This page created 10-14-2001 11:44:42

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Kilian's Robot Shop of Horrors - 10/12/2001

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We started out playing with batteries. Alan has several that won't take a charge anymore. So I suggested that we try putting more water in the batteries. I did this with two of my batteries and it revived them to the point where they were useable again. Unfortunately I put too much water in my batteries and they spit out water when I charge them.

We started with my soda bottle water injector. It makes it real easy to get the water into the battery. But you can't nearure it as you fill the battery. Alan found a hypodermic needle thing and we used that. We could measure the water in CCs as we added it. So we put water in the big battery and it still wouldn't take a charge. So we put water in his smaller battery. It wouldn't take a charger either. So we left the small one on the charger to see if it would come back to life.

Then we moved on to the pick-and-place robot. (See the last few weeks for more details.) Last week we wired up some DC amplifiers to the motor controller and got one channel working. Alan played with it during the week and decided the amplifiers weren't supplying enough power. They had been modified before ending up in the trash, so we had to figure out how to modify them back. Brynn brought his "wheel chair" balancing robot over. It has on of the amplifiers that had not been modified. So we changed some resistors on the amps and got one to put out 1.5A, which was the limit of the power supply.

Then we spent most of the night trying various combinations of parameters for the motor controller. We also measured the repeatablitiy of the arm and decided it has a problem. So we tried motor parameters and got it working fairly well.

We also discussed using paraffin wax to cool electronic components. We had various physics books out and we ran lots of calculations. We decided this should justify some experiments in the future.


Battery experiments

A 17AH battery with the caps
popped off.
Alan squirting some
distilled water into the
Trying to view the water
level. But the battery has a
white foam thing in the way.
Squirting a measured amout of
distilled water into a 4AH
Charging the 4AH battery.

Pick-and-place robot

A DC h-bridge amplifier
A partial reverse engineering
of the amplifier.
Brynn, Ron and Alan
discussing how to modify the
Ron is making measurements
after we replaced 3 of the
resistors on the module.
Alan trying endless
combinations of P, I and D
It was creeping one
direction. So we set up a
dial thingy to measure it.
Here it is pushing up against
the dial so we can get a
Since I (Jeff) am always
taking pictures of everyone
else, I made sure I got one
of me.

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