Kansas City Maker Faire: Lawn da Vinci is the Droid You’re Looking For

Summer is now in full swing, which means that mowing the lawn once a week is starting to get old. So why not build a robot do it for you? That’s what [Blake Hodgson] did, and he’s never been happier. It only took him a couple of weeks of quality time at one of the local makerspaces.

[Blake] was showing off Lawn da Vinci at this year’s Kansas City Maker Faire. He had his own booth around the corner from Hammerspace, the shop where it all came together. [Blake] started with a standard push mower from a garage sale and designed a frame around it using OnShape. The frame is made from angle iron, so it’s strong enough that he can ride on the thing. To each his own, we say. The wheels and motors came from a mobility scooter and match the beefiness of the frame. These are powered by two 12v car batteries wired in series. He drives it around his yard with an R/C airplane controller.

lawnmower gutsLawn da Vinci’s brainpower comes from two Arduino Pro Minis and a Raspberry Pi. One Arduino controls the motors and the R/C signal from the remoteThe other runs some extra kill switches that keep the Lawn da Vinci out of trouble.

So what’s the Raspi for? Right now, it’s for streaming video from the webcam attached to a mast on the frame back to his phone. [Blake] says he has had some latency issues with the webcam, so there could be a pair of drone racing goggles in his future. He also plans to add a GPS logger and to automate part of the mowing.

Now, about those kill switches: there are several of them. You probably can’t have too many of these on a remote control spinning suburban death machine. Lawn da Vinci will stop grazing if it goes out of range of the remote or if the remote is turned off. [Blake] also wired up a dedicated kill switch to a button on the remote and a fourth one on a separate key fob.

The Lawn da Vinci is one of many example projects that [Blake] uses to showcase the possibilities of KC Proto, a company he started to help local businesses realize their ideas by offering design solutions and assistance with prototyping. Between mowings, [Blake] puts the batteries on a trickle charger. If you make your own robot lawn mower, you might consider building a gas and solar hybrid.

48 thoughts on “Kansas City Maker Faire: Lawn da Vinci is the Droid You’re Looking For

      1. Aircraft frequencies are reserved for a purpose: stomp on an air control channel and that airplane promptly loses control, almost always crashing. At airfields the channel use is controlled. Some twit a few miles away operating without coordination can easily destroy a plane.

    1. And this is a *consulting business* that’s willfully using aircraft control frequencies without coordinating with other users. That kind of gross negligence can destroy aircraft and potentially cause damage on the ground too. I hope the rest of their engineering is more informed.

        1. (USA-centric, but similar regs exist throughout the civilized world too):

          https://www.fcc.gov/general/radio-control-rc-radio-service
          http://www.rc-airplane-world.com/rc-airplane-frequencies.html
          http://wireless.fcc.gov/services/index.htm?job=service_bandplan&id=radio_control

          And the doozy: 47CFR95 Subpart C,
          http://www.ecfr.gov/cgi-bin/text-idx?SID=8b06a53244abcefc85ac109c6ff26742&mc=true&tpl=/ecfrbrowse/Title47/47cfr95_main_02.tpl

          especially 95.218:
          §95.218 (R/C Rule 18) What are the penalties for violating these rules?

          (a) If the FCC finds that you have willfully or repeatedly violated the Communications Act or the FCC Rules, you may have to pay as much as $10,000 for each violation, up to a total of $75,000. (See Section 503(b) of the Communications Act.)

          Which is why stuff like this exists:
          https://www.amazon.com/Hobbico-72MHz-Frequency-Checker-HCAP0340

      1. From (USA) 47CFR95.207:
        (2) The following channels may only be used to operate a model aircraft device:

        MHz
        72.01 72.51
        72.03 72.53
        72.05 72.55
        72.07 72.57
        72.09 72.59
        72.11 72.61
        72.13 72.63
        72.15 72.65
        72.17 72.67
        72.19 72.69
        72.21 72.71
        72.23 72.73
        72.25 72.75
        72.27 72.77
        72.29 72.79
        72.31 72.81
        72.33 72.83
        72.35 72.85
        72.37 72.87
        72.39 72.89
        72.41 72.91
        72.43 72.93
        72.45 72.95
        72.47 72.97
        72.49 72.99
        (3) The following channels may only be used to operate a model surface craft devices:

        MHz
        75.41 75.71
        75.43 75.73
        75.45 75.75
        75.47 75.77
        75.49 75.79
        75.51 75.81
        75.53 75.83
        75.55 75.85
        75.57 75.87
        75.59 75.89
        75.61 75.91
        75.63 75.93
        75.65 75.95
        75.67 75.97
        75.69 75.99

        1. If you’re wondering why you’re comments didn’t go through immediately it’s because new usernames require a delay and/or moderator approval. ;)

          Multiple links in a post usually do the same thing.

