mentioned in various posts, you may be best using firmware retraction. That way you can tune retraction amount, extra unretract, retract/unretract speed etc on the fly. It just puts G10 and G11 commands in the gcode to retract and unretract respectively instead of G1 E commands.
The other advantage to this is you can use a post-processing script to change
G10
To
M201 E5000 ; increase extruder accel for retraction G10 M201 E500 ; reset extruder accel
Or whatever other values you want to change (accel, jerk etc). @deckingman may have a point on how much benefit you'll get from them, but I guess there's no harm in trying
Edit: M201 for accel!