The wires I had were too short to reach the ESC on one side. So I took this opportunity to make everything a little neater.
I soldered the + wires of each motor together and the – wires as well. These were then soldered to a 2 pin connector and all covered with heat-shrink.
Don’t forget to put your heat-shrink on BEFORE soldering 😛
After killing my batteries, I decided to invest in a battery monitor. I picked up a 2-pack of these from Amazon Here. They give the total voltage, and the voltage of each cell (up to 8!)
These things are pretty light-weight. But not quite light enough for me to always have it in the bot.
So I messed up. I let 2 of my 11.1v batteries drop down to ~7.5v 😦
Thankfully Frederick Moore, the creator of Road Rash, answered my call for help on the Combat Robots Facebook page and graciously took the time to walk me through the steps of bringing my batteries back to life.
First, we set my charger to Pb Charge mode and started to charge the battery set to 10v at .2 amps. The charger thought my battery wasn’t capable of 10v because of how low it was and wouldn’t charge it. This was fixed by setting it to 8v, letting it finish, and then going to 10v. Then I would let it charge on 10v for a few minutes until the battery was at a stable voltage again. It was normal LiPo charging from that point on!
It was also very important to make sure that each cell’s voltage did not get to high while Pb charging. So I just walked the volt meter across the balance connector every few seconds to make sure they were ok.
At the time of writing this, I don’t know how damaged the batteries currently are. I’m ordering 2 more Zippy’s just in case. And from now on, I need to be more careful with my battery usage.
Remember when Lucky took a hit from Beta’s hammer and knocked its flipper in creating that “cobra stance”? Check out the full fight Here. Well this happens when the rear section of a 4-bar flipper rotates too far forward.
The happened to my bot during testing. The rear part doesn’t want to rotate that far mechanically, but the inertia from the arm going up causes it to rotate a bit further than expected and then bend back into place.
This should be an easy fix of adding a brace to prevent it from physically rotating that far.
So I decided to go ahead and go with only 1 servo. This will save me about 2.5oz of weight from the servo, and another ~ounce from the removed aluminum and UHMW. It also makes Torsion 1″ less wide. Which is better in my opinion. The only slight annoyance out of this is that the arm is now offset. But hey, gives it some style I suppose. Shouldn’t affect the lifting much.
*Sigh* Overweight again. This doesn’t even include the top armor and the wedge. Though it is a little heavier because of the big battery I’m testing with and I could probably drill out some of the arm. But for now, I think it’s time to drop one of the servos. The HXT12kg should have 250oz-in of torque at 9v. Which should be enough one its own.
Since my servos are mirrored in orientation, I needed to reverse one of them so that they’d be at the same position given the same signal.
This ended up being a simple task. All I had to do was reverse the motor and potentiometer wires. For more details, check out the Youtube Video I learned from.