Return to Independent Study
04.19.17 Independent Study, Journal 12
04.19.17 Late Night
I stayed at school all day and late into the night building the new robot platform and working on the frame.
I worked so much and so long that I did not write anything down at all. This is a synopsis.
Gene didn’t respond again until the 22nd by which point Wade and I figured out that I basically just need new batteries and a new set of motors. I didn’t have time to figure that out so I had to go on with the design doing the best I could to be adaptable. I basically just made the bottom with a motor mount and the top with the Arduino. I skipped the battery layer.
I did a bunch of research and located motors and batteries but the motors are $40 each and the batteries will cost me about $70 since I’ll need a special charger.
I put the thing together with the first bad motors so that it would have a way of looking complete. Then I hoped I would be able to hook up all the electronics even if it had no power source. Then I could power it from a regular non-battery power supply. However, I ran out of time and didn’t get all that soldering done.
I ended up setting up all the individual robot components at the Expo. I think it actually looked ok. I was able to explain it to other people. I labeled it a “Prototyping Robot” and explained that it was designed to help me develop more robots in the future.
Despite all the grief, I do believe the robot will fulfill its purpose. I think that I will end up with a robot that has a stable power and drive system so that I can then add whatever sensors I wish to design the response behaviors that I want. I look forward to getting to that stage.
I feel like the project will eventually build the ecosystem I envision but I think that it will be more about robots interacting with people and inviting people to figure out their behaviors than it will be about creating something self-sustaining. I think my interest is moving more towards human interaction. I think I will likely make larger robots ranging from mouse-sized to kitten sized so that I can set them loose in a room with people.
The Follow-me system is working so I may expand on that with some “follow the color” robots but the robots will be various colors so that I can make a system that defines who will follow who and viewers have to figure it out. I think my current path makes this attainable.
04.22.17 E-mail from Gene:
Thanks for sending these details. It’s too bad there’s no spec sheet on the motors, but there is some good info listed there. The 3.24A stall time might be the biggest factor. That’s the amount of power it pulls when it’s first starting up until it gets to it’s full RPM when the current draw would lower. The other question is why did you go with such high rpm motors? I’m guessing you’re getting no where near 15,600 RPM nor would you want to, which means you’ll be pulling a lot of amps for most of the time their being used. You might want to look at some gear head motors that are low RPM but have lots of torque to handle the weight of the robot. They can still be zippy, but might also be more efficient. Here’s some options from a reputable company: http://www.jameco.com/shop/keyword=dc-gearhead-motors
As far as the batteries go, it looks like there Amp hours were a good match with 6800mAh / 6.8 Ah which should have lasted for 1 hour even at the maximum load of 2 motors pulling 3.25 / 6.5 total Amps continuously, but I think maybe the motors drained them too low and destroyed their capacitive memory.
Anyway, let me know who your newest experiments have gone and hopefully you find the right combination soon.