Problems Met During Testing

Our team's MCM and extenable arm has been manufactured. Once assembled, we would have our completed machine which is ready for testing.

Our MCM:


Our extendable arm:


We tested our machine on Thursday, and immediately ran a severe problem.

The meshing between the bevel gears on the side of the box was really bad. The torque could not be translated properly to the axle, and thus our whole machine cannot move at all. Also, we realized that the torque needed to rotate our machine is so large that a length of flexible tubing fitted onto the axle was actually twisted and torn.

Thus, we decided to give up our original idea and instead, use strings to pull the arm and the rack and pinion holder up. We attached the string to the rack and pinion guide rod because it is the most feasible point of attachment and the amount of torque needed to lift the arm and the rack and pinion holder is the least. Kevlar strings were used, and each length of Kevlar string we used was made up of 7 strands of Kevlar to ensure that the string will not snap during operation.

To help reduce radial load on the motor axle, we mounted a pair of brackets along the axle to help support it and reduce the radial load felt.
We also added in a second motor to help share the load of lifting the arm and the rack and pinion motor. To accomplish this, we drilled holes in the back of the pinion holder and ran a string through it, which is in turn attached to the motor.




Currently, we are planning to shift the location of the holes on the back of the pinion holder to a lower position to reduce the torque required to lift them. This will put less stress on the mounting walls and allow the motor to lift a larger load. This will be done on Monday (7^th December) morning before the lab sessions start.

This is how our machine will interact with the arena.

A close-up of the pinion holder and arm deployed.