We’ve heard quite a number of radio ads lately trying to sell an automatic lawn mowing robot (like a Roomba for your grass). But wouldn’t it be a lot more fun to hack your own from an existing lawnmower? That’s what [Daniel Epperson] did. In fact, the project has been ongoing for years. But he wrote in to share the latest development which adds solar charging capabilities to the robot mower.
First off let’s discuss the fact that this is not an electric lawnmower. This is the Prius of lawnmowers, bringing together hybrid technology to cut the grass with the gasoline powered motor, and to propel the rig with electricity. [Danny’s] worked hard to shoe-horn just about every feature imaginable (other than autonomy) into the thing, and that’s why the batteries can be charged from mains, an alternator powered by the gas motor, and now from the PV panel mounted on top of it. Get the entire project overview in his roundup post.
This a wireless video feed and the mower is driven by remote-controlled. So you can give your yard a trim without getting sweaty. After the jump we’ve embedded a clip of an earlier revision demonstrating that remote control. If you’re not interest in having all the features you could simply build an analog version.
Continue reading “Solar powered robot mows your lawn while you chill indoors”
Backyard parties are going to rock over at [Effin_dead_again’s] house. That’s because he just finished building this outdoor stereo. It carries its own power supply so you can take it on the road with you, and we don’t think you’ll have trouble hearing it with the 240 Watt amplifier hidden inside.
He shared the equipment details in his Reddit conversation. A 12V lawn mower battery sits in the base of the wooden enclosure. One of the commenters mentioned the dangers of hydrogen off-gassing from that power source, but [Effin_dead_again] thought of that and included venting around the lid. The subwoofer is an 8″ Alpine, and speakers are out of a Hyundai car. The head unit has Bluetooth built in for easy connection to your smart phone. It of course has the ability to play CDs and MP3s too, and we’d bet you can tune the radio if there’s an antenna connected.
Need similar power but a bit more portability? Check out this stereo built into a cooler.
As winter is officially upon us, we’re pretty sure that the last thing most of you are thinking about is mowing your lawn. We would argue that it’s actually the ideal time to do so – that is, if you are interested in automating the process a bit.
[Robert Smith] has spent a lot of time thinking about his lawn, wanting a way to sit back and relax while doing his weekly trimming. He set off for the workshop to build an R/C electric lawnmower, and thoroughly documented the process in order to help you do the same.
On his web site, you will find a series of videos detailing every bit of the solar charged R/C lawnmower’s construction, taking you through the planning phases all the way to completion. [Robert] has provided just about anything you could possibly need including parts lists, schematics, code, and more.
If the short introductory video below has you interested, be sure to swing by his site for everything you need to build one of your own.
Continue reading “Video series shows how to build your own solar-charged R/C lawnmower”
[Dan] wanted to learn a bit about solid state ignition in engines; to get started he needed a test subject, so he decided he would upgrade his old 12 horsepower lawnmower.
Originally the lawnmower engine used a magneto coil ignition system, magnetos are simple and very common in lawnmowers. The magneto is designed to produce a high voltage spike when influenced by a magnetic field. A magnet is attached to the engine’s crankshaft to time the voltage spikes, these spikes are fed directly into the spark plugs to cause ignition, this is why you don’t need a battery. [Dan] explains how the solid state ignition works on his site as he goes through the build details. Essentially it uses a hall effect sensor to detect a spinning magnet on the crankshaft for timing, and a transistor and battery to fire the spark plugs for ignition.
Once he got his circuit up and running on a breadboard, he fitted the entire system into a neat plastic box and fixed it to the front of the lawnmower, as if it was meant to be there all along.
[shadeydave] wanted to build his own Lawnbot, but he had no idea where to start. He purchased some DIY plans online which looked like they would get the job done, but then he strayed from the path in a big way and spent gobs of money in the process.
In his Instructable writeup, he details each misstep he made, explaining why his choices were bad as well as how much each mistake cost him. It sounds like pretty much everything that could go wrong did go wrong, from spending money on unnecessary microcontrollers to choosing the wrong wheels. Our favorite part is where he mentions that he couldn’t figure out how to create a “kill switch” for the Lawnbot in the event that his transmitter loses contact with the speedy whirling death machine.
[shadeydave] is well aware of how poorly his build went, and primarily wrote it up as a cautionary tale to others out there who might decide to take on a similar project. He says that the Lawnbot works for the most part, but with his newfound wisdom he will be revising the bot, having learned from his mistakes.
We actually like to see this kind of writeup as they can be quite beneficial to someone trying to put together a similar project. So if you have some major flubs under your belt, don’t be shy about digging them out and letting us know. As Thomas Edison said, “I have not failed. I have just found 10,000 ways that won’t work.”
Continue reading to see a quick video tour of [shadeydave’s] mostly working Lawnbot.
Continue reading “How not to build a robotic lawnmower”
[phantompinecone] has an electric mower that worked great for about 4 seasons, and then the battery started to die. A replacement was installed but it started being a pain after the first season. Since the battery was brand new (and probably costly too) there must be something else.
Checking the brushes, which were fine, the next logical place was the switch.These mowers are just a battery, motor, and switch. Yanking it apart there was indeed a problem, they were chewed up and corroded, not allowing full electrical contact. So [phantompinecone] replaced the simple mechanical switch with a MOSFET.
Electrically there is an IRF1405 MOSFET, some resistors to pull signals around and a couple diodes to A) keep the back emf from the motor in check, and B) drop the voltage going into the fet from 24volts to 12. Problem solved, and the motor should not have anymore trouble caused by a junked up switch.
There’s the quiet serenity of paddling through the backwoods in a canoe, and then there’s this. It’s a lawnmower motor powered canoe that comes complete with steering wheel, throttle, and a stereo system. To keep the craft balanced the driver rides in the front seat while the motor is hanging off the stern of the boat. The biggest trick is not swamping the thing while getting the motor running, but future plans do include adding an electric starter. There is a kill switch for safety and it appears that top speed will not cause any stability issues. It’s hard to tell for sure from the video after the break, but it sure does seem to be loud!
Continue reading “Giving a canoe lawnmower power”