Speed fluctuation since changing Rotex brushes

[imaginarynumber]

Hi all

I recently replaced the brushes on my 150mm Rotex. Since doing so the speed seems to fluctuate, not massively but enough to worry me. I opened it up again and noticed that the commutator was very, very slightly dirty so I gave it a light clean with a bit of webrax. I then noticed that I hadn't pushed the connections on the brushes home as much as I should have.

Neither seems to have made any difference. Do the brushes take a while to bed in?

The other possibility that I can think of is that it might be relate to the plugIT connectors. Over the years the arcing has made one of the pins noticeably thinner than the other. When that first became apparent I wedged some copper strands in the plug to maintain a contact and "vowed" to never remove the lead... until I had to replace the brushes...

Whilst on site today, I did try to bend the thinner pin slightly and I was going to replace the PlugIT socket with the one on my faulty RTS400 but discovered that the flexes on the ends are different lengths. 

Any advice will be gratefully received. Thanks

 

[AlexThePalex]

The brushes do take a while to bed in, de commutator is round and the brushes come as squares.

The way you describe your plug-it situation, I would replace that, both the cord and the socket on the tool. Retire the cord.

 

[Doug S]

The speed started fluctuating on my Rotex, I presumed it was the brushes but it was the plug it lead and socket. The sockets are cheap and easy to change.

 

[imaginarynumber]

Thanks Alex and Doug, will order a socket and lead.

 

[jimmyboygr]

is it speed changing or entirely switching off for a short time?the speed chaning would be very fast and continous,the plug it problem
would be like switching it of entirely.I tend to let the brushes settle at speed 4 with no load for 5-20 minutes depending on the commutator wear.
About plug it cable,you should be careful not to get the plug-it virus.When you use a faulty arcing cord with various machines and burn
their  plugit sockets.There is always the set 492780 available to make it fixed if you want to feel more safe,even though plug it cables
are upgraded since 2018 and are far more robust