Another rotary broach project

[melsdad]

I am in the process of making my own rotary broaching tool. There have been a few threads recently on the subject and that was my motivation to get this project going.

All the parts of made of S7 tool steel right out of the scrap bin. Once I am sure all works well and no tuning needs to be done I will heat treat all the parts and they will last forever! The broaches I make will be made of M2 or M4 material. The tool will also accommodate broaches from other sources with a .500" shank.

First project up will be a pentagon shape with an I.C. of .745".

Sorry I didn't get any pictures of the parts being machined in the lathe. I know how everyone loves those photos. I will be sure to take some action photos of the milling operations though.

The body of the tool that houses the bearings and the broach nest.


The broach nest



sent from my hand held hickymajig

 

[melsdad]

The tail piece that will have the 1° angle milled on the face.

All the pieces.

This is basically what it will look like when complete.


That is a 12mm hex broach in the nest.....

Stay tuned for the milling!

 

[Calibre]

I have been wanting to build one of these for years. Will be eagerly awaiting further updates!

Please include dimensions and part numbers.

 

[markknx]

melsdad,How are you using this? In the mill or lathe? If in the lathe how are you holding it?Thanks,Mark

 

[melsdad]

It will be able to be used in both the mill and lathe. The tail is .750" diameter to fit in the mill, and large drill chuck in the lathe tailstock

sent from my hand held hickymajig

 

[melsdad]

Calibre I will post drawings and part numbers for the bearings.

sent from my hand held hickymajig

 

[lotechman]

Great to see. I was given several thrust bearing assemblies from a bottling line thirty years ago. I now have a use for them:')

 

[melsdad]

I just got a 10" bison 3 jaw chuck for my troyke 15" rotary table off of ebay. Once i get that delivered and set-up I will continue on this project. I am still on the look out for a tail stock for the table just to have for future projects.

 

[Kevinb71]

Nice Looking work Brian! Looking forward to The diagrams. What registers the tailpiece with the broach holder bearing housing?

 

[melsdad]

The only real duty of the tail piece is retain the broach nest in the body. There is only .005 linear movement of the nest between the thrust washer and the retaining washer of the nest. The two roller bearings hold the nest concentric within the body.

Hopefully this assembly drawing will clear things up. Wish I could print in color

View attachment Rotary Broach Assembly.pdf