Green’s Dictionary of Slang

nigger rig v.

[nigger n.1 (1) + SE rig]

(US) to perform second-rate, sloppy work; thus as n., a bodged job, a piece of do-it-yourself assembly.

[US] in DARE.
[UK]J. Mowry Six Out Seven (1994) 29: Corbitt, Lamar, and Toby had built themselves one [i.e. a skateboard ramp] from scrap wood. It was a nigger-rig, and full of splinters, but it worked.
[US](con. 1950s) in DARE File n.p.: The N-word showed up in a lot of places back home among the hillbillies (which is to say, us). To Nigger-rig was to improvise. . . as in ‘I had to nigger-rig that exhaust system, Cletus.’ [DARE].
[US]‘Dutch’ ? (Pronounced Que) [ebook] The way the bumper had been ‘nigguh-rigged’ with electrical tape and a chain to stay attached to the car.

In derivatives

nigger-rigged (adj.)

(US) characterized by bad workmanship.

[US]Maledicta III:2 170: nigger rigged adj Characterized by shoddy workmanship.
[UK]J. Mowry Way Past Cool 119: The nigger-rigged plumbing was a leaky stinking joke even when it worked.