Cleaning Joystick Pots

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Cleaning Joystick Pots

I picked up an Apple 2 joystick that was having issues.  One of the buttons didn't work, I was able to remedy that by putting in new switches.  However, the pots also need to be cleaned/inspected.  I prefer to do that by actually opening up the pots and cleaning the contacts and track, vs. blasting the entire thing with a can of contact cleaner.  As contact cleaner also clears out any grease in there, and makes the pots feel too "loose".

 

But I can't figure out how to remove them from the X-Y actuator mechanism (for lack of a better term).  Unless you have to disassemble the whole X-Y mechanism inside the box to some how get them off.  I was hoping you could easily just pop them off from the outside.

 

Anyone know for sure how to get them off?  Thanks!

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There are small vents in the

There are small vents in the pots. Buy a pair of DeOxit F5 and DeOxit D5. The F5 formula is for faders. Spray a tiny but on both D5 an F5 into the vent, an turn the knob back and forth 100 times, each. 

 

I have one of the Joystick //e units open on my desk, so I will try to photograph it, and inicate where to inject the cleaner. 

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Yeah, I know how to spary

Yeah, I know how to spary/flood the pot either through the vents, or through where the terminals stick out.  I just don't like doing it.  There is usually a lump of grease in the back (and sometimes in the threaded collar around the shaft) that give the pot a nice smooth feel and ends up getting washed out with the spray.  And Faderlube doesn't even come close to mimicking the feel.  Its way too thin compared to real grease.  So I prefer a more surgical approach of opening it up, using some 99% IPA on the carbon track, the Deoxit 100% in a needle bottle to put a drop on the metal contact and clean it with a q-tip, and then put a few drops of Faderlube 100% in a needle bottle on the contacts, close it up, and work it around to lube the carbon track.

 

Anyway, after work tonight, I took a look at it.  You do have to dissemble each actuator to get the pot off.  I'll recap it here in the event someone else finds the info useful.  I also found this site that did pictures of a teardown, but with no instructions.  Between these pictures and what I have listed below, it should be pretty self explanitory.  Its not terrible, but not somethign i want to do on a regular basis.  I think it tallk me about an hour and fifteen minutes start to finish.

 

http://www.the-liberator.net/site-files/retro-games/hardware/Apple-iie-iic-joystick/apple-iie-iic-a2m2012-joystick.htm

 

Get the joystick open, and note the resistance on the wiper of each pot to the end with the other wire coming off.  Also make sure your trim adjusters are centered before doing that.  It will be important to know how to get the resting resistance close when the adjusters are in the middle for when you reassemble.  It's just friction fit on the pot shaft, so there is nothing to align it to a particular rotation spot in the pot.  I think mine were right around 48-51k ohms.  Also, take a picture.  In fact, take several as you go through this, so you know how it all goes back together.  Its not rocket science, but it helps you visually double check everything is back together right.

 

Next, remove the buttons and joystick assembly from the top half of the shell.  optionally, you can desolder the wires off both pots and leave the buttons as is in the top half.  In fact, it may be preferable as you could wind up breaking a wire at the solder joint while working on it.  Or drop one of the little springs from the button on the floor, and spend 10 minutes looking for it.  Don't ask me how I know these things.  Remove the 4 screws holding the bottom of the actuator box on, and remove the cover.  You'll see two half circle actuators perpendicular to each other, one passing over the top of the other, with the joystick shaft in the middle.  Lift up the pot that is connected to the actuator on the top.  The two panels it connects to will come up with it, sliding out of a groove in each pillar.  I highly recommend only doing one at a time, so you don't mix up the parts, and have another one to look at if you get stuck.

 

The panel furthest away from the put will just fall off the half circle actuator.  Use a small dental pick or other small pointy object to remove one side of the spring off the centering mechanism.  It will be easier to do this now, rather than once the actuator is off, as the actuator goes through the centering mechanism.  Next, take a small flat blade screwdriver and slide it between where the actuator connects to the pot, and the plastic piece behind it.  Gently work the actuator up off the end of the shaft.  Once you slide it up a little with the screw driver, you should be able to pull it off with your hand the rest of the way.  Slide the two centering mechanism pieces off the shaft.

