IMPORTANT TO NOTE: MY CHAMELEON HAS SINCE STOPPED WORKING PROPERLY OUT OF THE BLUE. IT IS NOT RELATED TO THIS TIP SHAPING BUT NONETHELESS HAS PREVENTED ME FROM CONTINUING. I AM LEAVING THIS NOTE SO MY POST IS NOT MISCONSTRUED AS AN EXAMPLE OF A PERFECTLY WORKING 3D CHAMELEON.
While trying to get my tip shaping to be more reliable I stumbled upon a way to swap colors without any cooling down or tip forging needed. The result is small string on the end of a perfect sharp tip. not perfect looking but loads great every time. I took inspiration from the built-in unload button on the printer. Instead of trying to form and cool the filament at the end of the nozzle I just push it out 10mm, so there is very little molten filament left, then quickly pull back 15mm. Then slowly retract by 10mm more, and finally quickly retract to snap and stringing attached and pull out of the extruder gears. I hope this can help out other people and save some print time! 100 color changes with this shaping is 33 minutes of time, with the default tip shaping profile 100 changes is almost 3 hours of time. That shaves 2.5 hours off per 100 changes. So for a 400 color-change print that is 10 hours saved!! Here is a pic of how the tips look:
G92 E0
M83
G90
G0 X284 Y293 F4000 ; MOVE TO BUTTON
G92 E0;
G0 E10 F500 ; push out the molten filament
G0 E-15 F4000 ; quickly retract
G0 E-10 F150 ; slowly retract
G0 E-60 F4000 ; quickly retract all the way out
M107
G91 ; relative mode
G0 Y3 F2000 ; press the button
What is happening?
Decided to make a mini version of my pup :)
432 color changes all executed perfectly! I had one single issue toward the end but it was due to the filament getting caught on something and not the chameleon or tip shaping (see the tail). luckily my new filament sensor paused and beeped at me to let me know it hadn't loaded, so I didn't lose 10 hours of print time! will probably make a post about this Took a little over 12 hours with this tip shaping, using 0.16mm layers. 500 layers total. I'm really feeling more confident in this system now that I am getting my filament to load perfectly next up a big 3 or 4 color print!
Actually, now that I look at the gcode... what are you pushing out the 10mm of filament into? Is it creating a blob. That would produce strings or blobs, and you're doing it at the button... is that actually the case? As an option, can you make it create that blob into a straight line that is attached just to the back of the purge block, so they're not free. If there are 4 colors, you can purge along the back in 4 spots per color.
Bill
This is epic! Thanks for sharing, excited to test. Is it ok to repost to Facebook fan group?
Wow! That's awesome. Have you tried it with different filaments... Also, what kind of filament is that?
It looks perfect.
Bill