My friend Dillon (aka Cmptrgk on these forums) and I are trying to find ways other than time to program next years robot's autonomous mode. One of the ways we thought we might do this is by using wheel encoders.
However, we are trying to figure out what type of wheel encoder to use. There's lots of information already on these forums about optical wheel encoders, but I was unable to find much good information about mechanical ones. Please point it out to me if I missed a thread about this while searching.
We are considering the use of either mechanical or optical, so my first few questions are:
1) Would you recommend the use of mechanical or optical sensors?
2) What are the benefits of one over the other?
But back to the mechanical ones...
We are thinking of making our own.
Attached is a paint sketch that I made of one of our ideas.
Basically, when the gear-like thing underneath the sensor rotates, the button is pushed up and down with the ridges. When the button is pushed up, and electrical contact is made and voltage is detected on one of the robots inputs. (this could also be done vice versa).
3) What do you think of it?
4) do you think it is better to make your own or buy one?
I did a little research about
mechanical encoders that I could buy from digikey.
Note: To find what I am talking about in the following questions, click on "mechanical" under encoder type, then hit "apply filter". It wont let me link to the results.
I am a little overwhelmed by the choices.
5) What do you think is the best choice? Do you know of any others from a different but legal part supplier that would work better?
I also am not sure what some stuff means. Some of these questions are probably dumb, but bear with me:
6) What does "PC Mount" mean? What does it mean to have a horizontal mount or a vertical mount or just a mount?
7)What is the difference between all of the different output types that are listed: what is the difference between binary, gray code, BCD, and serial?
8) Of the above, what could be used with a FIRST robot?
9) Under "features", what do they mean by with or without switch? What does it mean to have a switch?
10) What does "detent" mean? What is the significance of "yes" or "no" under this column?
and lastly...
Please share your experiences with mechanical encoders. I would appreciate it greatly.
Thank you so much for helping me out with this.
-- Jaine
<edit> another question:
11) how many "clicks" per revolution would you recommend? This encoder would be used for the drive train most likely, not for the angle of an arm. (meaning that the encoder doesnt need to be as accurate as one you would use for an arm) </edit>