Quick-Lock Threaded Dumbbell Collars, 5 sizes

Commercial License available here


Fast and Secure Collars for Threaded Dumbbells

Stop wasting time twisting traditional screw-on collars.
Quick-Lock Threaded Dumbbell Collars clip on in seconds, while still holding securely on right-hand threaded dumbbell bars. Perfect for lifters who want faster weight changes during supersets, circuits, and strength training.

Safety:
I tested the clamp with a load of around 85 kg, but I strongly recommend that you test your own printed clamp after printing it. I would also consider using standard nuts for exercises where the dumbbell is positioned above the face, especially when working with heavy weights.

How to use?

1. Place the clamp onto the dumbbell bar while it is in the open position.
2. Lock the clamp and tighten it securely.
3. Before removing the clamp from the bar, slightly loosen it first to avoid damage and ensure smooth removal.

⚠️ Important: Always loosen the clamp slightly before unlocking and removing it from the bar.

How to print and assemble?

• Follow the settings provided in the attached 3mf file
• The collar is print-in-place, so it does not require supports

• After printing, use a small amount of force to break the thin support lines for each movable part

  
   

  

  

• Use three M3x15 screws to assemble the parts
• Print from TPU, or cut anti-slip washers from SBR rubber
• Glue screw caps
   

Sizes:

Available in 5 sizes, designed to fit the diameter of your dumbbell bar:
- SM – approx. 23.7 mm (0.933 in)
- M – approx. 25.2 mm (0.992 in)
- L – approx. 26.8 mm (1.055 in)
- XL – approx. 27.7 mm (1.091 in)
- 2XL - approx. 30mm (1.181 in) (temporary removed)

How to print custom size?
To make the clamp fit your barbell perfectly:

• Use the SM size profile as a base
• Measure the outer diameter of your barbell
• Calculate the ratio and scale the thread tester in the X and Y plane (do not scale the Z axis!)

• Example:
  If the test model diameter is 23.7 mm and your barbell measures 28.5 mm:

  Scale = 28.5 / 23.7 ≈ 1.203 → scale to 120.3% in X and Y

• Print the scaled tester
• If the tester fits, scale the SM clamp in the same way
• Experiment with X-Y contour compensation for screw caps

• Experiment with X-Y hole compensation for M3 screw holes

   

  Scaling the model up to create larger sizes isn't an ideal solution. For very large threads, the screw holes may become too large. I'm currently working on a customizer that will generate models for specific thread sizes.
   

Important:

• Designed for right-hand threaded bars only. Not compatible with left-hand threads
• Check the thread shape (see comparison image)
• Not universal – compatibility depends on your specific dumbbell bar
• Like any threaded system, they may loosen over time, especially with dynamic workouts, so it’s recommended to check them occasionally while training.

Changelog

v1.0.1

- Added a new 2XL (30 mm) size
- Created separate print profiles for each size
- Adjusted hole and contour compensation for each profile for improved accuracy and fit