1. Spot Welder BY MOHAMED ABUZAID

2. Design Brief I will be building a spot welder. My spot welder will be able to weld two metal pieces together using electric power which creates heat. To complete this project I must first build and test the electronics. My second step will be to build the wooden case for the electronics meeting all specifications. Then combining the two and completing the project. I will attempt to complete the project before the end of the year.

3. Specifications  Stay on budget $75  Use 4 to 0 AWG wire  Use 120v 60Hz transformer  Use momentary pushbutton switch to prevent shock and unintended use  Use heavy gauge wire for input

4. Specifications  Students must be capable of transporting their project home.  Individual projects may have additional specification, determined by the individual student or instructor.  A professionally developed plan must be used to create a product.  Chosen designs must be approved by the instructor.  Products must be designed and built with attention to detail. Emphasis must be place on both form and function.  Designs must be capable of being completed by the end of the year.

5. Investigation 1. How can I dissipate the heat produced by the modified transformer? I can drill holes on the top of the case and add a fan. 2. What is the voltage to amperage ratio of the modified transformer? The voltage to amperage 2-3 volts and 600 amps < x 3. How big will the copper contacts need to be so that they do not melt? About a ¼” or thicker for long usage 4. What functions or components can be added to reduce chance of injury? I can add a circuit breaker, a momentary on/off button, and master power switch.

6. Investigation 5. Are there any materials which I will need to obtain myself? If yes, what is it, how much do I need, and where can I get it? 6 ft. of 4 to 0 gauge copper wire, 1 circuit breaker, two copper welding cable lugs, a foot of solid copper wire, 2 120v on/off switch and 2 copper offset these items can be found at Lowes other items needed include 60hz 120v transformer and input cabling can be found in any microwave. I also need a 120 mm fan, 5v transformer, and a multimeter for testing I have all of these items. 6. Will I be able to transport my project home after it is completed? The spot welder is small enough so that it can fit in my car

7. Research Small and easy to build but Momentary switch placement Is dangerous because it is near the Hot surface Many safety features Heat is dissipated well Switch placement is far enough To avoid injury but close enough To adjust objects in between the Copper contacts

8. Research Small portable but seem uncomfortable and get hot Because transformer is under the handle Large power requirements would be too high but the durability of the Contacts is good because the are large And will not melt easily

9. Possible Solutions Strength/ Durability SafetyFunctionalitySimplicityTotal Solution 1 8 7 7 8.5 30.5 Solution 2 5 0.510 8 23.5 Solution 3 2.5 52 12 Solution 4 10 5 1 26 The table above is based on a 1-10 scale. 1 is poor, 10 is the best

10. Chosen Solution

16. Bill of Materials Student(s)Mohamed AbuzaidPeriod6 ProjectSpot Welder Number of Pieces Name of PartLumber Species Size (INCHES) Board Feet Cost of Material Cost of Piece L W T 14 Gauge copper wire 72x x 6.00$0.99$5.94 160Hz 120v Transformer x x 0.00$0.00 1120v to 5v Transformer x x 0.00$0.00 1input power cable x x 0.00$0.00 1120 mm computer fan x x 0.00$0.00 1Momentary Switch x x 0.00$0.00 2120v on/off switch x x 0.00$5.00$10.00 1copper screw type lugs x x 0.00$4.50 1two copper welder calbe lugs x x 0.00$4.50 1 120v 15 to 20 amp circuit breaker x x 0.00$4.00 2ArmPoplar25x2x10.69$1.24$0.86 1BasePoplar42x6x11.75$1.24$2.17 2SidePoplar24x6x12.00$1.24$2.48 1TopPoplar24.5x7x11.19$1.24$1.48 2Arm HolderPoplar7x5x10.49$1.24$0.60 1BackPoplar7x6x10.29$1.24$0.36 Total Bd.Ft.6.41 20% Extra Bd.Ft.1.28 Subtotal of Pieces$36.89 Cost of 20% Extra$1.59 Shipping$2.25 Name:Mohamed Abuzaid Total Cost of Project$40.73

17. Sources  http://hackaday.com/2009/06/23/how-to-build- your-own-spot-welder/ http://hackaday.com/2009/06/23/how-to-build- your-own-spot-welder/