Sen. Chuck Schumer is warning the public to watch out for 3-D printed guns — that people will be able to legally download starting on Aug. 1.

Gun rights activists reached a settlement with the US State Department and Department of Justice last week that allows them to post detailed instructions, including plans, files and 3-D drawings of the weapons.

“This online site shows you, how at your home, with a simple 3D printer, you can make a plastic AR-15, an AR-10, a very dangerous semi-automatic assault-style weapons out of plastic in your own basement,” Schumer said at a Sunday press conference.

The June 29 settlement stems from 2013, when the US government shut down Texas-based Defense Distributed when the website began sharing printable 3-D gun plans online — saying they were violating laws that regulate the export of guns, since anyone anywhere could download their plans.

The site’s owner, Cody Wilson, sued and the US government reached a settlement with him allowing Defense Distributed to post the plans and agreeing to pay almost $40,000 of his legal fees.

Schumer warned that the results could be disastrous — and could potentially arm people who cannot legally purchase a gun under existing laws.

“The danger that could happen can be enormous,” he said. “To have crazy people have easy access, to have terrorists have easy access to this kind of website and allow them to make plastic AR 15s undetected — so-called ghost guns — justifies the imagination.”

The 3-D printed guns are inferior to weapons that firearms manufacturers traditionally make, but still work. Printers run anywhere from $200 to hundreds of thousands.

Schumer demanded the federal government reverse its decision. He’ll be making a bill with a solution to the ghost gun blueprints by the end of the week, his spokesperson said.

Additional reporting by Tamar Lapin