Making a gun on a 3D printer is not like hitting the Easy button at Staples, says a Harrisburg University of Science and Technology professor. It requires engineering know-how and some money.

Charles Palmer, who heads the university's Interactive Media Department, said pieces have to be assembled properly and likely require some metal to make a viable firearm.

Considering that it can cost anywhere from a few hundred dollars to tens of thousands of dollars for a 3D printer -- not including the cost of materials -- he asked: "Why would I buy that to make a gun? A gun is cheaper than that."

Concerned about untraceable guns on the streets, state Attorney General Josh Shapiro, Gov. Tom Wolf and the state police on Sunday went to court and succeeded in getting a Texas company to agree to make its downloadable gun blueprints unaccessible to Pennsylvania users and to not upload any plans for making new 3D guns.

FILE - In this May 10, 2013, file photo, Cody Wilson holds what he calls a Liberator pistol that was completely made on a 3-D-printer at his home in Austin, Texas. Eight states filed suit Monday, July 30, 2018, against the Trump administration over its decision to allow a Texas company to publish downloadable blueprints for a 3D-printed gun, contending the hard-to-trace plastic weapons are a boon to terrorists and criminals and threaten public safety.

The company, Defense Distributed, which in late June settled a lengthy lawsuit with the federal government allowing the company to make its 3D gun plans available online, had promised to make the gun files available starting on Wednesday although they began distributing them last week.

Now eight states, including Pennsylvania, are suing the Trump Administration over its decision to allow the company to publish downloadable blueprints for fully functioning 3-D printed guns.

Additionally, on Tuesday, U.S. Sen. Bob Casey, along with other senators, introduced legislation to block the online publication of those blueprints.

"The fact that these weapons can be made at home by criminals and domestic abusers, bypassing our laws, is simply outrageous," Casey said. "Congress has a duty to present a solution and this legislation is just that."

However, Chris Cox, executive director of the National Rifle Association Institute for Legislative Action, issued a statement on Tuesday blasting anti-gun politicians and the media for wrongly claiming that 3D printing would open the door to widespread proliferation of undetectable plastic firearms.

"Regardless of what a person may be able to publish on the Internet, undetectable plastic guns have been illegal for 30 years. Federal law passed in 1988, crafted with the NRA's support, makes it unlawful to manufacture, import, sell, ship, deliver, possess, transfer, or receive an undetectable firearm," he said.

Meanwhile, Cody Wilson, the founder of Defense Distributed, which first published downloadable gun designs for 3-D printers in 2013 until it was ordered by the federal government to cease, has filed his own lawsuit in Texas. In it, the company claims it is a victim of "ideologically-fueled program of intimidation and harassment" that violates the company's First Amendment rights.

Josh Blackman, the company's attorney, told Time on Monday that while states can enact gun control measure, they can't censor "the speech of another citizen in another state, and they can't regulate the commerce of another citizen in another state when that commerce is authorized by a federal government license." Blackman added, "It's a violation of the First Amendment, it's unconscionable and we're going to fight it to the very end."

Harrisburg University's Palmer said middle schools, high schools and universities all have 3D printers these days and their students know how to use them. But as an educational institution, he said, "we're not leaning on how these can be used in a negative light. We're looking at how these can change the industry of manufacturing."

The 3D printers, which essentially create objects by laying down successive layers of material, are used these days to make artificial limbs, ears, even temporary shelters in places where disaster leaves people homeless. But to do that, just as is the case with making a gun, it's not a matter of simply turning on a 3D printer and telling it to make one.

As with dressmaking, Palmer said he could buy material, buttons, and thread but that doesn't mean he knows how to transform that into a dress. The same goes with making a firearm on a 3D printer.

"There's still quite a bit of effort that goes into turning this 3D pattern essentially into a weapon," he said.

*This story was updated to include the statement from Chris Cox of the NRA's Institute for Legislative Action.