I think instructables.com is like,,, a bit un nescessary for making 4 diodes into a bridge rectifier, the most basic electronics introduction will show this, or u could wikapedia or google it, but I'll give u the lowdown here. I used 1N5819 type diodes. U need 4 to make a bridge & if u want barrier (blocking) diodes u need another 2, tho they ain't really nescessary.
Ok, u'll notice the diodes have a plain black body with a silver band at one end. The silver band end is the cathode (K) & the plain end the anode (A).
Take 2 diodes and solder them so u have a cathode connected to an anode, & also connect the black wire from the magneto there. That's 1/2 of ur bridge.
Take the other 2 diodes & connect the same as b4, cathode to anode, only this time also connect the white wire from ur magneto there. That's ur second 1/2 of the bridge.
Now connect the 2 remaining (free) cathodes together. This is the + out from the bridge & goes to ur battery's + terminal.
Now connect the 2 remaining (free) anodes together. This is the - out from the bridge & goes to ur battery's - terminal.
There u go. Ur bridge rectifier all constructed & connected to ur battery. Charge the battery b4 putting it on ur bike is maybe a good idea as the first charge conditions the battery. This basicly means it "forms" it & so u want to fully charge it in 1 go as if u don't, the battery will only charge to the point it was first charged to. Fully charge it properly the first time.
Ok, barrier, or blocking diodes aren't really needed as diodes only let current flow in 1 direction so the bridge isolates the battery from the magneto's stator coil, but if u want them they go between the bridge & battery in both + & - lines.
The 1 in the positive line goes with the anode toward the bridge & the cathode toward the + battery terminal.
The 1 in the negative line goes with the cathode toward the bridge & the anode toward the - battery terminal.
All these (1N5819 diodes & the 4.5A/h, 6V SLA battery), I got "over the counter" at my local electronics outlet, which here in Oz is "Jaycar", the equivalent of "radio shack" in the US. The small driving light & H3 Halogen bulbs are standard automotive items that I got from autopro or supercheap auto's. The H3 halogen bulbs are readilly available in 6V types as well as 12V types. Hope this helps. Cheers
Edit, I forgot to say insulate all 4 connections on ur bridge so they cant short to each other or anything else. Cheers