Anatomy of a Wico “Leaf” Joystick – 

Featuring Conversion to Optical Switches

Cracked and worn out grommets are the number one reason you’ll inevitably need to disassemble your Wico Leaf joysticks.  More about grommets HERE.


When a Wico leaf joystick is disassembled these are all the pieces you should have available.



At the top of the base you will place the dust washer, on a real machine this washer sits underneath a metal plate.


For home use, you can route a 1/8in deep hole, 3 inch diameter, and place the washer underneath 1/8th inch plexiglass, as found in any hardware store. Inexpensive, too!


The 2 main pieces of a joystick are the leaf holder on the left and the base on the right. Notice the 4 pegs on the left sit in the square box on the right piece.

In the base on the right you will place a plastic washer, which is important for grommet spacing.  Not all models have this plastic washer, though.


When installing the grommet, it is important to get the highest point facing up (toward the joystick ball when assembled)


After seating the grommet, place the metal washer directly on the grommet (note, that the base is pictured upside down from how it will eventually be mounted in the control panel.)


Now you will gently place the leaft base on top of the base holding the grommet.  GENTLY tighten the 4 self-tapping screws without over-tightening as they will quickly strip the plastic threads!


A 3.5 inch Wico handle has 3.5 inches of shaft below the balltop.  Robotron’s came with 4 inch handles, but you can easily route the joystick base into a 1 inch wooden control panel for a similar effect.  All wico shafts are interchangeable amongst joysticks, regardless of the shaft length.

In this picture, take note that there is a spring, then a nylon bushing that has a tapered end which faces toward the ball top. and finally a retaining clip.


Gently align the internal washers, and insert the shaft so as not to damage or break the plastic leafs.  Insert the spring


Install the bushing, tapered end toward the spring


This is THE HARDEST part of dealing with a wico joystick:  I tend to hold the balltop in toward my stomach, then pre-load the nylon bushing with my finger tips.  When done properly you will see the groove where the retaining clip will go.

IMPORTANT- this process creates a loaded spring pressure, and it is easy to shoot the bushing and clip clear across the room.  Do this in an uncluttered room unless you enjoy an adventure.  I have lost multiple clips and springs by slipping up.


Insert the C clip into the groove and gently release pressure on the nylon bushing


Gently use a pair of needle nose plyers to seat the clip.  Gently without excessive force!


Voila!  You have reassembled a Wico Leaf Joystick!


Converting a Leaf joystick to Optical

You may hear of Wico 360’s, or optical joysticks.  What this means is the leaf assembly is replaced with an electronic optical sensor.  The benefits are zero maintenance for leaf adjustments and lightning fast reaction of the switches. In the picture below, shows the simple jamma harness connections to run the joystick.  Be aware, +5v dc and a ground are necessary to run the optical board.  For Mame, you can obtain USB 5 volt cabling from many sources on ebay.

DISCLAIMER- If you like the tactile feel of the leaf pressure pushing back against the joystick, then this option is probably not for you.

Wiring is consolidated and simplified with the Optical switching plate.


This is the optical PCB inside the optical assemble, shown above.  I have circled the optical areas which replace the need for mechanical switches.  The nylon bushing of the joystick shaft passes near the sensor triggering the switching process.  Quite nifty.


On the top shows the shaft pieces for a leaf stick.  Below are the pieces for a Wico 360.  There are differences in the bushing, spacer, and spring.  BUT the shaft and C clip are identical.

You will be using the pieces for the original leaf shaft in the conversion process


Leaf sticks use smaller screws, seen on the top.  The optical board assembly is fatter so requires longer screws.

You will be using the longer screws in the conversion process


On the left is the base for an optical joystick.  On the right is the base/grommet for a leaf joystick.

Notice the heavy spring used in Wico 360’s, and the number one reason they are too heavy for games like Robotron and Berzerk.  The pressure slows reaction time and causes forearm fatigue.

You will be using the leaf base as seen on the right, for the conversion process.


On the left is an optical switch board.  On the right is the leaf assembly.

The leaf assembly, is obviously not used in the conversion process.


  1. Install the optical ring onto the leaf base with grommet.
  2. Gently tighten the long screws, without over-tightening.
  3. Place the spring and nylon bushing.
  4. Attach the C clip/retainer clip.
  5. Install the joystick in the control panel exactly as you would a normal wico leaf joystick.
  6. Attach the +5v and gnd wires to the power supply.
  7. And get ready to enjoy very fast and silent switches, with super light action since the grommet tension is the only thing fighting against your joystick movements.  Outstanding for a lighting fast reaction game like Berzerk!


Boneyard: When the conversion is complete, you will end up with these parts leftover.


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