OK, a word about 2d vs 3d.... yes, I'm sure I can do this wheel in 2d very easily. However, that rather defeats the point of the exercise, which is to find a good 3d partner to SW. Today a wheel, tomorrow a sump, the day after that around 2500 £2 coins to pay for a certain piece of software.
So, yes, I _could_ probably re-draw the wheel as a 2d drawing, but then I'm going to run into the same problems when I do my first complex 3d shape that isn't the same shape along the Z axis.
ANYWAY.... by removing the fillets, I got CamBam to produce some nice sensible tool paths and a relatively short program ( ~ 600 lines), unfortunately, the mill won't switch to ISO mode, it ignores my demands to change user parameters, mutter grumble.
Control is a Heidenhain TNC151. Press MOD -> up arrow -> up arrow (to get to User Parameters) -> ENT - nothing happens.
Everything else appears to be tickkety-boo, so I assume it's somehow locked (one of the machine params)? If anyone knows which one, I'd love to know... meanwhile, I will go googling.
Edit: I cheated & set the machine parameter, so now it's in ISO mode. Unfortunately, the CamBam output crashed the controller..... back to the drawing board...