The Modern Firepower Pinball Project - Prep for Wiring

In prep for wiring the playfield, I'm test fitting all of the various circuit boards and components onto the underside of the playfield.  I have to find a place for three LED-Wiz output driver boards, one U-HID switch input board, one Pinball Solenoid Power Driver board (of my own design), and a USB hub to tie them all together.

From the original design concept, I intended to install the circuit boards directly to the playfield.

It is not a requirement that I install any of these components to the playfield.  Alternatively I could have installed the circuit boards in the backbox, like a normal pinball machine.  To install the boards in the backbox would require me to fashion up several wiring harness connectors, as there would be around 150 wires connecting to the playfield.

But since my circuit boards are so small and fit on the playfield, I will only have 3 wires connecting to the playfield:  The 50v power supply, the 5v/12v power supply, and a single USB cable.

Now that's the definition of Modern.

The Modern Firepower Pinball Project - Cabinet Assembled

I finished painting the cabinet, and with Troy's help we got it mostly assembled.  For now I'm going to leave off any artwork, I find the all black cabinet to be classy and different.  The paint is a semi-gloss, so those are soft reflections you see on the side of the cabinet.

The cabinet looks classy its black and chrome motif.

I haven't painted the backbox.  The front wood panel that covers the monitor and holds the speakers needs to be designed, routed and installed before I paint it.  The speakers that are dangling from the monitor are the original speakers that came on the 32" TV.  Since they are not very good, I will replace them with either 6 1/2" or 6" x 9" car audio speakers, which I haven't yet picked out.

The Modern Firepower Pinball Project - Lights Installed

All of the lights have been installed on the playfield.  At this time, the underside hardware installation is 99% complete.  There is a mechanical beauty to an un-wired playfield.  If only it could stay looking this nice.

Take note of the open areas that remain on the playfield.  My selection of modern components have freed up additional room around the slingshots and eject holes.  This will allow me to do something pretty special - I will be mounting the circuit boards to the playfield itself.

I installed the lights in a tidy fashion to minimize wasting of open space.

More pics after the jump...

The Modern Firepower Pinball Project - Solenoid Power Driver Design

WARNING:  THE CIRCUITRY DESCRIBED IN THIS POST USES ELECTRICITY AT LEVELS DEADLY TO HUMANS.  SEEK PROFESSIONAL EXPERTISE IF YOU ARE NOT SURE HOW TO SAFELY USE THE PRESENTED INFORMATION.

During the course of The Modern Firepower Pinball Project, I've had to don many different caps.  At various times I've been a researcher, analyst, designer, carpenter, painter, mechanical engineer, programmer,  electrical engineer, project manager, financier and accountant.  Now that I think about it, since I'm writing this blog I'm also the writer, photographer, and publicist.  No wonder it has taken me over four years to get this far.

While all of the various tasks interest me (why else would I be doing this project), I understand that many pinball enthusiast, even diy hobbyist, just want to get to the good parts with videos of pinballs bouncing around.  To those readers, fair warning, this is not that post!  As if the title didn't already give that away.

This post is about circuit design and theory, and for most people I would expect this is an extremely boring topic.  Even worse, I plan to share some technical details that many won't understand, including me.  I have no formal education in electrical engineering, and I'm self taught outside of one class in college.  As I share this information, I'll be presenting it in mostly layman terms, not EE terms, as this is how my brain works - I suppose I have a layman's brain.  If you want to understand more about transistor design, usage and terminology, there's plenty of other resources on the web that cover those topics.

If you're a brave soul, you might find this post informative even if you don't have a real interest in electronic design.  I found many forum posts online where people were trying to figure out how to get an LED-Wiz to control pinball solenoids.  Well, this is how.

Now, to the topic at hand...

Rottendog Amusements makes modern replacement Driver Boards like this Williams WPC89/WPC-S replacement.    While it is better than the originals, this board is still rather large, though it does handle more than just solenoids.

The Modern Firepower Pinball Project - The Electronics

I have already provided many posts detailing the cabinet and playfield progress (with many more to come), and now it is time to talk about something different, the electronics of the pinball machine.

Anyone who has seen the inner workings of pinball machines is familiar with the large, complicated circuit boards hidden inside.  These electronic boards are custom designed for pinball machines - often specific to a single game design.  Hundreds of color coded wires run from these boards to other boards, the playfield, and other areas of the cabinet.  It's an electronic nightmare.

Found on the web, this ActionPinball.com image shows many of the common circuit boards hiding in a pinball backbox.

When I first started the project, I briefly considered using these original pinball circuit boards - after all, if it already works why re-invent the wheel.

But using 30 year old circuit boards, possibly designed for an incompatible game and running hard coded firmware, just didn't align with any of my goals.  Nothing modern about that approach.  Rather, I wanted to use off the shelf, generic circuitry where possible.  Besides, these pinball specific circuit boards are expensive.

I also looked at programmable microcontrollers like Arduino and Parallax.  +Ben Heck had chosen the programmable microcontroller path for his pinball machines, and I knew it was cost effective and functional, but I found this approach was too limited for some of my goals. Sure, these devices were powerful, and could easily control lights, solenoids, switches and audio, but I wanted video too.

More importantly, I wanted a solution that could adapt to any pinball machine without writing new code.

From this point forward I will begin to show you what makes the Modern Firepower Pinball Machine so special, and unique in all the world of pinball.

