Build Instructions

Collapse

• 1

  Step 1

  Step 1 – Preparing the coils (DIY make coil gun without camera)

                                                    Making the coils for the coil gun

  Take the PVC pipe and cut it , to get a length of 30-40cm. After that, take the insulation tape and wrap around the pipe from a distance of 1-2 inches from its end. Wrap the insulation tape above the pipe in succession until it reaches a thickness of 4-5 mm. Next do the same thing from a distance of 3-4 cm from the first wrapping.

  Now take the copper wire and after leaving some slack on the beginning, start wrapping around the pipe, the wrappings are to be tight and close to each other with no gaps between them. After wrapping the first layer, cover it with insulation tape, then start wrapping on top of it for the second layer. The copper wires should be wrapped side to side in the same direction , either clockwise/anti clockwise. Repeat the process for 6-7 layers. 

  For multiple coils, a spacing of 3 cm is required from the first coil . After preparing the coil, using sand paper sand the ends of the coil to remove the coating , to make them conducting.

• 2

  Step 2

  Step 2- Making the capacitor charger

  Camera flash circuitry and capacitors can also be used for this project, but since a large number of them are required, I found it easier to buy some high voltage capacitors and make a dedicated charger for them ; thus making a coil gun without a camera. To make the capacitor bank charger for the 400V, 3300uF capacitors, prepare a circuit as shown in the schematic :

                                              Coil gun charger circuit

  Set up the bridge rectifier as shown in the schematic , I have used a 600V D3SBA60 bridge rectifier. After looking at the marking in the rectifier wire the ac pins of the chip to live and neutral lines of your AC supply. The + and – marked pins on the chip provide the DC voltage, the positive voltage passes through a 100W incandescent bulb , acting as a high load resistor, a switch is used to toggle on/off the charging of the capacitors. When using multiple capacitors, always choose them with the same rating and connect in parallel to increase the current supplied.

                                                 Finished charger circuit setup

• 3

  Step 3

  Step 3- Making the coil gun circuitry

                                                    Coil gun circuit

  The coils on the coil gun have to be wired up based on the given schematic. Here an SCR (Silicon Controlled Rectifier) or thyristor is used to control the high voltage supplied to the coil, it acts like a switch. I am using a 50A rated stud type SCR , 50RIA120, smaller SCR’s like the TYN616 can also be used if 5 or 6 of them are connected in parallel as each provides a surge current rating of 200A. Conventional switches or relays cannot be used as it usually burns the contacts in them due to the high voltage and current.

                                                      Coil gun SCR

  The working of an SCR is simple, when a voltage is applied to its gate via a small battery the diode is activated and the cathode and anode can be connected to the coil just like a normal diode. A switch that controls the gate voltage being applied to the SCR essentially controls the current going to the coil and acts as our trigger to the coil gun. 

  Even if you are having a lot of capacitors hooked up in parallel , without an SCR capable of handling high current, you will not be able to supply the full power. High gauge copper wires should be used while connecting the capacitors and the coils. 

  All connections and terminals should be properly insulated to prevent yourself from getting electrocuted accidentally. While choosing an SCR , choose one with a high value for “Surge Current/Itsm”, after checking its datasheet.

View all 5 instructions