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Journal 5.3 Polishing the Gripper

Dizzy’s Journal Entry (Gripper Works, but Could be Better)

I was able to mount the servo to the gripper in no time flat. The new laminated wheels/gears look great! After only a few minutes of testing, it was obvious that our temporary arm is very limited. There was a big argument between the test crew and the arm-design team. The arm team wanted to get in and fix what they could now. The test team was frustrated because they were already behind schedule.

Coach was clearly disappointed in how we handled the disagreement. After a lot of cool-down, we were reminded that we already had a plan in place. According to the plan, this week’s priority is system wide testing. Note to self…Only after thorough testing should one draw conclusions.

The testing plan that Cupcake had drafted back in conceptual design phase.

Target Date Subject Trials Target Performance
Week 2 DC Motors tests on each motor Within manufacture’s limits
Week 3 Shaft Coupler torque transfer (slip torque)axial pull (force to slip off) No slip on stalled motor or 10 lbs in axial test
Week 4 Caster 90 deg turn with max load90 deg turn without loadreverse dir with max loadreverse dir without loadmax operational load No lock-up of the caster or more than 10% change to desired robot path
Meeting 5.0 Wheels traction with max loadtraction without loadimpact of different C.G.sspeed bump testsrough terrain tests 10% speed loss due to slip in any configuration
Week 5 System Wide arm precisionarm load capacitygripper effectivenessplacement precision ?

If we had been consulting this plan earlier, we would not have overlooked the shaft coupler design. Oh well, lesson learned.


This article demonstrates ways that sticking to your plan might be better than following impulse towards the end of the season.

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