pic: WCD Sheet Metal Concept Chassis

[JesseK]

Originally Posted by Chris is me

Spring loaded tensioners are notoriously unreliable. I would suggest the "traditional" west coast tensioning method of sliding bearing blocks, or possibly a nylon / delrin sliding standoff for each chain section.

I would think that most FRC spring loaded tensioners are unreliable due to lack of understanding in the design. A standard bicycle has used spring loaded tension for who knows how many years how, even with a shifting drive system. Yet teams who put them in on a 2-way torque transferring system must account for both directions, whereas a bike tensioner only has to deal with one. Thus, a team could easily make a spring loaded tensioner reliable so long as the design is sound. The mini-bike motor belt tensioners from 2006 would be a good place to start experimenting.

As for the CAD render: if the side rails are open on the bottom for chain accessibility, are there supports on the inside of the rail to keep it from buckling in on itself? The channel shown in the reflection of the render makes be believe the side rails are very prone to torsion.

I also like the rear-wheel drive; Drop-center drive train designs are TOO easily turned if the weight is close to the middle, so putting most of the drive train/electronics weight towards the back allows for more flexibility in weight distribution when designing manipulators. The tradeoff is less maneuverability if a chain comes off or breaks.