I'm new to all this so sorry if I ask something that has already been mentioned. But if you guys have any advice then please do help us out. Well me and my friend are.doing a project and we need to know how to lift 200 pounds about 10 cm into the air for about 10 minutes or close to that time Scale. Like I said I don't know much about this stuff but if anyone has any suggestions then any thing would be appreciated. We are planning on using brushed motors or if you guys can suggest anything else then go for it it, we are also planning to use four motors.
With the correct gearing you can lift a lot of mass with smaller motors that you think - in fact, friction in the system becomes the main limiting factor, not the mass.
We need to clarify a couple of things though:
~ you want the 10cm move to take 10mins or you want to lift the mass at a reasonable pace then hold for 10mins?
These are very different tasks, and if optimality is desired than they will have quite different solutions.
~ why four motors ? you already have 4 motors ? if so, more details will help
hya thanks for the reply, and yes I would like the process to lift the weight at a reasonable pace and then hold for ten minutes and no don't have four motors my friend thought the more motors we have the more it could lift but apparently not. I would probably want to use two motors only if that would be possible after the ten minutes is up I would like the motors to slow down to a complete stop
A used car windscreen wiper motor might be worth trying - but I have never measured how much they can lift. Like everything else there are big and small versions.
They have low gearing and powerful 12v motors. Also they have a worm drive so they will hold their position indefinitely without power.
um... yes I guess so, sorry I don't know much about this stuff, it was the only option they gave us at school so yeah. Do you have any idea on how I would do that? Referring back to my original question
PurpleGummyBear:
hya thanks for the reply, and yes I would like the process to lift the weight at a reasonable pace and then hold for ten minutes and no don't have four motors my friend thought the more motors we have the more it could lift but apparently not. I would probably want to use two motors only if that would be possible after the ten minutes is up I would like the motors to slow down to a complete stop
I'm confused.
So, they would 'hold' for ten minutes - then after the ten minutes they would slow down ?
Robins suggestion of a worm drive is good - lots of friction helping you out ...
However - the plot thickens - you're making a quadrotor now
200 pounds for 10mins - and you're new to all this?
right I'm going to try and explain What I need to a bit clearer, I need to lift 200 pounds 10 cm into the air for 10 minutes. Next I need to know how to do this and yes I am completely new to this, the only research I have done is on heavy lifting quadcopters and I don't fully understand it completel. So my initial question. I would like to know how to lift 200 pounds.witb ROTATING motoRs, is that a bit clearer?
If you are considering a tethered lift this is the way to calculate:
200 lb is approximately equal to 100kg (please use SI units, everthing is so much simpler then) that means the force needed to lift that weight is 1kN. You are goint to lift it 10cm or 0,1m means the energy needed for that job is 100J or 100Ws.
You do not give any specifications for the time to lift so 10s seems reasonable. That means the net power to do the lift has to be 100Ws/10s giving 10W. This does not account for losses so you have to multiply that with some reasonable factor. I would recomend a worm gear since it is self arresting and an as small drum diameter as possible since this will minimize the torque nedded.
If you on the other hand plan to do the lifting with propellers the story comes completely different. For a more thourough discussion on propeller performance have a look here
PurpleGummyBear:
right I'm going to try and explain What I need to a bit clearer, I need to lift 200 pounds 10 cm into the air for 10 minutes. Next I need to know how to do this and yes I am completely new to this, the only research I have done is on heavy lifting quadcopters and I don't fully understand it completel. So my initial question. I would like to know how to lift 200 pounds.witb ROTATING motoRs, is that a bit clearer?
Well, you mentioned quadcopters, which is new.
What is your intuition telling you?
Think about you personally lifting 200pounds ...
Now, think of the last drone you noticed flying about that wasn't priced over your budget, what would you estimate it's weight as being?
You should have mentioned that in your original post, that would have saved everybody a lot of time and effort. We like to help but please help us help you.
Since you are only lifting 10 cm you will have some help from something called "ground effect" this will reduce your power needs by a some factor.
Lifting 200lbs with any sort of affordable "helicopter" type of device is just ridiculous. This is man-carrying territory (not that I am volunteering to be the pilot).
It would be a substantial task with a winch firmly attached to the wall of a building.
If this is a school project my strong suspicion is that the OP has confused 200 grams with 200 lbs.
