I wanna lift a weight of 50kg, but how?

Other Hardware Motors, Mechanics, Power and CNC
1

Hello, guys, I wanna lift a weight of 50kg using this construction (it should move min. 1m/s), and i’ve got a few questions about it:

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  • Is this even possible?
  • Which motor should I use (Ac / Dc / Servo)
  • How strong should the motor be?
  • Where can I buy this motor?
  • Which motor controller should I buy?
  • Can I control it using Arduino?

Thanks in advance for the help!

2

Yes, that is possible.

Choice of motor or actuator depends on the construction details (pulley and rope friction, etc.) so build the setup, and measure the force required to perform the action at the required speed.

Buy an actuator and controller that can comfortably provide at least twice that measured force.

3

Zero to 1ms, how quickly? 1ms to zero, how quickly? What is the rope drum diameter?

4

You plan to lift a weight, but then what? Hold it? Let it return to it's original location? How will you know when it has been lifted? How will you know if the rope slips on the drive pulley? Will you need to repeat the lifting?

5

And how far is the mass lifted at 1meter per second?

6

How heavy is the counterweight?
Consider that the motor has to hold the weight of the counterweight if you disconnect the load (the weight you are lifting). Counterweight would commonly be 1/2 the maximum load, so that the force needed to lift the counterweight with no load is roughly equal to the force needed to lift the load at maximum load.

7

This whole post seems like a school assignment, doesn't it?

8

This is bordeline university grade asignment

9

Thank you for your help!
But i’ve still got some questions:

  • Isn’t there a way to calculate the force of the motor needed in advance? (I don’t think there will be much friction)

  • My main problem with the controller is: which one should I buy and where can I get it?

10

Yes there is, but only when you know the diameter of the pulley with the rope would around it.

11

As fast as possible I guess :joy:
The max diameter for the drum is 20cm. (Btw., if you know where I can buy such a thing, would help a lot)

12

Add 1/2 the diameter of the rope.

13

So my plan is this: The motor lifts the weight to a precise point between 0 an 4m. He holds it there for like a minute, and than he moves it to another point inbetween 0 and 4m.

14

I’m sorry, but what do you mean?

15

It's been too long since I took physics...

But you can research how much energy it takes to lift a certain weight a certain distance, and how much energy it takes to accelerate a given mass.

With a motor you'll have to convert that to torque and RPM.

If the counterweight is equal to the weight it takes zero energy to lift, but it takes energy to accelerate (to start it moving).

From what you told us you don't need a "controller". Just a motor, electrical power source, and a switch.

Oh... You don't want a servo motor. A servo is an "angle motor". And if you want to reverse, a DC motor is easier than an AC motor.

16

Ok, I already tried to calculate this by myself, but I guess I’m to dumb for it. And aren’t there any possibilities to control the motor with an Arduino?

17

I planned to give the counterweight +- the same weight as the object to lift, to make the work for the motor as easy as possible.

19

If ignoring friction and rope (or cable) bending losses the the question is how fast do you need to accelerate? Or in what distance will the load have to travel before reaching the speed goal.

Question for you..... knowing

F = ma what m (mass) would you think goes into this equation? 50 kg or 100 kg?

Also you need to be more specific on what you expect to happen (in text form).

For instance:

  • A button it pushed
  • the motor accelerates the load to 1m/s then does it keep accelerating? If so for how long?
  • What function is the Arduino bring to the actions?

In your original post you state (ask)

  • Can I control it using Arduino?

You need to sit back and think about what "control" you are thinking of. For whatever reason you are doing this, it will end up being a learning experience. So imagine someone offered you a brand new latest version X-Box, but you have to fully describe what will happen. So sit back and think this through with the mindset that the only things that will happen are what you describe.

20

Have you tried answering any of these questions yourself?

  • Of course it's possible - almost anything is possible.

  • A DC motor is probably best: they are easy to control and are available cheaply in a wide range of sizes/torques/speeds.

  • It's not possible to say, for reasons which are surely obvious to you. It depends on the mass of the counterweight and the friction at the pulleys.

  • You can look for motors online as well as any of us.

  • Others have more experience than me at controlling motors - they will advise on the best controller.

  • Yes. But why would you want to use an Arduino? Won't a big switch do?

PS: You "wanna"?? :roll_eyes:

21

Thank you for your help, I will try to explain you my plan as good as possible:
The construction should be capable to move the weight to a specific hight between 0 and 4 meters. For example, I want to type „243“ into my PC, which then sends the data to an Arduino, which controls the motor. The motor should be capable to move the weight in less than a second to the given height (2m 43cm), and stay there until I give the computer a new height.
You can imagine it a bit like an elevator. I hope that now you understand better what I mean…
(Sorry for bad english)