Is it just me, or does this whole post seem like spam, or shilling of some sort... 0 previous posts and a background that looks like a photoshoot...?
First, I've never heard of a FEIN machine...
Anyways, put some oil (I used mineral oil, but some use 10w/30 or silicone spray)on the felt ring of the
flex and re-install the backing plate, make sure to check the bolt that holds it on when re-installing, make sure it's tight.
Also, I've heard of somebody applying white lithium grease to the gears, and adding an 8mm washer.
The reason I mention this, is because the flex is notorious for having the backing plate rub against the felt ring and melting, causing a nasty mess of smoke and plastic shards.