Doing your own sheet metal fabrication is a fairly complex project that requires careful planning and a lot of time spent of creating the sheet metal item itself to make sure it holds enough quality to be useful. Planning is particularly important, and you should draw every aspect of the sheet metal fabrication before you set out on actually doing it. When planning a sheet metal fabrication project, there are a few particular things you should consider making sure the project turns out as good as possible.
Planning bend relief
If your project involves bending of the sheet metal, you need to make this clear as you're drawing. You should also make sure you remember planning for bend relief as well as the bend itself. Bend relief means that you make small cuts on both sides of the part of the material that needs to be bent. This makes bending much simpler and puts less stress on the material. If this is not done, you might end up distorting the material as you're bending it. Drawing these cuts out beforehand also makes it easier to plan the rest of the project, as you should want to avoid cutting or drilling too close to these cuts to avoid the material ripping.
Avoiding small holes
Another important thing to remember as you're planning your sheet metal fabrication project is to make sure that any holes made from drilling are large enough to not ruin any drill you might want to use. Small drills used on a thick sheet are very likely to snap. It's always better to use slightly larger holes and screws than you might need to avoid ruining your equipment. Avoid using drills that create holes whose diameter is smaller than the thickness of the sheet metal itself, as this largely increases the risk of breaking the drill or the drill bit.
Drilling close to a bend
It's also important to keep a distance between drilled holes and bends. If you do the drilling before the bending, the bend might distort the hole, making it useless. If you do the bending before the drilling, it might be difficult to get the right angle on the hole you're drilling. This is why you should drill first and keep at least double the thickness of the material as distance between a hole and a bend. Try avoiding drilling close to bends in general as you're drawing your project. It's easier to find alternative solutions when drawing than when you're working with the material itself where changes can be difficult or impossible to make if you've already bent or drilled the material.
