Chronos wrote:
On Wed, 20 Aug 2014 11:38:57 +0100
"gareth" wrote:
Nowadays, to manufacture an HF RX, with all the concomitant
high density ICs that are around, the biggest design chore
is to cut out the opening for the LCD display on the front
panel.
I have to say that anyone who can make a decent looking front panel has
my admiration. My attempts at chassis bashing have always looked like
something salvaged from a rather nasty car accident. The Dremel doesn't
help - it just makes making a mess faster ;-)
The tradition here, used to be nibbling tool + Hammond Box.
http://www.mpja.com/images/31197-large.jpg
http://www.ebay.com/itm/Deluxe-Nibbl...-/160459856656
http://angela.com/hammondaluminum17x...is1444-30.aspx
http://angela.com/images/products/de...Chassis.15.jpg
You drill a hole big enough to take the cutting head of the nibbler.
Then, like a jig saw, the nibbler cuts an arbitrary pattern in
the aluminum sheet. You can do square or round holes. The square
holes will be high quality (requires a steady hand, don't
rush it). The round holes need touch up with a round file
(depending on your level of patience, and availability of a bezel
to cover the mess).
The advert lists a few different materials it works in, but
let's be honest - it's only for aluminum, and only of a
limited thickness. If you have to fight with the tool,
you won't get nice looking results.
In this picture, you can see the nibbling tool has just cut an "L"
on its way to finishing a big square. While the person here drilled
four pilot holes for the nibbler (to do the square), only one is
really needed. You can do the entire square, racetrack style.
You could even drill a pilot in the middle of the square, and
"drive" to the edges to cut the square.
http://i5.photobucket.com/albums/y15...3/IMG_1326.jpg
http://www.diyaudio.com/forums/tubes...n7-preamp.html
That project cheated by using other tools to do the round holes.
The round holes are too high quality for the nibbler. But lacking
such tools, I wouldn't mind faking the round holes with the nibbler.
I could never afford a whole kit of tool n' die hole cutters
(the kind you work by compression with a wrench). One of the tools
in this promotional picture (mid-left), is a proper hole cutter.
http://angela.com/images/products/de...Chassis.15.jpg
Paul