3D Print The Blasphemous Helicopter Part Known As A Jesus Nut

Today, when we say “Jesus nut”, we’re not referring to the people who spend their days proselytizing down at the mall. The term, likely spawned in the Vietnam war, refers to the main nut holding the rotors on to the mast of a helicopter which is in the shape of the Christian cross. If the “Jesus nut” was to fail, the rotors would detach from the craft, and there would be little for crews to do except to pray.

[Marius] was presented with a failed Jesus nut, though thankfully from an R/C helicopter, meaning there was no loss of life. A friend needed the part replaced for their FQ777 copter, so it was time to bust out the 3D printer and get to work.

The first step was to reconstruct the broken piece so it could be measured and then modeled in CAD software with the help of calipers to determine the original dimensions. What followed will be familiar to many 3D printing enthusiasts — a case of educated trial and error, experimenting with different filaments and print settings until a usable part was produced. [Marius] notes on the part’s Thingiverse page  that they achieved the best print with an 0.2mm layer height, and printing two parts at once to allow the layers more time to cool during each pass. It was then a simple matter of tidying up the part with sandpaper and a drill bit before installing it on the vehicle.

[Marius] reports that the part was successful, being both strong enough to withstand the forces involved as well as having a fit that was just right to suit the rotor pin which needs to be able to turn freely within the Jesus nut. While they’re not always the right tool for the job, 3D printed replacement parts can sometimes surprise you. These prints that are used in repair work often don’t attract the same interest as printing cosplay armor, kinetic art, and low-poly Pokemon. But they quickly prove how transformative having a 3D printer, and the skills to use it, are. That’s why we’re running the Repairs You Can Print contest… take a few minutes to show off the really useful repairs you’ve pulled off with your 3D printer!

Win Big Prizes With Repairs You Can Print

Another month, another contest, and this time we’re looking for the best 3D printed repairs you’ve built.

The Repairs You Can Print Contest on Hackaday.io is a challenge to show off the real reason you bought a 3D printer. We want to see replacement parts, improved functionality, or a tool or jig that made a tough repair a snap. Think of this as the opposite of printing low poly Pokemon or Fallout armor. This is a contest to demonstrate the most utilitarian uses of a 3D printer. Whether you fixed your refrigerator, luggage, jet engine, vacuum cleaner, bike headlight, or anything else, we want to see how you did it!

The top twenty projects in the Repairs You Can Print contest will be rewarded with $100 in Tindie credit. That’s a Benjamin to spend on parts, upgrades, and components to take your next project to the next level!

Students and Organizations Can Win Big

The Best Student and Best Organization will win a Prusa i3 MK3!

This contest is open to everyone, but we’re also looking for the best projects to come from students and hackerspaces. We’ll be giving away two amazing 3D printers to the best Student entry and best Organization entry. These two top projects will be awarded an Original Prusa i3 MK3 with the Quad Material upgrade kit. This is one of the finest 3D printers you can buy right now, and we’re giving these away to the best student, hackerspaces, robotics club, or tool lending library.

If you have a project in mind, head on over to Hackaday.io and create a project demonstrating your 3D printed repair!

What is This Contest All About?

This contest is all about Repairs You Can Print, but what does that actually mean? Instead of printing Pokemon or plastic baubles on your desktop CNC machine, we’re looking for replacement parts. We’re looking for commercial, off the shelf items that were broken, but repaired with the help of a 3D printer. Is your repair good enough to show off as part of the contest? Yes! That’s the point, we want to see the clever repair jobs that people often don’t spend much time talking about because they just work.

Need some examples? Sure thing.

A while back, [Elliot Williams], one of the fantastic Hackaday Editors, had a broken vacuum cleaner. The wheels were crap, but luckily they were designed as a single part that snaps into a swivel socket. Over six or so years, the original wheels in this vacuum gave out, but a replacement part was quickly printed and stuffed into the socket. The new wheels have been going strong for a year now. That’s an entire year of use for a vacuum for five cents worth of plastic and an hour’s worth of printing time.

Need another example? My suitcase was apparently dragged behind a luggage cart for miles at either ORD or PHL. When it arrived on the baggage carousel, one wheel was shredded, and the wheel mount was ground down to almost the axle. The rest of the bag was still good, and I just removed the old wheel, salvaged the bearings, and printed a new wheel out of PLA. This suitcase has now traveled 60,000 miles with a 3D printed wheel, and it’s only now looking worse for wear.

How To Get In On The Action

We’re looking for the best repairs, jigs, and tools you’ve ever printed. To get started, head on over to Hackaday.io, create a new project, and document your repair. The Repairs You Can Print contest will run from Tuesday, January 16th, 2018 through 12 PM PST Tuesday, February 20th, 2018. Here’s a handy count down timer for ‘ya.