Topic: Motor snag ?

[Karl]

If you've read the Santa pod topic you will know that my 24v c5 "Voodoo" died on the drag strip 

Having taken the motor apart I found that the magnets had come away from the motor casing and were in contact with the armature, causing the motor to "lock";


This is fairly rare but not unheard of. However, on closer inspection of my stash of spare motor casings  I noticed this;




It seems that the armature hitting the outer magnets is more common that I first thought.

Raises the question , is the resin starting to fail due to age ? And also, is this an additional cause of some c5's being quicker than others ?

[plumber]

hi there boo boo, how is the 24 volt converstion cooled? i know i see you use the c5alive fan, but do you do more than that when you convert to 24 volt?.....are all the other casing from other 24 volt convestions?...i am just trying to work out what happend....i know with resin it getts harder as the older it gets

neil
c5 new boy lol

[Karl]

Both electricDave and C5Martin agree that heat may be an issue with Voodoo's snag.

Voodoo was running two fans, one for the controller and one across the rear of the motor. But, I didn't have the motor fan fitted for Santa Pod so I will refit it for the repaired motor and see how it goes.

When checking Voodoo after the first couple of runs the "Dragon" gearbox was warm, but not hot -  you could place your hand on it and easily leave it there. The motor body was the same, warm - but not hot. The end of the motor by the brushes did get hot though - so a fan will obviously help.

This still leaves the question of why standard 12v motors are having the same problem...

[andski]

Hi,
Looking at the pics of your collection of motor housings, is it possible that the marks on the laminations are due to a build up of corrosion on the armature causing it to rub? Early Smart car starter motors were very susceptable to this. If the cars weren't used much and left damp regularly, the armature would rust solid against the casing.
If the magnets haven't moved, worn bearings or a distorted plastic end casing are the only other options.
Andy

[Umpa]

I have fixed a motor with this problem by clamping the motor magnets and putting the whole assembly in the oven.  Depending on the temperature you might lose some magnetism though so care should be taken.

[radiomarty]

Hi Umpa - did you re-glue them or use the oven to melt the original resin to stick them back on - I am assuming the heat from running caused the resin to melt in the first place allowing the magnets to come away from the housing.