Unpowered Mechanical Gate Opener, the Video

Craft & Design Energy & Sustainability
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Okay, MichaelLubke is officially my favorite reader ever. In response to my recent post speculating about mechanical gate openers, not only did he run out and snap some photos of a working “Gandy Slide-A-Way” near his ranch, but in response to appreciative comments from our readers he went back and got this video of it in operation. Awesome! Look at it go! Thanks so much Michael!

22 thoughts on “Unpowered Mechanical Gate Opener, the Video

  1. Anonymous says:

    Wow, if I knew when I was wishing for a video of this gate my wish would have been granted I would have wished to win the lottery. Oh well, this is more realistic than being fabulously wealthy. Thanks MichaelLubke!

    1. ben colbourn says:

      thanks so much for this video Michael, can’t tell you how long I’ve sat wondering what it looks like in motion! and of course thanks MAKE for posting it!

  2. oh for crying out loud says:

    PLEASE stop calling this thing UNpowered. It’s not unpowered, it’s just not electrical. There ARE forces that are not electricity, you understand? Don’t you?

    People were creating clever solutions to problems before the fucking micro-controller came around! Surprise!

    People made fences based on terrain manipulation a thousand years ago, because above-ground fence posts were considered unsightly. We’re just too lazy to do it that way these days. So now we take a cheap shortcut, erect a fence, and somehow an automatic gate opener is revolutionary.

    This thing is powered by GRAVITY. Powered by GRAVITY is not UNPOWERED!

    1. Apis says:

      @oh for crying out loud: I would say it’s powered by the car, not gravity. Although I don’t think unpowered is entirely wrong here either; most languages is very inexact unfortunately. Would you call a normal door “human powered” or “hand powered”?

    2. japroach says:

      no need to be a dick

      When I read the title, I interpreted it exactly as the author had intended: this gate does not directly use an electrical power source.

    3. Sean Michael Ragan says:

      Do you say “power outlet?” “Power strip?” “Power cable?” “Power line?” “Power plant?” Personally, I think we’re all aware that power is not the same thing as electricity and can handle the context here. What’s interesting about it is not just that it’s “gravity-powered” but that it is NOT electrically powered. But “not-electrically-powered” just doesn’t headline very well.

      And no one is claiming revolutionary. “Neat,” is more like it, like an old steam locomotive or an Amsler planimeter or a mechanical calculator.

  3. dZed says:

    I’m with Apis, here. No one’s claiming that Michael has discovered perpetual motion or zero point energy in the form of a little used metal gate in rural Texas, @”oh for crying out loud,” nor do I think anyone but you has chosen to interpret it that way. Language is just inexact, and “oh for crying out loud” is probably correct in saying that gravity powered or car powered would be a better label for this fence.

    And I would disagree with “oh for crying out loud”‘s description of this as a “cheap shortcut.” Though I am not a machinist and have little idea of the investment of time involved here, it is definitely not cheaper than a typical gate in terms of materials and, from a construction point of view anyway, took only enviable shortcuts to create the intended effect. In other words, it definitely ain’t cheap, and the shortcuts it took are WHY it’s interesting, not a reason for derision.

    Lastly, thanks Michael for taking the video. I was one of the ones who requested a video, and now awake at 3AM with a shot of insomnia, I’m really glad it’s here.

    And this is the non-machinist and mechanic/engineer novice asking, anyone have any thoughts on slowing it down before it slams open like that? Or would that not beat the snot out of it over time like it seems to me that it would? Rubber stoppers? Some kind of brake on the cable? Too complicated for the rewards?

    1. r. medley sr. says:

      There are several ways to slow it down! Spring tensioners either stretch or coil will work and depends on the level of installation/fabrication difficulty you want to tackle. Change the round pulley to an eccentric. Automobile shock absorber could be used in many ways; at the end of of the stroke, coming or going directly on the gate or as a “shock absorber” waiting to receive the load at either or both ends of the gates stroke. You might also play with a hook on the gate that catches it before slamming. Utilizing a spring or spring tensioned cable, which would be visually stimulating if placed in an unusual place. Assuming the gate must remain horizontal in its complete cycle, one could mount brake pads of some frictional contrivance, side mount, top or bottom would be the easiest, utilizing the weight already present, thereby “free” pre-loaded friction enhancement.

      The one of enterest coming to mind would be a horizontal/perpendicular bar, mounted at just the right place on the gate, to funcion in the stroke of the gate, to colide with the cable suspending the weight. The contact would immediatly start transferring weight in the opposit direction and at a compatable rate of speed reduction and may well be the simplest, although not the most mechanically fun to fabricate, install and observe in operation.

      Others keep coming to mind but, time to go. Thanks for the stimulation………..rone

  4. alandove says:

    The video really helps show how the opener works, and it’s extremely clever. As for slowing it down, I think that’s the purpose of the flywheel on the far side of the mechanism – if that weren’t there, the gate would slam open even harder. Instead, it accelerates gradually while the vehicle mashes down on the ramp.

    Sure, it’s moving at a good clip toward the end of the cycle, but it’s metal, and from the rust on everything I’d guess it’s been doing this routine for quite awhile without falling apart. The closing phase follows the same pattern, accelerating until the gate slams shut hard enough to trip the latch. It’s not a perfect machine, but it looks like it’s as good as it needs to be.

    Bump gates are simpler and probably cheaper (fewer parts), but nowhere near as fun to watch.

  5. Marcel says:

    @oh for crying out loud: Calm down.

    @everybody else: I agree that some damping would be good, but on the whole it’s a great idea.

    Thanks for posting.

  6. David Warner says:

    Congratulations Michael and Sean both for developing and putting such an awesome and neat(as Sean says :) ) development on Gate Openers. It is indeed an awesome video. However, I feel that this is at conceptual level and need some perfections to come out as a commercial utility.

    Hope to see Michael turning his idea to the market level.


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I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and makezine.com. My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

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