Is there any way at all to use spur gear from tool box ? I need to make a gear train... and I can't find anywhere how to use the spur gear of custom size...

How to get a spur gear of required parameters?

I tried to make my own spur gear.. but SW cant just understand what i am trying to do.

Please help me with this...

There are spur gears in tool box... but how to get required size spur gears?

Thank you in advance