Hi Everyone, I have an Ender 3 V3 which was printing amazingly well so I thought I would upgrade to the CoPrint KCM Set 8 X Multicolour, all hardware changes made, although pre printed parts are definitely biased towards the V3 Plus, but that is minor, I am now at the stage of installing the filament, I insert all filaments press extrude for the 1st(E0) , and all is good, I then move on to the 2nd(E1), press extrude and the system starts to retract all 8 filaments then tries to extrude the 8th(E7) filament, not the 2nd, then comes up with a blockage on retraction error, I then have to remove printhead and clean it out, I have done this several times after checking all connections are correct, also trying to do the 2nd extrude on a different filament, but in all cases the first OK, 2nd goes completely wrong, I have even tried it as only a X4 and then the 2nd extrude tries to 4th (E3)filament very frustrated now, if anyone has any suggestions it would be most helpful, I have contacted support and am waiting for their suggestions. Firmware version is the V1.2.3.63.img and as stated before I have checked all connections correct as far as I can tell after following the manual word for word.
Hello !
Not going to lie but the Co-Print kit is quite bad. Heard tens of tens of users trying to install it but in most cases (like 80-90%), there were issues concerning the firmware….
CoPrint customer service is also quite inactive and they generally transfer your issue to Creality…
Just a suggestion, but keep your Ender 3V3 XZ without this mod and buy a Hi (or a K2Combo) if you want to print in multicolor..That’s what I did and I’m very happy with my choice ! 
Thanks, for the advice. I’m willing to give them a chance, as frustrating as it is to have to deal with this in the first place.
Hi just fitted a CoPrint 4X upgrade tp my Crealty - 3 V3 Plus, easy to fit with no problems …………………. untill I tried to print with Creality Print 6 you cant use 4 extruder units with Co print 6. Installed Orcaslicer perfect all sorted