I was prepping our Missile Command arcade for a customer who is renting the game for their office, but before it went out I was having some trouble getting the trackball to work right. Guiding my missiles up and down was a breeze, but trying to aim to the right or the left would barely move the target. Since the game isn’t very much fun when you constantly face nuclear annihilation, I thought that I’d open it up and see if I could figure out what was going on.
Like a lot of the trackball games, the ball has a tendency to suck up dirt like no one’s business. Part of this is because you’ve got a couple of moving parts that you need in order to make it work and they have a tendency to get dirt and grim caught in it’s pieces. Another part of it is that people put their hands all over the ball when they play it and can transfer dirt and oils onto the ball and ultimately into the sensors. Since this is a pretty common problem to come across, I thought that I’d do a blog post detailing how we go about cleaning our trackballs, so that you can get your trackball games to play smoothly as well.
The first step that you’ll need to do is gather together your tools. For this job we’ll need; rubbing alcohol, qtips, a clean rag, some warm soapy water, a little bit of oil (we used the same oil that you clean your shredders with), a phillips head screwdirver, a set of security screw bits, a pair of needle nose pliers, a 12mm wrench and a 9/64 allen wrench.
The next step is to remove the entire trackball assembly from the arcade cabinet. On the Missile Command game there are three bolts that hold the ball assembly in place. There are also two molex connectors that plug the trackball into the game. Using the 12mm wrench, we were able to remove all 3 bolts and unfasten both connectors.
Now that you’ve got the trackball out of your game and onto your workbench, you can start cleaning things up a bit. Using the 9/64 allen wrench, unscrew the metal plate that holds the trackball assembly together. You’ll also need to flip the assembly over and unscrew the plastic that covers it, in order to open things up. Once you have the assembly in pieces, you can tackle each component. Using your warm soapy water, gently clean the trackball, the pieces of the assembly that houses the ball and the ball bearings that rollers plug into. After cleaning each piece, you want to dry it off so that you can prevent any rust from occurring.
At the end of each roller, you’re going to find a giant gear with a bunch of scary looking teeth that are attached to a roller and some ball bearings.
In order to remove this gear, there is a E-Ring that you have to remove with your needle nose pliers and a screw that also holds it in. Once you get the gear off you want to also clean it with soapy water. You also want to clean the ball bearings with warm soapy water as well. Once you dry the bearings, you’ll want to add 2 – 3 drops of oil to each one, so that it spins easily.
Now that we have the gear off, we can get to the optical reader which is our primary target. The way that the trackballs work is that there is a vertical and a horizontal sensor that shoots a beam of light out of it. When you roll the ball, the teeth on the gears interrupt the flow of light and the system recognizes that as it’s signal to move on the screen. The faster you interrupt the light, the faster your target will move on the screen. In order to make sure that you’re getting a good signal, you want to take a qtip, dip it into rubbing alcohol and clean the sensors that read the light.
Once the rubbing alcohol has a chance to evaporate, you can go ahead and reassemble all of your parts. We opted not to replace the rollers on our trackball, but this would be a good time to add replacement rollers if yours are really worn down.
You can see on our rollers where the paint has started to wear off in the middle. If cleaning your trackball doesn’t solve your problem, this may be your most likely culprit. While we had everything open, we went ahead and used some of the rubbing alcohol to clean the rollers as well.
When you’re reassembling your trackball, you’ll notice that there is a ball bearing roller that the ball guides itself on. You want to make sure to leave a little bit of room when you screw everything down so that the ball moves freely. Too tight and the it won’t roll, too loose and the ball gets wobbly when you play the game.
Once the entire trackball is reassembled, you can bolt it back into your cabinet and you should be ready to roll (sorry couldn’t resist.) Hopefully, this helps to get your game playing a bit smoother or at least removes some of the apprehensiveness that you feel when you see a small child with an ice cream cone playing your game 😉
Do you have a different technique that you’ve had success with? Feel free to leave your own tips or questions in the comments below . . .
Update – So using the shredder oil turned out to be a big mistake. Better stick to the recommended 3 in 1 oil to make sure that it doesn’t get gunked up. You can find some at your local hardware store.