Billiard Ball Finds A New Home In Custom Trackball Mouse

They walk among us, unseen by polite society. They seem ordinary enough on the outside but they hide a dark secret – sitting beside their keyboards are trackballs instead of mice. We know, it’s hard to believe, but that’s the wacky world we live in these days.

But we here at Hackaday don’t judge based on alternate input lifestyles, and we quite like this billiard ball trackball mouse. A trackball aficionado, [Adam Haile] spotted a billiard ball trackball in a movie and couldn’t resist the urge to make one of his own, but better. He was hoping for a drop-in solution using an off-the-shelf trackball, but alas, finding one with the needed features that fit a standard American 2-1/4″ (57.3 mm) billiard ball. Besides, he’s in the thumb control camp, and most trackballs that even come close to fitting a billiard ball are designed to be fiddled with the fingers.

So he started from the ground up – almost. A 1980s arcade-style trackball – think Centipede or Missile Command – made reinventing the trackball mechanism unnecessary, and was already billiard ball compatible. [Adam] 3D-printed a case that perfectly fit his hand, with the ball right under his thumb and arcade buttons poised directly below his fingers. A palm swell rises up to position the hand naturally and give it support. The case, which contains a Teensy to translate the encoder signals into USB commands, is a bit on the large side, but that’s to be expected for a trackball.

Still curious about how the other half lives? We’ve got plenty of trackball hacks for you, from the military to the game controller embedded to the strangely organic looking.

38 thoughts on “Billiard Ball Finds A New Home In Custom Trackball Mouse

  1. I guess I’m a member of the “dark side”, as I far prefer a thumb trackball as a gaming controller. My “daily driver” input device, though, is a trackpad, but those are useless in FPS games and many other types.

      1. Elecom makes one. I expect it would track better after a ball-swap, though. I have both sizes of their finger operated versions, and the dark silver ball on the small one is not very good. I replaced it with a red one, and it works great.

      2. I want Microsoft to bring back their Trackball Optical 1.0, but with silicon carbide bearing points instead of steel. That was their weak point, it was vital to never use those with a dirty hand and to frequently pop the ball out to clean it and the bearing points to slow down the wear.

        For a while several people were charging as much as $60 to fix them by somehow extracting the little flat spotted steel balls and replacing them with silicon carbide *like every other trackball* had.

        The thumb ball version had a huge number of returns due to an assembly issue. The transistor driving the sensor LED was in a position where rough handling assembling the case would break one or two of its connections. Unfortunately they were made in the time when optical mice and trackballs just *had* to have an “I’m optical!” illumination LED. So the damage went un-noticed on the assembly line during the power function test. Plug into a USB power socket, an LED lights, but not the one that actually does anything, so down the line it would go as “good”.

        I’d hope that at some point someone caught on to the problem and instructed the testers to not simply look for *an* LED to light when plugged in, but to also *move the ball* and check for a *brighter* illumination.

    1. I’ve been using the same Microsoft Optical Trackball (thumb version) for 18 years and I don’t think I’ll ever be able to give it up. They save on desk space, wrist strain and just feel nicer than a generic oval mouse. Last I looked on Amazon and eBay, in box units were going for $100-$400!

      1. Have you had the steel bearing points replaced with silicon carbide? Or do you just obsessively wash your right hand before you use the trackball? ;)

        I mainly use an M570 but I also have a MTO1.0 I like better, and obsessively wash my hands before using it and very often pop the ball out to clean the bearings to try and prevent them from flat spotting.

    2. Eww.. thumb trackball users!
      I’m going to stick to my Kensington SlimBlade, still not sure I like it as much as their Expert Mouse trackball that I used for 10 years before the rubber on the scroll-ring fell apart(The ball still works great!)..
      I got into these as all the thumb ones I could find had the scroll-wheel-middle-button problem normal mice have and they have been a worthy addition to my computer.

      1. I’ve had that problem with the wheel click also and opened a bug in libinput. it would be easy to fix for them, just discard hardware wheel events when middle click is held. the dev declined though as nobody else requested it he didn’t want to break userspace.

  2. Quite some time ago, leading up to, and after, my elbow surgery, at the doc’s recommendation, I switched to a trackball. I had the Logitech Trackman Optical Wireless … I loved that thing. So much so, that at the next gig, I made them buy me one.

