Class got boring this afternoon

So I'm taking a green belt class for work.  If you don't know what that is, it's about eliminating waste in production (lean manufacturing).  The process is pretty interesting, and it's a great tool to learn.  Problem is, sometimes people ask dumb questions, or the teacher will spend far too much time on something that should be obvious to most students (like basic computer skills).  So rather than daydream, typically I'll keep my mind churning by putting it to work on my own personal projects (while still paying attention).

While green belt is really more about fixing existing processes (not a design), it does talk about non-value added waste.  This can be physical waste (un-necessary extra parts), or waste of time (extra steps, un-necessary labor).

So I'm thinking about the assembly of a pinball machine playfield.  I started simplifying all the parts that are needed:

Electrical: switches, solenoids, flashers, GI lighting, insert lighting... All of that requires a lot of connections to carry power and signals.

Mechanical: Posts, ramps/wireforms, guides, flippers, pop bumpers, plastics, spinners, targets, bash toys.

Now I've shopped a few pins, but never did a playfield swap.  This is mostly due to the fact that dis-assembling the under playfield is a fucking nightmare.  Seriously, the idea of unsoldering wires, unscrewing 30+ bayonet sockets (more so on older titles), all the mechs like flippers, drop targets, stationary targets, spinners, all the T-nuts.  Really I might be able to get past all the mechanical things, but that wiring harness.  If you've ever had to trouble shoot a switch or a lamp, it's a nightmare.  It's almost equivalent to an IT person troubleshooting a Cat-5 cable in a rats nest of a server.  Sure, there's colors to help seperate each strand, but often colors are re-used, and then there's the issue of wires overlapping in a giant bundle.

So then I think, do I go the way of jersey jack?  Do I impliment daughter PCB's?  That's costly.  I mean not really, in volume pcbs (single side anyway) are like pennies per square inch.  But that requires software, and volume parts (I'm making a one-off here).  So then I thought could I do it a simpler way?  I mean for lighting I'm going all LED, I only need enough gauge to carry 3-6V at like 20mah a piece.  I probably make home fabricated pcbs from conductive ink on non-metal material like fiberglass, or even some thin plywood.  Or maybe I do some sort of very thin metal, mask it off, and etch away what I don't need (creating a crude single-sides PCB).  Then I thought why stop at lighting, could I do a layer of switches?  Could I also mount solenoids on this layer?  Could I mount all the posts and ramps on a thin layer of clear plexiglass on top as well (with maybe the exception of a few switches tied to ramps, but this could be connectorized).
This would effectively make it possible to completely strip all components off of the playfield itself by stripping off these 3 layers.

That means shopping out a playfield is no big deal.  This means if there's an issue, that layer can be separated and troubleshooted on it's own.

Another deep thought I had was the insert lighting.  This is another relic that's been carried over from pinball from the 1950's.  Don't get me wrong, watching inserts pop with light is great, but is the reward worth the effort?  Inserts were made because there was originally no way of displaying information (segment displays/DMD's),or implimenting billboards (IE a lexan sign above the entrance of a ramp with LED's using a lamp matrix to simplify wiring).  I think a lot could be communicated off the playfield using alternate lighting.  Heck, for targets it can be backlit, even using multiple colors.  Why am I so against inserts?  They are a pain in the ass both from a maintenance standpoint and installation.  Shaped inserts require CNC, and the recess needs to be somewhat precise so that insert lies flush on the top (with a little sanding), and then there's the glueing to keep them in place (while making sure they don't cloud up).  Over time, inserts become dirty (blocked by the pain in the ass bayonet sockets), the inserts become cupped or stick out over time, sometimes they even crack requiring replacing (if you can even source a replacement).  RGB strips seem to be slowly creeping into pinball to add extra flash.  They use them for under cabinet lighting, in some cases they completely overlay RGB strips over the backbox lighting because it's simpler, and makes it easy to install an existing pin.