Anything special about trackball bearings?

[BadMouth]

Someday I want to add a trackball to my cab but don't think there is enough room inside the CP for a standard one, not even a 2.25".
I was thinking of designing and 3D printing my own trackball setup to fit the available space.  I have an Opti-Wiz and some high end optical encoders in the parts bin.  Have a cue ball for testing, but would buy a red bumper pool ball if things work out.
The issue is that the optical encoders use a 6mm shaft which I also have on hand.

I was ready to order some 6mm ID bearings to play around with and test the encoders, but then started to wonder if they are going to spin freely enough for the smooth ball to turn them.

Do trackball bearings have lighter grease or is anything else different to give them less resistance than a regular generic bearing?

[MartyKong]

While I can't answer all your question - When I took apart and cleaned my trackball, I added a little 3 in 1 household oil and it seemed to help.

[Fursphere]

My original cabinet had the same problem - control panel wasn't big enough for a normal trackball.   I ended up making the control panel bigger. 

I've got a 3" Happ trackball sitting in a box if you want me to open it up and check anything out for you.   I don't recall anything special about the bearing.   (My current cab uses a Ultimarc trackball that has a smaller footprint than the Happ trackball due to the large square top mount plate the Happ uses)

[lilshawn]

i soak the bearings in WD40 then work them a bit, the soak them some more in some clean WD40. blow them out with compressed air, then let them dry. a drop of light machine oil on the hub part to get it behind the shield, and they spin good as new.

a few drops of the silicone spray on a paper towel rubbed over a cleaned trackball and put all back together again... works like brand new again.

[nitrogen_widget]

i bought new bearings with no shields to replace some extremely crusty and frozen bearings on a 3" arcade ball from ebay
they were all rusted and frozen up.
the roller was pretty rough also.
there were mud daubers in the screw holes on the bottom.
it was filthy.
but really cheap.

I got the new bearings, read here to soak in wd-40 then use a drill bit with duck tape on the tip to spin the bearings like crazy with a drill motor to loosen them up, then 3 in 1 them.
so i did that.

i also put the roller in the drill like a bit and wet sanded it smooth by spinning it while holding sand paper wrapped around it.
i started with a more aggressive grit and worked it smaller.
the shafts still had the bevel worn in from the ball but it seemed to spin smoothly and for a bit like it's supposed to once put back together.
never actually used it though to play anything.

[Xiaou2]

Many bearings come with a heavier grease that makes too much resistance to the Trackball movement.

 Get a spray bottle of  "Electronics Cleaner"  from an Automotive store.

 Place a bearing on a clean surface, and spray at close range, using the small Extension-Tube that comes with the spray can.

 Now pick up the bearing between your fingers, and Free-Spin it for 60 seconds.

 Flip the bearing over, and repeat the process.

 If needed, repeat this once more, on the same side that you just did.


 Electronics cleaner easily flows into the Bearings (even bearings with covers on them)... eats the Grease,
and then Evaporates without any Residue left behind.

 If you want, once the Bearings are fully dried internally (wait a day, or use a heat gun / oven)  You can apply some
3-in-One oil  (a very light and fluid oil).   That will help protect the bearings from rust / corrosion, and give it enough protection
for typical gameplay usage.


 I personally do Not recommend using WD40.  I tried soaking some dirty rollerblade bearings... and it just ended up making things
even worse.


 As for the Bearings themselves...

 Ive noticed a huge difference in Rollerblade bearings.  The lower tier bearings have a LOT more friction... and require a lot more work
to get going + keep momentum.   The differences are in the accuracy and tolerance specs... and it really does make a huge difference.
Meaning... its well worth the extra money for higher quality bearings.

 As such... we have no way of telling what quality / rating of bearings you might intend to be using... and to what degree that may
impact the trackballs sustained free-rolling spin.

[lilshawn]

the shafts still had the bevel worn in from the ball

this is how they should be. this is common to some of the early trackballs. it's intentional. if you place a round ball on a flat ground shaft, there is only the tiniest of points touching it. it makes it very hard for the ball to "grip" the roller to spin it. so a bevel is carved out in the roller to provide a larger surface area for the ball to grip.

they used to make the area be REALLY deep, but in more recent rollers, it was reduced, and in modern ones it's almost non-existent... but it's still there.

also i wouldn't recommend to sanding the rollers, as they should be plated. (if not they are very old and should be replaced.) the chromium layer provides a nice hard surface for the ball and has less friction overall to keep the ball from being damaged. I know it sound counterintuitive to want to provide more traction by carving a bevel in the roller only to chrome plate it and make it more slippery... but it's more for longevity of the parts.

sanding them will only serve to introduce corrosion.

[BadMouth]

Thank you to everyone that responded.  Seems open cage ones in that size are fairly expensive.  For now I'm just gonna order some cheap ones and hopefully pop the covers off.
Even if the cheap ones turn out to be crap, I need them to verify the encoders work. 
A pack of 100 seems to only cost a few more bucks than 10 or 20.     Seems I have to find more uses for this size.

