The .DXF file to laser cut the base plate:  r2pv1.com/media/BasePlate-4-OmniRover.DXF 

The fastest and cheapest way to get all my .STL files FREE is to donate $5 to help fund school materials ... once I have $3,500 I'll convert all these files to FREE downloads.   https://www.gofundme.com/roboguts-kits-lessons

After laser cutting the base plate back about 2007 I've been sitting on this project until this year when I got back to it to get it off the ground and running ... the main components are the base plate  which can be plastic, cardboard, wood whatever is easy for you to use, then 3D print the WheelCups and the SpeakerBox to build the basic R2Pv1-OmniBot1 ... adding sensors comes next and making it more universal you can use one of many common UltraSonic sensors and/or IR Range Finders even use both at the same time on the UltraSonic-FrontMounts ... because the sensors are so light I recommend using the UltraSonic-miniFrontMount-4-OmniRover.STL using a smaller servomotor to turn the sensors back 'n forth.  

3D Printed R2Pv1-OmniRover1 Octogonal Path