Edge finder

[threesixesinarow]

Someone posted these irresistible old Belgian toolmaker apprentice prints for an edge finder to the “Machinist Museum” group on Facebook. They also showed a boring head, a hand drill, vernier calipers and depth gauge, and a surface gauge.

Based on those, mine’s only lightly modified and it’s 60% the size. I don’t know how that would affect my grade, but it seems to work alright and it’s a good size for my Unimat and other small machines.





Parts



Some operations



In a Unimat drill chuck, and next to a 3/8” shank Brown & Sharpe edge finder for scale

[old_toolmaker]

threesixesinarow,

That is a great little edge finder and well executed. I have been trying to find a tiny commercial version but no luck so far. The Unimat has a very short amount of travel in the Z axis making something like this almost invaluable. Thank you for posting this! I am going to make one for myself.

[threesixesinarow]

Thanks, Dick,

This should take you to the Facebook post where I found the drawings: https://www.facebook.com/groups/1687...5396386379373/


Did you check out the pair of little edge finders from Proxxon?


On the Unimat I usually leave the key screw disengaged so I can pull the quill out when there isn’t clearance in front of the chuck. I guess you could make the shank and the probe shorter, though - I’m not sure how useful it is having two smaller diameters on the working end.


I imagine it was a good apprentice project because of the different processes and tools involved, but didn’t take so long so what it teaches stays clear.

[old_toolmaker]

threesixesinarow,

Thanks for the tip on leaving the key screw disengaged. I never gave that any thought before, but it does allow one to retract the quill to change bits with no loss of location. That was my biggest frustration. I need to think more outside the box. I did go to the Proxxon website and saw the little edge finders. Well worth the asking price of $35, but I would like to build my own. There is satisfaction in doing.

[old_toolmaker]

threesixesinarow,

I forgot to ask if you wound your own spring.

[threesixesinarow]

threesixesinarow,

I forgot to ask if you wound your own spring.

Yeah, just with the lathe slow and in reverse and feeding and supporting the music wire mandrel by hand.

I guessed at the diameters and made the ends where the tension matched the B&S.

[old_toolmaker]

threesixesinarow,

I have some 4140 pre-hard steel. I am thinking of using that. What steel did you end up using for your edge finders? Did you harden them?

[threesixesinarow]

threesixesinarow,

I have some 4140 pre-hard steel. I am thinking of using that. What steel did you end up using for your edge finders? Did you harden them?

I think it’s about the same but I hardened it.

- Clark

[DIYer]

Thanks threesixesinarow! We've added your Edge Finder to our Measuring and Marking category,
as well as to your builder page: threesixesinarow's Homemade Tools. Your receipt:

Edge Finder by threesixesinarow

tags: edge finder

[old_toolmaker]

threesixesinarow,

Maybe I will use O-1