26 replies to this topic

[MSwiss]

 

Made sense to me until someone much more knowledgeable than I pointed out that spinning the arm by hand is not how the motor works when the arm is energized.

I may be repeating this statement from some time before;

 

Spinning an arm in the set-up, by hand, without the brushes, is important.

 

If you know it's a setup with a north and south magnet, the bearings aligned, the arm has side play, the stack is not hitting the magnets, and the comm is not hitting the brush hoods, but the arm doesn't spin freely (like it's hitting the brakes), most likely there is copper chips, or other conductive material in at least one comm slot, shorting out the arm.

[havlicek]

 

 

Everyone where I raced ran Camen setups that virtually had no cog at all. We took this as big plus, reasoning that the heavy cog of other cobalt setups somewhat held the arm back.

 

Hi Phil.  Just a quick note and not to be a hair-splitter...setups alone don't have cog.  I know it's obvious and I'm only mentioning this for anyone looking-in, but it's only when an armature is installed that cog happens.  That cog has a lot to do with the width of the armature crowns as well as the shape of the magnets, the airgap and whatever else.  If you took one of the other setups you mentioned and put a wider-crowned armature in them, the apparent cog would lessen.