Thomas Matthew Crooks -- the 20-year-old who clipped President Trump's ear during a 2024 rally -- allegedly texted with an "unknown contact" about 3D-printed parts ... a little over a year before the assassination attempt.

According to FBI Records obtained by Judicial Watch ... Crooks was texting with someone on February 9, 2023, who asked him ... "Did you 3D print the parts?"

The docs say the would-be assassin responded ... "Yes, except for the fan blades."

This exchange came after Crooks had sent something -- which was completely redacted in the records -- causing the mystery texter to say ... "woah that looks cool."

The FBI described the other person as an "unknown contact" and said the messages in the records were "deemed pertinent" to the attempted assassination investigation.

It's worth noting that The Post previously obtained FBI interviews with Crooks' father ... where he said his son once made a handgun with his 3D printer.

As you know, Crooks' 2024 assassination attempt failed when the bullet appeared to graze Trump's ear. He also hit members of the audience ... one of whom died immediately.

Crooks was taken out by snipers ... and the cost of his cremation was covered by an anonymous donor.