I haven’t seen any benchmark photos of how the wear is at a certain number of hours, so I thought I would post this. This is the old brush @ 250 hours compared to new. Spindle speed has never been over 1. (note- not long to go before it would have eaten into the lead wire itself)
-Just an FYI
By the way…This is an accurate 250 hours, not an estimate. I have an hour meter wired in parallel.