    Sadly, it’s out of production now, and it eventually wore out.

    1. I’ve used an old wired one for years (still on sale on ebay btw) and found it immensely more comfortable than the mouse. Then more and more applications started using the middle button plus scrollwheel, and I had to switch back to the rodent.
      After recently developing some wrist pains I’m considering to buy a new one as I gave the old one away, but I can’t find an equivalent with the same form factor (symmetric) plus support for the middle key without remapping it to a side button or elsewhere.

  3. Trackballs predate mice by a very long way. They were used post-WW2 for radar and missile tracking systems. I seem to remember one system using a much larger ball – like five inches diameter. It provided the “give it some angular momentum, start it rolling and apply brakes when you arrive at the destination” kind of action.

    1. Here’s one in an AN/FYQ-47 radar digitizer console: (1970s). This was in the computer room, but there was also the same trackball on the console that sat in front of the height-finder displays in the operations darkroom. They were used to update the positions of aircraft in 3D space – the trackball moved a full-screen ‘+’ cursor on the radar display itself. We also used them in the FYQ-9, but I can’t find a picture of that one. Both of these were massive, and like you said, start it rolling, and stop it when it gets where you wanted it to go.

        1. Now you have me thinking how much more awesome it would be if they were set on pedals too.. Not quite sure how you would use all the axis.. or how useful foot operated would be, but damn if it doesn’t sound like fun. Perhaps use them as a keyboard in similar fashion to the steam controllers trackpads in steam..

          1. *rainbowhands* accessibility. if someone has limited hand dexterity, the feet are available and generally unused. I can see a bowling-ball sized trackball being able to get fine movement control with the toes. so much inertia, it’s slow to start and slow to stop, so you could get it to cruise nicely

  4. That is a beautiful build, the printed case looks very slick! This reminded me of my own billiard ball trackball effort from about 36 years ago…
    Way back in 1982 or thereabouts a high school friend and I really wanted some exotic peripherals for our Apple ][‘s (his was real, I had a taiwanese clone) but the cost of the trackballs and mice we drooled over in US computer magazines were way out of reach for us, so we set about building our own.
    I had access to lathes and a workshop, and some junked IBM equipment, and my friend was a genius at 6502 assembly. Using a homemade dividing head I drilled some ballraced aluminium pulleys for the LED/phototransistors.
    We had no idea of what the mechanism in a trackball was actually like so we did four wheels contacting a pool/billiards cue ball (that cost a bit of pocket money at a sports store).
    The case for the unit was made from a highly prized sheet of styrene which was a cigarette advertisement another schoolfriend gave me from his parents’ milkbar. I also machined another set of rollers from al bar stock and scrap pieces of al angle. I think the smaller rollers in the photo might be from a Selectric platen paper holder. The al plate at right is from one of a number of unfinished mice attempts,this one using two discs at 90 degrees.
    We also built a VersaWriter that actually worked but not very accurately as we did not use wirewound pots, only cheap carbon ones, I recall the drawing code was in Applesoft Basic and a bit slow when calculating the trig.

    1. BTW the second ball was for the later v3 version, parts at right. The four rubber platen rollers were held in milled aluminium support brackets and encoder wheels were to go on the shafts extending outside of the bracket. The larger-than-needed holes for the opto’s came about because that was the smallest unbroken drillbit I could lay my hands on that day :)

    2. Thanks! And thanks for sharing yours! That was certainly quite an impressive build… I had it way easier in comparison. I mean, heck, the microcontroller I’m using to provide the USB Mouse interface is powerfull enough that I could likely emulate an entire Apple II on my mouse controller :P Funny how far things have come :)

  5. my last search for trackball modules was somewhat fruitless, sure you could get the blackberry trackball breakout or one of those huge arcade trackballs, but if you want something specific, like a one inch ball, you are sol. id have preferred a slightly larger trackball module, as well engineered as the bb ball is, its kind of small. not quite what i wanted for my raspi tablet.

  6. The original Kensington Expertmouse fit a standard size pool ball just fine. Predictably I wan an 8-ball in mine. The pool ball was heavier and thus was more precise under my slightly heavier touch because I didn’t overshoot all the time. I keep wondering if the current Expermouse will fit a snooker ball as I think the dimensions are very close.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.