The "other" solution is a kind of small plastic knife which is mounted in place of the spool of the roto-thread.
The trouble is that these knife dirt jams faster than their shadow (about 30 minutes), are made not to be disassembled / repaired easily (riveted without being blocked in rotation) ..... short c ' is no better / more durable than the rotofil solution.

The manufacturers of these devices have understood this opportunity to sell us these accessories me.des as expensive and fragile consumable with captive customers, .... finally the usual story, of course sold without vaseline ...

After retrieving an old ski boot from Emaus, I cut up pieces and cut new knives.
They are in (rilsan?), It is really very resistant, about 2 times thicker than the original knives ... and it works at the hair ..... size as well ..... the battery lasts for as long ... For the lifetime, I only tried it for the time of a discharge (about 30 minutes) but after this test, they are still like new!

I'll keep you posted.
