Does back dragging a metal file dull it? Pt. 1/2

I build the biggest file testing machine using my shaper in order to perform tens of thousands of perfect strokes as I put files to the test. After receiving a lot of spiteful comments for back-dragging my file, I decided to look into why it is frowned upon. That journey led me to create my very own file tester rig. I use the waterjet, go kart grinder, and Marvel bandsaw in order to fabricate a device to attach to my shaper, ensuring I can test files!

Pferd Files
https://fireballtool.com/10-file-set-5-machinist-files-in-pouch/

My Cincinnati Shaper
https://www.youtube.com/watch?v=I86XFZlje0c

Hardtail Vise
https://fireballtool.com/fireball-hardtail-vise-deposit-for-pre-order/

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