Problem with mbot ranger track / wheel tension?

#21

Hi Tech support.
The robot was built correct as per your instructions. it still was very stiff, using the plastic spacers. I resulted using chadman’s solution. I would recommend altering your instructions to use this solution too or manufacture/ship the robot with ball-bearings, similar to ones that come with any RC car kit. (I tried sourcing, from a few shops but did not manage to find ones that fit).

Using lithium batteries seem to work. I will try also using NiMH rechargeable and update on performance.
I would strongly suggest you alter your manual, which specifically say “alkaline”.

#22

Hi grushka,

Glad to hear that you got it fixed.
For your suggestions, we will provide feedback to our company, thanks for all your advice and we will keep improving.

#23

You can also use Lego Technics part as a spacer instead of first 2 nuts (closer to the wheel) in chadman’s solution (or any spacer of the length equal to the height of Lego Technics brick) - it works and looks elegant :wink:
But the 2 remaining nuts are mandatory, tighten against each other.

#24

Dear Tech Support,

At the rear to the mBot ranger the two motors are touching which splays out the back two wheels. The back two wheels are not in line with the front wheels which leads to the track coming off the wheels. Where have I gone wrong?

Many thanks
Rod

mBot2_LI.jpg1935x1451 794 KB

mBot1_LI.jpg1451x1935 784 KB

#25

Hi RodMorley,

May I know what’re the golden staff in the holes of the motor?

Normally there is no such thing in the holes of the motors, please see pictures below:

blob.jpg990x575 179 KB

blob.jpg724x422 130 KB

#26

We had exactly the same problem as chadman - if the wheels are tightened enough to not immediately loosen up and fall off, they won’t even turn. Used chadman’s solution with the nuts instead of the spacer and it works perfectly now.
Makeblock I’d suggest you come up with a better design than a single threaded nut - the turning wheel is pretty obviously going to loosen the nut. Aside from that the quality is very good and now that we finally got it working (it sat collecting dust since Christmas) my son is loving it.

#27

Hi saisai,

Glad to hear that the child love the robot and thanks for your suggestion.
It has been provided to our robot team.

#28