Buongiorno,
I have a project (just in my mind at the moment) where I need start 4 motors at the same time, ramp up, and reach different speeds and keep those speed constants. The idea was to use step motors but I need 2000rpm or more.
Can anyone suggest me a possible solution using Arduino ? What if the motors become 7, do I need more Arduino boards ?
Thanks in advance
Paolo*
As far as I know stepper motors can't go nearly as fast as 2000 rpm - perhaps not even 1000.
There should be no problem controlling DC motors but if you want careful speed control you will need some form of speed measurement that will use extra pins on the Arduino.
Any motor will need a driver board between it and the Arduino and it is the connections to the driver board that determine how many Arduino pins are needed.
If you look (for example) at the Pololu and Sparkfun websites you should get a good idea of the sorts of driver board that are available. Plane what is needed for one motor and then multiply it up for several motors.
An Arduino Mega might be an option if the Uno hasn't enough I/O pins.
...R
If your not using steppers you need to find a way to mount something on the motor shaft or whatever it is driving to use as flag
for a tachometer. What are the motors driving?
I want to unwind yarn from one bobbin and wind t on a carboard tube so Each motors has to spin a wheel which is driving the yarn for that I need to run fast if not it takes forever...
I was looking to reuse step otors from linear printers or inkjet ones, I have many of them to cannibalize.
Paolo*
You can't use stepper motors. You already know why.
I am completely new to this world and I know zero about how to control a motor with Arduino, that i why I am asking.
Paolo*
This is from your first Reply (Reply#1)
As far as I know stepper motors can't go nearly as fast as 2000 rpm - perhaps not even 1000.
According to the datasheet here
http://www.velmex.com/pdf/mc/vexta-nema23-motors.pdf
some of these motors can do 2500 RPM
http://www.velmex.com/motor_torque.html
You will need a stepper motor driver to create the current pulses, 20mA from Arduino pins won't do it.
FYI, the charts may show 2500 but the torque at those speeds is at it's lowest. The OP plans to use the motors for winding yarn
so maybe we should try to find out how much torque he needs.
Hi
at one fair I have seen a similar project that was using Step motors and pulleys to increase the speed, the motor label was HN200 3426 0280 AXR08 Mae Spa, this could be a starting point, is there any shield for arduino that can drive it or a drive that can be connected to the board ?
The other question is if it is possible via software to control in parallel more than one motor and apply different speeds (and maybe change the speed to just one motor).
Thanks in advance
Paolo*
My concept of winding yarn is that it has no demand for the accuracy of a stepper motor due to the "flexibility" of the yarn and the fact that the diameter of the bobbin keeps increasing by an unpredictable amount.
There should be no difficulty driving several motors at different speeds.
...R
oK
now software side: I read that for driving a step motor with arduino you have to use a loop where you send the steps to the motor and you have a delay between each step which at the end it makes up for the final speed.
Now the question: in case I have more motors may i run more loops in parallel so that i can have a different speed on each motor ?
Thanks in advance.
paolo*
Probably. Check out the stepper motor libraries & articles here
https://www.google.com/search?ie=UTF-8&oe=UTF-8&q=stepper&btnG=search&domains=http%3A%2F%2Fplayground.arduino.cc&sitesearch=http%3A%2F%2Fplayground.arduino.cc
paolostellini:
may i run more loops in parallel so that i can have a different speed on each motor ?
You should study the technique in the Blink Without Delay example sketch. When you want several things to happen simultaneously you can't use the delay() function. I wrote an extended demo of the technique in the first post of this Thread.
...R
Many many thanks, I hope I have all I need now, I owe you pizza and beer if you show up in Italy.
It's time to buy an Arduino board to make some trials.
One last advice: which Arduino model should I buy first ?
Paolo*