Task: roller designing for easier unwinding of an existing simple rod spool.

Since it is an indoor application, we chose PLA material for the task, which provides sufficient strength below 50°C. The base body of the rollers and the roller holder are also made of PLA. In order to increase the friction of the rollers, the rollers received a coating made of softer TPU.

The axle of the rollers is a dowel pin.

PLA is a hard, brittle material, and the dowel pin has a ground, very smooth surface, thanks to which there is extremely little friction between them.

Thanks to the above aspects, our planned part meets the requirements set in advance:

• rigid base body
• low friction shaft-roller connection
• higher friction roller-spool connection
• proper support and guidance of the spool with appropriate geometry designing