The Table

Final Assessment & Testing

The table works very well. I have been using it every day on top of my current desk. The table is able to move across its full range of motion of 230mm. The table is very sturdy. I have tried putting my body weight on the table, and it has been able to support that thus far.

Reflections

During the process of designing and building this table, I learnt a tremendous amount from Professor Slocum, the shop mentors, and my peers on error budgeting, wood-working, machining, and engineering best practices. I am greatly in-debt to these amazing people. This class has changed me in many ways. I feel empowered to think foolishly and creatively, and to experiment and test without the fear of failure. At the start of this class, Professor Slocum claimed that this class is about learning, and it truly is. The fundamentals of design 2.75x will be something that I carry with me for a long time to come. I plan to finish reading Professor Slocum's book Precision Machine Design by the end of this summer. There is so much knowledge in there. If you're a MIT student, I highly recommend taking this class before you graduating. It will be a life-changing experience.

Areas for Improvement

The whole idea of this designing and building this table is to be as LEAN as possible. I tried my best to minimize the amount of material that I am using to build this table to keep it as low-cost, and as lightweight as possible. While doing so, I made sure that my design is precise, and that my table’s structural stability and performance are not compromised.

That being said, there are still many areas for improvement:

1. Bearing plates:

(i) Even though great care was taken to ensure that the bearing plates are aligned, there still seem to be a lot of friction in my system. For better alignment, and hence less friction, I should have created my top and bottom bearing plates at the same time. By specifying the datum plane to be the back of the rails, I should be able to get the alignment to be perfect.

(ii) A more iterative way will be do the above, and test using laser-cut acrylic first. It will be fast and cheap. After a few fast iterations, I would have been able to ensure that my bearings and leadscrew are properly lined up. Only then, I will make the bearing plates out of wood.

2. Leadscrew:

Currently, if I push hard enough, the table will go down (i.e. the motor's holding torque is not high enough). However, in order to prevent that, I can use a lead screw with smaller lead. This will make it harder to push down, because of high frictional forces. But then I might also need a more powerful motor.

3. Lubrication:

Whenever my leadscrew jams on its way up, I will add some lubricant to the leadscrew nut. It helps the vertical motion significantly, and I can move up without a glitch.

4. Slanted tabletop:

Due to manufacturing error, the table is slightly slanted to the left at 0.5 degrees. I could potentially reattach my table top to fix it.

Book Synopsis

During the course of this semester, I came across three books that I think are very useful. The first two are books recommended by Professor Slocum. The last one is a book I happen to pick up, while sitting at a restaurant at the White Mountains.

1. Only the Paranoid Survive: Talks about what companies should do when it is at a strategic inflection point. This strategic inflection point refers to the point of time when balance of forces shifts from the old structure to the new. Companies need to correctly identify this strategic inflection point. Both senior managers, and middle level managers need to work together to rein in the chaos.

2. The Mythical Man-Month: Interesting take on project management. Basically talks about how throwing manpower at a problem is not the best solution, especially if the problem is not perfectly partitionable. The reason is because communication between people adds complexity, and it delays the solution.

3. Never Eat Alone: Dubbed the modern version of “How to Win Friends and Influence People.” It talks about important networking skills each and every one of us should and can have. You can find a quick synopsis here: http://www.patrickmckenna.com/pdfs/Never%20Eat%20Alone%20-%20The%20Murphy%20Notes%20Version.pdf

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