For anyone interested in the CAD files for my entry in the October 1st ROBOTalk design challenge, I have posed the files here.
If you are not familiar with the challenge, here is a description of the goal:
Design a conceptual model of a robot with a lift mechanism (i.e. scissor, slider, etc.) that can lift a wiffle ball 120 cm. The starting conditions for the robot are that it has to fit in a cube 18in x 18in x 18 in.
My description for the project is below:
I finished a model for my team, FTC team 542 WHS Robotics. The drive train is our CAD model from one of our robots from last season. The lift, however, is new and definitely only a conceptual model. It is a mixed design between a four bar linkage and a linear elevator: it uses drawer slides to extend the links in the four bar arm. This idea came from one of my team's potential designs for the Ring it up! season that was ultimately scrapped in the brainstorming phase. Please note that the two-part slide models were simplified from the three stage set that would be required for this over-extension layout. The blue box in the first picture represents the 120 cm height required for the design, while the white box in the last picture represents the starting size requirements.
You can find screenshots and the full discussion of the challenge in this discussion: http://communities.ptc.com/thread/57104?tstart=0
Anyone who would like to use the CAD's as a basis for your own design is welcome to do so. The full assembly file is named "robotalk_liftrobotconcept.asm". If you use them for your design, please reply to the thread just so I know the files were helpful to another team!
One note about the drive base if a team were to use the design is that the robot with this drive train had trouble turning because of the 4 wheel drive set up. My team eventually switched the double wheels out for single Tetrix 4" wheels. Also, the CAD is missing some supports between each side's plates that help keep the plates together. We only used a few stacked channels on the ends of each side for this support, which was really not enough and caused reliability problems as the drive train was used more.
Hopefully this helps someone with their own design!
Benjamin Domae
FTC Team 542, WHS Robotics
