Lego Stud No-Sew Button

Riffing on my oversized (6x) Lego stud (https://www.prusaprinters.org/prints/111317-oversized-lego-stud), this version is roughly 3x the size of the real 1x1 stud to make it the same size as a typical 20mm button found on many coats. At its largest (the middle ridge of the stud), it is just over 24mm.

At this size, it makes a fashion accessory that will fit a jacket or any other item with a buttonhole and really click with other Lego fans while still being printable with a 0.4mm nozzle!

Wear it as a pin in an unused buttonhole, decorate a lapel, or use it as an actual button to secure a jacket or backpack flap. If the stud is too large to fit through the opposite buttonhole, have no fear! The stud can be removed to reveal a smaller 16mm button (like those found on many pairs of jeans and button-up shirts). Pop the button through the hole and reattach the stylish stud with the threads. Now you're buttoned up and the button is secured in the hole until you remove the stud.

The Parts

The button comes in three pieces for maximum compatibility and fun:

• Backer
  • The piece that holds the button on your garment (or whatever) from the inside/backside
  • It has an M8x1 thread with six threads for a good connection to the button
  • Chamfered at the base to strengthen the center rod
  • Comes in 2mm, 4mm, and 6mm versions so you can attach your buttons to thinner items (2mm is good for light fabrics or single layers of denim) or thicker outerwear
• Button
  • This is the inner 16mm button
  • Inner M8x1 (right-handed) thread for the backers
  • Outer M16x1.25 (left-handed) thread for the Lego stud
• Stud
  • The true centerpiece that threads onto the button
  • Print a bunch in different colors and easily swap them to match your ensemble!

Assembly

1. Take the backer you selected and insert it through your buttonhole from the back/inside of the garment or bag.
2. Screw the double-threaded button onto the backer's post.
3. Thread the Lego stud onto the assembled button (it threads in reverse compared to what you are probably used to - i.e., left-handed).

Notes on Threads

The outer threading of the button and the inner threading of the Lego stud is left-handed so it turns opposite the backer and inner button threading. This makes it easy to swap your Lego stud buttons without worrying about the button coming off with the stud.

Twist left to thread and tighten the stud on the backer's post. Once fully threaded, twists to the left will begin to loosen the button. Keep going if you want to remove the button and stud at the same time.

This combination of right and left-handed threads makes it very unlikely you'll ever accidentally overtighten any of the pieces (risking layer separation).

If your threads feel loose or the button isn't staying tightened on the backer while threading the stud, hand tighten the button (twist right) until it's firmly seated against the bottom of the threads on the backer's rod. Then thread the Lego stud.

You may never need to remove the button from the post, so feel free use a little glue if you want it threaded permanently.

Threading has an added 0.15mm tolerance so everything should thread smoothly without being too loose or too tight. The threads work wonderfully with matte filament and silky filament. The waxy and shiny finishes seem to help the threads really glide over each other.

FDM Printing Tips

Print with supports under your Lego studs to help the overhangs. Everything else prints without supports. Even the LEGO logo on top will print nicely with a 0.4mm nozzle.

Print with a 1.5mm layer height. You can do 1mm and even 2mm might be fine, but 1.5 offers a nice balance between the print time and thread quality.

For an extra nice Lego stud, paint a seam line along the bottom (in relation to the Lego logo on top). This will make a huge difference if you print with a silky/shiny filament.

The 3MF file has the painted seam and supports.

Adding Color

You can print the LEGO logo in a different color by using PrusaSlicer's multilateral painting tool or by adding a filament swap for the very last layer (15.60 or 15.65mm for 1.5 and 1.0mm layer heights).

If you print the stud using 2.0mm layer heights the logo is part of the top-most layers, so you'll need to use multimaterial painting. Layers larger than 1.5mm are not recommended anyway because threads start to look ugly at 2.0mm and beyond.

If you use an SLA printer, you can have some fun with translucent resins. The inner button and top of the post will be visible through a translucent LEGO stud, so you can play with color combinations.