Archive for August 21st, 2009
I’m kludging up a clamp to grab AA cells around their positive terminal so that I can resistance-weld nickel strips to that button. The general idea is that the current passes through the strip, through the button, and out the side to the clamp, rather than trying to heat the button through the strip from the top.
A snap-ring pliers has pretty nearly all the right attributes, so I’m making up a set of copper jaws with a hole in the middle to grab the terminal. Basically, I whacked off a ring from a copper pipe, hacksawed it lengthwise, hammered it flat (work-hardening it in the process), and drilled some holes.
Then I grabbed it in the Sherline vise and set up a teeny 4-mil slitting saw. A bit of manual CNC ran the saw past the copper and, after a while, the top half just fell over dead with a perfectly shiny cut right down the middle!
Useful things to remember for the next time around:
- Cut only 0.2 mm into the copper per pass
- 100 mm/min feed is fine
- 4000 rpm is fast enough
- A drop of cutting lube is a bunch on this scale
This worked out a whole lot better than I expected…