Blockman was one of those lines that passed me right on by until I was in college. One of Takara's cool robot lines of the 80's, Blockman did see life in the US as part of the Robotech toy line and even bootlegs of the figures did appear in gumball machines. While I vaguely recall seeing the Robotech versions at Kaybee, I did have some of the gumball machine bootlegs. I don't know the specifics of distribution (the machine owner probably just ordered machine robot toys from a catalog), but I very strongly remember the Kroger we'd get groceries at had an awesome selection of gumball machine toys for awhile. Including one with a generic space robots art taped to the front and random robot toys inside.
Mostly I'd get various Mospeada (which I knew as the third season of Robotech) figure kits (probably were bootlegs of some candy kit) in a variety of colors from it. Occasionally I'd get some of these neat square robot dudes in that machine without any clue to who they were other than a neat robot. That machine rocked, though eventually it gave way to little rubber figures of various bootlegged characters, which too was awesome, just for different reasons.