How to make replacement motor brushes from scratch

I lost a couple motor brushes during a maintenance session and became very frustrated.  But, I was smart enough to google scratchbuilding motor brushes and turned up pretty much nothing.....

Except that a guy talked about his dad making brushed from the core of a dry cell battery.  So I tried that first with a AA cell. I used the graphite around the core, but it didn't quite work.  I may revisit that one again one of these days because I don't think the spring I used was strong enough.

That gave me a new idea...while shopping at Lowe's I picked up a couple contractor pencils, not flat ones, but large round ones.  So I said what the hell and cut a chunk off and filed it a bit and put it in.

It worked, actually pretty good too.  I might make a video about this...next up is to test it under load for several hours and see how durable it is....