I have two stepper motors with a roll around their shafts and a cloth. The two ends of the cloth are rolled on rolls. One acts as a supply roll and the other like a take up take. How do I synchronize the speeds of these motors using Arduino such that the cloth is not slacked or pulled?
I am confused as in where to begin.
Simple, for every pulse you give one motor you also give the other motor a pulse.
That's fine! The thing is the speed of both the motors will change as I roll or unroll
kumbhrageri:
That's fine! The thing is the speed of both the motors will change as I roll or unroll
Can you have some device that detects the tension in the cloth and uses that to adjust the speed of the take-up motor.
This might be a situation where a simple DC motor would be better for the take-up roll as it could be driven so as to maintain sufficient tension and would then adjust its speed automatically. Choose a motor that won't be damaged by over-heating if it is stalled.
The speed of the process could then be set by the stepper motor on the feed-out roll.
...R
A very simple mechanical tensioner roller is all you need. Synchronizing the two motors sounds like an unnecessary headache.
Could look up 'dancer' or 'dancer tension control systems'.
The usual thing to note, as you probably already found out ... is that when a roll diameter gets smaller and smaller on one roller (because the material is coming off it), and the other roll diameter gets larger and larger...... then the dynamics gradually change. So this is when things need to be done to make everything work nicely.
Obviously, if the system is very slow, then maybe no problem. But if you want the system to operate quickly, and get things done as quick as possible, then this is where all these other techniques come in handy, like tensioning and tension-control.
Can you guys guide me to some websites about tensioners? What are the devices available in the market?
Tensioners shouldn't be hard to find, it's a very common way of tensioning tapes and fabrics and paper sheets and lots of other things.
Have you tried Google already for such devices?
Yeah! There are too many results on tensioners. What could be the best kind of tensioner to be installed on a window for window shade control?
kumbhrageri:
What could be the best kind of tensioner to be installed on a window for window shade control?
I thought you were talking about rolls of cloth? I had in mind 10s of metres of cloth on 1.5 metre wide rolls.
Post a diagram of the thing you are trying to make.
...R
Very big windows maybe 
But your point stands: no chance to suggest parts without knowing detailed specs. And when you have those specs, it should be pretty easy to narrow it down to some suitable parts by browsing manufacturer's web sites.