[Solved] G92 E0 causes a lot of extrusion.

[AlanKilian]

Once again, G92 E0 moves nothing.

g.

However, G92 E0 resets the extruder actual position to zero, so the G28 X0 causes the extruder to go to its last known position and it makes a big pile of molten filament.

It's a bug in G28 when used with the X0 parameter CAUSED by the G92 E0.

Remove the G92 E0 and everything works fine,

So, even though the G92 E0 does not IMMEDIATELY cause motion, it indeed through a bug in G28 X0 causes the extruder to run during a G28 X0

[geneb]

G28 (in any flavor) doesn't interact with the E axis at all. In fact, the only axes that G28 support are X, Y, and Z.

Unless you've physically felt the extruder turn when the G28 X0 was issued, I'm still not buying it.

g.

[AlanKilian]

G92 E0 Doesn't cause the extruder to move, but REMOVING G92 E0 prevents the extruder from moving during a home operation.

How's that instead?

[AlanKilian]

Did you TRY the code I posted?

How about I undo my change and make a video?

[AlanKilian]

G28 (in any flavor) doesn't interact with the E axis at all.

When I look at the code, I see it CLEARLY interacting with the E axis.


case 28: //G28 Home all Axis one at a time
{
uint8_t homeAllAxis = (com->hasNoXYZ() && !com->hasE());
if(com->hasE())
Printer::currentPositionSteps[E_AXIS] = 0;
if(homeAllAxis || !com->hasNoXYZ())
Printer::homeAxis(homeAllAxis || com->hasX(),homeAllAxis || com->hasY(),homeAllAxis || com->hasZ());
Printer::updateCurrentPosition();
}

[AlanKilian]

OK, I made a video to demonstrate.

Enjoy. It's not likely to win any YouTube awards.

https://youtu.be/plyCrqTqO8s

[geneb]

Wouldn't have believed it if I hadn't seen it. Kudos to you sir.

Does it do the same thing if you try G28 Y0?

g.