Jess Ragan Posted April 21, 2017 Share Posted April 21, 2017 I've been thinking of taking an old USB mouse and turning it into a trackball. Right now I'm considering my options for giving the ball a friction-less spin. Metal rollers seem to be what most people use, but the ones especially designed for arcade trackballs are really expensive. I can't really justify paying $40 for something like this. http://www.ebay.com/itm/2-1-4-Trackball-Repair-Kit-Arcade-Games-/261456125394?hash=item3cdfffddd2:g:YnUAAOSwT6pVrw9j Do I have other, more cost-effective options? Would I be able to just stroll into a hardware store and pick up shafts, bearings, and rollers which could be used for the same purpose? Quote Link to comment Share on other sites More sharing options...
BigO Posted April 21, 2017 Share Posted April 21, 2017 I've kicked around thoughts about a project like this: Skate wheel bearings are pretty cheap. Most bearings I've seen in a store have a fairly heavy lubricant installed and don't spin freely but that can be overcome with some work. Skate bearings tend to be sealed though which makes them harder to spin and nearly impossible to wash the lubricant out of. As for the rollers, there are off the shelf spacers that you might be able to trap onto a piece of threaded rod (appropriately sized for the bearings) with a nut on each end to create the larger diameter roller. They tend to be mild steel but you might find some stainless ones. Getting something like that precisely centered about the rotating shaft might tricky. A threaded standoff might be a better bet for centering on a threaded rod. That might also let you get away with just one jam nut to build the roller assembly. A drill bushing will likely be more precise, but might put you back into the $ territory that you don't want to be in. Check out McMaster-Carr at least as a reference. Spacers: https://www.mcmaster.com/#spacers/=17ala44 Quote Link to comment Share on other sites More sharing options...
Jess Ragan Posted April 23, 2017 Author Share Posted April 23, 2017 I've done some research on this, and it sounds like some folks have had luck setting the trackball on a triad of smaller balls. The balls are held inside a trap with half of each exposed, kind of like a ballpoint pen or a bottle of Ramune. They're set in a triangle formation, letting the trackball spin freely while holding it in place. I'm going to look into this... it sounds like my best bet. I'll have to source some marbles or something for this experiment, though. Quote Link to comment Share on other sites More sharing options...
BigO Posted April 23, 2017 Share Posted April 23, 2017 How do you detect the motion in that setup? By "old usb mouse" do you mean the kind with quadrature encoders? Or is it an optical mouse with its sensor trained on the moving ball? Keep us posted as you progress. Quote Link to comment Share on other sites More sharing options...
Jess Ragan Posted April 23, 2017 Author Share Posted April 23, 2017 This is how this guy did it. https://deskthority.net/workshop-f7/custom-trackball-t4773.html I'm trying to filch some bearing balls from old equipment, but it hasn't been going so well... I may have to just bite the bullet and buy some from eBay. I guess small marbles might work in a pinch. Quote Link to comment Share on other sites More sharing options...
BigO Posted April 24, 2017 Share Posted April 24, 2017 It can't be terribly hard to find some ball bearings. A small, independent bicycle repair shop might have old ones laying around. Maybe you can find some old skates or power tools at a yard sale or thrift store. An old drill maybe: I believe I remember an old Black and Decker drill I once dismantled having ball type thrust bearing. Quote Link to comment Share on other sites More sharing options...
Jess Ragan Posted May 2, 2017 Author Share Posted May 2, 2017 (sigh) I wussed out and got a cheap trackball on eBay (a Kensington Orbit with Scroll Wheel) instead. It wasn't JUST that I wouldn't be using it that much, or that the parts for a homemade trackball would cost as much as getting one used. It was the fact that I don't have a lot of confidence in my craftsmanship after my spinner unexpectedly died on me. I spent a weekend trying to get it to work again, to no avail. I'm not even sure what went wrong... my guess is that the plastic container I used sagged just enough to keep the laser mouse from working properly. I hate having to work within a tolerance of a millimeter or less. Things have to be PERFECT, or they just won't work. Is there a way to strengthen the lens in a laser mouse, so things don't have to align so damned precisely? Quote Link to comment Share on other sites More sharing options...
Keatah Posted May 3, 2017 Share Posted May 3, 2017 Damnn!! Every time I see this thread title in the summary I can't stop remembering this.. Quote Link to comment Share on other sites More sharing options...
Keatah Posted May 3, 2017 Share Posted May 3, 2017 (sigh) I wussed out and got a cheap trackball on eBay (a Kensington Orbit with Scroll Wheel) instead. It wasn't JUST that I wouldn't be using it that much, or that the parts for a homemade trackball would cost as much as getting one used. It was the fact that I don't have a lot of confidence in my craftsmanship after my spinner unexpectedly died on me. I spent a weekend trying to get it to work again, to no avail. I'm not even sure what went wrong... my guess is that the plastic container I used sagged just enough to keep the laser mouse from working properly. I hate having to work within a tolerance of a millimeter or less. Things have to be PERFECT, or they just won't work. Is there a way to strengthen the lens in a laser mouse, so things don't have to align so damned precisely? You're going to have to play with the optics. I'm not an expert here, so I couldn't tell you what kind of lens to use. Maybe something from a garage door opener sensor assembly or something from an educational optics kit? Other things like replacing the photodiode and photodetector are also possibilities. You might need to re-do the front end circuitry if you go that route. Either that or you'll need to use heavy enough metal that doesn't sag. Quote Link to comment Share on other sites More sharing options...
Jess Ragan Posted May 3, 2017 Author Share Posted May 3, 2017 I was thinking about that. Problem is, heavy metal is THICK metal, and it's difficult to cut. There might not be enough room there for the bottom of the VCR head to spin, either. I've considered my options, but at the moment the dial is on the backburner. The trackball isn't IDEAL for playing brick breaker games, but it's better than a joystick. Quote Link to comment Share on other sites More sharing options...
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