How to drill square holes and several other interesting mechanical
principles.

http://www.youtube.com/watch?v=L5Azb...eature=related

http://www.youtube.com/watch?v=9qEhy...eature=related

On Apr 12, 3:03*am, "Bob-tx" Live Spam free wrote:
How to drill square holes and several other interesting mechanical
principles.

http://www.youtube.com/watch?v=L5Azb...eature=related

http://www.youtube.com/watch?v=9qEhy...eature=related

The Rouleau(sp?) triangle drill CANNOT drill a square hole ...exactly,
because it cannot reach completely into the corners.

On Thu, 12 Apr 2012 05:03:43 -0500, Bob-tx wrote:

How to drill square holes and several other interesting mechanical
principles.

http://www.youtube.com/watch?v=L5Azb...eature=related

http://www.youtube.com/watch?v=9qEhy...eature=related

Check out "rotary broaching"
http://www.slatertools.com/sales-sup...ry-broach-and-
tool-holder-demostration

Bob-tx wrote:
How to drill square holes and several other interesting mechanical
principles.

http://www.youtube.com/watch?v=L5Azb...eature=related

http://www.youtube.com/watch?v=9qEhy...eature=related

1. Mark the square
2. Mark the center
3. Drill a round hole
4. Take a triangle file to open up the corners

This works well, and I use it in metal whenever I want to use a carriage
bolt. This would obviously be too slow for production, though.

Jon

On Thu, 12 Apr 2012 10:18:10 -0700, "Jon Danniken"
wrote:

Bob-tx wrote:
How to drill square holes and several other interesting mechanical
principles.

http://www.youtube.com/watch?v=L5Azb...eature=related

http://www.youtube.com/watch?v=9qEhy...eature=related

1. Mark the square
2. Mark the center
3. Drill a round hole
4. Take a triangle file to open up the corners

Use a mortising bit/

This works well, and I use it in metal whenever I want to use a carriage
bolt. This would obviously be too slow for production, though.

Rotary broaching is a great way to make small square holes in precision machined products. Take a look at this video which shows internal and external forms:
(the video shows hexagons but square holes are made the same way)

https://www.youtube.com/watch?v=cpmWKUxwbiE

Also, see www.buybroaches.com for more information about the tools.