Today we utilized a 3D printed split-ring commutator with adhesive copper tape making contact with the brushes. We were expecting greater efficiency, but actually got less. The copper foil we are using isn’t ‘springy’ enough – a new brush system is needed or at least some thicker copper foil. (Granted it only has 2V through it in this video) Check it out.
Something else to consider when using 3D printed parts instead of balsa is that the extra weight causes the shaft to sag… If using 3D printed parts consider using something other than a wooden skewer – maybe a metallic skewer, knitting needle etc.
Find ‘Making a DC Motor’ Activity sheet available from download here, which also includes .skp files for the armature and commutator.
https://mega.co.nz/#!MchCjLJb!K0UQNSKNNGZ4tf9cDjL9JVJow-kiAZ8DVueE-06RPb4
We are currently working on a 4-pole DC motor. Two commutator’s will be needed placed 90 degrees out of phase to ensure maximum efficiency. (We think.)
*Instructions for a simpler DC motor can be found here.
Adrian Camm 
Leave a Reply