Introduction: Deployable Shield

This project is about the future of protection and defense from threats. In the modern world, danger is everywhere, and not many are prepared to defend themselves and others from it. It's time to fix this problem. Deployable defense systems are a passion of mine, stemming from my early fascination with both portable tech and defense systems. I wish to take this passion and make it a reality. Protecting people is the main goal of this project, and so the objectives are simple. Make it light, make it easy to carry, make it efficient, and make it strong. Below you will find the instructions on how to do just that.


The Deployable shield features an easy to carry system that can be equipped and deployed quickly. It features a series of strong panels that are connected via a rail and fastener system. These panels are spun by a motor, allowing a shield to deploy for quick and easy protection. With a toggle switch, the shield can be stored just as quickly as it was deployed.






Battery charger

Chicago screws

1 inch Number 6 screws

Number 4 screws

3 inch Number 10 screws

fender washers

washers for all screw sizes

any length 1/4th inch threaded rod

acorn nut

nuts for all screw sizes


soldering iron


masking tape

two 1/8th inch plywood sheets 2' by 4'



Step 1: Circuit Planning

Before we do anything, we need to figure out how the circuit for the shield will work. The images above show a test circuit I created on As you can see, I have two switches on a bread board with a 5V power supply and a volt meter. When both switches are thrown to the left, the Volt Meter reads five volts. When both are thrown to the right, the Volt meter reads Negative five volts. Why is this happening? Is the circuit violating physics and somehow has negative energy? Short answer, no. Long answer, It is all in the wiring. Now, let me preface this by saying that Tinkercad doesn't have a Double Pull Double Throw switch(or DPDT for short) so I had to use two switches to demonstrate this. If you look closely at the wiring to both switches, you will notice that each switch is the control switch for either positive or ground. This means that both switches have to be thrown to one side in order for current to flow through the circuit. Now comes the cool part. If you wire the opposing side of the switch so that it is the inverse of the other side, it changes the direction of current flow. This is known as reversing polarity and it is what is responsible for the negative voltage reading on the Volt meter. The current has changed direction, thus the Volt meter reads it as negative. Now, what is the purpose of this in our shield circuit? This circuit is how we will get the motor to change directions. Using a DPDT switch, which is basically the two switches from the circuit, but made into one switch, we can both deploy the shield and retract the shield.

Circuit Link:

Step 2: Design

The shield design is relatively simple panel design. It works by having ten identical panels placed in series on an axle.The axle is connected to the window lift motor, which, along with the battery, is held in place below the shield panels in the holding area pictured above. In between each panel lies a washer, this is to ensure that the panels move as smoothly as possible. At the end of the axle there is an acorn nut that serves as an end cap, and at the bottom of the axle lies a nut to serve as a stop. These two nuts hold the shield panels in place. Each panel has a slot cut out of it. This slot is where we will be putting our Chicago screws, which will serve as pegs. These pegs connect two panels together, allowing one panel to be pulled by the other as it rotates. The top panel is fixed to the axle, and the rest of the panels have free range of motion. When the motor spins the axle, the top panel moves. As it moves, it drags the Chicago screw pegs through the slot until it reaches the end. When this happens, it pulls the second panel along, which in turn does the same to the panel below it. This continues until each panel is deployed and the shield is complete. In order to wear and control the shield, there is a handle below the motor holder with two fastening belts. These belts tighten around the user's arm and can be adjusted. The user slips their hand through the handle and is met with a button on the thumb area. This button turns the motor on. Housed above the handle is a switch. This switch is the polarity reversal switch that determines the motor direction. Using the dimensions show above, we will be making a template out of poster board.First, make a construction jig using anything from a screw to a tack as a pivot point and a string tied around it. Measure the distance of the string to the dimensions shown, and tie a pencil to the string at that distance. place your poster board underneath the string and strike an arc to the specified dimensions. Using a straight edge, draw a line from the end points of your arc.

