Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

[leavemetogetonwithit]

Have one of these which I suspect of causing jumpy motor movement / & possibly followed by no m/action. Marked in plastic near legs of sensor device are:- Gnd , out , UB . These are linked to 6,7,8 on motor plug.
What is the device? What is best way to test it? Anyone ever sourced a replacement (not complete brush ring, I can get that OK)?
Mike.

[PINKY]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

20year old machine Mike, Is it really worth it?

Pinky

[leavemetogetonwithit]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

Probably not. But it’s been lovingly cared for, the old dear is passionately attached to it and what could she buy now to equal it?
It’s the age of it that makes me reluctant to spend big money on parts, but an hour or two of my time…
Mike.

[Martin]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

leavemetogetonwithit wrote:What is the device?

Is that not the tacho pick-up head you’re referring to?

[leavemetogetonwithit]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

The very same. I want to know how I can test it. It’s got three legs and I get an open circuit reading across all of them (whatever which way). I can’t seem to get any volts reading out from their terminals (6,7,8 ) when I spin the motor with my fingers. Is it dead?
Mike.

[leavemetogetonwithit]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

Well, I finally sussed out how to test it. Applied my old 4.5v test lamp to gnd and UB and meter across Gnd /out on mV scale. Then brought a magnet close to it and got a notable shift. So I was barking up the wrong tree. Or just barking.
Mike.

[Martin]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

leavemetogetonwithit wrote:So I was barking up the wrong tree.

We are all guilty of that once in a while. That module-controlled tacho system rarely if ever fails so it may be best just to look more closly at the motor plug harness? Also the TOC on the brush ring and the brushes as well of course? 😀

[leavemetogetonwithit]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

Thanks for the tips. I’ve had the motor completely dismantled and reassembled about twice. So I did look at the brushes while I was at it! On this one the toc is in a plastic housing alongside the field coil and completely seperate from the brush ring. It was reading a bit iffy when I first checked it at the job, but since then has been fine, so it could be that. It was the main reason I brought the motor away. Motor plug was first thing I looked at but will look again when I return Tuesday evening.
The question I’m dreading answering yet again when I get there is, “What would you recommend to replace it?” I’ve been thinking of producing a short piece to print out on one A4 sheet to hand to customers who ask this question and save myself time. Has anyone already done one?
Mike.

[leavemetogetonwithit]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

Re-installed motor and switched on. Still no motor action.
Took a deep breath and pulled out module.
Saw a little fuse therein.
Checked it.
Was open!
10 amps.
Replaced with smaller fuse I had in box.
Machine now runs (tested empty).
Just hope smaller fuse will hold out.
Mike.

[RocketMan]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

Sometimes, perseverance and persistance, (or in my case damn right stubbornness) pays off in the end. When it does, it makes you feel good and occasionally might even earn you a nice cuppa and some biscuits….

Well done fella…..

[leavemetogetonwithit]

Re: Bosch WFK6010GB/03 FD6907 brush ring / tacho sensor.

RocketMan wrote: might even earn you a nice cuppa and some biscuits….

Top quality selection of choccy biscuits and pot of tea on every visit is main reason for my going out of my way for this customer!
Mike.

[Author]

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