I'm using LEGO digital designer to model a LEGO tank. I don't seem to find parts that can be used to make the tank track and the inside wheels; I found a "caterpillar belt" but no wheels that can fit inside the track.
There is a part called "caterpillar track", and unlike the belt the track requires wheels of different diameter to fit inside it. Again, I can see the wheel for the wider end of the track but not the narrower end.
Are there any parts that can be used for tank tracks at all? Or should I look for an alternative solution?