Thursday, July 14, 2011

Right Depth Holes

When we make a stopped hole, it is always important to determine its depth accurately. A classic method is to use a colored tape wrapped around the drill bit shank at the desired height.

The method works but the accuracy is questionable, being provided only to our eyes. Depth stops for electric drill tips have a cylindrical shape, held in position by a grain screw; even in this case the solution has not great efficiency, due to poor screw sealing on the helix and to difficulty of keeping the cylinder perpendicular to the tip axis.

In addition, these cylinders cannot be mounted on the auger tips we use with a  vintage brace. Of course there is other solutions: here it is a depth stop by Stanley; it consists of two parts that fit perfectly together  around the shaft and it can be easily adjusted by thumb screws for different diameter tips. Quick to assemble and easy to fine tune. Of course it has to be found on the net (ebay). 

 I am using the stop for drilling a blind mortise before removing the waste with chisels. I use to do that mainly when I have to make several mortises and where the mortise chisel and mallet job would be quite long. The result is guaranteed. 
There is only a downside. Unlike tape, this stop leaves its use traces on the wood. No fear: a block plane shot and everything will return perfectly smooth!