Hi Alan,
I was able to sleep well at nights having determined by list consensus the
wiper motor carbon block brush 'grooves' went parallel with the motor shaft and
commutator lines - not perpendicular.
Now we have to delve deeper into this 'groove thang' again ... where's Dan
Masters when you need him?
My own belief is the grooved type carbon blocks are a later design (my TR4/4A
factory manual shows photographs of 'non-grooved' type brushes and my own
brushes were non grooved as far as I could tell).
Perhaps the 'grooved type' were designed for the later 2-speed motors.
Does anyone have a Lucas book showing later 1960's/70's style Wiper Motor
Brushes for clarification on which way the grooves go?
It just makes more sense to me that the grooves are to help seat the brushes
and should run parallel to the commutator and shaft.
'Molding' the grooves into the brush would eliminate the factory step of
'mechanically grinding' a curve into the brush for seating - saving a tedious
step
and money.
I'm sure someone knows the answer - and has proof - but who?
Regards and welcome back Alan - seems you took a couple years off from your
ongoing TR4A restoration (and I don't blame you!)
Carl
'63 TR4 since '74
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Hi Carl,
I just disassembled a TR4 1-speed wiper motor that appeared to never have
been apart.
Just the opposite of what you wrote. The grooves in the brushes are installed
at right angle or perpendicular to the motor shaft and commutator
separations. Over time they will form a series of three or four "stripes" on
the copper
commutator plates.
In other words, no they don't perform a wiping action. In fact I'd guess the
bushings would catch or wear rapidly on the edges of the commutator plates if
installed the way you wrote. I'm not sure why the grooves are there, would
guess to improve contact and indicate wear.
Alan Myers
San Jose, Calif.
AMfoto1@aol.com
http://hometown.aol.com/amfoto1/amfoto1.htm
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Hi Listers,
My brother is installing the two new carbon blocks (as sold by Moss) in his
1-speed TR4 wiper motor and wondering which way the grooves in the carbon
blocks go.
I figure the grooves should be installed parallel with the commutator
seperators - and are there to provide 'wiping action', for better starting
contact, and maybe to help with 'bedding in'. Is that right? Do the carbon
block's grooves go parallel with the shaft and commutator or should they run
perpendicular?
Regards,
Carl
'63 TR4 since '74
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