anvilfire! Power hammer Page!    Page 1   Back to Catalog of User Built Hammers

First French JYH!

Built by Fabien Chapaveire
Notice the laminated counter weight welded to the back of the crank wheel.
  • hammer mass : 17kgs (38#)
  • fly wheel stroke :160mm
  • spring   :2 leaves 6mm / 50mm precompressed
  • motor   :3Hp
  • speed   :~ 120 stroke per min
The power hammer's frame twists when we work to full speed, but it's very easy to forge with it.

I think it's the first French junk yard hammer but I'm sure it isn't the last...

Fabien Chapaveire is a knife maker and
Membre de la Guilde des Couteliers Forgerons (Guild of Blade Smiths - disolved 2001).

Fabien's comment about the frame twisting is a reminder that I-beam, while strong in one direction is not resistant to twisting moments. Unbalance in mechanical hammers will cause a lot of occilating twisting moment on a vertical column frame such as this one. Mechanical hammer frames need to either be tubular or boxed in. Thin plate welded to the sides of the beam will make it much stiffer.

I think the crank stroke is too long on this hammer. Toggle linkage hammers get extra stroke from over-travel due to the spring compression. A shorter stroke and stiffer spring would let the hammer run faster.

Copyright © 2000 by Jock Dempsey,!