Spacemouse Space Navigator Knob (glued revisions)

This is a replacement for early model Space Navigator knobs, as over time the rubberized grip starts to severely degrade, characterized by it falling apart and feeling sticky.

There are a few revisions of the space mouse. To identify, pop the top cover off the mouse using a spudger, guitar pick or a thin flathead screwdriver (covered with electrical tape to prevent marring). If you see three screws, congratulations as you have a much easier to replace part- please use the model in this printables page.

If you don't see screws, unfortunately you have an earlier "disposable" version of the mouse- the PCB and motion assembly is actually glued into the knob.

This model is the correct knob you'll need, but disassembly is more involved and does involve some permanent changes. A word of warning: There a risk of damage to your space mouse. The materials needed for this next step include the use of a drill, a bench vise, and some epoxy/glue. I do not take any responsibility for permanent damage to your mouse. If this sounds like too much, consider a printable TPU sock instead.

The quick/permanent way of removing the PCB:

Dremel or cut the knob carefully away from the inside PCB assembly. Near the top of the knob is where the PCB is actually touching/glued onto the knob so make sure you don't damage it there.

The non-destructive/reversible method of removing the PCB:

Underneath the base's rubber ring you will find 3 screws. The first is opposite the cable, the others are 120 degrees from that. Peel the minimum amount of rubber back to remove the screws without damaging the adhesive/rubber.

Once inside the base, remove 6 more screws, 2 for the PCB and 4 for the plastic mount. Pop the PCB off- just gently lift it with your fingers because it's using a socket connector to the knob PCB.

You should eventually be left with the knob and PCB assembly. 

Using a 1/4"/6mm or larger drill bit, drill one hole in the middle of the knob (you may want to drill a pilot hole first). Basically, drill until you feel you're past the top layer, and then stop. You want to drill through the top of the knob but not through the plastic carrier for the PCB, which is below. There is quite a bit of space between the two so you shouldn't accidentally do this if you go slow.  Reversing course at this point is easy if you're uncomfortable as the top cover will hide the hole and no functionality is affected.

Now you have to press the PCB assembly out of the knob by overcoming the glue. Start by inserting a drift/dowel/pin/bolt or something else cylindrical with a flat face through the hole so it touches the plastic carrier underneath.

You can try using gorilla strength to break the glue and push the PCB assembly out. If that doesn’t work, I would recommend using a vise and slowly pushing the PCB out. To do this, print out the knob. Orient the bolt, the original knob, and the printed knob as shown below, in the vise. Slowly tighten the vise until the PCB assembly pops out.

Reassembly

Clean the edges of PCB of remaining glue/epoxy. Apply new epoxy/glue and then insert it into the new knob. You can use anything from JB weld to hot glue (though note that you have to work quickly with hot glue while also not making a mess, whereas most epoxies give you at least some amount of working time). Note  alsothat there is a key in the knob that should match the keyway in the PCB. Once you've inserted the knob, check to make sure that it's sitting straight; if the PCB is not, gently move it around until it does. Wait until the glue dries.

Reverse directions for reassembly.