[nitrogen_widget]

the shafts still had the bevel worn in from the ball

this is how they should be. this is common to some of the early trackballs. it's intentional. if you place a round ball on a flat ground shaft, there is only the tiniest of points touching it. it makes it very hard for the ball to "grip" the roller to spin it. so a bevel is carved out in the roller to provide a larger surface area for the ball to grip.

they used to make the area be REALLY deep, but in more recent rollers, it was reduced, and in modern ones it's almost non-existent... but it's still there.

also i wouldn't recommend to sanding the rollers, as they should be plated. (if not they are very old and should be replaced.) the chromium layer provides a nice hard surface for the ball and has less friction overall to keep the ball from being damaged. I know it sound counterintuitive to want to provide more traction by carving a bevel in the roller only to chrome plate it and make it more slippery... but it's more for longevity of the parts.

sanding them will only serve to introduce corrosion.

Learned something new.
Thanks
Makes sense, I wondered how the ball grooved solid steel.
Actually I feel dumb now thinking about.
lol

[lilshawn]

A pack of 100 seems to only cost a few more bucks than 10 or 20.     Seems I have to find more uses for this size.

i made the kids "fidget spinners" out of my old ones back before fidget spinners were cool. but that ship has LONG sailed... you gonna have to figure out your own thing. 

[Xiaou2]

Thank you to everyone that responded.  Seems open cage ones in that size are fairly expensive.  For now I'm just gonna order some cheap ones and hopefully pop the covers off.
Even if the cheap ones turn out to be crap, I need them to verify the encoders work. 
A pack of 100 seems to only cost a few more bucks than 10 or 20.     Seems I have to find more uses for this size.

 You shouldnt need to pop off the covers.  In fact, you would might even end up damaging the bearing, while trying to do so.
(smaller bearings are more likely to suffer from stress related damages, due to thinner metal wall-thickness)

 Electronics cleaner will easily flow past the typical bearing coverings, because they are rarely ever sealed  "fluid-tight".
3-in-one oil, will also easily work its way past the bearing covers, in a very short amount of time (no need to soak overnight).

 You also really do not want to run your bearings "open-air", because dust and crud will eventually get inside of them.. and will start
to cause uneven friction and potential damages to the inner Races... and the bearing holders.


 If you put most of these sealed bearings into water... the water would easily flood into them, and start rusting them up internally.
Now... They probably make bearings that are completely fluid sealed.. but Im certain that they would be MUCH more expensive,
and it would Note it on their description.   They would likely need to have a special sealant, maybe similar to silicone, applied to the
Side-Caps.. and if you broke these seals, you would permanently damage their effective seal.. unless re-sealed with the same sealant.

[Xiaou2]

As for the Bevel comment...

 Trackball Rollers can and DO suffer metal wear damages.   Once they get worn past a certain degree... they no longer function properly, and the rollers
will need to be replaced.

 The thing about a trackball... is that it operates at a set vertical height, and in specific distances.  When the trackball rollers start to wear down.. that
height changes... and so does the spacing between each of the rollers, and the single 3rd bearing.

 This alters the way the ball sits, and rolls... as well as introduces "Play".. where the ball can come up off of the rollers... temporarily losing tracking.

 To help prevent Premature roller damages... clean the Ball and Rollers on a regular basis.  Stuff that gets onto the ball and rollers can end up causing
uneven friction, and helping to cause much faster wear.

 The bearings themselves, should also be free-spinning... and if and when they start to wear down.. should also be swapped out..  as bad bearings
will also speed up ball and roller wear.


 Ive had a few used trackball assemblies that had badly worn bearings, as well as severely worn rollers.  There is no repairing them... outside of replacing the
rollers and bearings.

[BadMouth]

Finally got around to messing with this.

WD40 and Contact Cleaner did not loosen them up very well, even with days of soaking because I forgot about them.
I popped the dust cover off one and saw it was still packed with thick blue grease, so moved on to a degreaser.

Dropped them in a container with some Simple Green and shook them for about a minute.
Half of them spun freely after that.  The other half needed a couple more rounds with clean Simple Green.

So....Simple Green is the definitely the way to go for de-greasing bearings.

Followed the simple green with contact cleaner (which I'm pretty sure was mostly acetone), then a drop of 3-in1 oil.

[lilshawn]

i should have probably mentioned when I soak in wd40, i do so in a sealed container. i use a small glass jar. aerosol wd40 has a solvent that evaporates fairly quickly. if left open, all you end up with is a thin oil. it's the solvent that does the work.

but you can use your own choice of solvents... paint thinner, varsol, acetone, etc.

[Xiaou2]

Those must be some very heavy duty bearings.   Things like Rollerblade bearings, tend to use much less / thinner grease... thus
they are much easier to strip / remove.