Mini Mill DTI Hole Alignment & Centring Attachment

As a bench top mill user, I often find myself with too little Z height when trying to centre an existing circular feature under the spindle. This rack and pinion DTI centring attachment made from a repurposed microscope stage gives more headroom than some other methods, and was a nice project to introduce me to cutting dovetails.

Activities include cutting a female dovetail in brass, making fluted knobs without the use of a rotary table, threading with a tailstock die holder and general drilling, milling, turning and tapping.

For clear and easy to follow information on measuring and making dovetails (and just about everything else machining related) see Mr Pete's@mrpete222 channel:

https://www.youtube.com/watch?v=0VGOa69sePo
https://www.youtube.com/watch?v=6S_iOU0C-Ug
https://www.youtube.com/watch?v=xT2oACFlB0c
If your maths is as rusty as mine, I can recommend Mark Ganson’s online dovetail calculator

https://mwganson.freeyellow.com/dovetails/

Construction details for the homemade tailstock die holder used in the video: https://youtu.be/bK_Is7QarxY
Approximate imperial sizes are shown. They're not direct equivalents, but are intended to give the non-metric viewer a rough feel for what I'm doing.
Made with subtitles -click the CC box.

-------------

Filmed and constructed during March and April 2020. The only place I could find a quiet spot to record the commentary during the UK's Covid 19 lockdown was in the car, hence the unusual ambience.

-------------

For the material I couldn't capture myself, my thanks goes to the following:
Drew Garrett for the use of his stills of the Verdict centring attachment.

@Swisstoolmaker for the use of his video of the Hauser centring tool.
Check out his YouTube channel at

https://www.youtube.com/channel/UCrks4ar5QjxvRhtTcW75kBQ
Whoosh by Aysonny
https://freesound.org/people/Aysonny/sounds/414422/
Licensed under a Creative Commons Attribution 3.0 Unported License ( https://creativecommons.org/licenses/by/3.0/ )

-------------
Shot: HDC-HS700 1920x1080 50P AVCHD
Edit: FCP7 ProRes 422
Mic: DR-05

Видео Mini Mill DTI Hole Alignment & Centring Attachment канала The Recreational Machinist