DIY Precision Lapping Plates from Scrap

In this video, I show how I used the Whitworth three-plate method to turn scrap cast iron from a damaged milling machine column into high-quality lapping plates. The Whitworth method is a proven technique for producing flat, parallel surfaces, making it an ideal method for creating lapping plates.

Special thanks go to Tom Lipton @oxtoolco for inspiring this project and for sharing his knowledge and expertise in the field of machining.

[KMegahertz]

Nice work! Made my own set based off the videos by Tom Lipton as well. Fun project!

[JohnGrimsmo]

Great work!! I also made a 3d printed spherometer for my lapping plates but I feel like it sags to much to fully trust it. More testing requited.

[be]

your livecenter/tailstock isnt very rigid, you can see it wobbel at minute 1.25 ?
cheers ben.

[ollysworkshop]

Nice! I haven't got the patience to do that😂

[jimwi]

Nice work . What are you going to use them for or how do you use them.

[termlimit]

Excellent project. Would you mind sharing the 3d printed holder design source files or step files? That was a neat little addition. Thank you!

[divermike]

What is the purpose of the grooves. I have a guess but would like to get an answer first.

[paradiselost]

If you had to do more...

Look at an orbital sander, a drill press... and combine the two.

Ie, gyrations whilst rotating, hang a weight on the arm and swap plates every half hour or so...

[ianboard]

very much like grinding a telescope mirror

[kingkasma]

why bbq lighter fluid? is other Alkohol working?

[sloppydoggy]

For the lapping process, I wonder if you couldn't have centered a strong magnet on one & then hooked it up to your drill or something haha. I guess, that might not actually produce an "even" surface since it would be the same surfaces always in contact via rotation.

[chronokoks]

This is interesting. Why is it shiny? Normally, you should get a dull grey color no matter the grit size of the diamond. The cast iron must be of weird quality (mythical chinesium) that it enables the diamond particles to "scratch" instead of "tumble".