Monday, October 1, 2012

how do you shrink metal?

Western Electric 16A update....

wow... pretty vertical pieces.... ahhh.... but... but... 

I have to be honest here... although I knew the 16a would be a formidable project, I was a little aloof and dismissed most of the work as just requiring labor as it was simple sheet metal, right?  wrong.  The initial impression from walking up to a 16a is that it is finished very simply and crudely.. and in many ways, it is.. but.. but... the more we looked, the more we realized it was very accurate.. very accurate... very smooth flares...

but we also noted a differing level of finish on the several examples we have seen up close... so we thought maybe the plans were just shipped around to regional metal shops.. but now, having tried to make some of these parts ourselves, we are convinced that at least the horizontal pieces were stamped... under very high pressures... there is no other way to get the flare that smooth...

so those of you who want to follow along in the geekery, here is an example of a section:

see that upturned lip of just under an inch running the length of each side?  yes.  that one... well, if the panel were flat, you could just take it to a sheet metal break and bend it.  but because this piece is helical, the lip must stretch on convex turns and SHRINK on concave turns!  how the heck do you shrink metal?  yes, I know stretchers and shrinkers exist.  But they are crude.  inexact.  there is no way to get this level of accuracy, much less repeatability, with a shrinker.  You have to use brute force over a die.  so in the name of doing this thing properly... so that every one will be the same... and so that each will flare smoothly... we are making dies... old school.. the proper way to build this...

but until we finish that, here are some pretty vertical pieces...


  1. That is impressive. I thought dies this size were pretty much limited to the auto and appliance industries. Show a pic of that big-ass press the dies will go into.

  2. Yeah, are you going to get these done in a press? Because then you're looking at steel dies which are spendy. You're insane (in a good way).

  3. man, i am just so fuckin blown away at the level of this project and just how crazy you are! i love this and can't wait to see it done. well, you are probably even more ready than me! but yeah...

  4. You should ask those guys like Chip Foose, who build hot rods, how to work with sheet metal. These people really know how to shrink, expand, bend and weld sheet metal.

    Greetings from Maurice.

  5. Just amazing!!
    Any update of this superb project?
    I want to make one myself :)