If you are going to CNC your playfield, that’s great. However, most people don’t have free access to a CNC machine, and paying someone to do the job for a one-off project may not be cost effective. So, for most of the blog, I will consider that the fabrication sections are going to be done by hand…
The second-most-difficult feature of the Playfield to create by hand is the Switch Slot (the most difficult being an Arrow Lens). The Playfield Switch is obviously one of the most important hardware features of a Pinball Machine, since the game is essentially a continuous electro-mechanical interaction, where the Pinball activates a Switch, which in turn activates a Solenoid, which in turn impacts the Pinball, and so on, and so on.
We start with a full-size 1:1 printout of our Playfield CAD drawing, but in this example I’m just focusing on the section where the Switch Slot will be. Spot-drilling all of the features at the same time with a full-size drawing will guaranty that holes are placed correctly relative to each other. Here is the Slot creation process in detail from start to finish.
Spot drill both ends of the slot using a 1:1 scale printout of the Playfield CAD for reference. Then, carve a small groove from center-to-center to keep the next set of pilot drill holes in line.
Establish the center line with an X-acto knife, then drill a set of pilot holes in the groove. Use the finish drill size (.198″) as a visual guide to set the spacing.
Once the spot drills are finished, follow-up with the finish drill (.198″) in each pilot hole.
Using the same X-acto, establish the outside walls of the slot with clean cut, using the outer diameter as a guide. Then come back with angled cuts until the slot is clear. Flip over the the other side to complete the slot.