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IEEERobotics / bot

Robot code for 2014.
BSD 2-Clause "Simplified" License
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Design Review/Mechanical Order #187

Closed whiteskulleton closed 10 years ago

whiteskulleton commented 10 years ago

I added all the parts for the arm to the things to buy list. I also added the things for the rubik's cube and simon to the wish list for you guy to view.

A few issues:

  1. They are out of stock for the motor mounts for the 25D Pololu motors but I added them to the things to buy list anyway with a note.
  2. The motor that I specified out is actually more powerful than what I originally specified simply because $2 gets you a lot of extra power. Instead of seeing the arm close in 4 seconds it will close in 2. However, I forgot to mention that the pololou motor that I wanted to get doesn't have an encoder so we will need to figure out a different way to stop supplying power to the motor after the arms have stopped. Without encoders there is not a way of tell if the object has slipped out of the arms (although the proof of concept of my arm design seemed to work and I feel confident in it). Justin seemed to know of many different ways to make encoders so I think we should talk to him about how to go about doing it. However, there is a hard stop that the arm will hit that I built into the rail system so there isn't really any reason to know where the arm are only just when they have hit something. How important do you think it is to have encoders on the motors that drive the ACME thread? Do you think we could use some other sensors to measure where the arm is? Is it even important to know the position of the arm?
  3. We might be able to do the stepper motor that Ahmed and them recommended. Please see that thread for more info of what stepper motor to buy.

Here is a picture of the rail system to make it more clear how it works: robot clarity

R00ney commented 10 years ago

In response to the encoder question: All you need is to be able to stop once the gripper is closed on the object (or open wide) right? That does not require encoders, just pushbuttons at the endpoint to feel the closed (or conversely open) position. use the KISS principle, why use encoders (more work) when buttons (less work) will do the job.