I have a QidiTech Dual Extruder, I’ve printed successfully in the past, but at the moment I am having problems and I’m not really sure what the issue is.

I have printed in ABS, PLA and PETG all how come out good and I’ve made notes of the various temperate settings…recently a received a batch of PETG filaments from Amazon, the reals were slightly wider than before, so much so that I had to purchase a new screw that was longer than the stock part. I also printed a cover for the screw so the filament is not in direct contact with the screw…This all looks fine and the filament real moves smoothly without problem.

However, all of my attempts to print with these new filaments have failed, resulting in blobs of filament on the bed and gathering around the extruder. I’m really not sure where the issue is.

I’ve re-levelled the bed several times, I’ve re-loaded the filament again several times making sure if is feeding smoothing and consistently.

The result is that when it starts printing the filament does not adhere to the bed well and I end up with blobs of filament and a build up around the extruder nozzle.