Remote-Operated Gate On A Budget

Sometimes, a simple fix is the best solution. Lacking extra funds for a proper remote-controlled gate-opener after the recent purchase of their farm, redditor [amaurer3210] built one as a birthday gift for his wife.

Supported on pillow block housings, a 10″ wheel is connected to the motor by via a 3D printed pulley and a timing belt turned inside-out to allow for slippage — in case of obstacles or manual opening of the gate. If you’ve ever worked with belts in your builds, [amaurer3210] adds that during sizing he uses a few layers of fiberglass tape as a stand-in for the belt to avoid frustration over final belt size and tension.

The motor is a a cordless SKIL drill motor, perfectly suited to the purpose with its low-rpm, high-torque planetary drive. Making heavy use of his 3D printer, the motor, a homemade wire-wound resistor (to step down the 12V power supply to 3V for the motor), and an eMylo 12V wireless wireless relay cheaply acquired online are all mounted with printed parts — as well as the housings, pulleys and brackets — in ABS plastic to avoid softening in the day’s heat. Perimeter security is maintained via a gate latch controlled by a solenoid wired in parallel with the motor to unlock when the motor starts.

A bungee acts as a tensioner to keep the wheel pressed against the ground while also allowing it to roll over obstacles. The simple ‘hold open until the gate is open and vice-versa’ remote operation completes a build that needs no extra flair to be effective.

Looking to facilitate other outdoor activities around the homestead? How about a remote-controlled lawnmower.

[via /r/DIY]

30 thoughts on “Remote-Operated Gate On A Budget

    1. No, it complies with UL-325 Class 1 Type A D
      Class 1 – Residential
      Type A – Belt acting as a slipper-clutch
      Type D – Remote needs to be pressed for the duration of opening/closing.

  1. Homemade wirewound resistor to step down 12V to 3V? Congratulations on getting the job done but surely there was a more efficient way?

    Generally motors can be driven by higher voltages as long as you don’t exceed the insulation rating. The main thing that kills them is heat in the winding created due to high current and ultimately high torque. Because thermal effects take time, brief overloads of 300% are often fine.

    Chances are with a different pulley ratio you could have run at 12V without an issue.

    1. P.S. – using a resistor to drop voltage on a variable load like this can also be counter productive. The resistance causes a drop based on current, so when the motor sees heavy load and needs to overcome it with higher torque, larger voltage drop is generated. This can lead to the motor stalling and being subjected to even higher currents for longer periods.

      It seems counter-intuative but underpowering a motor can often be worse than overpowering.

    2. Well that depends on how you define a “better way”.

      As for reliability, a string of nichrome (or fencing wire) wrapped into a loop, what could be more reliable. No thermal run away. Low temperature coefficient. Robust connections unlike die wires of a FET. Excessive current carrying capacity to handle any probable fault modes. And if it ever did fail well just go grab some more fencing wire!

      Someone also suggested running the motor at the higher voltage with a different gear reduction. Well to do that you have to through out the reduction gearbox conveniently attached to the motor because it was a battery drill and build a new gearbox, then you have issues of the momentum of the fence gate once it get moving so you may need to add a breaking system.

      I like what he has done. It simple, succinct, reliable until the wheels fall off literally, was easy to put together with some carefully selected used and now recycled materials along with some 3D printing and he has done this with a minimal effort and didn’t try to re-invent the wheel along the way.

      This *IS* a hack!

  2. 4 series resistors is how Jeep would regulate the speed of the fan motor for its air conditioner / heater in 1996 to 2006 model Jeeps.

    Because there isn’t a cheaper way to do it.

  3. What I hate the most on HaD: Un-informative article, cluttered by TWO huge GIFs (why two?) to obfuscate its vacuity, and no proof-reading: “connected to the motor BY VIA via a 3D printed pulley”.
    One good point, though: there is no click-bait title.
    Yep, WTF Hackaday ???

  4. Regarding the project… nice, very nice.

    Regarding the animated gifs: the size isn’t the problem for me (but I can understand people complaining about it)… it is the repetitiveness (and the annoying jump in time when it finishes in order to start over again… and again… and again). And then 2 of them… very large ones. It distracts heavily when I’m trying to read the text close to it. Why?!?!? When does the hurting stops? Animated gifs are nice for dancing bananas and that sort of thing no for filling my screen.

    1. My netbook and I both thank you. Crashed the tab /twice/ in Chromium last night.

      For the IT Dept., if necessary — Chromium 45.x in X-Tahr (XFCE Puppy Linux) on a 2009 ASUS 1000HE (N270 / 2gb RAM / 160gb platter drive that I really should replace with an SSD at some point). It’s no speed demon, even with Puppy — but it works pretty nicely for what it is.

      1. Damn, get a real computer, my shitbooks* are N450s! :-D Just kidding there’s what, 66mhz in it… I have one running with a 4GB class 10 SD card for readyboost under Win10 and it’s almost bearable. I somehow kept missing the 60GB SSD clearouts, waiting for 128s to go the same way. Running Tahrpuppy on an old PII-300 Toughbook, sorely needs a tad more ram yet puppy makes it useable for the odd them.

        * So named because they are hella beat up, brought back from the dead almost, pocket change yard sale finds.

    1. Meh. I live in the Minn-Kota area. just toss a few self tappers into the tread blocks to act as studs…unless the snow is hella deep. Then you need to make an automated snowblower…hmmmmm

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