EMRFD Message Archive 7251

Message Date From Subject
7251 2012-02-14 08:25:44 Tom subway construction
I put up a video on YouTube that shows one way that I use to build circuits. It involves modifying a brad point drill bit so that pads can be cut directly into PCB material with a handheld drill. This is a picture (fig 2.57) of the feedback amplifier on page 2.20 of EMRFD < http://tomnyc.no-ip.org/images/amp2_57hardware.jpg > built using this method.
The video is at < http://youtu.be/ErJWhwNKnEI >
I tried using a diamond cutter bit but found it was necessary to hold the bit in a drill press. And, I don't care for gluing pads. I find using the modified brad point bit an excellent way to quickly build a circuit.

Tom, ak2b
7258 2012-02-16 16:08:43 Paul Re: subway construction
I think I'll give that a try -- Thanks!

Paul - K0EET

7273 2012-02-20 05:36:29 Tim Re: subway construction
Maybe vaguely similar but even lower tech... for some projects, especially where I need wide low-inductance traces, or some lands for SMT parts, or some busses on the second side of a board, I will do it mostly "ugly" over ground plane, and additionally where I need real pads I cut up the copper foil on a PC board using a sturdy sharp knife. After doing the cutting, the heat from a soldering ir
7278 2012-02-21 10:07:37 Tom Re: subway construction
Hi Tim,
Thanks for the info. Good idea - heating the foil after cutting it.

As an update, here is a picture of a BF998 (SOT143) soldered onto 4 pads cut with a 3/16" bit.
< http://tomnyc.no-ip.org/images/bf998.jpg >

For larger IC's I've used this tip from NI5X for cutting the edge connectors off old ISA and PCI cards.
< http://www.eham.net/articles/16536 >

Tom, ak2b