Tuesday, April 9, 2019

Victoria Bergmeister transmission drawing (and ellipse guides)

 A cutaway drawing of an unusual motorcycle transmission, instead of meshing gears, in this case each ratio is a set of sprockets with double row chains. Sliding dogs and a drum still engage and disengage to determine ratios though. I don't recognize the artist's name (enlarged below) but it appears he is struggling with the ellipses that result from drawing circles on an angle in a perspective view. The first set of sprockets are on a different (incorrect) angle than the ones behind them and is painful to look at.  
In design school we tried to freehand the ellipses required to sketch car and motorcycle wheels in our vehicle concepts, I splurged and cheated by springing for both sets of ellipse guides- big dollars! so I had available, ellipses for every 5 degrees up to 4 inches diameter (height). When it became apparent that I was never going to master the technique- either with or without the guides, I passed them on to a friend/classmate Bruce- who really didn't need them- as perspective sketches and the required ellipses flow naturally onto paper for him.

See more at Bruce Thomson's Sketch Blog

No comments: