Comments on using MonsterBorg
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I have experienced two problems in using my MonsterBorg.
First I have had several wheels fall off (the grub screws on the axle loosening). I was being careful not to overtighten them, but maybe they need a bit more force? Is it worth adding loctite or similar?
Secondly, when using a PS3 controller with spring loaded joysticks, if I release the forward-backward one on the spring from full on forwards, then it give a motor error (purple led) and the machihe reboots. I find you have to be fairly careful in letting the joystick return to the zero position fairly gently.
piborg
Fri, 09/08/2017 - 20:50
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Suggestions
For the grub screws I would suggest a bit more force when tightening them to hold them in place. In the Formula Pi racing we tightened them up a fair amount by hand and did not have any major problems with them loosening. Loctite may help as well, but it should not really be required.
Given the Pi is rebooting I would guess the fault being reported is the batteries dipping in voltage too much under a sharp change in speed. Generally sharp speed changes are quite taxing on both the batteries and the board itself, but during our testing we did not seem to have trouble changing speed rapidly.
The rebooting part suggests that the batteries you are using are a likely culprit, they may getting flat or are unable to deliver enough power quickly to cope with the demand when changing speed. What batteries are you using in your MonsterBorg?
rbn
Fri, 09/08/2017 - 20:57
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I was using a 12v 3A mains
I was using a 12v 3A mains supply when this was happening. Got some hunky batteries arriving tomorrow so I'll try with them. Also the wheels were not loaded MonsterBorg was sitting on a box with wheels off the ground.
piborg
Sat, 09/09/2017 - 15:07
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Bench testing
Having the wheels of the ground will definitely make a difference, in that case the motors will have been reaching their highest possible RPM. Under this condition the motors will tend to produce larger power spikes when changing speeds.
It is quite likely that the motors were exceeding the 3A limit of the supply for a brief period when changing speed suddenly. This will have caused the supply to limit its power output to prevent damage and is the likely cause of both the motor fault and the Pi reset.