Readings on Motors
how electric motors work
- i learned that the electromagnetic field switches magnetic forces, causing the turning of an armature to continue.
- a question: What prevents the armature that has just made a 180^o^ turn, say counter-clockwise, to continue turning in that direction. Because once the electromagnetic field flips, the armature spin in the direction it came, no?
stepper motor, wikipedia
- stepper motor can do a very precise angle.
- a problem with a bipolar stepper motor that I had was that its shaft was so tiny and slippery that I couldn't attach anything big onto it. The attached thing will keep slipping off. how can I go about fixing this problem? A gear? Oh yeah, when I was playing with the lego, I noticed that the lego motor also has a very small shaft coming out, but then there are two gears attached onto that shaft. that might be the clue!
maxon DC motor and maxon EC motor
- i learned that speed decreases with increasing torque, so they have an opposite relationship.
- also, the article says "the smaller the speed-torque gradient, the less sensitive the speed reacts to torque (load) changes and the stronger the motor (35)." Does this speed-torque gradient mean the degree in which the speed and the torque are opposite?
- "The heat produced must be able to dissipate... (36)" Besides the fans, are there other things whose job is to lower the temperature?
- page 39 lists great questions to ask myself when i select a motor (note to self).
motor calculations, Faulhaber
- this is a hard reading, don't know where to begin to ask questions...
Lego : building a crane
- what determines that I should link one piece of lego with the other piece at the second piece's 4th hole. did somebody really calculated that? wow, cool. but how? I guess I should go through that lego reading written from the MIT Media Lab.
Readings on Gears
Howstuffworks "How Bearings Work"
- For all my intentions and purposes, I'm more likely to use ball bearings and ball thrust bearings than other types of bearings. ->Ball bearings: because the contact area is the smallest, it enables the most smooth motion, and I do not think that my artwork will need more than 150 pound of loads. (I'm guessing that ball bearings can handle up to about 150 lb, because it is used in inline skates and a person weighs about that much, no?)
Ball thrust bearings: because it's easy to use (I already know where it's used in everyday life - e.g. in a barstool and in a Chinese restaurant table!)
- Bearings are used to allow up to 20 inch leeway for a building column to shift around during an earthquake. (e.g. example of the San Francisco Int'l Airport structure in the last page) That's a lot of leeway that a ball bearing is giving... wait, how could a ball bearing support as much mass as one entire column?
Boston Gear Design Guide
- Spur gears: These are the gears that I've always seen.
- Helical gears: I want to use this gears in my work, because I can spend hours looking at the movement of the helical gears.. what's fascinating to me is that the gears stay stationary in one place, though I think that they should be moving to the left or right.
The pro's of helical gears are:
greater tooth strength because the greater area of helical teeth touch each other than in the spur gears
AND can handle greater load AND is smoother! (143)
FBD assignment
Chapter 1 Levers
- definition of a machine: any object that exists to make work more efficient, "by changing the amount of force or the speed of action" (p 1-1)
- machines
- transform energy : my example for this - a sound recorder is a machine that transforms a sound energy into electrical energy, is this correct?
- multiply force : my example would be a flat sheet of cloth that a mover places under, say, a grand piano, and pulls the sheet of cloth instead of pulling the grand piano.
- multiply speed: the text's example - a bicycle
- my earlier example of the flat sheet of cloth placed underneath a very heavy object, to be pulled and move the object above it more easily: Which class of lever does this belong to? Let's see... I drew a diagram to understand this. http://itp.nyu.edu/~jes527/mechanism/piano.html Since the fulcrum is in the middle and effort and resistance on the opposite sides, this example will fall into First Class Lever.
Using Gear in my current work
Thoughts after my midterm presentation
Future plans and concerns:
And please go to the link below if you want to see the documentation of my midterm presentation.
An inspiring artist...
Introducing a American pioneer artist in using industrial materials for sculptures