As a beginner I want to help others struggling with feeding issues. In my machine I had no problems using the 0.8mm wire. Then I tried to change roll, using a Supersix 0.6mm stainless steel, and nothing worked, I tried all sort of things, tension, hand feeding it etc, but nothing happened. So I thought maybe I need a new drive roller for 0.6mm wire, because the roller I had was accomodating only 0.8 and 1mm wires. But today I tried to inspect the Supersix roll, and I discovered there was sticky stuff coming from the label, on the plastic and on the roll holder disc. It wasn't particularly sticky, but it was sticky enough to stop it from feeding. So I cleaned up everything very well (just a bit of dust on top of it, and scrub it) and now finally it's feeding properly, and I don't even need to buy a new drive roller.