So, after trying all combinations of sensors for the steering limits (Hall Effect, Micro-switches, and hard stops with current shut off), I did not have a good solution yet.
I decided that since the limits were one issue, and holding the wheel straight while running was another issue, I would go back to trying a servo motor. But, not just any servo motor...a 1/4 scale gigantic torque-ridden beast that might be able to do the job! I got the idea watching a video of a couple guys that built a 1/4 scale model airplane out of aluminum and flew it! I thought if the servos could deal with that, they should be able to push the wheel on my 18 pound robot back and forth.
Scouring the web, I found a place that had not only the giant servo, but nice aluminum mounting brackets...out came the credit card.
After getting my package in the mail, I set about removing all the components I had recently and very carefully fit together (for the second time) and when I got back down to the bare chassis, I drilled holes and mounted my new servo. After mounting it, I had to make a 3/8" dowel with a hole through it for the connection to the steering plate below. The hole was so that a set screw could be mounted to keep the whole thing from slipping when under pressure while turning.
I got the whole system mounted up and then connected the H-bridge back on again because that was going to power the drive wheel like it was originally supposed to.
Here is how the whole thing looks now.
Once everything was mounted, I placed the EZ_Robot controller inside to see how everything would fit. I think the EZ-Robot Micro-controller will handle the steering of the robot and the interface to my cell phone and computer. That seems like the easiest way to work it out at the moment.
I will use an Arduino Mega up top to power all the head sensors, the keypad and LED's. I will also use Arduinos for the arms to control them and synchronize everything through a few drivers and libraries I am making for the Arduinos.
My goal now is to try and get this robot rolling by the end of the weekend so that I can start working on my circuit boards for the sensors and then get the arms together.
I am starting to feel more ideas in my head and I want to keep working while they are all still making some sense to me.
The two collars above are holding a 3/8" shaft with set screws travelling through it to keep it from slipping while the wheel is turning.
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