Extrude Left, Move Right!

[wcogen]

FF Creator Pro,
From Version Information:
Sailfish FF Creator X
Free SRAM 753
Thing 32084 14/08/21
Sailfish v7.7 r01416

After upgrading the firmware, I used the 'FF Creator Pro - ReplicatorG - Sailfish - 40r30' to test the machines functionality.

Control Panel:
In the Mk8 Left Plastic Extruder Tab, Pressing 'forward' or 'reverse' causes movement in the +X direction. Yes, that's right. It is like pressing the 'X+' button in the Jog Controls section. The Right Extruder Tab works fine.

Has anyone else seen this?

Thanks,
Bill

[dnewman]

FF Creator Pro,
Control Panel:
In the Mk8 Left Plastic Extruder Tab, Pressing 'forward' or 'reverse' causes movement in the +X direction. Yes, that's right. It is like pressing the 'X+' button in the Jog Controls section. The Right Extruder Tab works fine.

Has anyone else seen this?

Thanks,
Bill

This is expected behavior: by selecting the left extruder, a tool change has to occur since by default the right extruder was selected. So, as soon as a motion command occurs -- and extruding plastic is a motion command -- the extruder carriage is moved to the right by ~33 mm (Rep 1, WanHao, MBot3D), ~34 mm (FlashForge), or ~35 mm (Rep 2X). And the motion may be very slow since it is combined with that of the extrusion and thus will take the expected length of the extrusion (e.g., 30s or whatever). Sometimes the motion is odd since RepG's control panel sometimes generates some funky motion commands (including extrusion commands).

Note that MBI's firmware does the same thing -- this isn't unique to Sailfish.

As an aside, the Control Panel in RepG has largely been broken since about RepG 28 or so: basically when MBI whacked on it to support their then new Rep 1 and dual extrusion. So for somethings RepG's Control Panel works fine but for other things it doesn't (e.g., reporting the current position).

[wcogen]

Thank you for the clear explanation. Thank you very much. I thought I had lost my mind, again. That is exactly what happens.
Now, if I could figure out the sequence of things that leads to some of my prints sometimes leaning, seemingly to print at a 30 degree angle, all would be well with my world.

[dnewman]

Thank you for the clear explanation. Thank you very much. I thought I had lost my mind, again. That is exactly what happens.
Now, if I could figure out the sequence of things that leads to some of my prints sometimes leaning, seemingly to print at a 30 degree angle, all would be well with my world.

If you use an old version of ReplicatorG *and* a RepRap slicer, then you can see this behavior caused by a bug in RepG interacting with the heavy use of G92 commands by RepRap slicers.

Alternatively, this may mean that your print is too large or poorly positioned and whilst printing, one of the endstops keeps on being triggered. That will cause lost steps and this exact effect. Or, you may have a failing endstop cable which keeps on sending false triggers. (Note that the LED on an endstop lighting is independent of whether or not an endstop trigger is sent.) Finally, it's possible for their to be electrical noise induced into the endstop cables and cause false triggers. This is more common with the X-axis endstop cable than the Y-axis since the X endstop cable and X motor cable run a good long distance next to one another.

If the print tilts to the left or right, it's an issue with the X endstop. If it leans forward or back, then the Y endstop. If it leans in both directions, then either both or that RepG bug + G92 interaction would be suspect.

[dnewman]

BTW, there is a very active forum of FlashForge users over at groups.google.com. You may want to join that group.

[wcogen]

I will. Thank you.