Tutorial: The Gyroscope

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    Post The Gyroscope

    Difficulty
    Beginner
    Estimated Time
    1-2 hours
    Skills Required

    • basic electrical skills

    • basic woodworking skills

    • basic MacGyvering skills

    Parts Required

    • $1.00 - A square peice of wood 10" to 12" in size

    • $2.00 - A small potentiometer (best if it's worked in a bit or turns with little effort)

    • $3.50 - A hobbie motor (needs to be able to handle 9V to 12V and if you can find one with a
      dual shaft all the better)
      here is one on ebay


    • $0.69 - A dowel 1/4" diameter 3' long

    • $0.75 - A dowel 7/16" diameter 3' long

    • A strip of copper 1/2" wide and about 2' long (or other conductive metal)

    • $4.50 - 8 "AAA" batteries

    Tools Required

    • A Multimeter

    • A Drill

    • A Drill bits

    • A Jig saw

    • A length of string

    • A pencil

    • A nail (Yes, in this case the nail is a tool!)

    • A bottle of wood glue


    The Gyroscope
    By Ben Wood (DroidCommander)



    About:

    However much we humans like to think weíre the smartest species on the planet, it took us thousands of years to come up with something that Mother Nature has been developing for millions or years. She beat us to the punch but we took it a step further, (Take that Mother Nature Ha!). Gyroscopes are a device that relies on the basic principles of nature to stabilize or resist the various forces that act on it. The first gyroscope was created by Johann Bohnenberger in 1817 and he simply called it ďThe MachineĒ.

    Gyroscopes come in many forms and surely many of you are familiar with the American toy known as the "Chandler gyroscope," developed by the Chandler Company in 1917. This toy is simply a weighted disk attached to a rod and suspended in a fixed frame. When played with you pull the string wound round the rod it sets the gyro in motion and produces a number of interesting affects.

    In particular, two affects that the gyroscope produces are precession and nutation. Precession is basically the gyroscopes ability to resist the other forces that are acting on it, like gravity, movement, or in the case of the Chandler gyroscope tilting it. This affect can be easily tested at home with a bicycle wheel and a length of rope shown here from (How Stuff Works). Nutation is the ability of a gyroscope to detect the irregular motion of an object such as the earth.

    For more information on the history of the gyroscope I suggest reading the articles listed below from (How Stuff Works) and (Wikipedia).


    How it works:

    Gyroscopes come in various shapes and sizes. Todayís high tech gyros are integrated into single ICs that can be put together with other discrete components to provide sensor input to your robot. Various manufacturers produce gyroscope ICs the two that I found were Analog Devices angular rate sensor and the NEC/Tokin Ceramic Gyro [CG-L43]. Either of these devices, properly integrated would give you the sensor data you would need.

    So how do they work without having mechanical spinning wheels? (although that might look really cool!)

    Well the chip from NEC has a nice little diagram:

    Well thatís simple isnít it?

    Letís talk a little about what this means in terms that the regular person can understand. Typically a gyroscope works because the wheel spins and as the top edge of the wheel tries to pull the wheel over on itsí side the wheel rotates and the force that was trying to pull the wheel over is now pulling the wheel strait. You can see this and try it by following the instructions on (How Stuff Works).

    But that still doesnít explain the picture above. Well in addition to rotating gyroscopes there are vibrating gyroscopes. Vibrating gyroscopes work because when a rod shaped object is vibrated back and forth it tends to want to continue to do that in the same direction (due to Isaac Newtonís handy dandy first law of motion) as you can read about in (the Physics Classroom). So while the rod is vibrating (Even if it is vibrating by a very, very small amount, as in these Integrated Circuits) it wants to keep vibrating in the same way.

    Thus when you move it in another direction the rod bends and changes the resistance of the electrodes printed on it sides. Mother Nature invented these kinds of gyroscopes. When insects fly around and dodge our every attempt to smash them into bug paste little knobs that used to be wings vibrate up and down and when the insect moves the movement influences these vibrating knobs and the insect can sense which direction it is moving (good one Mother Nature!)




    What can it do?:

    Alright, so what does that mean to me? Heck I donít care how a bug flies and I donít plan on putting spinning bicycle wheels on my robot so how does this help me at all?

    Well if you plan on building anything that flies, floats, stands, or tilts a gyro can give you the information on how your robot should act so it doesnít become scrap parts. Additionally, with a gyro and some circuitry you can make a directional gyro and help improve your robots direction sensing.


    Implementation:

    Now that we know what a gyro can do letís look at what we can do to start using gyros. You might think that itís going to be incredibly hard to use a gyroscope and that all depends on how accurate and complex you want to make it.

    First off the materials:
    • $1.00 - A square peice of wood 10" to 12" in size
    • $2.00 - A small potentiometer (best if it's worked in a bit or turns with little effort)
    • $3.50 - A hobbie motor (needs to be able to handle 9V to 12V and if you can find one with a dual shaft all the better) here is one on ebay
    • $0.69 - A dowel 1/4" diameter 3' long
    • $0.75 - A dowel 7/16" diameter 3' long
    • A strip of copper 1/2" wide and about 2' long (or other conductive metal)
    • $4.50 - 8 "AAA" batteries


    Tools Required:
    • A Multimeter
    • A Drill
    • A Drill bits
    • A Jig saw
    • A length of string
    • A pencil
    • A nail (Yes, in this case the nail is a tool!)
    • A bottle of wood glue

    Attachment 1250

    So we will take a peice of wood 10" x 10" x 3/4" in size, cut two circles in it, attach legs and the rings with dowels then motorize the rotor and attach a potentiometer to the gimbal in order to read the gyroscope angle.

