One week until the design expo!

The end of the semester looks a whole lot closer from this side of Thanksgiving!  We demonstrated our Most Critical Module (the arm) last week for Jean, as well as showed the remaining engineering.  This week, we've worked on making the rest of the components for the machine.  By tomorrow, we should have a testable machine, so we can run the arm though the arena and see what happens, and make sure everything is working for our machine demo on Monday.

I finally found my camera, so we finally have pictures of our machine in the arena!

Our most critical module came out without too many difficulties.  Machining the PVC was more difficult than we expected, but now that we're done, it works just like we planned.  We now have a lot of experience using the lathe.  We made quite a few little aluminum pins to hold everything together.  I decided during lab that the arm needed some spicing up, so I decorated it with permanent marker.

For the leadscrew to arm connector, we decided to make our own "nut" of a sort to run on the screw.  We used aluminum stock and the lathe to create something that would fit tightly in the PVC, and then drilled and tapped a hole.  Once we had that, it took a couple of times running the connector through the screw to get rid of all the debris left over from the manufacturing, but now the screw runs with no interference.

One of the biggest discussions we had was how to connect the motor to leadscrew.  Anthony came up with an awesome flexible coupling made from CPVC that clamps down on both the screw and the motor shaft, and slots in the middle to allow for some misalignment.  We decided this would work better than the tube we used for the motor in HW 5, as it is much more robust.

I had planned on testing it a little bit this morning, but due to a complication (one of the wires on the motor fell off, and I didn't have time to put it back on and run a couple tests), I wasn't able to.  Hopefully we'll run it either today or tomorrow.  Just a few more components to fabricate, and then we'll have a completed machine!