# Thread: How many Newton Meters needed for this amount of weight

1. ## How many Newton Meters needed for this amount of weight

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I am looking to use a high torq tubular electric motor mounted on one end to flip up and flip down my lcd flatscreen tv on my patio ceiling. These tubular motors are sized by how many newton meters they will lift while rotating. I do not have an engineering background so I can't figure out what size motor I would need for the weight I'm trying to raise and lower. If that is what this forum is for, great, I've finally found one. If not, I'm sorry to try to post this.

What I have is, a 48" flat screen that weighs about 100 pounds. I will raise the tv using this motor attached to the top and it will raise and lower it 90 degrees from how it is mounted. Can someone tell me how many newton meters it would take to raise this weight?

Thanks to everyone that tries to help with this problem.

2. The 100 lb weight is equivalent to 445 newtons.
Next, you have to determine the vertical distance from the center of the motor shaft to what we call the "center of gravity" of the TV set (This a point where if you placed the TV on a single support it would be balanced and not tip any direction). This might be a point 1/2 of the distance from the top to the bottom of the set but it probably is not: because, the internal electronics may well be in the bottom of the set and this will move that point closer to the bottom of the TV. If you want to be safe you can simply use the distance from the shaft centerline to the bottom of the TV.
The minimum N-M torque that will lift the TV to a full horizontal postion is then 445 x the distance from the shaft centerline to the balance point or bottom (in meters). Once this is determined, then you should multiply that value by a minimum of 4 or by the amount stated by the motor supplier to provide an appropriate safety factor.
With all of this said, you need to realize there are a number of operating and mounting components as well as ceiling reinforcements that need to properly addressed in any installation like this, particularly in one that is going to be a falling hazard to anyone passing below it.

3. ## Thank you thank you thank you

WOW, thank you for that invaluable information. The motor I was looking at was good for 300 Newtons, and I really didn't think it would be heavy enough to handle the weight I was going to put it through. Using your calcs, it looks like I'll need a 1800 Newton motor to pull this amount of weight. Or, wait until I buy an LED which is considerably lighter in weight. 445 x 1 meter and then 445 x 4. I cannot thank you enough for taking the time and trouble to give me this information. I hope someday you are rewarded in life for this. Thanks again.

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