The first thing you'll notice when looking at Calculon is that it appears like it is driving the wheel chair chassis backwards. Well that is incorrect; the large drive wheels are actually the front of the Storm Series Ranger II powered wheelchair. And if you still don't believe us, we have the manuals for the wheel chair here:
User Manual (.pdf) | Detailed Parts Manual (.pdf)

  A powered wheel chair makes a great platform to start from as stated earlier in the introduction to the mechanical systems. The chair we received was donated to us as is, and was in excellent condition. In addition to the entire wheel chair, a 24 V batter charger was also supplied. Throughout the modification process to the wheel chair, we kept the charging port accessible for easy recharging of batteries while they are on the vehicle.

  Unfortunately, we don't have any photographs of the chair before we started to strip it, but there are photographs of it before any other modifications were done. In the pictures below you can see that we removed the chair, two additional front caster wheels, and any plastic covers from the wheel chair. When we were finished all we had left was a nice clean bare bones chassis ready for development. The next stage in development of the vehicle was to made frame modifications for mounting the various electronics needed to make an autonomous robot.