 

Now you should see a white plastic nut.  This holds the the pot to the large plastic panel.  Remove the nut, and the panel should come right off.  Then you can pull off the centering gear, and the plastic bracket that connects the gear to the pot.  From here, I'm assuming you know how to open and clean a pot out using whatever method/cleaners you prefer.

 

Then just do everything in reverse.  Put the plastic bracket back on the pot, making sure the long piece that sticks out from it is in the same direction as the terminals on the pot.  Putting it on 180 degrees the other way will wind up with you having to disassemble everything and flip it around.  Again, don't ask how I know this.  Attach the adjustment gear to the bracket, and then attach the side panel to the gear.  Thread the white nut back on to the pot.  Place the centering brackets over the pot shaft, leaving the spring loose for now.  make sure your adjustment gear is centered, and your resistance reading on the pot is back to where it was when you started.  Slide the actuator back on the shaft, making sure the actuator is centered with the adjustment screw.  Once it's on, recheck your resistance.  If needed you can use a flat blade screw driver to tweak the pot shaft while you hold all the other parts still to get the proper resistance with everything centered.  Put the other side panel back on the far end of the actuator.

 

Once you have cleaned and reassembled both actuators/pots, put them back into the joy stick bok, paying attention to the orientation, making sure the joystick shaft goes into the slot on the actuator, and noting which actuator is shorter height.  The shorter one needs to go back in first, then the taller one will hover over it.  Put the 4 screws back in through the cover, re-solder any wires you took off, and put everything back in the case and screw it shut.

 

I noticed mine had a lot of black dust floating around inside the joystick housing, and the actuator box.  I took the opportunity to clean that all out, and add some grease to any friction points to help prevent wear in the future.  If you do so, make sure to use a plastic safe grease.  i uses some Molykote 44 medium I had lying around.  Its what a lot of the guys who work on arcade machines use to lubricate their sticks, so I figure it can't hurt.  I applied a thin layer anywhere one plastic face rubbed on another.  I also liberally coated the slots in each actuator so the metal shaft can slide freely without wearing down the plastic as well.  just be careful not to get any on the exposed part of the pot shafts, as the actuator needs to have a a good friction grip on the shaft, and grease could allow it to slip without turning the shaft.

 

Now the joystick feels nice ans mooth, and seems to work right - for the most part.  Thexder and Silphed on my IIgs don't seem to like it, but Gauntlet played fine.  As did several non-gs  Apple II games I threw at it.  And the IIgs diagnostic disk seems to read the values fine.  But depending on which basic program I use to read the paddle registers and peek at the buttons, it sometimes does odd things.  Your basic "print pdl(0), pdl(1), goto 10" loop seems to read everything fine.  but if I use a 9 line program that reads everythign to variables and then print the variables before looping, causes some strange values to appear as I move the stick around (like when I move the X axis about 3/4 of the way to the left, the Y axis drops frorm 128 to 12 even though I didn't move Y).  I'm not sure what the heck is going on.  And as for Thexder and silphed, I have a byte boosters digital to analog board.  They seem to like that no problem.  They just don't like the real joystick for some reason.  I'm open to suggestions on what the heck is going on there.

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nick3092 wrote:Yeah, I know
nick3092 wrote:

Yeah, I know how to spary/flood the pot either through the vents, or through where the terminals stick out.  I just don't like doing it.  There is usually a lump of grease in the back (and sometimes in the threaded collar around the shaft) that give the pot a nice smooth feel and ends up getting washed out with the spray.  And Faderlube doesn't even come close to mimicking the fe

 

You can use carbon conductive grease (I suggest MG) in conjunction with the F5. Dab some in first, spray in the F5, and it will help to push it inward, then give it 100 to 200 rotations while rotating its pitch and yaw, so that you have a gravity assist. 

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