Society of Robots - Robot Forum
Mechanics and Construction => Mechanics and Construction => Topic started by: Eithman on April 28, 2012, 12:48:44 PM
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Hello everyone. This is my first time on this forum but I really like the layout of the site. Very easy to use and helpful. My question is regarding whether or not my RMF math is correct before I go ahead and buy this motor. I read through the statics and dynamics tutorials. Using that knowledge I checked online and found this motor http://www.robotshop.com/solarbotics-gm2-gear-motor-2-offset.html (http://www.robotshop.com/solarbotics-gm2-gear-motor-2-offset.html). I plan on buying two of these to be the front wheels on the base of a robot I am building. I will use regular wheels for the back. Here is what I came up with when calculating.
https://docs.google.com/document/d/1_BfaLPuMPeYCOFPSX-UcX8mNfMZ36hYB7RN_iL7Rg0Q/edit (https://docs.google.com/document/d/1_BfaLPuMPeYCOFPSX-UcX8mNfMZ36hYB7RN_iL7Rg0Q/edit)
So it would seem that I should be fine and even have a little extra, correct? Does anyone see any problems or should I go ahead with the buy? Thanks for the help!
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Hi,
https://docs.google.com/document/d/1_BfaLPuMPeYCOFPSX-UcX8mNfMZ36hYB7RN_iL7Rg0Q/edit (https://docs.google.com/document/d/1_BfaLPuMPeYCOFPSX-UcX8mNfMZ36hYB7RN_iL7Rg0Q/edit)
So it would seem that I should be fine and even have a little extra, correct? Does anyone see any problems or should I go ahead with the buy?
Sorry, I'm still in a long aftermath of a Google redirect virus :( and even going by the IP number I cannot get through to your document, but anyway, if you want people to bother, it's better to post the file here, rather than on any other site. A .doc or whatever will do if your options are limited, but .pdf is the preferred cross platform format that is readable to all (just don't make it compatible with the newest edition only).
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Sorry about that :( For sake of ease, I will just type out the results as to avoid any other confusion.
Mass - 3 lbs
Desired Velocity - 0.5 ft/s
Desired Acceleration - 1 ft/s^2
Expected Efficiency - 90%
Incline Angle - 0 degrees
Wheel Diameter - 0.32 feet
# of Powered Wheels - 2 Wheels
RMF - 0.133 lb*ft*rps
RMF (zero incline) - 0.133 lb*ft*rps
Momentum - 1.5 lb*ft*s
Motor Rotation Speed - .497 rps
Energy/second - 0.00231 Watts
Torque - 0.036 kg*m
Speed - 0.63 rps
Motor RMF - 0.164
This is copied directly from the RMF calculator offered in the dynamics section. If there is any other information you need, please let me know. Thanks!