On Tue, 04 Aug 2020 22:25:28 +0100, T i m wrote:

snip

However, I suspect the electric brake is sticking but took the motor
out just to 1) check that was running freely (it was) and 2) check the
brushes (they were 'ok' but will get new ones [1]) and that 3) the
transmission seemed free (it did).

I'll see if I can get the electric brake to bits tomorrow, see if
there is anything that can be freed / etc. I think the micro switch
works as when the brake is in the 'free' position it disables the
throttle.

snip

I actually did so last night and I think that was the problem but
haven't worked out how / why yet?

When you release the outer friction plate (3 small Allen screws on
spacers) and you then find the friction plate, the inner friction
plate (so like a conventional flywheel, friction plate, pressure
plate) and then the coil and possibly a strong permanent magnet.

The mechanical override arm appears to release the 'pressure' /
'sandwich' on the friction plate (this must 'fail safe' (= brake on))
so in the non-override position it makes sense the brake is enabled.
However, if you rotate the override to what should be the released
position it doesn't release?

Now the strange thing is that all 3 screws were loose, and I wondered
if someone has loosened them to give a bit of slack and allow it to
sorta work? With them tight and the brake in the mechanically released
position it feels solid. Slacken all 3 screws a couple of turns and
the friction disk is free again?

https://ibb.co/LrkCbXK
https://ibb.co/1rn14Z2
https://ibb.co/DLr4Gyf

I'm not sure if the main actuator is spring loaded or held together by
a magnet and turning the screw in the middle doesn't do anything (it
remains tight so whatever it's going into is also going round)?

I'll try it with 12V on it later to see what moves and by how much.

On the grounds I have little to lose at this point, I'm wondering if I
could add some small washers to the tubular spacers (the screws are
long enough) as that might be easier than skimming the friction plate
thinner on the lathe?

Cheers, T i m