--- In
Homebrew_PCBs@yahoogroups.com, michael tenore <wb2lcw@...> wrote:
>
> What thickness of board are you talking about?
>
> I have great success cutting 1/32 board with a carbide scoring tool from Home DEpot ($7)!
>
> I use a good quality combination square I bought at Harbor freight on sale ($25).
>
> I use a carbide scriber (Home Depot $5) to scratch the where the edge of the board is on both sides.
> Then I hold the combination square next to the scoring tool blade after the point of the blade is set in the scribed mark.
> Then I score each side 4 to 5 times then I snap it off on the edge of a board . After It is snapped off a couple of strokes with a file and the edge is smooth. This method works on 1/16 board also but the scoring needs more strokes.!
>
> On rthe question of the combo brake/shear machine plastics etc. can be somewhat thicker than the metal specs ,as stell sheeting is harder to shear off!
>
> 73
>
> Mike
>
>
>
>
> ________________________________
> From: DJ Delorie <dj@...>
> To: Homebrew_PCBs@yahoogroups.com
> Sent: Wednesday, April 1, 2009 7:30:42 PM
> Subject: [Homebrew_PCBs] v-scoring
>
>
>
> Today's project was to see if I could cut v-scoring with a table saw.
> I found an old steel plywood blade (no carbide to break off, lots of
> teeth) and reground it to a V point:
>
> ∗ mount the blade backwards to avoid cutting your grinding wheels
>
> ∗ run the saw
>
> ∗ initial grind with an angle grinder
>
> ∗ use a 30-60-90 triangle to position a ginding stone for final grind.
>
> GENTLE pressure is all that's needed, and very little actual grinding
> time.
>
> The result snapped cleanly and showed no signs of burning. Obvious
> drawback is that plain steel will need sharpening more often, but it's
> better than trying to resharpen a router bit or scrollsaw blade.
>
> (yes, I know about metal shears, but I don't own one of those - yet)
>
>
>
> [Non-text portions of this message have been removed]
>
Sheet metal shears are the only way to go! I tried scoring, hacksaws, drilling perf holes, even heavy paper guillotines (which despite what I read on various blogs, were absolutely useless on FR4). Finally, I bought the $79 8" sheet metal shear from Grizzly -- 100's of PCBs later, it still cuts like a knife through butter, and board edges are surprisingly clean and straight.
Ristone64