I wanted to make a prototype for a retro recipe card holder. My goal is to powder coat it, then give them as gifts with a bottle of wine.
Step 1: Make a Template and Scribe Around It
It turns out that TechShop has a class in angular sheet metal and already had the template that I needed -- So I took the class.
Start with a square of 16 gauge steel. It is about 1/8 of an inch thick.
Take a scribe an trace around the template.
Step 2: Use a Turret Punch to Punch Out Relief Holes
Instead of drilling holes, you can punch holes using a "Turret Punch" to pop the metal out. Not only is it faster, but since there are many different dies on a rotating assembly, it allows you to change sizes quickly. You can also make half holes (crescent shaped) near another hole without the issue of having a drill bit "walk"
Note the "key holes" that were punched to allow a screw to hold up the box by slipping it over the head of a screw.
The relief holes allow space when you're going to bend the sheet metal.
Step 3: Use a Corner Punch to Punch Out the Corners
You could use tin snips to do this, but the corner punch "shears" the metal in one step with a right angle.
Line up the previously scribed lines under the cutter and pull the handle. Do this for all for corners.
Step 4: Cut the Tight Angles With a Shear
The parabolic knife on the shear allows you to make cuts in tight places.
Use the shear to cut the metal near the relief holes.
When you're done, you have a piece of sheet metal that is ready to bend.
Step 5: Bend the Box Using a Finger Brake
The Finger Brake is used to hold metal and allows you to bend it to any angle between 0 and 100 degrees.
The black "Fingers" can move out of the way so that you can hold your part where you need to do so.
Bend the sides with 90 degree angles one by one.
Step 6: Spot Weld the Sides
Place the part where you want to place a weld. The spot welder works by running a current between the two copper electrodes. You only need to apply the current for a second or two to make the welds.
Step 7: File Off All of the Burrs
Use a file to smooth the burrs. Do this before you you bend and also after you bend.
You can also use a needle file to clean up the key holes.
Step 8: Ready for Powder Coating
That's all it takes!
This took about an hour to do. I made it at Tech Shop!