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Unread 25-03-2010, 12:17
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VEX Robotics
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Join Date: Feb 2005
Rookie Year: 2005
Location: Greenville, TX
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Re: pic: Daisy Bell Going Over The Bump

Early on we decided that is was important to quickly and easily traverse the bumps. As such, we designed the robot to be able to withstand the shock of maneuvers like this. Trust me, we did not get it right the first time - it was definitely an iterative process to make sure that the drivetrain components were strong enough and that the electronics could withstand the shock.

When we first started driving at the start of week 5 everyone (students, mentors, parents, teachers... i mean everyone) cringed whenever we went over the bump. It was not a pleasant sight to see or hear.

When the robot was finally assembled and working we actually set up a course and had our driver go over the bump 50 times without A) breaking something or B) losing communication... That was a very-very long night.

In San Diego we did have one issue early on in qualification rounds. We did a 'Dukes of Hazard maneuver' (as the FTA's liked to call it) over the bump and the robot lost communication with the field.

After the match we determined that it could have been a couple things:

A) The shock of hitting the floor was either damaging components inside the radio or knocking a cable loose.

B) Due to the positioning of the antenna inside the radio and the direction of the antenna used on the field, the robot gateways are actually most effective when mounted vertically.

After that match took a 1/16" piece of polycarbonate and made an L bracket out of it. We then mounted the radio vertically on the sheet of poly carbonate and left a little strain relief on the power and ethernet cables. This way when we do do a 'Dukes of Hazard maneuver' the shock is absorbed by the flex in the plastic. Since then, we've had no problems at all.

We haven't had any electrical issues that can be attributed to us pulling a 'Dukes of Hazard maneuver'. What we've done to help prevent that is to mount our electronics board on strips of foam. So far we have yet to lose power or comms when going over the bump.

Another thing that probably helps a little bit is that we run pre- and post-match systems checks. During these, we run through every system on the robot (drive, ball control, kicker). These allow us to do a couple things:

- We can replicate any problems we've had on the field so we can fix them.
- We can find potential problems that may not have affected us the previous match, but could in future matches
- We can go into a match knowing that all the sub-systems work.
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