The donut gives excellent grip for the hand and I imagine that it will slip on the pulley before my hand will slip on the donut. It is used for MT3 holders on the lathe and rarely for MT3 collets. ER32 collets are what I use most with a D1-4 mounted chuck. I have never had to torque the donut hand wheel to the limit but I do not think it offers as much as a 5'' knurled wheel. But if I needed to torque the draw bar more chances are it would involve a wrench.
That yellow thing is an old engine oil jug that seems to be a bit stiffer than most. It was cut out to simply slip down over the knurled nut at the top of the gear cover.
That yellow thing is an old engine oil jug that seems to be a bit stiffer than most. It was cut out to simply slip down over the knurled nut at the top of the gear cover.