Pre-Tensioned Sofa Armrest Tray Table

Finally! A firm and reliable sofa armrest table. This one uses elastic cord to hold its leaflets in your preferred shape. 

This one is 7 inches wide and 0.5 inches thick. In its pictured config it can accommodate ANY sofa arms between about 5 and 13 inches thick. The entire tray can also rest flat, or be folded in on itself to elevate!

*snacks not included.

Requirements 

• Requires three equal pieces of 1/8in (3mm) diameter elastic bungee/shock cord. This can be found at most craft stores and online sellers around the world.

• Printed parts:

  • 1x Center_Tray.stl

  • 2x End_Bar.stl

  • 8x Middle_Bar-1in.stl 

  • Optional: Middle_Bar is also available in 0.75 and 0.5 inch increments for a snug sofa fit. Alternatively, you can Substitute all the middle bars for a different aesthetic choice. 

Printing:

• 0.2mm Balanced preset or equivalent

• (Enable brim if warping is a concern)

• 10% Infill

• No Support

Assemble:

1. Tie a knot in the end of your 3mm elastic cord. 

2. Feed the other end through the center hole of the printed parts as pictured; starting with an End Bar. 

3. Finish on an End Bar by pulling the elastic tight, and tie another knot.

4. Cut the excess elastic cord and repeat for remaining holes. 

Woodgrain?:

• Follow the method featured here by PandaN: https://hackaday.com/2025/06/03/add-wood-grain-texture-to-3d-prints-with-a-model-of-a-log