Designing a Rotating Holder: Tips and Tricks

[lankan_ice_405]

Hey,

I need to design somethign that rotates the holder drawn below, to a full 180 degrees and stops. And should be able to repeat that process as required. It should be also precise, that is, stop at the same place each time.

Any ideas on how to implement this? needs to be cheap and simple.


What kind of parts would I need and how would I put it together?

 

[DaveC426913]

A stepper motor? Stepper motors are designed to turn a very specific amount within tolerances.

Ask around at an electronic surplus store. You may have to build some sort of controller.

 

[Proton Soup]

a worm drive might be OK. wouldn't be fast, tho.

 

[berkeman]

From your description, you should be able to just use a DC motor with hard stops and limit switches.

 

[lankan_ice_405]

I'm thinking of going the stepper motor route,
and I already have a 16 series PIC , any tips ?
how would I do the circuitry for it and make it go 180 degrees exactly?

 

[pantaz]

I'm thinking of going the stepper motor route,
and I already have a 16 series PIC , any tips ?
how would I do the circuitry for it and make it go 180 degrees exactly?

http://www.mastincrosbie.com/mark/electronics/pic/stepper.html"
http://websupport1.citytech.cuny.edu/Faculty/fzia/weblinks/Stepper%20Motor%20Tutorials%20and%20Driver%20Circuits.htm"
http://www.parex.org/weblog/archive/000049.html"

 

[lankan_ice_405]

Since i need to connect more than 3 motors I'm thinking of making a few of my own controllers (4)
using this
http://www.aaroncake.net/Circuits/stepper.asp

If I went about that, all I would need to do is just connect the STEP line to the pins of the PIC and when required to move 1 of all of the motors juts send the pulses thru the Pic, correct?


Is that diagram one that would produce a good controller for what I need to do?

 

[lankan_ice_405]

Actually I've changed my mind and I'm going to go with a Stepper Motor controller chip instead of building the whole thing. (The Phillips SAA1027) It'll cost ~the same
So I'll need to have 4x this because I need to control 4 different motors separately.

Any precautions or anything I should take?

 

[Proton Soup]

n/m...