Making twin cylinder cranks

[John S]

Spotted this on another forum and although it related to the 12" to the foot brigade the principle is the same.

http://www.practicalmachinist.com/vb/showthread.php?t=170860

Thought it would be interesting.

John S.

 

[DICKEYBIRD]

Thanks John, I wouldn't have thought such a thing was possible. Very interesting stuff, that's for sure!

You'd think that the part would be severely weakened after twisting it like that but I guess the high heat and slow twisting allows the metal to re-flow. I suppose you could call it "twist-forging."