I am working on building a mechanism which pulls a sheet of paper and rolls it onto a shaft attached to a motor. I need to pull a certain length of paper, stop, and then repeat.
For eg. Pull 2 cm of paper, wait (while a camera clicks a picture), and then pull 2 cm again so that the paper moves forward.
It is basically a feed forward mechanism, wherein I can control when to have a rotation. I checked online about which motor would be better, but I read that step motors tend to overheat if on heavy loads, and servos have a restricted range of motion. I need to keep this mechanism running for a few hours, and hence I was wondering which motor to use, and whether there exists a compatible arduino board + interface for it.
This definitely sounds like a job for a stepper motor. The load has no adverse impact on a stepper motor except that a heavy load will cause it to miss steps - hence the need to choose a motor that is capable of doing the job.
Thank you for the response @Robin2. I'll test the project out with the stepper motor you mentioned in the links above, and then let you know if there is any other issue.
Also, is there a particular Arduino model and driver you would suggest for this particular project of mine? Another question I had was the strength of a stepper motor, since the paper I am planning for the motor to suck in might be a little heavy.
This is my first time working with Arduinos, and I would greatly appreciate any help.
harbarex:
I'll test the project out with the stepper motor you mentioned in the links above,
harbarex:
Also, is there a particular Arduino model and driver you would suggest for this particular project of mine?
I don't recall mentioning any particular stepper motor. If I used the acronym Nema17 you should be aware that there are hundreds of different motors that come within that description - it just means that the front face is 1.7 inches across.
As I indicate in Stepper Motor Basics you must first determine the torque required, then select a motor and only then select a motor driver. Be aware that stepper motor torque falls of quickly as speed increases. The better manufacturers have graphs showing the relationship between torque and speed for different motor supply voltages.
Any Arduino should be capable. It would be best to choose a 5v Arduino (rather than 3.3v) unless you first confirm that the stepper driver will work with 3.3v signals.
Bear in mind that as the paper rolls up on the shaft the diameter changes so the amount the paper moves in the linear direction varies per one revolution of the shaft.
I would use an encoder wheel that measures the length of the paper and use the stepper to control the amount that is moved by counting the pulses from the encoder.
harbarex:
Also, is there a particular Arduino model and driver you would suggest for this particular project of mine? Another question I had was the strength of a stepper motor, since the paper I am planning for the motor to suck in might be a little heavy.
This is my first time working with Arduinos, and I would greatly appreciate any help.
You need to figure out the speed and torque your mechanism requires first...