Background

Materials

You will need:

• A mouse

The key here is to get one that is opti-mechanical (has an encoder wheel). No big deal, as all modern mice have this, but if you get some cheap 5 year old mouse from some PC surplus store (like I did originally), it might have mechanical parts inside. In an opti-mechanical mouse, the mouse ball should rub against a shaft, which spins an encoder wheel, but the wheel itself should have no contact with any of the electronics.

The other thing to look out for is you will need to be able to easily remove the encoder wheel and shaft from the mouse. Some mice (most notably the Logitech Mouseman) have the encoder wheels embedded in some kind of half-dome, which you have to break apart to get to the encoder wheel. You can usually take the ball out of the mouse in the store and look inside to see - if you aren't sure, just buy from a store with a good return policy, take the mouse out to the parking lot and unscrew the back to make sure it's usable before you bring it home.

I had access to a bunch of different mice at work, so I was able to take a bunch apart and see which ones were good. The Microsoft mice are good, with easily removed encoder wheels, but the circuit board was kind of big, and they are moderately expensive ($20+). The mouse I ended up buying was a 2-button Dexxa mouse ($9.95 from Office Depot). It has a really nice small circuit board (about 3cm by 4cm), and easily removable encoder wheels. As an added bonus, if you buy the 2-button mouse, it already has holes on the circuit board (intended for the missing 3rd button) where you can solder in some wires to connect arcade pushbuttons to act as the mouse buttons.

Finally, for PC users, you need to figure out what type of mouse to get (serial, PS/2, or bus). If you currently have a serial mouse on your system, you are in luck - you can get a serial mouse, convert it to a spinner, and just swap it with your regular mouse when you want to use your spinner. If you have a PS/2 or Bus mouse, it's a little more painful, as you aren't supposed to swap these devices while your PC is powered up, but there are devices that let you connect multiple mice to the same port. For Mac users, I've been told that you can't swap Mac mouse devices on the fly, so I don't  know what your options are.

There is another option for non-serial mouse users, if you have COM1 free - you can build your spinner out of a serial mouse and have both your normal mouse and the spinner connected at the same time. The default Win95 mouse driver should support both mice connected at the same time - if not, you can download and install the latest Win95 mouse driver from Logitech (www.logitech.com), which definitely supports two mouse devices connected simultaneously.

• A freely spinning shaft and a knob

You have lots of options here - what you need is something you can attach to the mouse encoder wheel so you can spin it in your hand. You also need some way to mount this on some flat surface (see next item). If you are feeling fairly ambitious, you can call around your local arcade distributors (see "Amusement Devices" in your local yellow pages) and get an authentic Tempest or Arkanoid or other arcade spinner (they are kinda scarce, as they aren't made any more and most distributors just throw them out once the electronics go bad - you can probably find some mail-order sources, though). If you go this route, just get the hardware (not the electronics) as control panels with working electronics are very scarce these days - some arcade collector out there will be very thankful that you didn't strip a working panel.

Otherwise, you can be fairly creative. I've heard of some people using a wheel from a toy car. I tried (and failed) to find an authentic arcade spinner, then thought about using a knob from an old car radio, but finally I found a fairly decent freely spinning shaft from a local electronics store (Radar Electric in Seattle, WA - (206) 282-2511). It is an "H.H. Smith 1/4" Shaft Extender - 6" long -- part #149". It cost less than $2, and you can get a knob to attach to the end for another buck or so at Radio Shack. It's too long, so I ended up sawing the shaft down to about 1/2" before attaching the encoder wheel. You can find a local distributor from their web site: www.hhsmith.com.

• A box or something else to mount it on

What you use here depends on what kind of shaft you bought - if you bought an arcade spinner, you can probably build a nice wooden box and mount it on there. The knob/shaft I bought couldn't be mounted on wood, so I bought a little plastic project box at Radar Electric for about $6 (CALRAD Plastic Utility Box #90-883). You can use whatever you want, but you'll want something halfway sturdy (no cardboard). You'll also want a sytrofoam block, which you can use to mount the mouse electronics in the correct position.
• Tools

You'll need a drill and some appropriately-sized drill bits to make a hole in the box for the spin-knob shaft and any pushbuttons you use. You also will need a thin (3/32?) drill bit to drill a hole in your shaft extender.

You'll want some kind of glue to secure your circuit board, and to attach the encoder wheel to the shaft extender. I used a hot glue gun, but you might be able to use some epoxy or other glue you can get at the hardware store.
 
 
 

• Arcade pushbuttons

These are easy to get - you can order the "Competition Pushbuttons" from Happ Controls, but pretty much any arcade distributor will carry them as well. I would get the "pushbutton with horizontal microswitch", unless the box you are mounting them in is really tall.

