I'm at the point where I've got the 3D Chameleon mounted, tested the switch, loading, unloading, etc. On first print test, it did not go well as hoped, and now on test version 7.
With the first print test, T0 did not load, but I let it continue to print. When T0 unloaded, it unloaded about 140mm too far. T1 loaded and actually printed (hoorah!). T1 backed off about 25mm farther than T0. T2 and T3 attempted loading, but did not load, and as with T0 and T1, they backed off 140mm and 165mm respectively too far.
Originally, I had aligned all of the tips to be at the same distance (as per a comment made by Bill on Chris Riley's Part 3 Video). Hence the tape markers on the tubing at 25mm from the top of the "Y".
Help needed: Where do I need to tune this back-off distance? I don't see anything that stands out in the generated code that should be adjusted unless I'm simply overlooking it.
After running through test v7 and many adjustments to the E values for loading, it was pretty clear things were not working. No more filaments would load into the extruder. I took everything apart and discovered first that there was a very short piece of red filament (T2) and just behind that, the blue filament (likely from the first test print) left between the cutter, direct drive extruder and the hot end.
At this point, I'm not sure what steps to take. If the filament is getting cut and left inside the extruder, that seems to be a problem I don't know how to resolve.
Otherwise, I can continue to tweak the tuning, but am not sure I'll get far with that, noting the issue above.
As far as my approach to tuning, attached are two files I saved to disk, the primary modifications I had made were to the E values for loading (until I discovered the blocked extruder issue).
I've watched all of Chris's Riley's videos and haven't found anything that might help resolve my printer's issues. Any insights would be welcome and appreciated.
Trent
This is the original code generated before I made any changes. The distance from the extruder gears to 25mm past the top of the "Y" is about 225-230mm. I think I rounded up to 8 seconds, instead of 7 seconds. 230/32=6.764 seconds. Will go to 6 seconds and try that.
; Auto generated 3D Chameleon Mk4 Mode 3 Tool Change GCode for PrusaSlicer; - 3D Chameleon Mk4 Tool T{next_extruder} -;begin switch from extruder {previous_extruder} to extruder #{next_extruder}M117 Unloading Tool T[previous_extruder]M83 ; turn relative distances for the extruder; unload extruder {previous_extruder}G92 E0; go to holding position to unload the stock extruderG0 Y376.4 F2000 ; <<----- EDIT THIS LINE TO SET THE INITIAL LOCATION OF THE BUTTON; if this is the first load, then don't unloadG91 ; move to relative modeM83; load extruder #{next_extruder}M117 Loading Tool T{next_extruder}{if previous_extruder>-1}; back out the filament for cuttingG0 E-20 F500 ; retract a bit, adjust this to tune waste; <<<< insert mechanical cutter code here! >>>>;<<< Start Of Tip Shaping- Remove If No Cutter! >>>M109 R180; cool down to prevent swellingM302 S0 ; enable cold extrusionM106 S255G0 E20 F1500 ;G0 E-5 F500 ;M109 R165; cool down to prevent swellingG0 E5 F1500 ;G0 E-1 F500 ;M109 R155; cool down to prevent swellingG0 E1 F1500 ;G0 E-25 F500 ;M109 R150; cool down to prevent swellingG0 E24 F1500 ; last tip dip with cold tipG0 E-24 ; last tip dip with cold tipM109 R180; ok... go back up in temp so we can move the extruderG0 E-80 F500 ; back out of the extruderG92 E0M104 S[temperature];;<<< End Of Tip Shaping >>>; we skipped to here if it was extruder -1{endif}{if previous_extruder>-1}; retract it back out of the extruderG92 E0G0 E-0 F2000G92 E0G0 E-30 F2000 ; <<<---- if mechanical cutter, change to a positive value of at least 5mmG92 E0; ok - out of extruder - press button to remove it all the wayG91 ; move to relative modeM82; we skipped to here if it was extruder -1{endif}; press the button to select the new extruderG0 Y3 F2000{if next_extruder==0}G4 P500 ; dwell for .5 seconds - adjust this to match your machines single pulse time{endif}{if next_extruder==1}G4 P1000 ; dwell for 1.0 seconds - adjust this to match your machines two pulse time{endif}{if next_extruder==2}G4 P1500 ; dwell for 1.5 seconds - adjust this to match your machines three pulse time{endif}{if next_extruder==3}G4 P2000 ; dwell for 2.0 seconds - adjust this to match your machines four pulse time{endif}G0 Y-3G4 P2000 ; wait for cutter to work; ok command selected - back out filament if needed after cut{if previous_extruder>-1}G0 Y3 F2000 ;G4 P8000 ;G0 Y-3;G4 P400{endif}G0 Y3 F2000 ;G4 P8000 ;G0 E25 F1500; <<<--- adjust this E value to tune extruder loadingG0 Y-3;G4 P400G92 E0G90 ; move back to absolute modeM83 ; but make sure the extruder stays in relative; reload filament all the way into extruderG92 E0G0 E-25 F2000 ; <<<<<----------- EDIT THIS DISTANCE TO FINE TUNE THE FILAMENT LOADING TO STOP BLOBBING OR UNDEREXTRUSIONG92 E0M83 ; turn relative distances for the extruderM302 S180 ; prevent cold extrusionM117 3D Chameleon Tool T{next_extruder}I think this applies to back out in seconds. And you have about only one or two seconds of backout, from the look. Normally the christmas tree plus the 4" of tube they have at the end equals 10" total, so your backout distance should be 250mm divided by however many MM per second you calculated the extruder to be capable of when you tested it. It should be around 34 mm per second, so it should be around 7.3 seconds. I can't see what the end tube is, but clearly its not 4" So I'm guessing your backout should be around 4.5 seconds. Then tune as needed. Chris Riley's 3rd video at about 25 minutes goes over this. What you have will look different because you are right on top of the extruder. But it should be in this section of your tool change gcode:
G92 E0
G90 ; move back to absolute mode
M83 ; but make sure the extruder stays in relative
; reload filament all the way into extruder
G92 E0
G0 E-5 F2000 ; <<<<<----------- EDIT THIS DISTANCE TO FINE TUNE THE FILAMENT LOADING TO STOP BLOBBING OR UNDEREXTRUSION
G92 E0
It appears that I can't upload gcode files, so no sure how to provide them for review.