I picked up several smaller wheels (2") on ebay as well to put in the die grinder which is great for large edges and large enough holes.
I find that the large wheels on the grinder tend to catch the parts and cause issues but it might be technique or I need to get a variable speed wheel and slow it down.
I use a disc sander attached to a drill with 80 grit sand paper (I think that is the grit paper I use) to grind this wheel down when the grooves get too deep.
2. I bought 10 of 1" by 1" wheels and have gone through all of them (finished deburring all of wing parts and empennage parts). They are small enough to fit into a lot of the holes. Once you get groves that are too big, the sand down on a belt sander. U can sand them down pretty small, such that you can deburr most holes on the wings and empennage. I did buy cheaper ones from ebay, but they sucked.
5. a box of these from ebay. these things kick butt for deburring the edges of ribs or any place where the metal is folded at a corner. I used about 15 on the wings/empennage.
I find that the large wheels on the grinder tend to catch the parts and cause issues but it might be technique or I need to get a variable speed wheel and slow it down.
Builders have been using these tools for a long time with great success...
My guess is that it is your technique. Parts must always make contact with the wheel in such a way that the wheel rotation is trailing off of the edge you are deburring. Never with the wheel rotation turning into the edge of piece.
Initially I just had 6" cut and polish wheel and found out that it removes too much material. I bought 6" soft wheel from Cleveland tools and now most of the time I use this wheel for any kind of polishing or deburring. I only use cut and polish wheel if I have to remove material.