There is very important information regarding the set up of the MIG welding machine discussed in the MIG welding SBU. This instructable is only to guide you during your first set-up of the machine. Please remember to follow the rules and instructions provided in the class!
After teaching hundreds of hours of welding classes at TechShop I have found that students have a hard time remembering some of the steps to get the machine set up. This instructable is to serve as a guide for people that have passed my MIG welding class but need a bit of a refresher on how to set up the machine.
NOTE: This instructable is not meant to replace the MIG welding SBU at TechShop Menlo Park, it is merely here as a supplement for those that have already taken and passed the class.
Step 1: Getting Ready to Get Ready
There are a few things you will need to take care of before you can assemble the the torch and weld.
1) Get the welding cage open. If you can find a staff member roaming the shop ask them to open the welding cage. If you can't find anybody, the front desk will be happy to page the appropriate staff member for you.
2) Grab the MIG kit that is specific to your machine (either 1 or 2). Fill in the tool check out form on the clipboard. Make sure to check the MIG box before filling out the tool checkout. There should be both a contact tip and a gas cup in the box.
3) Grab a pair of MIG welding gloves, an auto-darkening helmet, the MIG pliers, and the MIG dip (nozzle gel).
Step 2: Assembling the Torch
1) The bare torch. Do not try and weld with a bare torch! If you strike an arc without properly assembling the torch you may be billed for damage to the machine.
2) A look at the contact tip (the small thing on the left) and the gas cup (the big thing on the right).
3) Install the contact tip by sliding it over the exposed wire.
4) Now screw in the contact tip barely finger tight.
5) Put the gas cup and screw it on to the front of the torch.
6) Check to make sure that the contact tip is recessed down inside the gas cup. If the contact tip is sticking out of the gas cup get a staff member to see what is wrong with your setup.
Step 3: Plugging in the Machine
Plugging in the machine poses a serious risk of shock. Please make sure to follow the directions exactly!
1) Make sure your machine is off (the switch on the front of the machine).
2) Make sure your breaker is switched to off.
3) Plug the machine into an outlet with the breaker switched off.
4) Once the machine is plugged in to the outlet, switch the breaker on. After the breaker is on, turn the machine on.
Step 4: Getting Ready to Set Gas Flow
1) Put the ground clamp on the ground so that you will not accidentally start welding while you are setting the gas flow.
2) Turn the wire feed speed all the way down so that you don't waste wire while setting the gas flow.
Step 5: Open Cylinder and Set Gas Flow
1) The first picture shows the proper order to set the gas flow. Start by turning the regulator off (#1)
2) Be safe when you open the bottle, make sure you are standing in the safe zone (the safe zone is where the camera perspective is for shot #2) and make sure that your hand is on the side of the valve, not the top (shot #3). Open the bottle all the way.
3) Make sure that your bottle is in the safe range of pressures. It should have between 250psi and 2200psi.
4) Set your gas flow to 15cfh by pulling down on the trigger (on the gun) while simultaneously opening the regulator valve. You will see a ball rise in the cylinder. Make sure the center of the ball is aligned with 15cfh on the Argon & CO2 mixture scale.
Step 6: Verify Wire and Set Voltage/wire Feed
1) Make sure that you are using the right wire. For welding mild steel we use ER70S-6. It should look like a copper wire (it is only coated in copper).
2) Find the thickness of your material listed inside the machine. Set the machine to its recommended wire feed speed and voltage on the front of the machine. If you need to weld material that is thicker than any of the machine recommendations, set the machine to the maximum voltage and wire feed that is recommended.
3) The third picture shows the machine set to E-5 which is the proper setting for 16 gauge (on MIG station #2).
Now all you need to do is set your ground clamp. You should set your ground between 6" and 2' away from where you will be welding.