Chief Delphi - Robot loosing communication when switching directions

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- - Robot loosing communication when switching directions (http://www.chiefdelphi.com/forums/showthread.php?t=98128)

Re: Robot loosing communication when switching directions

Quote:

Originally Posted by kinganu123 (Post 1084408)

@Ether, could you please explain to me what you mean by a 2.4X reduction? We are using 8" Mecs and I believe the ratio is 1:3 or some absurdly low number.

I said 2.4x additional reduction.

You said in an earlier post "I'm wondering if direct driving Mechanum Wheels using 4 - CIMple Boxes wasn't enough of a mechanical reduction and hence cause too much draw".

If you are direct-driving 8" wheels with nothing but a CIMPLE box for gear reduction, your motors are overloaded. CIMPLE box provides 4.67:1 reduction. You need more gear reduction. Preferably at least 2.4x more gear reduction. So, 2.4x4.67 = 11.2 total reduction from CIM shaft to wheel.

Re: Robot loosing communication when switching directions

Quote:

Originally Posted by Ether (Post 1084421)

I said 2.4x additional reduction...

I think this should be treated as a separate issue, possibly in a separate thread. Incorrect motor reductions should be unable to cause the root issue, provided the electrical system is fine. They can definitely aggravate the issue, but they won't be the root cause. Even if the problem appears to go away after changing the reduction, it will still be lingering in the background (and harder to debug when it returns).

As many other have already said, move the radio to the dedicated radio power supply. Also, add a few things to your standard pre-flight checklist - electrical connector security, chassis fault, motor chassis fault.

Re: Robot loosing communication when switching directions

Quote:

Originally Posted by EricVanWyk (Post 1084428)

Incorrect motor reductions should be unable to cause the root issue, provided the electrical system is fine. They can definitely aggravate the issue, but they won't be the root cause.

I agree the motor reduction is not the root cause, I should have been clearer.

You still should consider changing that gear ratio though, kinganu123. PM me if you'd like some additional useful links.

Re: Robot loosing communication when switching directions

Quote:

Originally Posted by Mark McLeod (Post 1084412)

If your radio is taking 5 minutes to reconnect to the field, then it could be that the manual switch on the back of the DLink is in the Auto position rather than Bridge.

Actually, at Brunswick Eruption, we had no connection to the networks for the first 3/4 for matches. So we did a manual override by setting it to AP and connecting the netbook to the receiver.

Quote:

Originally Posted by Joe Ross (Post 1084414)

Have you rewired the robot since competition, or were you able to pass inspection twice with the radio wired to a PD breaker?

We have rewired the robot because it was atrocious, but the freshmen who were assigned to the job were told to wire it the same exact way it was before they redid it. So that could be where the problem started. But I don't recall wiring the bridge to the dedicated port in the first place.
and yes, we did pass inspection the way the radio was wired
Twice at Trenton and twice at Philly

Re: Robot loosing communication when switching directions

Check the power chords and the way they are fixed. There might be a loose contact and due to the movement they might be missing contact with the power and stopping its function.

Re: Robot loosing communication when switching directions

sorry for not following up with you guys, but I went ahead and wired the router to the dedicated power source and it worked!
thanks a bunch guys! :D