The Home Depot

A guide to Baltimore's emerging maker culture

The 3-foot-tall robot looks like a Roomba vacuum cleaner with a cardboard tower on it, a small electronic tablet for a head. The face is a video of me, watching the thing roll up, then reverse back toward the work table, where Gerald Knight sits in front of a laptop with the same video playing on it.

"Normally, robots like that are like $10,000," Knight, a middle-aged African-American guy in a ball cap and glasses, says. "This is $350. The tablet is from Walmart."

We're at the Baltimore Hackerspace on a Wednesday night. The location, on Landay Avenue, between the Player's strip club and a business that seems to involve moving a lot of...