Let's Make Robots!

Ignoble Idiocy

"Those who cannot remember the past are condemned to repeat it." - George Santayana


Nobody's perfect, least of all me.  Here I intend to record some of my roboting mistakes for my own good.  Perhaps you can learn from my errors, or even contribute your own.

Latest Update: 2010-02-04

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

On my first robot build, I thought I'd be smart and use some extra heavy gauge wire for the motors. Not only was it overkill for the intended current, but I wound up breaking one of the motor contacts, requiring this fix.

Now I stick to the proper wire gauge for the application at hand.

I think you could reinforce it with some hot glue, that's what i usually do.
Good tip! I could have learned from that one.  However, there really was no good reason to use 18 gauge wire.  Waaaaaay to heavy.

I just received ten mini servos from DAGU. I was so excited to get them working. I also bought the nicely LMR branded sensor mounts. So I combined these great DAGU parts to make a pan/tilt mount.

However, during programming on the PICAXE, I typed "255" for the servo position, instead of 225.  The PICAXE manual advises NEVER to go higher than 225, and now I have personally experienced why.  The poor little servo started spinning around! I broke right through its own mechanical stop (nice torque on those mini servos!).

The servo is still working... sort of. But it is definately out of whack.  Lesson learned. Check your code before you run it!

It would be nice if the program would see that in your code and yell DANGER WILL ROBINSON DANGER!!!!

I know! I need to create a robot that is better at programming than me (probably not hard to do). Then it can stand over my shoulder and shout warnings, encouragement, and derision as most appropriate my coding efforts.

Oh, wait. That's what you folks at LMR are for. ; j

I took a shortcut drilling out the center hole of a gear to accomodate a larger diameter shaft. Although I have a drillpress, I didn't spare the few minutes it would have taken to make an accurate hole that is perpendicular to the gear. I used a hand drill instead.

Now I have a wobbly gear. It doesn't matter in my application. My son just wanted to see a fan-like add on on the back on my Shovel Head Fred robot, "to make it go faster". 

So it doesn't matter that it wobbles, but if I ever need that gear for another project, I'm out of luck. Two more minutes and a little patience and I could have avoided this. Lesson learned.

awsome, I shall visit here regularly. I had the feeling that my general impatiance and hence incompetance in construction was an isolated case. It's good to know that for other people naturally choosing the correct method is also hard won! :D
Glad to know you like it. I've promised myself to post my mistakes, and not be embarrassed by them. I will learn from them. Others will be amused, disgusted, or entertained as is their wont. I'm cool with that.
Alright so I ordered these servos http://www.pololu.com/catalog/product/1040. I had the intent of modifying them in the usual way. I opened the case and took the first three gears off. I couldn't find a stop so I put the gears back on in their proper places. I reassembled the whole thing and when I rotated it by hand it rotated continuously. This happened for both. I hooked it up to my board and used 0, 90, & 180 for full speed one way, neutral, and full speed other way. The first servo just sorta spun in one direction full speed, and stopped and twitched, then spun full speed until one of the gearshafts broke and took a few gears with it... :(. So I thought I'd try the second servo. I hooked it up and it spun way with 180, and was nuetral at 90. When I entered 0, the gears stopped moving and only the pager motor was spinning. It got really hot and just went caput. So yeah, I think part of the problem was that these servos were just pieces of crap and poorly built. So I recommend you don't buy these... Anyone know of good reliable and relatively cheap micro servos?