Wednesday, August 19, 2009

PHEW! Dodged a bullet

hey guys. i was planning to have it all glueing tonight and ready for christening tomorrow but I ran into a bit of a problem. in fact, it was a 'holy crap i'm not, not the battleship, the whole project is over' type problem. ya, pretty frightening. heres what happened.

so, like i said, i zip tied all the wires to the sides and to the various components such that there was minimal stress on the leads and also to keep as organized as possible. i showed you a picture yesterday of that. well, sometime yesterday and then also today, the speed controller started acting up. i went and read the instructions for the ESC (a piece of junk manual) and learned of a possible issue that i then internet researched and learned i should do something about it. i needed to remove the positive battery wire so that the bec (which i just learned about today and is basically like an internal battery) wouldn't interfere with the actual battery. so i did. then things stopped working. by things i mean the speed controller wasn't passing on voltage. 7.4 V in, .1 V out. essentially, BAD. so i put back the wire. still nothing. i started disconnecting things left and right. BY THE WAY. this was right before i was about to go out and do a last pre-deck test before assemblying the deck. i had already put on the back deck

and taped it up to keep out the water as best as possible. so i was super excited to go and test both the drive and the pump. (if you notice the water gun video, the boat is not moving. thats because the problem was on and off that day too. thats why i went looking at the manual, thats why i did the research and pulled the positive battery wire. thats where our story started) however, it was not to be. like i said the ESC wasn't working and i was flipping out. i removed all sorts of things and nothing was helping. i broke out the voltmeter and worked back from the motors. .1V at the motors. .1 at the parallel split point. .1 after the ESC. 7.4 before the ESC. obviously, something was wrong with the ESC. what? Spent all afternoon debugging. nothing.

i called my contact, looking for help, right around dinner time. that wasn't really very considerate, but i was getting desperate. this isn't a part i can replace in lest than a week or so. and i go to vassar in exactly a week (HOLY MOLY THATs EXCiTING!). so this kills the project.

like last time, i described stuff to him, he suggested some things i had already tried, so i threw out some possible keyterms that might help him remember a solution. but this time, didn't help.

i went and had dinner, after which stephen called back with a new suggestion. didn't help. we agreed to talk again tomorrow before giving up. after the call, i was upset and so i started over again. this time i took EVERYTHING out. no servos connected, no pump system, just the battery to the ESC to the voltmeter. and it worked! so i started putting things back in, hoping it would stop working at some point so i would know what the problem was. if i got all the way to the end, i'd be nervous that it was just being spotty again and i hadn't fixed anything.

however, i put in the rudder servo and it stopped working. it turns out, the rudder servo fits in right-side-up and upside-down. upside-down screws up the reciever and also the ESC. so, flipping over the rudder servo kept things working. i kept adding things on. the next thing that disrupted the system was the switch+fuse that i installed. i didn't figure out why tonight, but i'll look into it tomorrow. i was just happy to have figured out what happened. and rather, i was just happy to have a working ESC.

so, while i didn't get much done today - though i installed the back deck - i still have a project. that is, i'm not hosed. which is good. :)

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