Getting Intimate with Dimpling and Machine Countersinking

The past couple of work sessions had me doing a lot of dimpling (creating a uniform depression around a drilled hole so that a flush rivet will sit flush). The DRDT-2 machine earned its keep in doing nearly all of the vertical stabilizer skin, and the new Tatco manual squeezer (which, at first, I didn’t think I needed) did its fair share of dimpling in places where the DRDT-2 doesn’t reach.

Dimpling works great on sheet aluminum (thin surface), but won’t work on heavier/thicker aluminum. So, then you do what’s called “machine countersinking”. You’re essentially cutting out a divot around the hole, and the mating surface (for example, a dimpled sheet of aluminum) fits into that divot.

I found adjusting a countersink cage to be more difficult than I figured it would be … not sure if my cage is having issues, or if (most likely) I just haven’t gotten the hang of it. I did notice that the drill-side cap kept coming loose – it looks like I’ll need a spanner wrench to tighten that up, as it should not be coming loose (that will affect the distance between the drill and the cage, therefore adversely affecting how deep the countersink goes).