Is there any electrical reason not to put the bearings in a metal bushing
instead of the nylon one?

Bob La Londe wrote:
Is there any electrical reason not to put the bearings in a metal
bushing instead of the nylon one?

Ed H will probably give you an authoritative answer.

As long as the bearings don't heat up so much that
they grow, bind, grow some more and fail, I don't
see why not. With nylon, there would be some give,
but not in metal.

Bob La Londe wrote:

Is there any electrical reason not to put the bearings in a metal bushing
instead of the nylon one?


Not if the frame is grounded. Otherwise, it's an attempt to isolate
the frame from the armature. that will prevent a shock while using the
tool, but could kill you if you touch the motor shaft & a good ground
when the insulation fails.


--
You can't have a sense of humor, if you have no sense.

"Michael A. Terrell" wrote in message
m...

Bob La Londe wrote:

Is there any electrical reason not to put the bearings in a metal bushing
instead of the nylon one?


Not if the frame is grounded. Otherwise, it's an attempt to isolate
the frame from the armature. that will prevent a shock while using the
tool, but could kill you if you touch the motor shaft & a good ground
when the insulation fails.


I was thinking something along those lines. There is an internal brush like
contact that touches the metal nose/frame of the router when it is assembled
properly. I suppose its time to get out my meter and see how good the
ground is.

"Bob La Londe" wrote in message
...
Is there any electrical reason not to put the bearings in a metal bushing
instead of the nylon one?





That's the "double insulated" concept. Ground the thing so as not to become
a conductor yourself.

No reason at all for a bearing to be electrically isolated from a case. They
utilized that nylon bushing for their convenience.. assembly method, loose
bore dimension tolerances, potential production change in parts source, etc.

Nearly all motor types have bearings mounted in metal frames, there is no
electrical reason to attempt to isolate the rotor from the case.

Most routers (and various power tools) with metal nose pieces have
pressed-in or snug fitting bearings (some with retainers) fitted into a bore
in the housing.

There are no perfect insulators (nor conductors), so all insulation types
have a minute amount of leakage current. This miniscule leakage level won't
be harmful to the operator or the bearings.

The high rate of fan-blown airflow over a high speed rotor would generate
static (Van Der Graff type effect) likely moreso on a plastic housing.

There is a potential for bearing damage when elevated currents pass thru
bearings in some applications such as a turntable used for welding.

--
WB
..........


"Bob La Londe" wrote in message
...
Is there any electrical reason not to put the bearings in a metal bushing
instead of the nylon one?