        2. If it’s not a digital PCM one, that’s what you want to get. The olde AM RC radios are verboten to use and the FCC may be looking squinty eyed at the analog FM ones.

          A big benefit of the digital ones is many of them can be programmed for a few to 100+ setups. That way you only need one control unit for all your radio control aircraft, boats and land vehicles.

    2. Could you explain the issue? I’ve no idea what that means.
      Tower Hobbies System 3000 (7 channel)

      Nice lawn bot [Blake], and the website looks good on my mobile device.

      1. Frequency use for RC aircraft is assigned to the 72mhz band, which is about 1mhz wide. When two transmitters are transmitting on the same frequency, it causes whatever model aircraft is flying to stop responding to input, and this is a Bad Thing because it will likely crash the airplane. Because RC aircraft are at higher altitudes, they get much longer line of sight to transmitters, and therefore it’s a Bad Idea to run a 72mhz transmitter willy nilly. I could get away with it out here in the country (probably) but in any densely populated environment, no way. This is why the 75mhz band is designated for ground vehicles, and that’s what should have been used for this.

  1. I’d like to see an actuated boom with a string-trimmer attachment and second camera for trimming. That would really seal the deal for me to drop that kind of investment into mowing the yard.

    1. I’ve thought a lot about this and will probably be my next step. It would be a little tricky to make but totally doable. With as big as this is, it is hard to get into tight corners and along the fence. You can make one like this for $500-$600 if you shop around.

          1. Yes! That would be sweet. Then you could turn them on only when needed to save battery time. You could even rig up a small generator to the engine to help keep your battery charged.

      1. That’s what people dislike about the Neuton electric mowers. The wheels are so far out to the corners that it can’t be used to cut up close along the front or sides. Look at how riding mowers have their blades. Two with a slight stagger fore-aft so they don’t leave an uncut stripe in the middle, or three in a row with the middle one slightly forward.

        You could do that with three smaller blades, one in front and one on each side, then the mower could trim close on the sides and run forward up against things to cut close.

        For more fun and compactness, use chains and sprockets or shafts and gears to keep things perfectly aligned so the blades can intermesh without hitting each other. Can’t do that with belt drives.

    1. The only sheep miniatures I’ve seen recently have been either too plastic or too wooden to help much with the mowing. Besides, what sort of multitudes of miniatures would you need when their stomachs, if they worked, are so small?!

    1. Get a Cheerson CX 10WD-TX micro quadcopter. World’s smallest and cheapest WiFi controlled quad with FPV to a smartphone. The TX has a controller with a phone mount. Under $40. Without the -TX it has onscreen controls for throttle and motion, or motion can be done by tilting the phone. Cheaper than the -TX. Both have an altitude hold function so you can circle strafe around things while recording video.

      Looks like plenty of hacking potential there, even if only for a dirt cheap FPV system to mount onto other things.

  2. Maybe put in a gyro so it knows when it’s upside down or kicked up by something and tries to stop the blade from doing any harm. , and if you add gyro you might aswell add magnetic detection an bury a signal wire around the lawn.

    add a solar panel for partial battery re-gen, add some flashy leds & decals and you got yourself a product.

    1. This thing is so heavy it would take a serious brah, who lifts, to overturn it. It’s not rolling over unless you are sideways at over a 45 degree angle. the solar panel is a good idea but it wouldn’t replenish a fraction of the power it uses.

  3. Any videos of it running and cutting grass? I’m curios how well this handles turning in grass.

    I built a very similar setup with my mower and parts from an old electric wheelchair but ended up going back to the drawing board because of difficulty turning in grass and driving on hills.

    In my experience, with the drive wheels in the back like that and with such a long frame, the wheels need a lot of traction to keep it on course; especially when driving across an incline. The little 10 inch wheelchair wheels slipped to much and I spent most of my RC mowing time fighting to keep it going straight or trying to turn and line up for the next pass. Better wheels might help but I’m curios to know if you found any other solutions.

    1. It does pretty well for traction. the battery packs are right above the the wheels so it has a lot of weight on them. It only slides if the grass is wet. The wheelchair motors I use have a lot of torque so it doesn’t have much trouble climbing little hills.

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