Cup vs. Disc style wire wheel

[joshuabardwell]

If you only had one, which would it be, and why? I'm kind of going back and forth. Cup style is kind of better for cleaning flat surfaces, but I also kind of find myself going to the edge of the wheel more often than not, and think maybe I should just use a disc. The cup wheel is bigger and heavier, and it seems to make my grinder work harder than the lighter disc wheels. Also, there is a cost difference.

 

[CurlyDave]

On larger grinders ~7" the cup style flattens out and looks like a disk in use. Centrifugal force at work.

I have both kinds for my small grinder and use the one appropriate to the task.

 

[undercut]

Part of your decision might depend on the power of your grinder. As CurlyDave mentions, the larger grinders won't get slowed down nearly as much as the smaller grinders and will want to flatten the cup out as it spins. But keep in mind, flattening of the cup will also depend on the no load speed of the grinder. Grinders with a high rotational speed and enough power not to get bogged down will flatten the cup more regardless of whether it is a 4 1/2" grinder or a 7". Personally, I like the cup.