I notice some filers have a kind of clamp follower, not sure if related to this or a general safety thing?
That stops the work from lifting. As Gerrit notes, without it, it will bite your fingers. I would encourage people to incorporate something into the design. You
think you'll just be smart and it'll be ok, but its easy to get tripped up. Might be better in a lathe where you can control the speed, but the point in part is of to go faster than hand filling. I've found that clamp a necessary feature. The file is going at speed...and while the down force is the greatest there is still up-force. The small part starts oscillating up down without the clamp until.... DANG! that hurt. Its not really a clamp I guess, you just set it above the work to stop it from lifting.
Xyphota, if you can modify files that's a good solution. A challenge is finding ones that are small enough around, still long enough, and aren't tapered.
There is a place in Mississauga that had them. I think they were around $30 each. Not outrageous but $300 for a set of 10 triggered the Scotch gene, way more than the filer cost. i eventually found a hoard at an auction, Fierce competition (maybe Gerrit?) for them but I prevailed (too many years of waiting for a stash to let it get away)