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View Full Version : Urgent! How many motors can we use?

M. Hicken
10-02-2004, 09:30
Hi,

I am currtenly working on the robot and there is a disagreement about the number of drill motors allowed to be used. I saw nothing in my fast sweep of the manuel. Am i allowed to use more than 2 drill motors?

Thanks alot

Marcus
219
NateBot16
10-02-2004, 09:33
You may only use the number of motors in your kit. Since there were 2 drill motors, you may only use 2 drill motors.
M. Hicken
10-02-2004, 10:55
thanks alot nate, man, there goes my design
EIROBOTICS86
10-02-2004, 13:18
use the cim motors as a replacement for two drills. They run at about the same speed.
Alavinus
10-02-2004, 13:29
The CIM motor does NOT run at the same speed as the Drill motors, with or without their transmissions. Please refer to any of Paul Cipioli's posts for the comparision. Roughly, the Drill motors run at 450 RPM and 1000 RPM with the transmission and 20000 without. The CIM motor run at 5500 RPM. Those are not close enough to match without some gearing.
KenWittlief
10-02-2004, 14:06
engineers work in orders of magnitude, so 4X faster is 'about the same speed'

10X faster or slower is 'significantly different' :c)
Alavinus
10-02-2004, 14:09
engineers work in orders of magnitude, so 4X faster is 'about the same speed'

10X faster or slower is 'significantly different' :c)

It depends on where you work. I work in a lab in research and 4X can be huge. For the purposes of FIRST, you still would have much greater efficiency and overall effectiveness if you gear down the CIMs to match the Drills
KenWittlief
10-02-2004, 14:14
you definately need to match the gearing so the torque speed curves match up. My point was with a 4X difference you are in the ball park, and can play with gear ratios or wheel sizes to get there
Chris Hibner
10-02-2004, 14:47
The CIM motor does NOT run at the same speed as the Drill motors, with or without their transmissions. Please refer to any of Paul Cipioli's posts for the comparision. Roughly, the Drill motors run at 450 RPM and 1000 RPM with the transmission and 20000 without. The CIM motor run at 5500 RPM. Those are not close enough to match without some gearing.

You are correct, they do not run at the same speed. However, they put out approximately the same PEAK POWER. Therefore, if you do your gearing right, you should get the same output out of the drill or the CIM.

-Chris
BillyGoats
17-02-2004, 17:39
Yeah they run about the same speed if geared correctly look at this from our robot.

http://www.valleytech.k12.ma.us/robotics/images/2004Pictures/2004_29electronics2.JPG

There left and right drive side. Drills on one Chips(CIM's) on the other. There is a slight difference when you go full throatal but all you do is keep the Chips full and let down a little on the Drills. Works easy and have been driving it for almost 3 weeks now.

Last year we did the same thing and it also worked well.