PlotClock Arm for Artline 500A Whiteboard Marker

First of all a big thank you to Joo - the PlotClock really is a fantastic idea!

I have printed the PlotClock and found that the markers I bought were just a little too big to fit (I snapped the original trying to get the pen in). So,I have created this remix to fit the Artline 500A whiteboard marker. It is basically the same as the original but allows for a slightly wider pen and the grip is slightly higher to give some extra strength.

I since found that this arm also fits the Staedtler Lu