What type of electric motor and control can be used for keeping a load at specific heights?

[name444]

Hello,

We are planning to adjust the level of a load (around 50 kg) by using an electrical motor. Now we are using a hand crank and we want to get rid of this manual process.

For example we want to implement a control where one can adjust the height of the load. The load is hanging down on a pulley. We want to keep the load at 4 different fixed heights by using an easy push button system or a computer. When one sends signal to the motor the motor will adjust the load to a particular height depending on the signal and then will stop there.

What type of motor and electronic control can be used?

Thanks,

 

[Skogsgurra]

You could use a simple induction motor with a brake and you could use a servo drive and anything in-between.
How fast do you need the load to move? If speed isn't important, I would use a low voltage DC motor and a worm gear. Then you don't need a brake.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[jraef]

There are a lot of safety issues involved, were I you, I would just go out and buy a small hoist with a built-in pendant control.

You can get them from most industrial supply houses. Something simple like this.

Automating it to stop at specific heights without human intervention vs just having someone hit the Up-Down button until it stops where you want it will likely cost you a lot more than it's worth to be honest. Most of us who do control systems in our sleep would not have trouble with it, but if you were unaware of what a hoist was, this is not likely a task you can take on without help, which means hiring someone qualified and then you have to evaluate how much that precision is worth to you.

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> faq731-376

 

[name444]

Speed is not important. But what type of servo do I need? How many Volts? And can I control it via micro controller such as Arduino easily?

 

[name444]

Also I want to know is 24 Volt DC servo motor is enough to lift 50 kg?

 

[Skogsgurra]

To lift 50 kg at 1 m/s you will need around 500 W. At .1 m/s you need 50 W. Add same power to cover bad efficiency in motor and gear and you end up with around 100 W. There are plenty of geared DC motors in that power range.
The simplest way to go is using a constant 24 V DC source and two relays. One for up and one for down. The Arduino has lots of "shields" for relays and such, so it will be very easy to get the hardware up and running.
For the four stops, you can either use limit switches (that you can slide to the needed position) or a position sensor of some sort. The simplest would probably be a potentiometer coupled to the drum. May work with a multi-turn so you can avoid gear for the potentiometer. Or use a string sensor with a pot. Or anything that you can think of.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[itsmoked]

The complete lack of supporting information and failure "to discuss" your application in not boding well for our ability to help you. You questions lack so much other needed info that I believe you really should be looking very closely at jraef's hoist suggestion before you take a major wallet shellacking.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[jraef]

Or drop something on someone's head...


"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> faq731-376

 

[tygerdawg]

Keith is absolutely correct. You're missing a whole bunch of required information, and therefore your're going to get nothing useful. There could be many solutions to this problem, some easy, some hard, but you must define it.

positioning accuracy tolerance
time to move
distance moved
moves per unit time
available electrical power
safety regime
environment
your budget

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[name444]

I agree. Thank you.