Trade Notice

We have traded our 3/8" diameter aluminum rod ($2.44) for another 1/4" diameter aluminum rod ($2.31). The value of the rod we traded in is 13 cents more than the rod we received.

Machine Manufacturing Update

As of today, our team walked out of the water-jet lab with two freshly cut diagonal bars and vertical bars. The diagonal bar's ends, however, were not fully cut off, and still attached to the main shaft. This was a result of slight water-jet complications pertaining to the type of bar we needed to be cut (1"x1" hollow square tube) and slight carelessness of the water-jet operator. It is important to understand that the cut path was programmed into the water-jet correctly, but the edge finding was carried out by the operator by approximation and not with an actual edge finder. Furthermore, because the tube was hollow, the physical geometry of the tube meant that the water jet would be cutting through two different thicknesses. At the ends, the depth of the cut was a full 1" while the inside had a thickness of 1/8" (on top and bottom) so a total of depth of 1/4" was required. The water-jet operator combated this feat by cutting the thicker part of the tube at a slower feed rate while the inside of the tube was cut at a faster rate. After the cutting process, the neglect of edge finding resulted with an incomplete cut on one side. Luckily, the uncut length was less than 1/8" and the solution for removing the unnecessary stock was using a band saw as well as a file to smooth out the surface area to specification. On a positive note, the cutting of the vertical bars was done correctly.

Updates

After re-calculating the torque needed for our machine to be able to push the tower, we decided that the safest way to ensure our strategy's success would be to implement two metal-gear motors as opposed to the originally planned Double Gearbox. We also found, after drilling the holes in one of our brackets, that the bolts used for the diameter that we had selected were too large and could not fit on the bracket together. We had to then alter the diameter so that the bolts could comfortably fit and then update the CAD drawings for the brackets. The change in motors and brackets lead us to eventually re-CAD most of our model.

Trade Notice

We have traded our planetary motor ($14.25) and our Aluminum 1/2" square stock ($6.11) for a metal motor ($19.76). The items we traded are worth 60 cents more than the item we received. In addition we received a metal motor from the crib as allowed by the rules.

Most Critical Module

The most critical module to the success of our machine is the drive train. The major components of this system are the wheel and axle, double gearbox, vertical structure, and ball caster. We decided to replace the front wheels shown in our concept design with the ball caster available in the kit because it will offer less resistance to turning and give us more maneuverability. Also, we have completed all the drawings needed for the assembly of this module as well as a bill of materials and machining processes. We are on schedule and plan to start machining the individual pieces next Tuesday, November 15th.