There’s a bunch of different electric scooters available nowadays, including those hoverboards that keep catching fire. [TK] had an older Razor E300 that uses lead acid batteries. After getting tired of the low speeds and 12 hour charge times, [TK] decided it was time to swap for lithium batteries.
The new batteries were sourced from a Ryobi drill. Each provides 18 V, giving 36 V in series. The original batteries only ran at 24 V, which caused some issues with the motor controller. It refused to start up with the higher voltage. The solution: disable the safety shutdown relay on the motor controller by bridging it with a wire.
With the voltage issue sorted out, it was time for the current limit to be modified. This motor controller uses a TI TL494 to generate the PWM waveforms that drive a MOSFET to provide variable power to the motor. Cutting the trace to the TL494’s current sense pin removed the current limit all together.
We’re not saying it’s advisable to disable all current and voltage limits on your scooter, but it seems to be working out for [TK]. The $200 scooter now does 28 km/h, up from 22 km/h and charges much faster. With gearing mods, he’s hoping to eke out some more performance.
After the break, the full conversion video.
Continue reading “Converting an Electric Scooter to Lithium Batteries and Disabling the Safeties”
Hackaday contributor and new homeowner [James Hobson] had a dilemma on his hands. He had rented a commercial drum sander to begin a floor refinishing project. Like many before him, James was a bit too aggressive with the drum sander in places. The uneven stripes didn’t show up until the sander was returned and the floor was stained. Renting the sander again would be an expensive prospect. There had to be a better answer…
That’s when [James] put on his [Hacksmith] cape and got to work. He built himself a DIY floor sander (YouTube Link) using four Ryobi orbital sanders, some scrap wood, and a bit of ingenuity. [James] screwed the four sanders to a plywood sub plate, then added a top plate with a handle. He even gave the sander its own outlet strip so he wouldn’t be dragging four power cords behind him.
[James] found that synthetic steel wool pads weren’t cutting through the floor very well, so he upgraded to 220 grit sandpaper. That did the trick, and the sander worked great. Now he won’t have to rent a drum sander when it comes time to refinish the first floor of his new house!
Continue reading “[James] and the Giant Floor Sander”
[Don Eduardo] took matters into his own hands after experiencing a days-long power outage at his house. And like most of us have done at least one, he managed to burn his fingers on a regulator in the process. That’s because he prototyped a way to use power tool batteries as an emergency source — basing his circuit on a 7812 linear regulator which got piping hot in no time flat.
His next autodidactic undertaking carried him into the realm of switch-mode buck converters (learn a bit about these if unfamiliar). The device steps down the ~18V output to 12V regulated for devices meant for automotive or marine. We really like see the different solutions he came up with for interfacing with the batteries which have a U-shaped prong with contacts on opposite sides.
The final iteration, which is pictured above, builds a house of cards on top of the buck converter. After regulating down to 12V he feeds the output into a “cigarette-lighter” style inverter to boost back to 110V AC. The hardware is housed inside of a scrapped charger for the batteries, with the appropriate 3-prong socket hanging out the back. We think it’s a nice touch to include LED feedback for the battery level.
We would like to hear your thoughts on this technique. Is there a better way that’s as easy and adaptive (you don’t have to alter the devices you’re powering) as this one?
Continue reading “Emergency Power Based on Cordless Drill Batteries”
[Brett Graham] and [David Cox] are taking the Kinect out into the world thanks to this handheld hack they call the Drill of Depth. Apparently, the Kinect wants 12V at 1A which is quite easy to provide with a rechargeable power tool like this Ryobi drill. The setup features a 4.3″ touchscreen display, connected to the Gumstix Overo Air that is running Linux. They claim that there’s a “legitimate scientific reason” for building the device but they’re not sharing it yet.
So what would you use this for? We wonder if it would be possible to roll a GPS into the mix, then use post processing from the captured data to recreate the environment in a virtual setting? Imagine if a weekend spent walking around campus and processing the results let you model your University and make it an add-on level for your favorite game. Or perhaps this could be paired with a regular camera to generate high-quality 3D skinning data for Google Earth. That’s what we came up with, what do you think?