Summary I made the excellent ninjaflex spring loaded exstruder mods referensed from eliscott02 a while back. It got a bitt wobbly after some use, so i made a more sturdy version with a little better cooling access and for mounting dual pull springs on top as shown in picture. There are 2 versions one for normal cable chain feed in front and one for cable chain feed in the back.and hence no bracket in front. This thing is solid and does not skipp at all. I havent had a single print fail due to filament sinse using this last version, and i have printed some hairsy material like super brittle carbon pla, and several flexible materials. I have tried it on every filament type i have been able to get my hands on without any problems . This is version 5 with better clearences and with a bigger hold edge that makes pressing the spring loaded arm easy without grabbing under (the hot area) and burning yourself like i did (about 15 times) I am working on an addon for a top mounted 12 mm guide for making the exstruder carriage a bit more sturdy. I might also make a snap on cap for even better cooling. I hope i can get some fellow testers like the last time to look at it and give me some feedback. The final version is made in ABS printed at 240 degrees with 50% infill The Cables goes in the middle as normal, you will have to turn the fan vires to the top. Instructions you will need some additionall 4 mm skrews some small wood skrews and 2 pull springs. I recomend drilling out the holes at 2,5 mm for the filament in the base. the internal sides in the hole needs to be perfectly smooth for some filaments. Align the pulley for the motor with the filament hole lokking down at it from the top from the top before mounting the arms. Make sure its perfectly aligned. Before tightening the skrews enter 2 filaments so that they go into the hotends below, Make sure the filament moves freely, then tighten the 8 motor skrews. Tighten them evenly a little at the time in a xrossvise pattern for the best possible fit.