Electric brakes
What is the right way to check those electric magnets on the brakes to make sure they are activating. Thanks in advance.
Forum Discussion
Maybe a bit on how they work...IMHO
The shoes are 'leveraged' onto the drum
'Leveraged' from the arm connected to the pivot at one end and the
magnet at the other end
The magnet slides on the drum center (AKA spider, plate). It is smooth
and the mating face of the magnet is liewise smooth
When the brake controller sends voltage to the magnet...it grabs the
smooth surface of the drum's plate
As it 'grabs' the surface...the rotating tire/wheel/drum moves the
lever arm...that then pivots the other end of that lever to push the
shoes outwards
That then touches the drum braking surface to create heat by scrubbing
the friction material against it
The 'reach' of the shoe is limited and as the friction material wears...
it needs to be adjusted via the star wheel...which moves the shoe
closer to the drum.
The self adjuster, star wheel, is supposted ot auto adjust, but they
normally don't work well enough. So manually adjusting the star
wheel is the norm
Electrically...there is a relationship between voltage and current
(amperage).
The size/condition of the feed wires...to the wires coming out
of the magnets makes up the 'fed' circuit. If the wires are too small
or frayed, etc...it can NOT deliver enough amperage...even while it
may deliver full voltage under no or very light load (like spinning
it by hand)
Good controllers will have self diagnostic circuitry to tell you if
it thinks there is something wrong
The OP can learn if they havfe the proper manuals, tools and someone
who knows enough to teach...but this is a huge safety area and suggest
having a certified ASE Brake mechanic review the situatioun
The shoes are 'leveraged' onto the drum
'Leveraged' from the arm connected to the pivot at one end and the
magnet at the other end
The magnet slides on the drum center (AKA spider, plate). It is smooth
and the mating face of the magnet is liewise smooth
When the brake controller sends voltage to the magnet...it grabs the
smooth surface of the drum's plate
As it 'grabs' the surface...the rotating tire/wheel/drum moves the
lever arm...that then pivots the other end of that lever to push the
shoes outwards
That then touches the drum braking surface to create heat by scrubbing
the friction material against it
The 'reach' of the shoe is limited and as the friction material wears...
it needs to be adjusted via the star wheel...which moves the shoe
closer to the drum.
The self adjuster, star wheel, is supposted ot auto adjust, but they
normally don't work well enough. So manually adjusting the star
wheel is the norm
Electrically...there is a relationship between voltage and current
(amperage).
The size/condition of the feed wires...to the wires coming out
of the magnets makes up the 'fed' circuit. If the wires are too small
or frayed, etc...it can NOT deliver enough amperage...even while it
may deliver full voltage under no or very light load (like spinning
it by hand)
Good controllers will have self diagnostic circuitry to tell you if
it thinks there is something wrong
The OP can learn if they havfe the proper manuals, tools and someone
who knows enough to teach...but this is a huge safety area and suggest
having a certified ASE Brake mechanic review the situatioun
