RC lawnmower


Author Message
nickskethisniks
Guru

Joined: 17/10/2017
Location: Belgium
Posts: 437
Posted: 07:15pm 06 May 2020      

Disaster struck, I was talking about a strange noise in the left wheel previous post, so I discovered there were magnets loose…. 5 of them… And after opening the wheel it was an easy job to loosen all the other magnets….  It’s a mystery how that can, what I did notice was that I didn’t positioned the hall sensors optimal last time.

The controller is acting badly as well, timing is bad, and I think that’s why my controller ran hot after 20min. Thinking about that it’s a wonder I didn’t blow mosfets… I think the current limit is working well. The wheel was not spinning properly, and no load current would be extremely high I guess.

So since it will not be a joy to put the magnets back in I spent a whole afternoon putting hall sensors in another wheel. I have 5 hubmotor wheels like this… But they don’t have the hall sensors in yet, there are, but only 2, I use 3. It’s possible they are cos sin for more accuracy.

I now put 6 sensors in, 3 with the right position in my opinion now, and 3 with the position the other wheel had. That I put in when I first started with my “learning curve”. That way I can learn some things.

Here you can see the loose magnets:





Removing all magnets of the rotor:





Clear view on the stator:




Preparing the hall sensors: (I use TLE4905 )





Finding the right position for the hall sensor:





What I think would be better (NOT):





All wired up:



Edited 2020-05-07 05:21 by nickskethisniks