Teufel Rockster Air Carrying Handle

Even though the Teufel Rockster Air is the smaller version of Teufel's big portable speakers, weighing 15kg it still is inconvenient to move around. Out of the box it just features a thin strap to carry the speaker over the shoulder, but no handles like other PA type speakers.

This handle utilizes the eyebolt that screws into the side to securely attach to the speaker. A plus is, that this way the shoulder strap can still be used. The handle features a folding design so that it doesn't interfere when not being used. The hinges consist of of two M8x20 bolts with nuts. To keep the handle from twisting I used addtional doublesided tape.

The inner width of the handle is 80mm, the diameter is 30mm. The distance from the eyebolt to the handle is 30mm.

I did a simple FEM analysis to see how the construction performs under load. I assumed a force of 300N (30kg) acting onto the surface of the hole for the eyebolt. This should equal about four times the usual load the handle experiences. I set the cylinder surface of the handle as fixed. The evaluated material is printed PETG with a yield strength of 23 MPa.

The minimum safety factor of the construction is 1.278 meaning the maximum load experienced by the material is 18 MPa. The position of the highest load is at the contact surface between handle and base. The shown deformations are greatly exagerated for analysis purposes.

For sufficient strength I printed the handle with 100% infill. This results in about 260g of filament being used and a print time of 12 hours. Depending on the filament quality, it might be necessary to reduce the flow rate. I achieved good results with the flow rate set to 90% after the first layer.