Thread: Elu MOF96E speed control

Give Gerhard a call he is very good and a forum member, he's a tool collector in the Netherlands he will be able to advise you.

Hi all,

failure of variable resistors is often caused either by carbon strip wear or by dust. The same effect was known in sound amplifiers; unreliable contact between the carbon strip and the rotating arm behind the volume knob caused sound fluctuations and a lot of crackling. If it was just dust you were in luck; if the carbon layer was scratched away from the pertinax carrier inside the resistor unit, you needed to order and replace it.

The electronics inside the 96E are robust and built into a sealed module. The switching semiconductor in your router is fine. Such a component either works or not, if damaged it is shorted inside (full rpm only) or it will not react to triggering (zero rpm only). In your router the rpm is spurious because of spurious firing of the semiconductor, in fact it is the same as the crackling in the sound amp.The resistor in the 96E's electronics is one of the few components exposed to outside air. Try blowing compressed air into it to blow away the dust, this may avoid the need to take anything apart. The electronics sit on top of the motor, built around the tacho ring magnet on the top end of the motor's axle. Taking off the motor housing hood will give better access to it and will give you a good oversight of all the parts soiled by dust. A good cleaning is also beneficial for the motor's wound coils, since the accumulated dust traps heat and gets in the way of proper cooling.

When using compressed air and a cleaning nozzle gun, set the pressure to max. 3 bar and avoid blowing into the top ball bearing, because you may force dust past its seal ring. The upper ball bearings in routers are also known to fail because of penetrated dust, since they are in the middle of the dust laden cooling air stream that is sucked in through the topside motor hood louvre slits.

Forum member Damienhazo is a true Elu 96 addict, so his practical experiences with this model are accurate and valuable.

succes en groeten uit Mokum!

Gerhard

My reply to this thread is late I know, but I had a similar experience with a 96E many years ago.
Having used the router extensively inverted in an Elu mini-table, I found the speed control had gone awry.
It appears that the small magnet press-fitted to the top of the motor shaft had loosened itself, and was no longer accurately aligning to the speed sensor.
Realigning the ring and adding small drop of Loctite fixed the problem once and for all.