Quoted from TheCnyPinGuy:Does anyone offer the 3rd Magnet Kit anymore
I see Pinbits is sold out
Any links or leads would be cool
My field is brand new but my old TZ I did this for and was super impressed
No more kits, but you don't need one. dmacy and myself installed a 3rd magnet/opto in my game during his swap just a month or so ago. If you're already familiar with the process having installed it on your previous game, the hardest part in the whole process is drilling into the stainless ball guides, and making sure the areas you've drilled into are perfectly lined up for the opto beam.
Some takeaways from my kit-less installation:
Optos must be "shimmed" up about 3mm from the playfield in order for the ball to break the opto beam at the ball's widest diameter, and to ensure proper timing of the magnet's ability to catch the ball. I found that a paint stirrer from the hardware store is about 3mm thick, but any material can be used. I used digital calipers to take all measurements before drilling the holes in the guides. No template or anything was required. "Measure twice, cut once." It doesn't have to be perfect, but it has to be damn close.
My process: With the guides installed, stick a ruler across the top directly over the center of the magnet core. Mark in sharpie along the top on each side. Then, with calipers, measure the distance from the base of the opto to the center of the beam PLUS the added 3mm of shim. Mark that on each side of the guide under each mark you made from the ruler. That got me perfectly centered and ready for the drill. There's a few guides that show the use of painters tape to help with alignment. I didn't think that was necessary, and didn't use it.
Regarding the drilling, a drill press is absolutely necessary, as are a ton of sharp bits, oil to cool the bits, and a LOT of patience. Go low and slow, and let the bit do all the work. Start with a small diameter drill bit, and work your way up to 17/64 size. This was by far the most time consuming portion of the installation.
https://pinside.com/pinball/forum/topic/imagine-if-you-will-a-twilight-zone-playfield-swap/page/2#post-6717814
Solder the wires onto the optos, and run them through the playfield, screw down the guides, then screw down the optos just behind the holes. Everything should line up.
I cheated with the wiring of the optos into the 10-opto board. Pinsider "Dumbass" has a "plug and play" board that installs over the connector. All you'd need to do is wire in a connector for the extra opto pair, and crimp in a connector. No hacking of the original board is required. The process is highlighted here:
https://pinside.com/pinball/forum/topic/imagine-if-you-will-a-twilight-zone-playfield-swap/page/3#post-6743681
Lastly, add the associated driver board hardware, install the magnet, and punch the wiring into the existing connector.
https://pinside.com/pinball/forum/topic/imagine-if-you-will-a-twilight-zone-playfield-swap/page/2#post-6734791
And that's really all there is to it. It's not a technically demanding job, but it's not at all easy. With Dumbass's board, all the challenge goes into measuring and drilling the rails for the optos.