“Sister Christian, oh the time has come…” 🙂

Got two new Lego Mindstorms motors in the mail yesterday (which I had bought off eBay). My old ones were sticking and my robot was having trouble getting around.

When I plugged in the new ones, I immediately noticed the difference. They sounded quieter and smoother and seemed to turn faster.

With the new motors, my robot could get around a bit better, but it was still acting kind of retarded and whenever I stop the brickOS program (which came from a book), the firmware crashes and I have to take the battery out to even shut the RCX off. Annoying.

So I decided to scrap the brickOS program and try an NQC program instead – that one works quite a bit better even though the program is much simpler. The robot does an OK job of going towards light, although it sometimes misses it, especially it’s coming towards it at an angle, and sometimes it sees the reflection of its own light on my white wall and gets all excited and tries to make love to the wall.

I guess building a robot that does the dishes is going to be a long way off…

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Lego Mindstorms motor problems

Damn. I guess I’ll try lubricating it with 3-in-1 oil as my friend Todd suggested, but it’s quite likely that I’m going to need to buy new motors.

I posted this to lugnet.robotics.rcx.legos:

My robot is having a hard time getting around and I think that it’s because the
motors seem to be sticking. Even on my linoleum floor, my little tank robot
often gets stuck and goes in slow circles, because one motor gets stuck. Once I
nudge it or pick the robot up, the motor kicks in again but only for a little
while and then gets stuck again a few seconds later.

I am thinking that the motors need lubrication. Is this a good idea and if so,
what type of lubrication to use? I have WD-40 and Tri-Flow, a teflon-based
lubricant that is used for bikes, skates, etc.

Would either of these work and not damage the motor?

and I got the following response:

You may want to check if your motors are the new type 9V geared motor (#43362).

If so, please be aware it is prone to failure, the first sign being sticking. Pl
see my previous post on this ailment:

No amount of lubrication is going to help. In due course the motor will become
permanently stuck and useless. Such is the natural history.

C S Soh

LEGO Mindstorms Robotic Invention 2.0