Rotary Broaching on a Bridgeport

See how to Rotary Broach a hex (hexagon) form using a Bridgeport vertical milling machine and a rotary broach and rotary broach tool holder from Polygon Solutions. This video is for a prototype part with a 3/8" hex going 2x or twice the depth. The set-up is basic, but the result was a successful rotary or wobble broaching demonstration.
http://www.polygonsolutions.com

Category:

Howto & Style

Tags:

• rotary broach
• rotary broaching
• wobble broaching
• hex broach
• rotary broach tool holder
• rotary broach tools

[polygonsolution]

The broach holder spindle turns freely and will not align the form while machining. If you need to hold orientation of the hex, square, or other feature to another feature on the part, this can be done with an orientation fixture.

[polygonsolution]

Broaching a 3/8" hex about 1/2" deep in mild steel is no problem. The chamfer at the front of the pilot hole guides the broach, and Polygon Solution's rotary broach holder has a very sturdy bearing. Adjusting the speeds and feeds not only improves tool wear and surface finish, but may also eliminate some machine vibration. As you can see here, even manual broaching can be done with ease.

[MandMMachining]

What is the practical depth for rotary broaching?

[hoarp001]

Also what do you do if you need to index a flat of the hex, or some other feature in a certain place? It seems the shape of the hex lands up in whatever place its at when it first contacts the surface..

[hoarp001]

Do you find the wobble broaching puts much vibration into the machine? Your quill is quite far out there, does it not deflect the quill a little bit as the broach wobbles?