Step 3: Cutting Your Panels

Now comes the fun part. It's time to start building. You will need your sheets of Plywood, template, jigsaw, drill with appropriate drill bits(more on that later),routing table,sander,sawhorses, measuring tape or ruler, clamps, painter's tape, and a pencil. Start by placing your sheet of plywood on your saw horses. Place your template on the edge of your sheet of plywood. This is to make cutting easier and to get 1 free,perfectly straight edge. After you have placed your template, tape parts of it down so it is secure when tracing. Trace the template and be sure to go over it multiple times for maximum visibility. Once you have done this, remove your template. Now place painter's tape over the marks you have already made. Make sure there are no bubbles or creases in the tape. This is to prevent splintering of the plywood. Place the template back and trace onto the tape. Remove your template once more but leave your tape outline. Now its time for cutting. Place your jigsaw on a line that intersects the edge of the plywood. You could do this with either the arced line or straight line, but i would recommend starting with the straight line. Cut slowly on your line. Be sure to control your blade alignment well in order to not veer off course. Correct any small deviations from the line quickly. Do this until you have reached the end of the line. Once you have, reposition your jigsaw to the other line and repeat the process described above until you have all ten panels cut out.

Step 4: Sanding the Panels

Now it's time to sand. Take the panel and place it on a sturdy table or bench. Begin Sanding the top edge of the panel horizontally. You want to do this to get a smooth edge that rolls into the top of the panel and also to prevent splintering. After you have sufficiently sanded horizontally, you can proceed to angle your sander to the edge. Sand with light strokes. Don't push too hard on the wood and don't stay in one spot for too long. Sand the corners by placing them on the face of the sander and gyrating the sander. Do this process to each side, front and back.

Step 5: Drill the Hole for the Axel

Take all ten panels and line them up so they are all even. Use clamps to secure the panels for drilling. Place the clamped panels on a hard surface and back it with anything you are willing to drill into. Measure an inch and half down from the Apex directly in the center, and drill a quarter inch hole. Be sure to hold your panels together firmly while doing this to ensure a straight hole alignment. Once you have drilled the holes in each panel, take the threaded rod and insert it into the holes. Make sure that the rod can spin freely once inserted. If it cannot, bore the hole out more until the rod can spin freely. Just be sure to not allow too much room for the rod. Test the assembly by placing each panel in alternation with washers. Start by threading a nut onto the back of the axle to prevent the panels from slipping, and then placing two washers, a panel, two more washers and so on until you place the acorn nut. test to make sure the panels can spin freely and do not have too much friction. After confirming this, disassemble the parts. Now take the top panel and drill four 1/8th inch holes around the axle hole. Make sure these holes correspond perfectly with the coupler. Take the bottom panel and drill a 1/4 inch hole to the dimensions shown. This will be used to put the retaining screw into during the final assembly.

Step 6: Route the Rails

Now we must route the rails that we will insert the Chicago screws into. Measure your panel eight inches from the apex. Use your pencil to mark this line. From here, use a string tied around a shaft inserted into the axle hole to draw an arc from the eight inch center point to the edges of the panel. Now measure one inch in from the edge of the panel. Mark these dimensions down on your panel. Now is time for preparing the routing table. We will be using a one fourth inch straight routing bit for this hole, as it is the proper size for our Chicago screws. Insert the bit into the router and secure firmly. After you have done this, measure the six and a half inches outward from your router bit and secure a screw the same size as the axle. We drilled the screw into the routing table, but if you can find some alternative solution that does not require modifying the routing table you are free to use it. Lower your routing bit. Secure the panel to the screw on the routing table so that it can spin freely. Hold a marker or pencil at the eight inch mark on your panel and spin the panel until you reach the one inch marker. Record where on your routing table this is and mark the location. Do this on both sides.Take scrap pieces of plywood or anything solid you have and clamp them to the tables at the points you marked and recorded. These will serve as stopping points for the panel to ensure that the rail is the correct dimensions.Now, drill a 1/4 inch hole 1 and 1/8 inch away from the edge on the same arc. This is to serve as a stopping point. Drill a 1/4 inch hole at the eight inch mark on your panel. Place the panel directly above the lowered router bit and raise the routing bit until it is at the proper level with the panel. Turn on the router and move the panel slowly about it's axis. Be sure not to apply too much force while routing or you could damage the piece. Repeat this process until all panels are completed. Once they are completed, use the sander to smooth the edges of the rails using the same techniques discussed in the previous sanding section. Assemble your panels on the axle once again, and select the ten millimeter Chicago screws. Place the screws in the rails so that each panel is connect to one another. Once every panel is connected, grab the top panel and spin it around the axis. If assembled correctly, every panel should unfold behind the first one as it it pulled.

