This is a long one. my first project with motors. using 3 motor i need to rotate only 2 motors at any given time. the rotation angle can be various.

Motor1, M2 and M3. M1 is ON al the time. Either m2 or m3 is ON at any given time. The user inputs angular movent (degree) and increment steps(degree) for each motor and pushes enter, the motors should then move each increment and pause for 5seconds before moving to the next increment. The increments should be a minimum of 1 degree. for example move M1 from 0deg to 60deg in 1deg increment and from 61deg to 180deg use 5deg increments.

This is for a Goniometer - photometric purposes to be used in a dark room. The motors will move a frame around a lumenair. the frame weighs 20kgs. The pause after each incerment is for a photo-diode to take light intensity measurment which will be converted ADC and recorded in a table to be plotted.

Can all the intelligent people help me to determine which motors will be best to use? I have looked at a few Allen Bradley systems costing up to $4000. i'm a university student and i will do the entire project myself on a $500 budget.

Can someone help me??
Thanks all.

 

You probably want to look at Steppers for that price range. A good stepper should get you +/- 1 degree of accuracy. You cna drive it with a parallel port or Microcontroller if you have some low level programming skills.

Also, some inexpensive PLCs can drive two steppers. Take a look at Automation Direct, Siemens S200, Keyence, Mitsubishi FX series. For the actual motor, you may even get one at a surplus place like Jameco or www.MPJA.com. This may be a good approach because you can write the program and it will run reliably until the motor bearings die, which will be pretty much forever, opposed to a PC which will require continual maintenance and have long associated bootup times. I would not recommend Allen Bradley, they will be too overkill and expensive for this application, as you have found. I'd call Mitsubishi, Siemens, and Automation Direct and see if someone can help you out with a student or otherwise evaluation package for one of their micro (sometimes called brick) PLCs.

~Ken

 

Take a look at the IMS MDrive steppers which include a step motor, step drive and indexer with RS485 serial, multi-drop interface and digital I/O in one package. Depending upon the size, three of these can be obtained for within your budget. One drive can send commands to others via the serial link.

http://www.imshome.com