    Step 1

    First, we need to find the exact center of the peice of wood, so using a ruler draw lines with the pencil from one corner to the oposite corner forming an "X". Then measure 5" in on each side and make a small mark on your peice of wood and then connect those lines so that you've drawn an astrisk on the board.

    Step 2

    Next, take the nail and hammer it into the wood at the center. Attach the string to the nail and then tie the string to the pencil so that you can draw a perfect circle about 8" in diameter. Optionally you can use a compass to do this step.

    Step 3

    Okay, now Drill a hole large enough to fit your jigsaw blade into and cut out the circle so that you have the frame (Square peice with a circular hole in it. And the gimble and rotor (still to be cut).

    Step 4

    Repeat the same procedure for the rotor, make sure that the hole you drill for the jigsaw blade is positioned as much as possible on the gimble instead of the rotor. We want the rotor as perfectly round as possible and the gimble simply needs to be weighted right. So position the hole oposite to the hole drilled to start the cutout of the frame.

    Step 5

    Now notch out the frame and secure your potentiometer to the frame and to the gimbal. Make sure that the potentiometer is halfway through it's turn when the gimble is perpendicular to the frame this will allow the most motion of the gimble once we mount the rotor. Secure the other side of the gimble with a dowel. Glue the dowel into the gimble and then drill an oversized hole in the frame so that when the gimble is placed in the frame it can turn easily.

    Step 6

    Drill holes for the legs in your frame. Cut dowels at least long enough to give the gimble clearance to swing back and forth. Mount those dowels in the frame and secure them with wood glue.

    Step 7

    Now to prepare the rotor. Drill a hole and cut out a hole in the center of the rotor the same size as your motor, you want the motor to fit snugly because your going to secure it with wood glue. Using the lines you drew in the first step Drill 8 holes 42.85mm from the outer edge. This is because we are going to use "AAA" batteries to power our rotor and that is how long they are. For more info see:(here)

    Step 8

    Notch either side of the holes you drilled for the "AAA" battery. Cut a small strip of copper 1/2" wide by 3/4" long bend this into an "L" shape and slide it into the notch so it makes a contact for the battery. Then screw this contact down with the tab on top of the rotor. Drill 8 shafts from the outer edge of the rotor connecting to the holes drilled for the battery contacts using an 11mm drill bit this should be wide enough to fit the "AAA" battery into. For more info see:(here)

    Step 9

    Load a "AAA" battery into each slot and cap it off with a small strip of copper 1/2" wide and long enough to be secured on either side of the rotor with a small screw. Connect each negative (inner) contact to the next positive (outer) contact (Connect the contacts in series) with wire. Measure the voltage accross the pack and make sure that it measures somewhere around 12v.

    Step 10

    Wire a small switch in between the motor and the battery pack and connect the switch to the motor. seat the motor in the rotor (making sure to position the motor as perpendicular as possible. Slide the motor out and run a bead of wood glue around the inner edge of the rotor. Cut two lengths of dowel from the 7/16" dowel long enough to go from your gimble to the motor shafts. Drill holes in the dowels and glue them onto the ends of your motor shafts. Secure the motor back in the rotor.

    Step 11

    Drill two 7/16" holes in the gimble using your lines as a guide. Notch out the holes so you can slide the rotor assembly into the gimble. Replace the notched out peices and secure with wood glue. You should now have a movable gimble, a solid connection between your gimble and the rotor shaft, and the rotor should spin on the motors' bearings. Let all peices dry overnight.

    Step 12

    Make sure that all peices are secure and that the rotor moves smoothly and does not wobble. At this point the gyroscope is done. You should be able to flip the switch on and the rotor will spin rapidly and if you tilt the frame, the gimble will tilt since the force of the spinning rotor is keeping it in alignment. Measure the resistance comming off your gyro and you can see how it changes based on how much you tilt your frame.

    Building this gyroscope should present little problem for someone with basic electrical skills, basic woodworking skills, and basic MacGyvering skills. Also the materials used are easily available at Wal-Mart, Radioshack, Home Improvement Store (Lowes, Home Depot), and ebay. Finally I designed this tutorial so that the materials required would not exceed 20$


    Summary:

    * UNDER CONSTRUCTION *


    Sources(literary [Sorry programmers]):

    1. How Stuff Works (Gyroscopes)
      http://www.howstuffworks.com/gyroscope.htm
    2. Wikipedia (Gyroscopes)
      http://en.wikipedia.org/wiki/Gyroscope
    3. NEC / Tokin (Ceramic Gyro)
      http://www.nec-tokin.com/english/pro...ramicgyro.html
    4. The Physics Classroom
      http://www.physicsclassroom.com/Clas...laws/u2l1a.cfm
    5. Battery Specialists
      http://www.batteryspecialist.com/Mer...e-aaa-dim.html

    Attached Files
    • Gyroscope
    • insect
    • CeramicGyro
    • Plan
    • step1_Plan
    • step2_Plan
    • step3_Plan
    • step4_Plan
    • step5_Plan
    • step6_Plan
    • step7_Plan
    • step8_Plan
    • step9_Plan
    • step10_Plan
    • step11_Plan
    • TBT
    • insect


Replies to Tutorial: The Gyroscope
  1. Join Date
    Dec 2007
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    Posts
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    Re: The Gyroscope

    This is turning into a really good resource. I'm going to have my robotics club members start checking this out!
        

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