Starter Armature

[sugargrovefarmer]

52 Super M Farmall, Starter armature turned on a lathe until groves are gone, Will that cause the brushes to try and weld themselves to the surface when the starter is engaged and will regroving the armature solve the problem?
Any suggestions?

 

[Soundguy]

so no mica insulator left either?

 

[sugargrovefarmer]

Well at the risk of sounding stupid, What is the mica insulator?

 

[Jerry/MT]

Well at the risk of sounding stupid, What is the mica insulator?

Nor stupid , just an honest question.

The armature has a segmented commutator that use mica as an insulator between the segments. Mica is a naturally occuring mineral that is semitransparent (I believe it's a silcate). Before the advent of high temperature glass, it was used for windows on furnaces and wood stoves etc . It's an electrical insulator also.

 

[sugargrovefarmer]

Well! Thank you very much, Do I replace the comutator? If so is there a good source for just the comutator or do I replace the starter?
Thank you!

 

[sugargrovefarmer]

so no mica insulator left either?

No Sir! The commutator is completely smooth, Do I replace it?

 

[pat32rf]

Each segment of the com should be separated by a thin strip of mica or similar material. After turning these strips should be slightly undercut so they don't keep the brushes from making good contact with the com....

 

[sugargrovefarmer]

Now it makes sense, Man what an education, Now the next question is can a shop that rebuilds starters do the undercutting?
Thank you very Much!

 

[Soundguy]

a broke hacksaw blade can do the undercutting! only needs to be like 1mm or so.. just to keep the brushes from riding up...