The attached 3mf and STL files are custom brackets designed to easily allow 2x4s to fit together in the appropriate pattern to create your own custom DIY workbench from nothing but some PLA, 2x4s and plywood. As you can see from the pictures this came out great. I am still using it today and it is stronger than anything else I have around the house. However, there are some things that need to be disclosed here. 

Firstly, I worked on this project several months ago with the intention of posting it, but things came up and it took awhile to get around to it. I know that the first 2x4 bracket that I used was based on a 3D model somewhere online and I tried to link to it to attribute the remix, but I simply cannot find it. Honestly that highlights why I am bothering to post this model now after so much time. I knew that there were kits that you could buy from the store to do this type of thing, but surely it had to exist for me to print for free. I was shocked at how hard it was to find anything remotely close to what I was looking for. If you are the author of the original model for this please contact me so that I can properly attribute your work.

Second, these models will print fine and be plenty strong enough for you to construct a workbench, but the final design of the bench is not perfect. Try as I might, I still ended up with one end of the workbench being 1 inch shorter than the other end. Do I care? No. I'm not worried about my workbench for 3D printing looking beautiful. I want it to be sturdy and functional and it really is. 

Third, I'm not a great 3D modeler. Many of these were created in Tinkercad with alot of hand-editing and eyeballing. They all print perfectly and work perfectly, but if you see a random screw hole in some place where it doesn't make sense, then that was an artifact of me duplicating sides of the objects and merging them together. Sorry. 

This is as easy as it looks.

1. Download the 3mf and print one to two copies of the models depending on how many “tiers” you want to your work bench. I printed 2. 
2. Buy all the 2x4s and plywood.
3. Decide how long and wide you want each side to be and sketch it in advance to help yourself with a cut list.
4. Cut the wood and slide it into the brackets.
5. Attach each 2x4 to each other with 2.5 inch screws.

It's important to point out if it's not obvious that the brackets are absolutely not the thing holding this workbench together. All they do is make it dead simple to create the shape you want and screw the 2x4s to each other. It's also worth noting that if you don't want an L-shape I'm sure you can simply make a standard rectangle easily with these.

I debated on posting these models or not given that you still have to understand the task at hand and  you don't magically get a perfectly square workbench without doing all the appropriate DIY work, but given how hard it was to find something acceptable online I really wanted to contribute it back to the community so that someone else out there could benefit from the work as well. 

Please take the time to scroll through all the pictures. I tried to document as much as I could along the way