Drill bit that drills a square hole

[stevehuckss396]

My son sent me a link to this. New to me. Maybe the broach will be a thing of the past.


[ame]http://www.youtube.com/watch?v=tqOe2In9ShQ[/ame]

 

[Tin Falcon]

looks like a form of rotary broach. there are primitive forms of this that have been around for a while The complete modern blacksmith by Alexander Weygers shows how to drill a square hole with a triangular bit . One method uses a long bit that wobbles and is constrained with a hardened square guide bushing. the other uses a short bit the work piece is restrained from twisting but allowed to move in the x-y plane.
Tin

 

[ShedBoy]

Looks interesting. Looks like no ordinary drive mechanism. While on the subject of square holes anyone got a picture of a broach for the same job? Or how do you cut a square hole?
Brock

 

[metalshaper]

looks to be an updated<?> version of the Watts drill..

Respect Always
Metalshaper/Jonathan

 

[Paulsv]

looks to be an updated<?> version of the Watts drill..

Respect Always
Metalshaper/Jonathan

The interesting difference from the classic Watts Drill is that there is no guide plate on the work, so it seems tht somehow the chuck is holding the drill in registration with the work.