Pair of linear actuators (found on eBay for 150)
Premium pine (Home Depot 50 bucks)
12v power supply (found in my electronics junk box)
Step 1: Design
Step 2: Gather all the parts
I went to Home Depot to find some wood, I ended up spending about 50 dollars for premium pine. All the cheap pine was warped and I figured a telescoping column should probably have straight edges.
Step 3: Cut and assemble the legs
I mounted the linear actuator to a small wood base, then built the inner column around it. Then the outer column around the inner.
I tested the first leg built to see if it could lift the table top. It did, so I built another one.