The Modern Firepower Pinball Project - Ablaze 9-LED #89 Flasher Lamps

In the previous update I showed that the Ablaze 9-LED flasher lamps, which run on 12 volts, would not light up at all on 5 volts.  I dug out my 12 volt power source and tried again, this time to spectacular results.

With 12 volts now running through its veins, the 9-LED #89 bulb shone brightly.  On the left is the 4-LED #44/#47 bulb.

The Modern FIrepower Pinball Project - Lighting Issues

The curse of incorrect parts has reared its ugly head again.

I can't blame the vendors, as I've always been delivered exactly what I ordered.  I don't really want to accept blame myself either, as you can't deduce everything from photos of individual parts.  I guess once again I'll blame the parts ecosystem that simply isn't designed to support the diy pinball hobbyist.  I've never seen any write-ups detailing the correct style bulbs to use when making your own pinball from scratch.  I guess it is up to me, then.

So here's what I chose for lighting, why it was wrong, and what I chose to replace it.

The Modern Firepower Pinball Project - Painting the Cabinet

Since I had some downtime waiting for replacement parts to come in (more on that later) I decided to go ahead an paint the cabinet.

First I finished cutting the ventilation holes and the hole for the ball shooter.  I post later about how I lined up the ball shooter.

Then I sanded, puttied, sanded, puttied, and sanded some more.

Finally, I primed the cabinet.  Primer reveals all kinds of imperfections, so I then spent another day applying wood filler and sanding everything down.

First of many many coats of primer.  I'm using Rust-Oleum Painter's Touch white spray primer.

The Modern Firepower Pinball Project - Targets & Switches

The various targets, stand up leaf switches and rollover switches were all very easy to install.

The targets took the most work, since they are visible and I wanted their alignment visually correct.

The leaf switches I installed by tapping the rubber rings (simulating a pinball hitting them) while positioning each switch - when correctly positioned I could hear the small metallic tap tap tap of the switch contacts.  I then marked and drilled the holes.  The rollover switches I simply visually aligned.

 

Read on to see more pictures...

The Modern Firepower Pinball Project - Playfield Machinery

After installing the various posts on the playfield, I turned my attention to the playfield machinery.

I had already decided that there was a correct order for installing all parts on the playfield.  Posts first, simply because they are small and on the top.  Then machinery, because there's normally only one correct way to install these large metal assemblies.  Next come targets and stand up switches, as they too can only be installed one way.  Then come the rollover switches, which have a little more leeway in installation location.  Last come the lights, as they have the most flexibility in installation location - so long as they are under the correct insert or hole, you can mount them however you like.

I installed the pop bumpers first.  These are standard Williams style pop bumpers.

The Modern Firepower Pinball Project - Playfield Posts Installed

It should be quite obvious by now that I did not achieve my goal of having a playable pinball machine by New Year's.  The factors were twofold:  missing or incorrect parts, but more importantly a massive underestimation of the work it takes to assemble a playfield.

I foolishly expected assembly to be somewhat plug and play, and thought I would crank it out in a few hours.  Reality is that you have to carefully check every part, align every hole, drill every hole (making sure not to drill all the way through the board!), and then screw in very carefully each part.

The posts alone were taking about 10-20 minutes each, and there's a lot of posts.  Part of the challenge is making sure the right post, or post screw/bolt, is being used at each location.  Make the wrong choice and you might drill the hole incorrectly.  There's really only one shot to get everything right, so I took my time.

I also learned the hard way to make sure to drill the pilot holes to the correct size.  I was slightly small on many of my holes, and actually snapped a screw post off in the playfield!  The post broke off flush with the playfield, and my attempts to simply remove or drill out the post, without damanging the playfield, were unsuccessful.  I finally drilled small pilot holes all around the sides of the broken post until I could free it.  To fix the playfield, I drilled a larger hole to permit the use of a bolt post and T-Nut.  Then end result is even better than stock, so I consider myself lucky.  I really wish all post holes used T-nuts and bolts instead of wood screws - they install faster and seem more robust.

The Modern Firepower Pinball Project - Playfield Support Rails

Progress on the cabinet is coming along nicely.  Time to make sure everything fits correctly and install the playfield support rails inside the cabinet.

Test fit of all cabinet hardware.Time to install the playfield support rails.

The Modern Firepower Pinball Project - Coin Door Luck

While I spent a lot of time and effort measuring, test fitting, and reverse engineering how all the various cabinet components had to be installed, on a few occasions lady luck was on my side.

I got really lucky when I installed the coin door.  It never occured to me that the coin door and the lockdown bar retention bracket bolt together.  When I cut the hole for the coin door, I simply centered it left to right, and arbitrarily picked a height that looked appropriate.  Sure, I stared at dozens of pictures before deciding where to locate the coin door, but the pictures below show luck was on my side.

The coin door is installed with four bolts, centered on the bottom, sides and top.  The top hole goes through the bracket.

The vertical alignment was perfect, and I was able to install the bolt and nut without issue.

 Now that you know, you don't have to be lucky like me.  Plan ahead.

The Modern Firepower Pinball Project - Stern Backbox Hinges

The parts for the Stern Backbox Hinges came in from Marco Specialties.  I took plenty of pictures, so I'll let the pics do most of the talking this time.  Note, I did not have the washer in the photos, nor did I install the washer.  Everything seems to work without the washer, and as rarely as I will every pivot the backbox, I probably will never use a washer.  If I change my mind, I can always install it later.

The Stern Backbox Hinge Bolt assembly includes a Hex Spacer Nut, a Carriage Bolt, a plastic spacer, and a washer (no pic).

Click through for all the details...