Calculating how fast a motor can move something in horizontal motion


by caljuice
Tags: horizontal, motion, motor
caljuice
caljuice is offline
#1
Sep17-11, 02:45 AM
P: 70
1. The problem statement, all variables and given/known data
So I need a motor for a project. The motor i'm looking at creates circular motion. I want to make the motor move some object in a horizontal motion but I want to know how fast it can move the object horizontally before getting it. How can I find out how fast the motor can move it?
Motor in mind:
http://www.servodatabase.com/servo/hitec/hs-322

Sorry if there are unnecessary unit conversions. Seems like engines are explained in imperial units.

2. Relevant equations

Using this equation to find horsepower = (Torque x Engine speed (rpm)) / 5,252 = Horsepower
Found from:http://www.howstuffworks.com/question622.htm

Torque for engine = 3.70 kg*cm = 0.03 kg per m = 0.22 lb/ft

speed = 0.15 sec/60 (not really sure what this is? Assuming 60 degrees every .15 sec. So one revolution (360 degrees) = 0.15 sec x 6 = .90 sec. Then rpm = 66.7

Mass of object being rotated =0.2 kg



3. The attempt at a solution

One way I thought of calculating this was converting the torque output to Power then converting power to work then to kinetic energy to velocity.

Horse power = 0.22 * 66.7 /5252 = .0028 horse power

Mechanical horse power = 33,00 lb*ft/min so (0.028 * 33,000)/60s= 1.54 lb*ft =2.09 n*m

I'll assume all work will equal KE. 2.09 J = 0.5 *0.2*v2

V= 4.6m/s.
Does it look right? Any help would be appreciated.
Phys.Org News Partner Science news on Phys.org
Going nuts? Turkey looks to pistachios to heat new eco-city
Space-tested fluid flow concept advances infectious disease diagnoses
SpaceX launches supplies to space station (Update)
rude man
rude man is offline
#2
Sep17-11, 03:49 PM
HW Helper
Thanks
PF Gold
rude man's Avatar
P: 4,408
Think about this: you said 'horizontal' motion. What if anything limits the velocity if you continually apply a certain amount of power to a mass moving horizontally?

BTW on the rhs equation of 'mechanical horse power' the dimension is energy, not power, so I would check that. Always check dimensions on any work you do. Every single term. I find more mistakes I make that way than with any other, by a mile!
caljuice
caljuice is offline
#3
Sep17-11, 07:17 PM
P: 70
Quote Quote by rude man View Post
Think about this: you said 'horizontal' motion. What if anything limits the velocity if you continually apply a certain amount of power to a mass moving horizontally?
I'm guessing you mean drag and friction? Would it still affect it a lot with the device being so small? I don't think I would be able to calculate it with the information I'd have.



Quote Quote by rude man View Post
BTW on the rhs equation of 'mechanical horse power' the dimension is energy, not power, so I would check that. Always check dimensions on any work you do. Every single term. I find more mistakes I make that way than with any other, by a mile!
Sorry isn't it in energy already? 2.09 Nm is Joules.


Register to reply

Related Discussions
Calculating vertical and horizontal components in projectile motion at a certain time Introductory Physics Homework 3
How to Change a Horizontal Vector to Move in a 45 degree angle Introductory Physics Homework 6
How fast does the planets move away from the Sun ? Astrophysics 0