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Just a simple question. What type of motor should I get so that my robot can get an average of 15 fps?
Danny McC
07-01-2008, 21:14
The CIM motors in the KoP can easily do 15 FPS.
ya, a CIM, and possibly a banebots tranny
Billfred
08-01-2008, 08:48
In theory, any motor will get you to 15 fps...eventually.
The best advice I can offer is to download JVN's design spreadsheets (newer (http://www.chiefdelphi.com/media/papers/2059), older (http://www.chiefdelphi.com/media/papers/1469)) and start fiddling with numbers. The newer spreadsheet is a little more user-friendly, though the older one lets you have a little more fun with numbers (particularly when you're trying to figure out how quickly a robot will accelerate).
Another thing worth noting in the spreadsheet is the output at maximum load. Conventional wisdom says that the safe route for a drivetrain entails being able to slip your wheels/treads/doohickey in your lowest gear when pushing against a wall, and do so while drawing less than the 40 amps it takes to trip your robot breakers. If you want a higher speed than what will allow that, you'll either have to add motors or shift. (A good thread on the matter is here (http://www.chiefdelphi.com/forums/showthread.php?t=59473).)
But to answer your original question, it is possible to use four CIM motors with the right gearing and wheel choices and hit 15 feet per second. (Matter of fact, you can even do it using COTS parts exclusively.) I'll leave the math to the reader, since all the tools are already posted.
Hope this helps!
I think you have the answer to your question, however, you should also make sure you have a well trained driver. 15 fps is very fast, and unless your driver is capable of making the robot go where she wants at this speed, it might not do you much good.
Why 15fps? Is there a strategic reasoning behind that number?
Wetzel
caraddicted101
08-01-2008, 15:43
Why 15fps? Is there a strategic reasoning behind that number?
Wetzel
That is a good point - does your team think that there is an advantage to that? The other thing that you have to consider is that if you are trying to go this fast on a one speed tranny then you will probably not have a whole lot of torque. I agree with everyone else though, the cim motors are the most effective for speed.
Ian Curtis
08-01-2008, 15:58
Just a simple question. What type of motor should I get so that my robot can get an average of 15 fps?
You better have a darn good software team, and one heck of a driver to keep control of a robot at 15 fpgs.
We gave our driver a 15 fps mode last year. While the game didn't really warrant it, he still used it twice. One of those times he collided with the alliance station, and the robot required some hammering out before our next match.
But, as other posters have pointed out you want the CIMs. In fact, no matter what drive speed you end up using, you want the CIMs. Most likely two per side to get some good acceleration so you can actually take advantage of your 15 fps. If you do end up using the second CIM, you'll need to buy a few additional parts from AndyMark.biz.
Yeah I have a good reason.
'bout to have a meeting with my team in a few hours. So if the idea gets rejected. I'll let yall know and maybe someone can do better with it. :P
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