# Production Spot And Toolpost Drill Combo



## Andre (May 9, 2016)

Very simple design, the only catch is you need a self acting or automatic tightening boring bar holder for this to be be fast at it. You can use a regular clamp type boring bar holder with two Allen wrenches in the screws, that would work, but it would be a bit slower.

3/4" round with 1/2-20 threads for the drill chuck on one end, and 5/16" reamed hole on the other for the center or spot drill. The center drill is clamped using two 10-32 set screws. These must be flush or slightly countersunk. Chuck is a $8 Jacobs from harbor freight. It's not good quality at all, but for the price it should serve its purpose.







Spotted and drilled a #7 ( 1/4-20 tap drill) in under 13 seconds. 





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