Since the control panel is basically the "human interface" to the cabinet, it's probably the most important part of it. Let's face it, if the controls don't feel just right you're not going to enjoy gameplay as much as you should. The design of the controls should come down to one thing: playability. I designed my control panel so that I could play the games that I wanted to, and play them comfortably.
Once again, after scouring the websites of people who have built their own control panels and doing a lot of brainstorming and doodling on the graph paper, I came up with a design that encompassed everything that I wanted. Aside from the normal "gameplay" buttons, I also wanted to make sure that I had some MAME control buttons on there as well. I used black buttons for the more sensitive keys like Esc (exit) and F3 (reset), which keeps them relatively hidden on the black-finished control panel.
All of the holes for the buttons and the joysticks were drilled out using a 1-1/8" forstner drill bit. All of the cuts for the spinner and the trackball were made simply by tracing out the shape that I needed and then cutting it out with a jigsaw. The control panel top itself is 32" x 14" on 3/4" MDF. This picture shows the exact dimensions of where I placed the joysticks and buttons. (All measurements are in inches.)
I didn't go with designing both players to have left-handed sticks with right-handed buttons, because I wanted to leave the option open of using the Player 2 side in a "right-handed stick" configuration for 1-player games if I wanted to. I went with a more symmetrical layout with the sticks on the outside of the panel and the buttons toward the inside.
Instead of dorking around with coin mechs (I mean, come on...who's really going to be putting money in there??), I just mounted a green "coin button" on the front of the cabinet, and the 1P and 2P Start buttons right next to it.
I just used Happ Controls' Horizonal Microswitch Pushbuttons for all of the buttons. I'd recommend 'em...they have a really good feel. Hammering away on these buttons in games like Track & Field sure beats clacking away on your keyboard. Six buttons per stick seems to be the norm for most people who have built their own control panels (this is usually referred to as the "Street Fighter configuration"), so that's what I went with as well. Make sure to stock up on extra buttons of every color when you place your order. Since Happs has a $25 minimum order, you're better off just doing it now.
The 8-way Super Joystick from Happ Controls seemed to be the stick of choice among the regulars at the Build Your Own Arcade Controls FAQ, so those are the ones that I got. They're great sticks, and I'd recommend them to anyone. There's an actuator on the bottom that you can flip over to make them either 4-way or 8-way; I made mine 8-way. There is a slight bit of difficulty of control in 4-way games like Pac Man or Frogger (since those games were meant to played on a true 4-way joystick), but it's more than offset by the superb 8-way control that you garner in games like Robotron. Plus, once you get used to just being more accurate with your (*ahem*) stick handling, using the 8-way stick shouldn't hinder you that much.
Of course, you've got to have a trackball for games like Centipede, Marble Madness, and Missle Command. Plus, my trackball doubles as the mouse for navigation in Windows on my machine. On recommendation of a couple of people on the BYOAC FAQ board, I got the "Kidsball" trackball from Kye corp. Oofah, what a piece of junk that thing was. The ball felt way too light, and the bulbous shape of the case looked like it would make mounting it a real chore. I popped over to CompUSA and picked up their "CompUSA Easy Roller Trackball" for about $12 or so. It's increasingly difficult to find this thing (and heaven forbid that the typical CompUSA employee actually helps you find something), so good luck finding this one if you want it. If it helps any, it's SKU # 192300.
The CompUSA model has a 2" ball, and it has a really solid feel to it. I'm very happy with it. I thought about ripping the top of the casing off, mounting the PCB underneath the board with the ball sticking out of a hole, and wiring the trackball buttons up near the ball itself, but why? Yeah, it would make the thing appear a bit more "realistic" perhaps, but that's an awful lot of work for what I considered to be a minor cosmetic attribute. Besides, I think that it's a good-looking piece of equipment, so I pretty much left it "as-is" and mounted it right onto the control panel.
Although, one thing that had to go was that drab "PC beige" color, so I disassembled the whole thing and painted the casing with a gloss black spray paint. I just cut a hole in the control panel the size of the trackball casing, and then used a piece of wood across the bottom of the panel and screwed it into the holes of the bottom of the trackball. All of the slapping in the world doesn't budge it from where it's mounted.
I have the trackball plugged into the PS/2 port on the PC, and it acts like the primary mouse while in Windows.
I took a look at a couple of the people who have built their own spinners and started the groundwork to build one myself. I unfortunately came to two realizations: 1) I just don't quite have the expertise to put one of these together, and 2) I couldn't find a lot of the parts needed. So I decided to just suck it up and buy one from TwistyGrip. Good thing too, since they no long manufacture them anymore! And yes, I bought the spinner just to play the single greatest arcade game ever: Tempest. Actually, the more I think about it, a good deal of this entire project was done just so that I could play Tempest arcade-style. Although, the spinner makes Tron pretty cool, too.
The TwistyGrip spinner came as a boxed unit, with the spinner and two buttons mounted on it. Obviously, that configuration ain't gonna fly on an arcade control panel. I thought about completely removing the knob from the box and mounting it to the wood of the control panel, but it mounted just fine in the box, so I used tin snips, a file, and a sander to cut out a square of the metal surrounding the knob. I then unscrewed the knob and painted the metal black with gloss spray paint, drilled holes in the metal plate, and mounted that directly on to the control panel. It looks and feels great. Here are a couple of "before" and "after" shots of the spinner.
I have the spinner plugged into the COM1 port on the PC, and Windows treats it as a second serial mouse.
Of course, I had to figure out a way to actually mount this thing into my cabinet. After drilling and cutting all of the holes in the top of the 32" x 14" panel, I attached 4" wide pieces of board to all sides of the bottom to make it into a "box". I also attached a 4" wide piece along the bottom toward the back to mount the encoder and the terminal blocks to it (I wanted the encoder to be mounted right side up). I put hinges on that piece so that the bottom could swing out for access to the encoder and the terminal blocks while the control panel box is out of the cabinet, and I also put normal barrel locks on it to keep it closed when it's mounted in its normal "upright" position.
The control panel box mounts to the sides of the cabinet using four carriage bolts - two on each side. I spray-painted the heads of these carriage bolts as well as the washers that go underneath them gloss black. I also counter-sunk the bolts so that the bottoms of the heads rest flush against the washers.
I probably should have devised some way to swing the whole top of the control panel out while still keeping it mounted in the cabinet, but I didn't. Since I got the whole thing done and wired I'm banking on the fact that I won't have to screw around with it all that much. It looks good where it is, so that's where it's gonna stay. It doesn't budge at all, even when put through two grown men beating the daylights out of the top of it while playing cutthroat Joust.
Update: I've already had to replace one button that was sticking. With the keyboard drawer folded out, accessing the bottom of the control panel wasn't nearly as bad as I thought it would be.