T-bar Row / Landmine Dumbbell attachment

Parametric T-Bar Row Dumbbell Attachment

I designed this T-Bar Row attachment to create a simple and compact landmine-style setup using a dumbbell as the anchor point. The main pivot rotates on bearings for smooth movement during exercises, and a separate printable protective cover helps prevent impacts and protects the attachment.

The model is fully parametric and can be adjusted to fit different equipment sizes. 

Adjustable Parameters (Dimensions in sliced model)

• Dumbbell hole diameter       (28mm)
• Barbell hole diameter            (25 mm)
• Barbell hole length                 (80 mm)
• Bearing outer diameter (OutBearing)       (24,1 mm)
• Bearing inner diameter (InBearing)           (14,9 mm)
• Protective cover thickness     (3 mm)
• NoBearing dimension

Bearing and Bearing-Free Versions

The attachment is designed to use bearings for the smoothest operation and minimal wear (default 24x15mm).

If bearings are not available, it is possible to print a thicker integrated pivot pin instead. For reliable rotation, a clearance of approximately 0.2 mm on diameter is recommended between mating parts. Keep in mind that a fully printed pivot will gradually wear over time.

For a bearing-free setup:

• Set OutBearing approximately 0.2 mm larger than InBearing.
• Print the integrated pivot pin.

Alternatively, you can use your own metal shaft or bolt. In that case, set NoBearing = 100 to remove the integrated bearing pin from the model.

Alternative Mounting Part

An alternative mounting part is included for users who prefer to use metal bolts instead of printed fasteners, providing improved durability and strength.

The mounting holes are fully customizable. By default, they are set to 10 mm in diameter. Keep in mind that increasing the hole diameter may cause interference with the dumbbell mounting hole due to the limited available space.

Printing Notes

• PETG, ABS, ASA, or other durable materials are recommended.
• Use sufficient wall count and infill appropriate for the loads involved.
• Inspect the printed part regularly and use at your own risk.
• May need sanding, depending on your printer and settings.
• There is a small support structure between the main parts that must be removed to allow the attachment to move freely.

If you make improvements or adaptations for different equipment sizes, feel free to share them.