"Motors and Drive train edition" of Fresh From the Forum

[Ken Leung]

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I. FIRST 2002 Motors in General
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Team 639 put together a page with picture of all the motors that came with the kit of parts this year. Take a look at the pictures @ http://www.startateam.com/639/motors.php if you aren’t familiar with the motors and their name already.
http://www.chiefdelphi.com/forums/sh...&threadid=1469

These are the only motors you can use on your robot (and the two servos that came in the kit): 3 Drill motors with transmission, 2 Chiaphua motors, 2 fisher price motors with gearbox, 1 Mabuchi motor (=fisher price motor), 2 globe motor with gearbox, 2 seat motor with attachment, 2 Jideco window motors (left and right), 1 Johnson motor, 1 torque motor. These motors are covered under the “parts found in the Kit of parts” rule, and you are limited by these numbers. Any more of the same kind of motor can only be used as replacements. Info regarding ordering spare motors can be found in the manual (should be after “The robot”). Also, you have to watch out for reusing motors from past years, as there’s no van door motors in the 2002 kit, and window motors and fisher price gearbox are different this year.
http://www.chiefdelphi.com/forums/sh...&threadid=1588
http://www.chiefdelphi.com/forums/sh...&threadid=1590
http://www.chiefdelphi.com/forums/sh...&threadid=2131


Chris Mikus did a wonderful job of putting together all the specs of motors available to use through out these few years (Thanks Chris!). It is up in his webpage, @ http://www.nuts4first.net/ There are a lot of really good guides of different aspect of the FIRST competition, especially useful for rookie teams and beginner teams out there. For the purpose of this newsletter, I will only point readers to a specific part of the web page: the library @
http://www.nuts4first.net/html/library.html with description of what’s in here. If you click any one of the post, it will bring you to an index page of where the documents are. The one with all the specs of motors is: http://www.nuts4first.net/library/Motors.htm
Just make sure you look at the Jideco window motors instead of the old one. Other than that, the chart is really easy to understand. Also, I will put the specs below in the “in depth discussion of specific motors” just so everything is together in one place.
http://www.chiefdelphi.com/forums/sh...&threadid=1321


Morgan Jones posted an excel spread sheet of weights for motors and components (Thanks Morgan!). Check out this thread:
http://www.chiefdelphi.com/forums/sh...&threadid=2085
http://www.chiefdelphi.com/forums/sh...ghlight=weight


About motors in general…
Motors is a good way to power components on your robot. The motors from the kit are electric motors powered by the 12v battery. It will worth your time to learn about how motors work, and characteristic of each of them. A lot of good paper inside the white paper section of chiefdelphi.com, you want to pay attention to is the two motors presentation by Joe J. and Mike C. I also put up a lecture note with detailed description on what I learned from those presentations. They are all at http://www.chiefdelphi.com/forums/papers.php?s= (page 2 & 3)

Also, here is a good thread about physics behind motors and gears…
http://www.chiefdelphi.com/forums/sh...&threadid=1873
“But, with electric motors, torque is related to current, and speed is related to voltage. And they are locked in a struggle with the internal 'resistance' of the motor.” -Lloyd Burns
“The most important about the electric motors we get from the kit is the speed torque curve… you should really pay attention to it… So basically, the speed torque curve explains how a motor will react under load.” –Ken Leung
“I'm sure most people on this thread are aware by now, but torque/rpm curves of DC electric motors are MUCH DIFFERENT from those of internal combustion engines.” -Kit Gerhart

And a good post by Andy Baker about applying the motors to your robot…
http://www.chiefdelphi.com/forums/sh...&threadid=1179
“--The globe motors and window lift motors are also good for actuations...
--Seat motors are mainly used these days to collect balls (by driving a spinning roller)
--Torque motors were only used as triggers last year...” -Andy Baker


A little general advice… With the new chiaphua motors in the kit, there are new engineering challenges you have to think of when designing your robot around those motors, especially with this year’s game and all the robots bumping into each other. Just make sure you give enough thoughts before you put motors on robot.
http://www.chiefdelphi.com/forums/sh...&threadid=1828
“Holy cow, what a lot of trouble two motors can cause! With the addition of the Chiapua motors, we have some new engineering challenges. I don't know about the rest of you, but here are some of the things I've had to to investigate for the first time since college” -Andy Baker
“Isn't it nice to have to THINK about what to do with the various motors in the kit? It has been a no brainer for so long which motors to drive with. Now comes a new challenge. I LOVE having new motors to play with.” -Joe J.


About Heat sink…
If your motors are running hot, try using heat sink or mount fans next to the motor.
“While we were running our robot we noticed the BOSCH and FP were running a little warm, so we found some heatsinks that are BAM extruded aluminum.” - Matt Reiland
http://www.chiefdelphi.com/forums/sh...&threadid=2141

About the tapped holes on the motor…
“M4 on the drills, M3 on the Fisher Price, M6 on the window, #10-32 on the Chiaphuas..” -Joe J.
http://www.chiefdelphi.com/forums/sh...&threadid=1833