Problem with drivetrain and we can't figure it out.

[mshafer1]

Originally Posted by Shaif

I noticed it said brownout protection on the dash whenever the problem occurred so we switched out the battery and everything seem to go a little better. We no longer loose connection from driving the 4 motors but out of curiosity how many CIMS can we drive at the same time at full power?

It depends on a lot of things. Including the gear reduction, and weight of the robot - on top of that, if you have enough CIM's running, your robot will be able to move, but no for very long because it would drain the battery.

If you want a more technical answer (I could work the numbers for you, or document how to do it for you), let me know (reply, private message, or email). I recently did a bit of research into gear box design for the sake of an engineering project, and have developed some tools to allow me to quickly analyze a motor/gear ratio/robot weight combination. I also have a stack of references available if you would like to do your own research.

[Shaif]

Replacing the battery fixed it oddly. Thanks for the help guys!

[Ether]

Originally Posted by Shaif

Replacing the battery fixed it oddly.

You should test that battery (3 amps for 2 hours while monitoring voltage works nicely).

[gpetilli]

Originally Posted by Shaif

Replacing the battery fixed it oddly. Thanks for the help guys!

How old are your batteries? We find they last maybe three seasons. We hold aside new batteries for competitions and dont use them for practice or debug. I strongly recommend investing in a "battery beak" http://www.andymark.com/product-p/am-0995.htm
We use it at the beginning of every season to test every battery.

[MrForbes]

It's very common to find the "low battery" issue causing a few posts every year on CD. It seems to take some teams a while to figure out that you have to charge the batteries often! And that the FIRST thing to do when you have odd, unexplained robot performance, is to glance at the battery voltage reading on the driver station. If it's less than 12.5 v when the robot is enabled, but not doing anything, then you need a fresh battery.