On Wed, 21 Mar 2012 13:05:05 -0500, Lloyd E. Sponenburgh wrote:

Tim Wescott fired this volley in
:

If I must go with rounded corners, can I expect that there is a
standard? What is it? Is there a place I might find it on the web?


Tim,
Have you checked smallparts.com? Most big-box home improvement centers
and ACE hardware carry a good selection of aluminum angles, some with
unequal legs.

I just bought 4' of 4"x4"x1/2" aluminum channel from MSC. They carry
other sizes, but few with unequal legs.

On the MSC metal, the INSIDE corners (all) are rounded (ends of the legs
as well as the crotch), but the outside corners are all square.

4x4x1/2" should be big enough for your little TO-220 sink, yes?

I'll take a look. It really needs to be something that's commonly
available for machine shops, though, and for the entire life of the
product -- I'm going to be specifying this to the manufacturer for whom I
am designing the board; I'm sure they'd rather not have to send out a guy
to dig through the racks at Home Depot for something that might disappear
at any moment over the next ten years or so.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com