Step 7: Fitting the Axle

Now we will cut and grind the axle. Remove the acorn nut from the top of the shaft. Measure the length of your coupler and move your panels downward and inch longer than the coupler. Mark the axle directly below and above the coupler. These marks will be used later when grinding. Now select the motor adapter and place it on the motor.Measure the length from the base of the motor adapter hole to the top. Take this measurement and mark it down from the bottom panel. This is where you will be cutting the axle. I would advise leaving extra room so that you have room to make mistakes. Once you have this distance marked,Remove the axle from the shield panels, but leave the panels assembled. Place your axle in a vice with two wood blocks on either side. Secure it tightly. Cut the axle with either a hacksaw or a dremel. Once the axle is cut, proceed to grinding. For the bottom of the shaft, grind two flat points on opposite sides of the axle bellow the mark.You can also take this time to grind off any burs left from cutting. Do the same for the top of the shaft, but keep it within the marks you made using the coupler. Do not grind all the way around the axle, only the two opposing points, and do not grind outside the lines.

Step 8: Base Plates

Cut two 17" by 4" pieces of plywood using the jigsaw. These sizes are to the specifications of my arm, so if you wish to match your own measurements, measure from the tip of your fingers to just past your elbow. Once you have cut the two rectangular pieces of wood, use superglue or wood glue to secure the two panels together. For superglue, clamp tightly for about a minute. For wood glue, leave clamped for an hour. After the glue has dried,cut diagonally at a two inch over 1 inch slope on both sides. Sand the plate as instructed in the first sanding section. Repeat this process one more time in order to get a second base plate. Once you have the base plates fabricated, drill six number ten screw holes in both plates, four number six holes,retaining screw hole, and a motor adapter hole matching the dimensions shown above.Start with screwing in the motor. Place the 1 inch number six screws through the holes with five washers on the top of the top plate and four on the bottom of the top plate, and screw the motor in. On the top of the top plate, place a washer over the number ten screw holes and put screws through all of them. Then put two 1 inch nylon spacers on each screw in between the plates. On the bottom of the bottom plate, place a washer and nut on each screw.

Step 9: Making the Handle

Cut out a piece of three quarter inch MDF the same as the dimensions shown above. After you have cut out this block, cut out the center dimensions labeled. Sand the edges of the block using the same technique described in the first sanding section, and sand the inside cut until it fits your knuckles. Now is where you decide which hand you want your shield on. I am right handed so i decided on a left handed shield. Measure the dimensions of your button and use the appropriate drill bit to bore out a hole near where your thumb would rest. Make sure your button fits before you proceed. If the button fits, use super glue to secure the handle two and a half inches from the tip of the base plate.

Step 10: Making the Battery and Switch Manifold

Now we will make the manifold for the battery and switch. Cut two 3 inch by 2 inch three fourths of an inch MDF blocks. Place them at a 90 degree angle with each other, with the face of the back block being eleven and half inches from the tip. Nail these blocks into the base plate using a brad nail-gun. Angle the nail gun so that the nails do not protrude from the bottom or top base plate. Now cut out a two and a half by two inch three fourths of an inch MDF block. Using your switch dimensions, cut a hole through the center. My switch dimensions were 1 inch by 3/4 of an inch. Check to see if the switch fits tightly within the block. If so, superglue this block 4 and a half inches from the nearest face to the tip of the base plate and on which ever side is easiest to access for you. The battery should friction fit in the base plate, so the manifold is just to prevent sliding.

