AMS Spring 2023

Screw Threading in 3D Printed Objects Now a Reality, Thanks to Formlabs

Inkbit

Share this Article

Think of the last thing you 3D printed, or even just the most recent object you used. Chances are it had some moving parts, or at least parts joined together from separately made pieces. From my computer mouse to my space heater, most of the manufactured items on anformlabs logod around my desk (and the desk itself) have connecting pieces. Sure, none of these things were made on a 3D printer, but as they’re put together now… well, they couldn’t have been.

The reason why is pretty small, but immediately recognizable: metal threads.

3D printed pieces are used frequently in prototyping, which leads to experimental opportunities for product design and assembly. The team over at Formlabs has had plenty of experience designing, tweaking, and redesigning prototypes to be 3D printed on their Form 1+. A common solution to connecting components of 3D printed models is the character key, a sort of male-female connecting piece assembly. Check it out in action:

That’s a pretty clever construction method, but it isn’t very realistic to use in something that might need to be connected, unconnected, and reconnected repeatedly. Many traditionally manufactured pieces utilize metal threads for their effectiveness in secure connections and ability to be repeatedly used. Makers have been looking for ways to work metal threading into 3D printed pieces for some time. And now, after some trial and error, the Formlabs team has come up with some options. It has ranked them, for convenience, starting with the most effective method and going down to the least effective.

  1.  Print a pocket for metal threads (add a nut).jason_screws
  2. Print threads and chase with a tap.
  3. Use thread-cutting screws designed for plastics.

It also notes (emphasis is Formlabs):

AVOID using press-fit or heat set threaded inserts! Even if they are designed for ‘plastic,’ they do not work well in our acrylate photopolymer resins.”

Of course, they go into more detail about methods and findings in their Inside Formlabs blog post.

The Formlabs team has tested these techniques thoroughly. Note that with male and female thread sizes, 1⁄4-20 or larger have the best chance to form functional parts without necessitating post processing, and smaller screws tend to require more customization for better fastening. “For example,” it notes, “printing a semi-circular thread profile (on screw and nut) and using a 0.1 mm offset gives better thread engagement with improved wear characteristics.”

thread_drawing

Formlabs offers an STL download for its most successful test so you can try it at home. It also recommends ordering steel hex nuts, coupling nuts, and forming screws from McMaster.

Will you try one of these methods? How did it work for you? Let us know what your thoughts on the process are in the 3D Printed with Screw Threads forum at 3DPB.com.

screw threads

Share this Article


Recent News

Startup to 3D Print Data Centers Using $7M in Funding

All-Female Vehicle Builds and International Trade Anchor Women in 3D Printing Conference in Dreams and Reality



Categories

3D Design

3D Printed Art

3D Printed Food

3D Printed Guns


You May Also Like

3D Printing Webinar and Event Roundup: January 22, 2023

For this weekend’s roundup, the TIPE 3D Printing Conference kicks things off with its third iteration on Tuesday, and ASTM International will hold an AM construction workshop. There will also...

Featured

Learn About 3D Printing at Wi3DP’s Third TIPE Conference

After a year in which many businesses learned to navigate new challenges and risks, 2022 taught many in the 3D printing industry how to better prepare for the future. With...

AMS to Bring Unique Networking to 3D Printing Community in NYC

Thanks to the contributions of our sponsors and participants, Additive Manufacturing Strategies (AMS) 2023 will feature some truly fun and novel networking activities in New York, February 7 – 9,...

2023 3D Printing Predictions: The Future of ESG in AM

Historically written off as an externality to finance, factors of environment, social, and governance (ESG) have become increasingly important to not only how a business is perceived but how successfully...