Looking at the problems we've noticed from our first demonstration, We worked on improving the drivetrain. Our first issue with the drivetrain was the uneven motor powers. At the time, we were uncertain whether or not this was a mechanical flaw (too much weight/ friction on one side), an electrical problem (motors are about to die), or a programming mistake (motors spinning the wrong way). For the sake of speed (and experience) we changed our code to tank drive. Once the code was changed, we tested the drivetrain and found out the code, in fact, was the problem. Because of this, we spent the full time tweaking the code. Just before we were about to give up, a freshman from one of our FTC teams stepped in and looked at our code. After a few minutes of fiddling with the code, we had a fully functional, standard code for holonomic drive (a feature which took us the whole season to figure out last year)!! After this, we took the drivetrain out for a spin. The drive was easy to control and very fluid. The robot had precise turning and didn't "rainbow" or "U" when strafing. The only cons were that driving speed was mediocre, and we had a tendency to flip the robot if the arm wasn't controlled well. Because of this, it may be in our best interest to gear the drivetrain from 1:1.25 speed, to something more radical like 1:2. When we first flipped, we had a pleasent surprise. The funnels system acted like a rollguard. We have the ability to revert the lift back to it's original position to right the robot. We don't want to rely too much on that ability, so a combination of good driver practice and engineering is a necessity. For one, we know that the lift can easily reach the 24 mark. If the intake rollers starts hovering over the drivetrain, then we know we don't need to raise the lift any further. As for engineering, we know we want to minimize the weight we add to the robot (we're slow already), so we are planning to move our heavy electronics, like our battery, closer to the front. Another, more ambitious project, could be reducing the length of the lift and moving the tower more forward. After repeating our flipping stunt multiple times, screws from one of our lift motors fell out. Because of this, we need to take apart the lift system to reinstall the motors. This suggests that we should apply a few modular additions.
Today, we focused on the lift system. After stress testing the robot on monday, motors started getting undone. Because of this, we opened up the lift system and remounted the motors. Additionally, we also worked on the funneling system. When we tested the robot, the funnels opened at different rates. This is because the funnels catch onto the drivetrain. The weight and the length of the funnels causes the system to bend and catch. This setback in extension causes the chain to skip and permanently alter the system for the remainder of the match. Because the funneling system isn't a primary system, we'll hold modifications until next week
On wednesday, we also demonstrated the frisbee shooter at the "Solita's House". After the presentation, we got a $500 dollar grant for the team!!
Now that the lift and drivetrain were all tackled hard, we started improving our intake. we attached standoff limiters to the intake system to prevent the rollers from closing all the way. Then, we attached elastic to shut the intake as much as possible. This change allowed the intake to squeeze and grab the balls, giving the rollers more frictional force to push balls inward. We also did 3 tests. We gently pushed balls inward and balls were easily grabbed. We tried grabbing stationary balls. Those were quickly and easily grabbed as well. However, our third test was a ball rushing towards the intake. this was suppose to simulate the robot driving towards a ball, and a ball rolling towards the robot. It was very rare for the robot to grab in these types of scenarios. Typically, the ball would rest in front of the intake. We can try manipulating the following factors for a better result:
In addition to this, our sister FTC team tested out their winch system for hanging. We decided to use those prototyping results to help us engineer our hanging system
Looking at our timeframe, we're split on what we should do. We changed our view from last year and we want a lot of driver and programming practice. Because of this, we're squeezing the time we have for mechanics. We can either improve our large ball and bucky ball capabilities with the large ball storage and funnel, or we can improve our reliability with small, minute changes
Righting The Robot
Intake Test 2
Intake Test 3
Hanging System Test
Not exactly vex, but one of the FTC hanging systems were based off of our hanging system prototype. Since it's easier to prototype in FTC, we're using these results to influence our results
Their Website: http://solitashouse.com/
Youtube Channel: http://www.youtube.com/channel/UC6d9PnePfpUGmpxSzoDciBg?feature=watch
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