motor selection guide
motor selection guide
(OP)
Hello,
This is a basic question and while I did do a search beforehand, none of the answers really helped.
I need to select a motor to drive a sheet rolling application. The motor spins the shaft, which is initially empty and then gradually it rolls up sheet material until its around 250lbs heavy.
The only other requirement is the sheet must be fed in at 100fpm. Which for an empty roller equates to 107rpm, and when the roller is full of sheet material, it seems like 25rpm would be the required speed.
It has been so long since I've even looked at motors, where do I begin selection? What factors do I consider? This doesn't seem to complicated but I'm at a loss as where to begin.
Any guidance (links to pertinent answers, faqs, etc) will be really appreciated.
Thanks!
This is a basic question and while I did do a search beforehand, none of the answers really helped.
I need to select a motor to drive a sheet rolling application. The motor spins the shaft, which is initially empty and then gradually it rolls up sheet material until its around 250lbs heavy.
The only other requirement is the sheet must be fed in at 100fpm. Which for an empty roller equates to 107rpm, and when the roller is full of sheet material, it seems like 25rpm would be the required speed.
It has been so long since I've even looked at motors, where do I begin selection? What factors do I consider? This doesn't seem to complicated but I'm at a loss as where to begin.
Any guidance (links to pertinent answers, faqs, etc) will be really appreciated.
Thanks!





RE: motor selection guide
I see no reason not to use a standard solution here. Or do you have very special demands?
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: motor selection guide
RE: motor selection guide
I was hoping this was something where I could just get a motor, pulleys and belts at my local Grainger and then machine/weld the fixtures for it? Is that not possible?
What I was really hoping for was a guide on how to go from knowing my basics like weight and speed up to what style of motor to get from a really common industrial supplier like Grainger. Is there a sort of guide like that out there anyone has seen?
RE: motor selection guide
If you want a really simple solution and don't have high web tension or fast acceleration, you could use a standard induction motor and an adjustable friction coupling.
If you want to automate it, just let the friction coupling be controlled by a dancer roll. Very common on small take-up reels.
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: motor selection guide
For example, when I go to a website like Grainger, I see a list of AC motors and there's several types and each type has 20 - 30 different motors. I have a feeling the ability to know exactly what you need is out there, I just can't find a guide to that (I even looked in my old machine design books and didn't find much guidance).
RE: motor selection guide
Then look at your reel and see what diameters it moves between. Lets assume a mandrel diameter around 20 cm (8 inches) and a maximum reel diameter around 60 cm (24 inches). Then your motor needs to run at around (100/60)/(.2*3.14) = 2.65 RPS or 160 RPM.
Assuming (again) that you do use an adjustable clutch, your maximum torque will be web tension times maximum reel radius. Torque = 500*.3 = 150 Nm.
Maximum output from clutch will then be torque times speed (Nm and rad/s) which is 150*2.65*2*3.14 = 2500 W.
You have losses and you also need a safety margin. So, I think that a geared motor with around 5 HP and output speed around 160 RPM will do the job.
For other web tension, speed etcetera, plug in your data.
I didn't do a second check on this. Someone may want to do that.
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: motor selection guide
Furthermore, if I want your 5HP/160RPM motor, how do I go about getting it? What type to do I search for? Is any 5HP/160RPM output motor ok or do the different types of motors really affect my performance?
RE: motor selection guide
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: motor selection guide
RE: motor selection guide
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...