PCB Edges

hi all!
i once read that it's best to connect the ground trace of a pcb to the edge frame trace in order for it to act as "Faradei's cage" thus eliminating outer interfirences. the problem is that i read somewhere else that if you do connect the traces it forms a harmfull magnetic field, that could affect badly on the PCB components...
witch one of these statements is true??

also, how the hell do you cut a PCB?????

Cutting PCB material

The easiest way to cut PCB material is with a shear, similar to one used to cut steel plate and such. Trouble is, a shear is a bit pricey (available from Kepro through places such as Kelvin Electronics), but worth the cost if you do a lot of fabrication. Otherwise, a hacksaw works. I've often ground a hacksaw blade down to fit my scroll saw and worked them that way. G-10 is rough on blades, though (just as it is on HSS drill bits), so a carbide blade will work better, although leave a wider kerf. Phenolic boards are far easier on tooling, but not as good electrically.

Dean

Yeah that faradays cage thing works. It wont damage the onboard components. I cut PCB's with a knife, by scoring both sides afew times. Then bend open the cuts slightly, and keep scoring.

This ain't healthy for the blade so i use a stanley knife with snapable blades.

Then file the egdes for a smooth finish. I like to coat the edges with a sealer so they don't absorb the etchant and warp the whole board. (mums varnish works quite well)!

I use a coping saw (the kind for cutting plywood and balsa) the blades last ages too.

Its fast and accurate, PCB is no tougher than thin hardwood anyway. I find that junior hacksaws tend to follow their own paths and end up destroying your design.

I cut out PCBs using a fiber cutoff wheel, as used for metal cutting, in my table saw. It makes a smooth edge with no cracking or splitting and cuts fast enuf.

dremel works fine for me

i use a scroll saw. get nice clean cuts with it but it's hard to get them to go strait