Purchase connectors for the DIY modular computer desk online. Choose 1 1/4 inch water pipe with a thick wall or lighter-weight and less-expensive chain-link fence post pipe. The choice is based on the importance of strength over cost and weight.
Clamp the pipe in a vice. Cut it with a heavy-duty pipe cutter, a hacksaw with an 18 to 24 teeth-per-inch blade, a cordless portable band saw, or a metal cutoff saw with an abrasive blade (requires face shield).
Fit the pipes and Kee Klamp connectors together like TINKERTOYS. Secure each connector with a recessed set screw. Tighten manually with an Allen wrench or a hex key bit in your power driver with torque adjusted to avoid stripping the threads.
Construct two feet for the modular computer desk. First, thread a vertical fitting onto a pipe for the uprights in the next step, and then add a flanged fitting at each end of the pipes to serve as feet.
Insert an upright pipe length into the vertical fitting on each foot assembly. Use a level to confirm they are upright and snug the fitting with a T-handled Allen wrench. Add a spreader or brace to the uprights.
Thread horizontal shelf supports over the uprights at desired levels and positions and Fix them in place by tightening the set screws. Typically, these shelves will hold the CPU and printer in the modular computer desk.
Add a horizontal support over each upright to support the desktop for the modular computer desk. These fittings are adjustable so that the desktop can be flat or tilted to the desired angle. Secure the fittings with set screws.
Install shelf supports on the uprights for the speaker shelves. Connect the two uprights with a top spreader which doubles as the top shelf support for the modular computer desk.
Make shelves of high-density particle board or cabinet-grade plywood. Attach to pipes with metal slip-on supports. Secure shelves with coarsely threaded screws and fender washers. Snap end-caps into pipes to give the modular computer desk a more finished look.
Suspend the monitor from the top spreader of the modular computer desk via a special fitting. Secure the monitor with a monitor mounting bracket to position it at any height and swivel or tilt it for the best view.