angle of conicity different from 45° toothed wheels sw2007

[ste8]

Bye to all,
I've been reading you for a few days and I haven't been able to find the answer to my saying: I'm trying to make a couple of straight toothed conical wheels. use sw07 and my problem is that I can't generate wheels with conical angle of the primitive cone different from 45°!
I insert the wheels from the toolbox, but I have no chance to change the angle!
I forgot to add that the wheels are to orthogonal axles and the angle I need is 12.5°.
How to do that?
Thanks for the answers!
steak

 

[meccanicamg]

I have abandoned toolboxes for the generation of all models and prefer to download the bearing from sks, support from traceparts and make me gears with freecad that is free with the fcgear module and export it in step.