Very poor mans cnc setup

Hi All
This is the only way I could think of to machine six internal radius on a gear for my Foden Steam Wagon. As can be seen from the photos I used a rotary table in conjunction with an indexing head. With some careful setting, up I was able to use the rotary table to cut the radius between the two-known start and finish angles (hand to calculate) and the indexing head simply allowed for the gear blank to be positioned at the six equally spaced positions. The rotary table, after cutting the first radius was returned to its original start position and the indexing head moved to the next location, this radius was then cut to the same start/finish angle as before and so on until all 6 radiuses were cut.

A CNC machine would have made this a whole lot easier, but as I don’t have one the challenge was overcome with a little bit of thinking outside the box.

Attachment 22211 Attachment 22212 Attachment 22213

Bottom left gear, finished with the six internal radius cut
Attachment 22214

Thank you for viewing
The Home Engineer

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Thanks thehomeengineer! We've added your Internal Radius Cutting Method to our Machining category,
as well as to your builder page: thehomeengineer's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-internal-radius-cutting-method"> <img src="/uploads/210508/homemade-internal-radius-cutting-method.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-internal-radius-cutting-method">Internal Radius Cutting Method</a> <span> by <a href="http://www.homemadetools.net/builder/thehomeengineer">thehomeengineer</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/cutting'>cutting</a>, <a href='http://www.homemadetools.net/tag/radius'>radius</a>, <a href='http://www.homemadetools.net/tag/indexing-unit'>indexing unit</a>, <a href='http://www.homemadetools.net/tag/rotary-table'>rotary table</a> </div> </div> </div> </div>
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Beautiful work! I wish my mind was as dialed in as yours.

Necessity is definitely the mutha#%&er of invention.


Hand, Head and Heart(mostly hands)

How many times we think "I don't have a CNC, but I want to make..."

It's good to run into that, if next thoughts are "...but I have a _____ and ______..."

I figure translation is "I'll do what THEY would have had done".
Milling machines hum along doing certain things, but like homeengineer demonstrates here, tooling really makes them sing.

Don't let automation erase creativity. Let desire or need pull the strings.