team 2175 fighting calculators 2012 robot
 

Better late then never but here's team 2175s unveil video
http://www.youtube.com/watch?v=jG9Di730AZk

specs
Drive train
10 4in plaction wheels
driving wide
Using Custom shifting gearboxes powered by two CIMs each

Shooter
fixed angle shooter
4 8in plaction wheels
powered by custom four motor gearbox
gearbox uses two fisher price 0673 (5:1 ratio) and two 550's (~4.615:1)

Any questions feel free to ask

Re: team 2175 fighting calculators 2012 robot
 

Why did you guys decide to go with the 4 in wheels...And why 10 of them?

Re: team 2175 fighting calculators 2012 robot
 

we did 4 inch wheels to keep our CoG low and ten wheels to make barrier crossing easier. even though we designed to cross the bump we prefer the ramp because the bump is a little rough on the robot, and so far we haven't experienced any bottlenecks at the ramps. So we'll probably not be crossing the bump except as a last resort.

Re: team 2175 fighting calculators 2012 robot
 

Our drive base is similar to yours. FRC 2046 went with 10 4-in wheels also, using WCD type cantilevered axles. The smaller wheel lets us use smaller gearing in the transmissions, but more importantly gives a longer wheelbase for stability in traversing the barrier and with balancing. We raise the 4 outermost wheels approximately 1/8 inch to further improve our turning. Our "multi-tool" appendage is designed to help us traverse the barrier. We pretty much ignore the bridges except for balancing.

Re: team 2175 fighting calculators 2012 robot
 

Good looking robot but I have to ask why the need for 4 motors on the shooter?

Re: team 2175 fighting calculators 2012 robot
 

first of all we we are aware that four motors is overkill
having the 3rd and 4th motors reduces the amount of time required for the wheels to spin back up to speed. It also allows us to fire a key shot at 40% power instead of 90% power (just guessing percents here) and plus its just awesome :D

Re: team 2175 fighting calculators 2012 robot
 

Our key shot is about 40% with only 2 775s... Methinks four motors is overkilling your battery, but that is my opinion. Also, what was the reason of your poor ranking at superior?

Re: team 2175 fighting calculators 2012 robot
 

the main reason was probably not getting our shooter tuned in, and our bridge appendage got hit and snapped on one side and bent on the other (our ski was out while the bridge was pushed down on the other side and it fell onto our ski). through all this we did manage to balance quick and efficiently almost every match which got us a spot on the third seed alliance.
ultimately we lost in quarters due to some great defense by team 93.

Re: team 2175 fighting calculators 2012 robot
 

That's too bad. May I ask if you were using encoders or how you controlled the speed to maintain constant depending on battery charge? Did vision work for you?

Re: team 2175 fighting calculators 2012 robot
 

we did use encoders to keep constant speed on our wheels, it was really just figuring out the speed we needed. as far as i know our vision lined us up most of the time. The balls just vary so much from new to slightly used to dead which varied distance by a lot. why cant all the balls be exactly the same that's all i'm asking for FIRST please