Filament change mid print for multi-color prints

I was looking to get a dual extruder for multi - color prints when i started to wonder if it is possible to get good multi - color prints by simply changing the filament mid print with some sort of software pause feature. With this pause method i’d imagine you’d be limited to color changes along the Z - axis only but it would be a good segway into a dual extruder if it became needed.

Is anybody currently doing this? and if so what is your method? Do you simply pause the machine and manually move things around?

I’ve done it a few time without issue.

Just pause the print and jog the extruder away from the part. Swap filament, manually extrude the old color out and resume the print.

After pausing the print and moving the extruder away do you have to manually re position the extruder back to where it was? or can you just simply press resume and have it go back to work?

Is this a function of the filament change via LCD currently seen on the taz 4 or did you write a m600 code to perform this?

Just resume… I was using Repetier when I did it. I don’t know if you can do it with the LCD controller.

I’m using pronterface and I paused to swap filament.

Paused print.
I moved extruder head to one side by using the 100mm move button.
I installed the new roll of ABS, then moved the extruder head back using the 100mm move button in the other direction.
Then hit the resume button

My print did not complete without issue.
The layers after the filament swap had shifted to one side by a tiny bit. Less than 1/10 of an inch, but definitely noticeable.
All the layers after the swap were shifted.

I remember seeing somewhere burried in the LCD menus on my taz 4.1 an option for filament change. but i don’t see it while i’m not printing so perhaps its only available during a print. I can’t seem to find any support information about it oddly enough. sometimes you just have to push the big red button and see what happens i guess.

When changing filament mid-print I try to minimize as many variables as possible. Personally, pausing the print during infill and not moving anything has the best record of success.

Wonder if there would be a way to bond the end of a filament to the next spool? Say a small 3mm length-wise sliced tube with a heater? You insert the two ends when the red “heater ready” light comes on, wait 5s, then wait for the red-light to go off as the compressed/joined/3mm diameter filament cools below Tg and voila, joined filament.

I hereby donate the above idea to the public domain for any and all commercial and non-commercial users. This statement intended to prevent future patent filings, with this being prior-art WRT that particular claim. Yes, even by me. Have at it, no doubt some usable pocket-change could come from something like that.



Prior art.

Almost; I was thinking a thin tube with a circular heater, not a mondo block of aluminum. But yes, glad it’s been done :smiley:.

I tried early on many times and many ways to splice ABS filament together. I tried heat in many ways even took a smooth jaw pliers and drilled them out exactly to fit the filament then heated with mini torch. Also tried a hot knife (made to cut plastics and foam) and made a jig so both filaments ends were melted then the knife was moved and the ends were pushed together, it made a little ring around the joint but that was easily removed.

I also tried acetone to melt it then push together and hold in a jig.

The problem every time was that the joint was a bit brittle and would snap very easy. I would have to very gently hold the material in the machine until it fed into the hotend.

I have not tried PLA at all as I did not use it back then to print.