Linear Advance Question
I am looking for some clarification.
I was looking through my gcode and I saw two M900 commands back to back.
M900 K0.03 ; Filament gcode LA 1.5
M900 K30 ; Filament gcode LA 1.0
Why are there two? Wouldn't the second one cancel out the first?
Best Answer by bobstro:
Just to add to Joan's answer. Prusa recently migrated from Linear Advance v1.0 (LA1.0) to v1.5 (LA1.5). LA1.5 uses a range of values well below 2, while LA1.0 values tend to be 10 or higher.
Prusa built some smarts into the new firmware to recognize the difference. If a LA1.5 value is seen in the gcode, it is used. If both exist, the LA1. 5 setting is used. If only a LA1. 0 value is seen, it is translated to a LA1. 5 equivalent.
Meanwhile, the approach of providing both values is for backwards compatibility with older firmware. As you suspected, the last value is used for the remainder of the print. On a printer running older firmware, the same gcode will work as expected.
RE: Linear Advance Question
Hi Qlmmy
one value
is for LA 1.0 the other
Is for LA1.5
I believe
LA 1.0 ignores the LA1.5 value, and
LA1.5 Igores the LA 1.0 value
I trust that that makes sense for you
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Linear Advance Question
Just to add to Joan's answer. Prusa recently migrated from Linear Advance v1.0 (LA1.0) to v1.5 (LA1.5). LA1.5 uses a range of values well below 2, while LA1.0 values tend to be 10 or higher.
Prusa built some smarts into the new firmware to recognize the difference. If a LA1.5 value is seen in the gcode, it is used. If both exist, the LA1. 5 setting is used. If only a LA1. 0 value is seen, it is translated to a LA1. 5 equivalent.
Meanwhile, the approach of providing both values is for backwards compatibility with older firmware. As you suspected, the last value is used for the remainder of the print. On a printer running older firmware, the same gcode will work as expected.
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