5 MCM parts manufactured!

Hurray! We are done building and assembling the 5 MCM parts! However, we came across certain problems that we did not foresee while planning. Thankfully, we have come out with solutions for these problems.

Brackets

Original plan:
-For the assembly of the box, we decided to use screws to constrain the whole box together. The plan was to screw the sides of the box and the top of the box together.

Problem:
-This method does not hold the box well. Firstly, by screwing the box together, the screws could only withstand moments from one axis, leaving it unstable if any external forces would apply on our box. Secondly, the wood is really thin for us to put some screws on, and this would cause the woods to splinter, which is not desirable.

Solution:
-We decided to utilize brackets to constrain the sides and the top of the box together. This is a much better idea as the brackets are able to hold of moments from 3 axis, making our box fundamentally sound.

-We manufactured the brackets by using the aluminum 90 degree angle stock. First, we band saw the long piece of aluminum to the bracket sizes that we wanted. Then, we marked the brackets for us to drill holes. Finally, the brackets are drilled using the drilling machine to create holes for the screws to enter. We also created more holes on the sides and the top of the box for the brackets to function.

Guide Rails

Original Plan:
- The guide rails are to be constrained to the base of the MCM by using screws.

Problem:
- Since the guide rails are only constrained at one point, they will be able to rotate about its pivot since there are no counteracting moment at the pivot.

-The guide rails are not parallel to each other, causing our guide rails rod to be misaligned.

Solution:
-We decided to buy a 4" long #4-40 threaded rod that goes through both holes on the guide rails. Firstly, this will ensure that the distance between both the guide rails are kept constant. Meaning, the guide rails will be parallel to each other. Secondly, due to the square shaped holes on the acrylic, the guide rails will not rotate about the pivot's axis uncontrollably. Having said that, there is some space for the guide rails to rotate slightly to prevent overconstraining the part.

Another issue that we have is how to apply a torque onto the rotating shaft using a motor. This is what we plan to do:
1. Construct a mounting platform using the plywood that we have left into slightly a bigger size than the motor.
2. Constrain the mounting platform to the side of the box by using 2 brackets.
3. Tap 4 holes on the mounting platform to constrain the motor by using screws.
4. Utilize bevel gears to translate the direction of torque which allows the rotating shaft to rotate.please click to enlarge picture