Motor Case for Mabuchi 775, Ryobi saw motor

thingiverse

If you're looking for a small electric motor that packs a lot of punch, this setup won't break the bank. In fact, it's surprisingly inexpensive. You can score an 18V, 5 1/2" trim saw from Ryobi - specifically the R10633 model - on eBay for around 20-25 bucks. Inside that saw lies a powerhouse: the Mabuchi RS-775WC-8514 motor, which is available new for $50-$70 without the gearbox. Since you get the gearbox and motor case with the saw, use them to pair with your own custom-made 3D printed casing. Ryobi's gearbox boasts extremely durable 9-42 tooth gears that'll hold strong against high loads. Plus, the motor output shaft measures a spacious 10mm - large enough for either a 3/4" OD flexible coupler or ServoCity's 10mm set-screw hub to fit snugly on top. Don't overlook the massive 6000Z ball bearing installed in the gear case output shaft; this little gem will easily integrate into your custom-printed housing. Speaking of specs, let's get down to brass tacks: the Mabuchi RS-775 motor puts out an impressive 1561 g-cm at 17,040 RPM on a mere 18Volts - that's a full five times more than its predecessor, the RS540. What's more? This monster motor will work perfectly well under voltage ranging from 6-20 volts. However, pairing it with the Ryobi gearbox results in a drastically different dynamic. The gear reduction effectively slows down the RPM to an astonishing 3651 and more importantly bumps torque up to an impressive 7285 g-cm - essentially doubling the raw power! Feel free to dial back further, though: the motor still delivers robust performance even after multiple gear reductions. In fact, the spec sheet can be perused in all its glory over here. For visual reference, consider the illustration which juxtaposes four motors together: a Titan RS-550 takes center stage, with a smaller 370 and a rather petite RS540 in tow - all this amidst the lumbering behemoth that is the RS775 motor. One look says it all: these are titans. To attach your Ryobi casing securely to its printed counterpart, simply drive eight 3/4" sheet metal screws home firmly - no messing around. There are actually two types of gearbox mounts here, offering users options: either a bottom-mount that employs a generous 2.5x0.625 bolt pattern or the simpler (yet more straightforward) option which directly connects to the output shaft side. Needless to say, when these guys were originally earmarked for a custom Cat bulldozer project of epic scale (yes, you guessed it: 1/6th that massive machine in RC form!), they just wouldn't fit - an unyielding obstacle the maker didn't care to address with makeshift solutions or any of the like. They instead adapted on their own. While it's all fun and games building DIY projects around this beast of a motor, remember you need one that packs sufficient power - and that would be anything over 12V. Using these guys under such low voltage may sound thrilling at first, but really you should aim to use them where they belong: cranked up all the way! One possible catch: to properly govern its performance in robotized systems or perhaps large scale vehicles (especially if they pack a whallop like your RC bulldozer does), a dedicated motor speed controller might have to be employed that supports up to 30A load current. After all, no child should ever, for their safety and for everyone's, go near any whirring parts of machinery unless completely out of range. That pinch point - now there's where things get interesting: always beware that point around the motor gears and other spinning bits or just be careful when plugging away with this mighty machine in your next maker project - and most certainly have loads of fun at all costs!