4 ms·

Does anyone know how the dovetails of the individual jaw pieces are machined on a curved surface? I can’t figure it out even using a 4 or 5 axis CNC.

xtagon 3y ago
I don't actually know, but maybe electric discharge machining?
mitthrowaway2 3y ago
I must be missing the difficulty. It looks to me like you could turn those dovetails on a lathe. You cut them into round stock before sawing it in half and facing. The female dovetails are done directly on the OD of the round stock. For the male dovetails, it would require mounting the work offset (eg. on a faceplate); alternatively, you could do it more awkwardly on a mill with the tool offset in the spindle like a boring bar. Either way, it could be done with manual machines.
- doubleg72 3y ago
  Exactly.. turned on lathe, millwork if not 5 axis, hardened, and then ground to finish.
- userbinator 3y ago
  The male dovetails might've been made with something resembling a hole saw, but with the teeth angled appropriately.
- mdorazio 3y ago
  That's fine for the outer pieces, but the ones they mount into have dovetails on both inner crescents. I can't see how you could turn those on a lathe without some weird offset going on.
  - mitthrowaway2 3y ago
    >> For the male dovetails, it would require mounting the work offset (eg. on a faceplate)
  - genter 3y ago
    Well, yes, that's what you do. It's called eccentric turning. With that much of an offset, a normal chuck wouldn't work, you'd have to use a faceplate. http://www.steves-workshop.co.uk/tips/lathetech/eccentrics/eccentricindex.htm http://www.steves-workshop.co.uk/tips/lathetech/eccentrics/e...
    - mdorazio 3y ago
      That explains it! I didn't know about faceplates - thanks for the info.
deleted 3y ago
[deleted]
noman-land 3y ago
Hand Tool Rescue restored one of these and he ends up having to rebuild some of the semicircle pieces. It's a fun watch! https://www.youtube.com/watch?v=QBeOgGt_oWU https://www.youtube.com/watch?v=QBeOgGt_oWU
- bee_rider 3y ago
  The way the little arms sorta appear to reach out while it tightens is kind of adorable. Fractals always seem to have oddly biological looking behavior, for things made with such simple rules.

xtagon 3y ago

I don't actually know, but maybe electric discharge machining?

mitthrowaway2 3y ago

I must be missing the difficulty. It looks to me like you could turn those dovetails on a lathe. You cut them into round stock before sawing it in half and facing. The female dovetails are done directly on the OD of the round stock. For the male dovetails, it would require mounting the work offset (eg. on a faceplate); alternatively, you could do it more awkwardly on a mill with the tool offset in the spindle like a boring bar. Either way, it could be done with manual machines.

doubleg72 3y ago
Exactly.. turned on lathe, millwork if not 5 axis, hardened, and then ground to finish.
userbinator 3y ago
The male dovetails might've been made with something resembling a hole saw, but with the teeth angled appropriately.
mdorazio 3y ago
That's fine for the outer pieces, but the ones they mount into have dovetails on both inner crescents. I can't see how you could turn those on a lathe without some weird offset going on.
- mitthrowaway2 3y ago
  >> For the male dovetails, it would require mounting the work offset (eg. on a faceplate)
- genter 3y ago
  Well, yes, that's what you do. It's called eccentric turning. With that much of an offset, a normal chuck wouldn't work, you'd have to use a faceplate. http://www.steves-workshop.co.uk/tips/lathetech/eccentrics/eccentricindex.htm http://www.steves-workshop.co.uk/tips/lathetech/eccentrics/e...
  - mdorazio 3y ago
    That explains it! I didn't know about faceplates - thanks for the info.

deleted 3y ago

[deleted]

noman-land 3y ago

Hand Tool Rescue restored one of these and he ends up having to rebuild some of the semicircle pieces. It's a fun watch! https://www.youtube.com/watch?v=QBeOgGt_oWU https://www.youtube.com/watch?v=QBeOgGt_oWU

bee_rider 3y ago
The way the little arms sorta appear to reach out while it tightens is kind of adorable. Fractals always seem to have oddly biological looking behavior, for things made with such simple rules.