DIY Autonomous Nerf Turret
Linus Tech Tips
·Linus Tech Tips
·2017-05-06
·
1,467 words · ~7 min read
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so for those of you who follow the lus tech tips Twitter and Instagram
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um you'll already be aware that there
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was recently a crisis at our
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headquarters um sorry sorry still a
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little difficult for me to talk about this but I became aware after returning
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from a brief absence that someone had been at my desk touching my things
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sorry excuse me
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so naturally at that point there were two
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Avenues available to me the first would
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be calm measured discourse with my
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trusted employees about the importance of respecting one's personal space and
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possessions while the second would be to
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over engineer some manner of mechanical
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deterrent that would give any Interlopers a much needed Taste of
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justice so in the end I
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decided well let's just say this isn't a
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video detailing how to host a discussion about office
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protocol Mast drop is currently featuring their exclusive case 7xx red
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headphones built by AKG learn more and buy one today at the link in the video
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description meet the enforcer out of the box the elite strike
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Rhino fire is a fully automatic fixed
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Point anti-personnel Nerf gun with a 2.8
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Dart per second rate of fire an arc range of up to 81 ft and a 50 Dart
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ammunition drum capacity it's a beast in
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its own right but it only works when I'm
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around to operate it which means I needed to turn this Hefty foam Blaster
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into a fully automated motion detecting
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stationary Sentry turret so to accomplish this we'll need the following
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three servos an Arduino a webcam and a
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laptop to coordinate it all not to mention some quick rewiring and just a
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touch of fine woodworking now in much the same way
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that you can't make an omelet without breaking a couple of eggs you can't
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modify a Nerf gun without first voiding the crap out of the warranty so step one
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then is to carefully mind you these things are over a hundred bucks
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disassemble the Rhino fire our main objective here is to access the internal
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wiring but the lighter our gun is the
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easier it will be for our servos to turn it and the aptly named Rhino has a
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little more junk in the trunk than we'd like out of the box which which means
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we'll want to remove our bulky trigger assembly not to mention the six D Cel
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batteries that also have got to go once
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the gun is in pieces this is also a great time to give it a quick makeover
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doing it up right involves laboriously sanding off all the logos then taping
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and painting in layers etc etc etc but that's literally as interesting as
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watching paint dry so we're going to skip over that with some video Magic
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ah much better so as you can see we've
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removed some excess weight at the back pulled out the battery pack and isolated
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the internal switch that turns on the motor next we need to assemble the body
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of the turret that this will sit on this
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bottom box is where we install the webcam and laptop so it needs to be nice
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and roomy our first Servo goes inside
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the top of the box and the gun bracket is mounted on top which allows rotation
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along the x-axis we want to keep the load on the servos as light as possible
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especially when at rest which means keeping the weight off of the moving
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components themselves now our first plan
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was to Simply place this ring of ball bearings between the box and the gun
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bracket but during the prototyping stage
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we found that to be insufficient the wood was just too rough and the bearings
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were too small for this to be an effective solution so the way we Sol
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that then was to layer the Ring of ball
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bearings between some discarded CDs thanks AOL that we attached to the wood
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the CDs are the perfect size though some minor modification was necessary to make
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room for the servo and they're smooth enough that the bearings were able to
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roll properly greatly reducing the strain on our servos now that we had
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turn we needed tilt good news though the
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Rhino comes with a tripod mount already ready that is located close to Center
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Mass so we gently modified this to allow
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a dowel to be inserted the dowel fits into two ball bearings that are housed
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in wood panels on either side allowing for ease of movement since the gun isn't
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perfectly balanced we added some small weights until it required very little
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effort to tilt it up and down now our
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Servo installed at the end of the dowel can tilt the gun more quickly
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drastically improving the ability of our s entry to track its Target so with the
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wood frame built we next mounted the remaining servos the Arduino and our
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battery packs now while our initial plan
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was to wire the internal motor of the Rhino directly to the Arduino in the end
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we decided to go with a third Servo and a 3D printed prong controlling a
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mechanical switch then with all of that in place we just needed to neatly wire
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it all together then hook it up to the laptop and webcam in the base and and
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run the software that we downloaded from Project Sentry gun. Rudolf Labs.com a
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super awesome open-source Sentry project that you should totally check out by the
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way now I'll take a moment to give you guys a quick Pro tip when you set out to
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do a wiring job like this no matter how small the project is or how simple you
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initially assume it will be pick up at least two different colors of wire red
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and black for positive and negative are pretty standard don't just get one color
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because you're confident that you can keep keep everything straight and you
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think green is pretty you will end up 4 hours deep into the project surrounded
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by hastily marked wires from five different Motors and two different batteries in a hopeless tangle deeply
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confused and full of regret so so much
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regret all right let's get back on topic before our final test we've got one more
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housekeeping item our final job looks a little messy so uh hey can we get some
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of that video magic going on here I guess we're just going to have to
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embrace the whole junkyard Chic
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aesthetic thing testing
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time oh my
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God oh my God success I can now feel comfortable
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leaving the office knowing that my tools pens and prawns will rest
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unmolested of course for the majority of the time when I'm here I don't actually
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want this thing hovering behind me so I needed to find a way for it to pull
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double duty fortunately with the help of a little open- Source facial recognition
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software it can be easily repurposed as an employee morale
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booster now that's what I call a motivational
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it since 1929 they have more than 3,000 products
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not all of which are nuts so we got some cashews chocolate covered
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pretzels can you believe the brand expected me to make it all the way
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through this without making any jokes
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about eating nuts so in a nutshell nuts.com has lots of hard-to find items
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including gluten-free and organic ones they have 100% satisfaction guarantee
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out over at nuts.com thanks for watching
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guys if this video sucked you know what to do but if it was awesome get subscribed hit that like button or check
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out the link to where to buy the stuff we featured at Amazon in the video
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description also linked in the description is our merch store which has
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cool shirts like this one and our community Forum which you should totally join now that you're done doing all that
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stuff you're probably wondering what to watch next so click that little button
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in the top right corner to check out the latest video over on Channel Super Fun