Thursday, December 19, 2013

scanner: drilling blind holes with no drill stop

Here's a simple thing that I do when I want to drill some shallow blind holes and I don't want to take the time to set the drill press depth stop. My old press has a great depth stop, but it just takes forever to set and then un-do. In this case I wanted to keep my bracket set-up in the vise, center-drill, drill with my number 7, and then use the press as a tapping jig to get my tap started square to the hole. This meant I would be switching back and forth between bits until the bracket was finally finished and removed from the vise. This is hardly a case where I can use the depth stop. 

My usual quick solution is to measure the depth that I would like to drill to and then place a piece of masking tape or duct tape where I want the drill to stop at the surface of the part. Granted, this is not super consistent, as the swarf traveling up the flutes of the bit usually wants to lift the tape up a bit, but this is good enough for parts that don't require extreme precision. I've been using this trick for quite some time. I noticed Eric was still using it when I was helping him out with some work a few weeks ago. He had some tape on a tap that he was using, and when I pulled the tap out of the case I knew immediately what he had been doing. In my case I just didn't want to drill through into the large hole in the side of the bracket; that would be unsightly. These holes are for attaching the scanner handles to the back plate of the scanner.

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