Review on 🔩 IVY Classic 46152 Forstner Extension: Achieve Precise and Extended Drilling Performance by Vincent Blitz

I had no problem mounting the ⅜" shaft inboard. I didn't have a problem with the ¾" bit either, as the set screws didn't protrude and the thick end of this extension is ¾" in diameter. However, there is some jiggling in the bit when using this extension. I believe this is due to careless tolerance and poor construction. If the hole is slightly larger than ⅜" or the shank of the bit is slightly smaller than ⅜" then the bit will move to one side as you tighten the two set screws and this will contribute to wobbling. I used it in a hand drill so wobbling wasn't an issue. However, if you clamp your work on the drill table and the drill bit wobbles, there is no way around it as the wobble will create a messy hole.