Busted Leg/A Look at the Drivetrain

By Agustin April 8, 2011

Well, my first Hexbug hiccup happened a few days ago, and tonight, I managed to fix it. Basically one of the joints on the lower set of legs popped out of it’s socket, after some horsing around with my little son. It is still one of our favorite toys here at home. I hope that when I finish the project, the robot will be even more fun for everyone.

Hexbug Spider drivetrain
Fixing the joint was a bit tricky due to the tiny little parts, and how tightly everything is fit together in there. However, I think it was an important step to get in there and figure out how to take everything on the underside apart – what I guess would be called the drivetrain, the mechanical system that drives the legs and steering. The whole thing is really ingenious, it uses one motor to swivel around, but all of the locomotion is handled by a single motor moving a piston with all six legs attached. The linkages on the legs are pretty cool looking.


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hewhosnameisunknown says

This happened to me as well, exept it was with one of the upper legs. I cannot figure out how to fix it. I'm not sure how to get the plastic bottom off without breaking it (i took out the three screws, but the lower legs seem to be permently attached). Do you have any suggestions on how to fix it? Anything would be appreciated greatly!

Hewhosnameisunknown says

Whenever I try to push the two pieces back together, the joint on the drive train moves and won't let me connect the top bar (attached to the leg). ( The blueish stuff around the joint is sticky tack. It was a failed attempt to try to stop it from moving when I tried to snap the leg back on).



Hewhosnameisunkown says

Oh yes! I see what you're talking about! (Grooves=the U shaped divot on the bar, right?)
The problem is, whenever I try to push the leg in, the axel (is that what you called it) slips and moves out of the way. Am I not getting it in the groove completely?

hewhosnameisunkown says

Thanks! I managed to sort of get it in, then i nudged the axel around (using a tiny screwdriver) and i managed to twist it until it clicked into the joint! It is now walking across my desk gleefully...
Again, I'd like to thank you for all your help! (I shall follow your blog! ;) )

Guy says

Well i need help, after loosing my remote control for a while i finally got it back and was excited to start it back up, after soon realizing nothing happened, i made sure the robot was on, checked channel A and B, and it didnt respond at all

Glenn says

Is it a requirement to remove the three metal rivets? I have the same dislocation described above.

Brookes says

I know this topic is fairly old but I though this tip was worth passing on. My son was playing with one of these and ended up dislocating one of the legs and lost one of those dumb little rivets/pins so I figured the toy was trash but the hacker in me decided to give a small nail a try and I was able to fix it. Simply start with a 19ga nail and cut it to length, it fits a little loose so I simply bent the nail a little in a couple places and it fit nice and tight after. The thing works like new and if it ever happens again I have plenty of spares. Just thought some other dads out there would like to know.

Disporsche says

Anybody know where to get parts? The "complete list" Vex parts guide on their website had what looked like an older gen spider. And did not show the metal pins in the legs. It was probably pushed out from being stepped on by my 3yr old.

Gordon says

Hey, thanks for posting this. Had to fix my sons spider and your comments gave me enough courage to dismantle the thing and get it back together. I took out all the rivets, they came out easily and that helped a lot. My trick was to use a small wedge to keep the leg end open enough to slip it over the axle and get the divots into the holes.
One working spider and one happy boy.

Narniacraft1 says

My hexbug spider xl has an issue where all of its legs stop moving for no apparent reason, could this be an issue to a damaged leg or legs. The robot is fairly new and has been used for about 48 hours since Christmas. I discovered the issue with the first few minutes of testing, any response will be appreciated. Thanks