When given a forward motion command via laptop or remote, the mbot pulls to the slightly to the left. I’ve tried to ensure that both wheels are equally tight in their connection. Any other ideas?
Mbot pulling slightly to left
burdoj
#2
Mine is having a similar problem, but the left wheel turns slightly faster than the right, which causes a slight left turn in automatic mode or joystick mode when driving straight ahead. I tried switching the M1 and M2 wires, which causes the right wheel to turn slightly faster, so it seems like it’s a board problem for me and not just a motor problem.
In addition, when switching from automatic to joystick mode, the left wheel spins at top speed while the right wheel stops, so the robot does a zero radius right turn continuously until I touch the joystick control.
Anyone else have similar issues?
I’ve seen 2 causes to this issue:
- one of the wires for your line follower or LED matrix board is rubbing up against one of the wheels (most common error)
- the rubber on one of the tires is not completely on the wheel hub
The last issue might be the ground you’re on. If it is very slippery, this could cause problems. I have had the best success on carpet.
sacrophyte
#4
I have had the same issue. I checked to make sure no wires were rubbing, and I even swapped wheels to no affect. When I switch the wires, the mBot still pulls to the left, but instead goes backward when I tell it to go forward, and vice versa.
Please provide a way to troubleshoot this problem.
sacrophyte
#5
I switched the motors and now it pulls to the right; this is clearly a case where one motor spins at a different rate than the other, given the same voltage.
How does makeblock suggest we fix this problem? Can you send us two synchronized motors?
Traley6074
#6
Have you found any solution? I’ve tried everything suggested and the problem persists… Has even gotten worse.
sacrophyte
#7
The response I received was:
“Actaully, the problem exist more or less. The speed of the two motors cant be made into aboslutely coincident, and the problem cant be thoroughly solved.
For example, if the robot swerve slightly to the left, which means the right motor run faster than left one at the same speed value.
If you want to keep the motors go straight, you can program to make the value different, thanks!”
I responded that this is unacceptable. I suspect the motors are exceptionally low quality and have little to no QA, and I suggested the makeblock look around for different vendors.
Pheppy
#8
Many people seem to have the same issue see http://forum.makeblock.cc/t/mbot-not-travelling-in-straight-line/1534/6
I got a new motor, but now I have 3 motors all running at a different speed. No solution for 6 weeks. mBot seems to have a batch of ill performing motors. In this condition my son cannot play with mBot. I think that I’ll look for better motors myself. Does anyone have a suggestion for reliable motors that will work for mBot?
tobor
#9
I honestly wish I knew more about this topic, but to answer all of this:
- It could be a faulty motor. Message @Pioneer
- Take apart your robot, and assemble it carefully again. There may be loose wires or problems with your wheels, as @NewInnovators.ca said.
Obviously, mBot is built for beginners, so it’s not going to be perfect… but you could replace your motor with anything of similar voltage and such. Arduino is very flexible in that aspect.
oxygen
#10
I ordered 2 new motors from my local store and it now drives in a straight line in every speed 
maybe it (also) has to do with how tight you bolt the motors to the mBot frame???
Traley6074
#11
I’m new to this. What kind of local store carries these type motors and what kind do I specially ask for? I’m trying to remedy the problem before I give the mbot to my grandson. Thanks!!!
that is local