Fault diagnosis on a Trend T11e Router

[NicoWilson]

My router has decided to work only intermittently.

I’ve opened the case, and have checked continuity on the switch, the cable and the fuse. All seems fine.

I’ve taken the speed control board out and there’s 3 terminals. Should I be able to find any continuity between any 2 of these 3 terminals?

 

[Deadeye]

I have a Trend that had a similar intermittent fault. It was sawdust in the carbon brush contacts.

 

[Myfordman]

Nothing likely to be measurable unless the contrroller has gone short circuit in which case you get max speed only.
Just like any universal motor, intermittent performance is most likely to be brush gear. Check for adequate length and spring pressure as well as free movement in the brush boxes.

 

[Racers]

Check the mains lead for break, the end of the strain releaf is the usual place.

Pete

 

[NicoWilson]

Thanks all. I’ve rechecked the mains cable and it seems OK.

I’ve ordered a new set of brushes from Trend.

 

[Hatter]

1st post so go gently. :?
When you take the top cover off, there is a plastic vane wheel that works with the speed controller sensor? My one was spinning loose on the small shaft that it sits on and causing intermittent speeds and occasional cut out. A small dab of CA glue sorted this. Not sure if they have changed the design? But could be worth checking along with the brushes.

 

[Eric The Viking]

This might help, or not!

router-woes-anyone-else-with-a-t10-t11-or-dw625-had-this-t57533.html?hilit=T11%20speed%20Trend

The symptom isn't intermittent function, but a tendency to run flat-out (very fast), and for the speed control to have no effect.

On mine, it's not a vaned wheel, but a spinning magnet (hold a compass close to it and slowly rotate it by hand to check). Look at the pictures in the thread above. The design might have been modified recently but it's a dumb move: you don't want anything optical because of the dust and chips that get in and interfere. I know of one manufacturer who recently went the other way - abandoned their optical system for a Hall-effect (magnetic pulse) one, similar to Elu, Trend, DeWalt, CMT, etc.

Given the symptoms, my prime suspects would either be the switch or a loose connection/damage to a wire somewhere. Unless it's really obvious it might be hard to find, simply because of the difficulty of making a good connection with a test meter.

You might try, VERY CAREFULLY, wiring out the switch and firing it up from a wall switch (make sure the router is safe when you do this, with no cutter nor collet fitted - I'd hold the baseplate to the bench with a clamp). When it's started, give it a good physical shake while it's running to see if you can reproduce the fault. If not, replace the switch and try again. Also the plastic, thumb-operated slider on the outside is rather vulnerable to sawdust too, so I'd give the whole switch assembly a thorough clean...

On the pictures you posted, they seem to have reduced the amount of potting on the circuit board. It's been a while, but I think mine is a solid block inside the plastic case of the circuit board.

I have a feeling this is an annoying problem that won't give you a clear "broken--fixed!" result. But you might make it go away - hope so.

E.

 

[Racers]

Thanks all. I’ve rechecked the mains cable and it seems OK.

I’ve ordered a new set of brushes from Trend.

What I would do is to remove the top cover and the cable clamp then give each wire a really good pull, if one comes out or stretches then you have found the fault. It’s very common on drills sanders and anything with a cord that gets moved around a lot.

Pete

 

[NicoWilson]

Thanks all for your help. New brushes fitted. Router re-assembled, and it all works fine.


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