Check your Anderson battery connectors

[rammsey]

Originally Posted by philso

You seem to be focusing only on the battery connectors.

Because that's what our problem was 2 of our matches.

After each of those matches, when going to take the robot off the field, you could see that the battery connector was not seated in right. Even though before, like I had said. We made sure it was in there properly.

Rest of our matches we used zip ties so there was no chance of it getting unseated and we had no issues.

We just can't seem to figure out how that connector could have come loose going over rock wall those two matches.

[Ether]

Originally Posted by rammsey

We just can't seem to figure out how that connector could have come loose going over rock wall those two matches.

How is your battery secured??

[thinker&planner]

Originally Posted by Ether

How is your battery secured??

Here's a bad picture, but it's the best I could find.

There is velcro strapping holding the battery down into a "box" of sorts. In neither of the two matches where the connector separated did the velcro become undone. It's pretty hard to get the battery in and out, you could even say that it's a "press fit."
All of our battery leads are that long, so the battery would have to be launched up 6 inches to pull the connectors apart.


The best theory that I came up with is that it has something to do with the robot-side connector being bolted solidly to the frame (the "attacking side" that hits the defenses before anything else.)

[Ether]

Originally Posted by thinker&planner

Here's a bad picture, but it's the best I could find.

Thank you, but... please use JPG for photos, not PNG.

[rammsey]

Originally Posted by Ether

Thank you, but... please use JPG for photos, not PNG.

Any reason why? I don't see anything wrong with using PNG

[Ether]

Originally Posted by rammsey

Any reason why? I don't see anything wrong with using PNG

Here's the reason:

[rammsey]

The only difference is file size, and the difference between them is ~600 KB, which is negligible.

I'm still failing to see what's wrong.

[Knufire]

Originally Posted by Kevin Sevcik

Crooked cuts from wire cutters can exacerbate this problem, because they make it hard to fully seat the tube. Using a $7 tubing cutter from McMaster helps immensely.

We've been getting tons of these free with our Automation Direct orders as well. Super useful.

[philso]

Originally Posted by thinker&planner

Here's a bad picture, but it's the best I could find.

There is velcro strapping holding the battery down into a "box" of sorts. In neither of the two matches where the connector separated did the velcro become undone. It's pretty hard to get the battery in and out, you could even say that it's a "press fit."
All of our battery leads are that long, so the battery would have to be launched up 6 inches to pull the connectors apart.


The best theory that I came up with is that it has something to do with the robot-side connector being bolted solidly to the frame (the "attacking side" that hits the defenses before anything else.)

The pictures really help people understand your situation.

The loops in your battery cables are long enough that the movement that is possible should not cause a good pair of connectors to come apart. How much force is needed to pull them apart? Try pulling at different angles. I don't see where your bumpers end up. Is it possible that another robot is hitting the battery wires? It seems that the constant in this is the connector on the robot side. Have you tried replacing it? Try putting painters tape so part of it is on the battery and part of it is on the bracket. Put other pieces so they are on one of the battery wires and the frame next to it. If anything is moving more than a few millimeters, the tape on it should tear and give you some clues.

[rammsey]

Originally Posted by philso

How much force is needed to pull them apart? Try pulling at different angles. clues.

We tried tugging on it pretty hard, and at all different angles. It is not at all easy to just pop that connector out.

Originally Posted by philso

I don't see where your bumpers end up. Is it possible that another robot is hitting the battery wires? I

The inside of the bumper comes right up against the outside face of the aluminum on the other side of the connector. Sorry if I'm not explaining it properly, we don't really have good pictures.

And both times the connector did dislodge, it happened during the second (this really baffles us) crossing of the rock wall. So no robot was hitting the connector at the time.

[Kevin Ray]

I'm not sure that this will alleviate the problems that some teams are experiencing regarding connections and Anderson connectors, however, for the past 10 years or so we require all new connectors to be back-filled from the wire side with hot glue. This helps with stability issues sometimes related to those who continue to lift the battery by the cables (WRONG) or separate the connectors by pulling on just the cables.

[philso]

Originally Posted by rammsey

We tried tugging on it pretty hard, and at all different angles. It is not at all easy to just pop that connector out.

The inside of the bumper comes right up against the outside face of the aluminum on the other side of the connector. Sorry if I'm not explaining it properly, we don't really have good pictures.

And both times the connector did dislodge, it happened during the second (this really baffles us) crossing of the rock wall. So no robot was hitting the connector at the time.

Have you tried installing the battery and putting the Velcro strap on then try lifting the robot by lifting the battery? Perhaps the battery is "jumping up" and stretching the Velcro strap then popping back into position during the violent manoeuvre.

At Bayou yesterday, we popped our PDP panel off and separated all the Anderson connectors to our motor controllers when we hit the Portcullis too hard. It was stuck on with two long strips of Duo Lock which holds more strongly than Velcro. We (and others) have broken things that have never broken before.

[adciv]

We've had a few issues with the contacts separating slightly woke the connector was mated. One of these was supposedly from the contacts having come off the retaining clips (not sure how, but I've seen this before on our battery charger ). On the other, if I rotated the wire, then the contact also rotated in the connector. We've instituted an inspection since they on order to catch these and I've had some spare cables made up on case we see more. I think we're starting to see aging issues with the wiring. These connectors are mated and unmated frequently and may be wearing out the housings and contacts.