Would an arduino need to be used for a project to turn a motor at 1 rev, per hour - 24 hours in a function which requires 24 hours a day none running stop?
Would a stepper motor be the way to go?
The motor requires very little torque - it will be simply lifting the weight of a small bike chain.
Thought and opinions welcome!
Yes but - this will be mains powered so current consumption is not an issue? How accurate need it be (defines the sort of timebase)? What resolution is required for the rotation, etc. etc.?
You may not need a microcontroller, just a counter. What other gymnastics do you want? Manual override/ operation?
For one rotation per hour, a standard motor will not be sutable. Either a standard motor with a lot of gear reduction, or a stepping motor would work better.
So, in 5 hours, you expect 5 rotations, in the same direction?
How about a geared synchronous motor?
http://www.mclennan.co.uk/datasheets/european/geared/p5sssp.pdf has some that rotate at 1RPH (on a 50Hz supply).
Synchronous motors are very accurate and were used in clocks until quarz movements were invented.
I would use a stepper motor
1.8 degrees per step at full stepping
If torque is really low use 1/16 steps giving just over 0.1 degrees per step
3200 steps per hour is one step every 1,125 mS
Dead easy to code and oodles of time to do something else
Remember to leave the stepper energised to stop it moving between steps
mmcp42:
I would use a stepper motor
1.8 degrees per step at full stepping
If torque is really low use 1/16 steps giving just over 0.1 degrees per step
3200 steps per hour is one step every 1,125 mS
Dead easy to code and oodles of time to do something else
Remember to leave the stepper energised to stop it moving between steps
+1 for the stepper - the easiest to do it.
If load is not an issue then i would look at the EasyDriver and one of the small steppers from sparkfun.
Buy one of their mounting brackets whilst at it and an appropriate toothet sprocket to match your bike chain.
Add an Arduino clone for less than $20 and you have a solution for less than $60
Craig