You can solder these to the appropriate traces on the mouse circuit board, so that when you close the circuit it acts as if you had pressed a mouse button. Every mouse circuit board is different, so I don't have any real advice for you if you can't trace the circuit yourself - if worst comes to worst, you could unsolder the existing mouse switches, and replace them with wires leading to your pushbuttons.

I used stranded 20 gauge wire, but if I were doing it over I would use 22 gauge - the 20 gauge wire is too stiff. Also, I recommend that you buy some quick-connect terminals, so it's easy to connect and disconnect the wires to your pushbuttons without having to unsolder/resolder the connections - if you do this, you'll need a crimper, but pliers would probably work too. Finally, you'll need a 1 1/8" drill bit to make the holes in the box that the pushbuttons fit in.

Procedure

1. Go out and get your materials. I bought a Dexxa mouse, a couple of arcade pushbuttons, some wire and quick connect terminals, a shaft extender, and a box to put it all in.
2. Take apart the mouse (one of the screws holding the mouse together was covered by a sticker that I had to peel back) and take the circuit board out - you may need to take the encoder wheels off to do this, but they should just snap on/off. This is a good time to hook the mouse to your PC to make sure it works, and to get a feel for how the whole encoder-wheel mechanism works.
3. If you are attaching arcade pushbuttons, solder the wires to the circuit board now, and crimp on your quick-connect terminals (you don't want to attach the ends to the pushbuttons yet).
4. If you bought a mouse (like the Logitech models) that has a small circuit board, use a hacksaw to cut off the parts of the mouse casing that you don't need (the part with the mouse ball, etc). All you need is the part that the circuit board sits on, and the part that holds the encoder wheel in place (BTW, the encoder wheel is attached to the mouse casing in two places - you only want to keep the part that is near the LEDs, as the other end of the shaft will connect to your spin knob). Even if you don't have a small circuit board, you'll still need to cut away parts of the mouse casing so you can connect the X-axis encoder wheel to the shaft extender.  It's up to you whether you want to keep the top half of your mouse casing or not - if you glue it on, it probably will help to hold the circuit board in place, but it's kind of a pain to take it off if/when you want to make adjustments to the position of the encoder wheel. I got so tired of removing/regluing the top part that I just used a hot-glue gun to glue the circuit board to the bottom casing. If you choose to go this route, go ahead and glue the circuit board to the bottom casing now - avoid getting glue on any electronic components.

 

 

When doing all this, remember that you'll be using the X-axis encoder wheel (the one that spins when you move your mouse from left to right) - just make sure that there's nothing blocking you from attaching your knob/shaft to the shaft of the encoder wheel.

5. Take your box and drill your holes for your knob/shaft, and for any pushbuttons you are using.
6. Attach your shaft extender to the box, and put the mouse electronics in the box alongside it, about where you expect it to sit. Figure out how much of the shaft extender you need to cut off - it should be just long enough that you can mount the encoder wheel shaft to the end of it, and attach it to the mouse circuit board.
7. Cut the shaft extender to the appropriate length, and drill a hole in the end to fit the encoder shaft into. Make sure that you drill the hole in the center of the shaft - if you don't, your encoder wheel will wobble when you spin the shaft.
8. Mount the shaft extender to your box, and secure it by tightening the nuts, etc (geez, that sounds provocative ;-). Now you can put the encoder shaft in the hole you drilled in the end of the shaft extender, and glue it in place. You can also attach the knob to the other end of the shaft extender now.
9. Now take your mouse casing/circuit board, and position it so the encoder wheel spins freely in the correct position when you spin the knob. You can run a test by plugging the mouse in to your PC, and spinning the knob - the mouse cursor should move smoothly from left to right.
10. Take the styrofoam block and shave it down so it just fits between the edge of your box and the mouse circuit board. The idea here is that you can glue the styrofoam to the box, then glue the mouse casing to the sytrofoam with the encoder wheel in the correct position. If you do this correctly, the mouse circuit board will be securely mounted, and you can spin the encoder wheel to move the mouse cursor on your PC. It should look something like this. Here is another view. The hard part is now done!
11. If you want to, you can glue the top of your mouse casing onto the bottom of the mouse casing. I don't think this is worthwhile, and it's much easier to make adjustments (say, if the encoder wheel comes loose from the shaft extender) if you don't have the top casing on there. If you glued the circuit board to the mouse casing, you are fine.
12. If you have pushbuttons, mount them on the box now, and attach the wires to the correct terminals.
13. Put the bottom on your box. Before you do this, you'll need to cut/drill a little notch that the mouse cable can fit through. I left a little slack in the serial cable inside the box, then tied a knot in the cable before feeding it through the notch - that way, if you accidentally tug on the serial cable, the strain is taken up by the knot, rather than ripping your circuit board loose.

Please email me at drews-arcade_AT_aqualion.net if you have questions or comments.

Go back to Drew's Arcade Page