Step 11: Wiring

Now time to put that circuit lesson to good use. Let's start with the battery. The battery is pretty straight forward. Take the ends of the wires connected to your battery and strip them. Select one of the male battery connectors and cut the wires. This should leave you with a male connector with some wire hanging from it. Strip the wires and proceed to splice them with the battery. now, take the excess wire you cut off from the male connector and splice them onto the battery wires as well. Make sure the positive and ground do not touch during this process. Clean the spliced wires thoroughly with a scotch brite pad and prepare to solder. Heat the wire, not the solder, and feed the solder on the wire. Try to wrap the solder around the wire for a good solder joint. Once you have finished soldering, place your heat shrink tubing over the spliced wires and put a lighter under it or hit it with a heat gun. Once you have done that you can move on to the Switch.

Now for the DPDT switch. Use a scotch brite pad to clean the terminals of the DPDT switch. Finger oils and any residue will make the soldering job much more difficult. Start by taking some wire and cutting it to a good size. make it about an inch and a half to two inches. Make two of these, as they will serve as out jumper cables. Be sure to make one of them black and one of them red, or some other way to distinguish from ground and positive. Now, solder your black jumper cable from terminal 1 to terminal 6. Be sure to heat the terminal and feed the solder in, do not directly heat the solder. Now, solder terminal 2 to terminal 5. Same advice as last time. If you are having trouble soldering, try cleaning your jumper cables, terminals, and even soldering iron. Try to control where the solder lands rather than just trying to smear it on. Let it drip and control the bubble. Try to not use too much solder, as large clumps can cause problems. Now that your terminals have jumper cables, solder two more cables to terminal 1 and terminal 2. These cables will go to your switch and motor. Feed your wire carefully through the hole you have made for your switch and then place the switch in. Now wire your commons. Take the loose wire you have connected to the battery and connect ground to terminal three and positive to terminal four. Now we can move on to the motor and switch.

Place heat shrink tubing on the terminal 1 and 2 wires. Splice the terminal 1 wire and the ground of the motor. Solder these wires and then shrink the heat shrink tubing on that solder joint. Next take your terminal 2 lead and solder it to one of the terminals of the button, preferably the one that would put the least stress on the wire. Now take some spare wire and solder it to the other lead. Make sure you do this after you put the button in the handle. Put heat shrink tuning on the wire and splice the wire from the non-connected lead with the positive of the motor. Solder the wires together and then shrink the tubing. Test to see if everything is functioning. If the switch changes direction of the motor and the motor only activates when you press the button, your circuit is full operational. Manage the loose cables and prepare for final assembly.

Step 12: Final Assembly

Now is the culmination of everything done so far. The first course of action is to make sure you can wear the shield. Select the elastic band and cut it to a size that can wrap around the bottom base plate one and a half times and still be loose. This isn't an exact science, so play around with what distance from the tip of the base plate and what amount of elastic is best for you. Now, drill a hole through the wood and the elastic band and insert a screw with a washer. On the other side, put a washer and a nut to keep the screw in place. Now is time to assemble the shield. Insert the axle into the shield assembly. Remember to have two washer in between each plate. Screw the coupler into the top panel tightly.Place two washer on top of the coupler and then screw on and tighten the acorn nut. Use the 1/16th inch Allen wrench to tighten the coupler to the axle. Make sure the flat parts are aligned with the screws.Now, insert the axle into the motor adapter. Make sure the flat sections and hex screws are aligned and tighten using an Allen wrench(gotta find the right size). Place the retaining Chicago screw into the bottom shield panel and base plate. The shield assembly is officially complete. I had a blast making this project. It was a very fun build and I believe anyone who loves crafting and useful mechanics should try building it.