How to weld a frame without an expensive welding table

For my senior design project, I am working on a hybrid go-kart that leverages a gas-powered engine and an electric motor to provide a lot of torque at low speeds, and a very fast high speed. To show off our power train at demo day, obviously we need a strong chassis to mount everything to, for driving. In order to make this chassis, we need to find a way to cheaply align all the cut frame rails and weld them together with enough accuracy so that we don’t need to gap any welds when cutting frame rails to length right off of the SolidWorks cut list. Professional studios will do this with expensive welding tables that are the size of the entire chassis, with precise holes to bolt frame rails to for welding. For our project, we don’t have such a table, so we are going to build our own, and use laser cut wood to line everything up with great precision. Then, we can bolt down 3d printed jigs to lock down the pipes for welding.

How does this relate to M5? Well, at M5, Robert and I have been designing and building a 600-pound boombox, with twin 2.5 horsepower electric motors to propel two massive JBL speakers and an audio equipment rack to terrify the residents of downtown Amherst with loud music. To build the frame for the boombox, I will be employing a similar strategy to align everything to match what is in FreeCAD. Although, I don’t need a perfectly flat surface, so I will be 3d printng alignment jigs to square the corners, and then just slot in the cut segments I cut at the makerspace.