Helical grinding fixture - video

Helical grinding fixture. By NOidea Machining. 55:32 video:

https://www.youtube.com/watch?v=Y-9LfdDVmvU

Part 2. By NOidea Machining. 54:46 video:

https://www.youtube.com/watch?v=vB4M4jOHAUo

Part 3. By NOidea Machining. 25:33 video:

https://www.youtube.com/watch?v=ZpR47jqTzI0

Part 4. By NOidea Machining. 30:49 video:

https://www.youtube.com/watch?v=9IajfhRcM7I

Part 5. By NOidea Machining. 39:24 video:

https://www.youtube.com/watch?v=yJT5WZQi7m4

These are pricey anytime I see them on FacebookMarketplace locally. And they look abused.
I see he has a tool and cutter grinder, and this is a project to enable the use of 5C or ER32 collets, from the single quill/spindle, with each end having that taper. I've not seen anyone else do that, and if you have both the Imperial 5C, and the Metric ER32 spin indexer, type of table jig/fixture, you're covered if you don't have complete sets.

Part 6. By NOidea Machining. 1:04:17 video:

https://www.youtube.com/watch?v=muP_UOnTy7g