Removing iron filings on a moving coil?

[Franz Gysi]

Hello

I was wondering, why my DL103 cartridge sometimes sounded better and sometimes worse.

After removing the enclosure and the dust cover, I discovered iron filings touching the moving coil.



Any idea, how to remove this dust without destroying the windings?

Some years ago, my turntable spent some time in my workshop, where I also did metal work

Franz

[richie00boy]

See if you can blast them off with a can of isopropyl alcohol fitted with a tube in the nozzle?

http://cpc.farnell.com/SAIPA400H/ele...rolube-ipa400h

[Franz Gysi]

Yes, seems to be a good idea, using a blast of isopropyl acohol. I'll try it.

I could remove some of the dust with a strong magnet. But not all.

Another view before cleaning:



Franz

[dnsey]

Adhesive tape (with the strongest adhesive you can find) will remove most of the visible filings, but what about any that have got into the yoke gap?

[cannext]

Yes I 've seen that before.
Use a fine brush to sweep them away ,be carefull not to rip any wire.
Compressed air, to blow it of?

Hope this helps.
F.

[bulgin]

Hi

With respect, the advices given here are sure to break the coil wires. Blowing air or anything else will almost certainly shear the wires. Firsthand experience. I make 'em.

It would be best to take a small blob of well used plasticine (the stuff you stick notices with or kids play with). 'Knead' it in your hands until it becomes very pliable and then roll one end into a sharpish toothpick shape. Touch the magnetic particles and they will be adhering to the plasticine.

If it is likely you'll have more filings attracted to your cartridge, you can make a very thin membrane from high temperature silicone (the blue stuff). Squeeze a blob of the stuff on lintfree wax paper and put another piece of similar paper on top. Place on a sheet of glass with another shhet on top. Place a few kgs of weight on it and let it cure.

You will now have a very thin silicone membrane and ensure it has the thickness of rice paper.

Punch a disc of +-4mm dia from the membrane and cut a tiny slit with an NT cutter blade no longer than 1mm. Ensure there's enough space inside the casing and then slide the membrane over the cantilever. Ensure the disc is large enough to cover the coils but small enough to avoid snagging on the casing's inside.

WARNING: If you decide to try this, ensure the membrane does not pull the cantilever downwards when you insert the motor into the casing.

bulgin

[Greg Erskine]

I was going to suggest Blu-tack. I use this the clean up smalll DC electric motors.

http://en.wikipedia.org/wiki/Blu-tack

[mandym]

Originally posted by Greg Erskine
I was going to suggest Blu-tack. I use this the clean up smalll DC electric motors.

http://en.wikipedia.org/wiki/Blu-tack

Indeed I have used Blu-tak to clean up magnetic particles from the cartridge. I stick a pinhead-sized bead of blu-tak at the tip of a toothpick and GENTLY dab it unto the particles. Takes them right off the magnet. Particles that are not easily reachable are first CAREFULLY "swept" into position with a toothpick.

I have done this successfully many times. The only requirements are a feather touch and a little magnification. Also remember to keep your eyes ( I use a stereo microscope) on the delicate coils.

The blu-tak bead have to be changed every 3 or 4 dabs because it clogs up very fast.

Best practice first on a bad cartridge. You might find the procedure is not too difficult.

[Allen Wright]

Bulgin's advice is good.

My $4000 Andriolli "Blue" got put down on a recent field of filings (Not me!) and after a total freakout, we took it to a fine machinist, who with the aid of a powerful microscope and the mentioned toothpick and bluetack,AND A LOT OF CARE, it cleaned up perfectly.

You can never hope to blow they off, they are too small to be bothered by the aitflow, and held too tight to the very sy=trong magnet, and you may damage the cartridge even more!

Regards, Allen

[Franz Gysi]

Thanks to all

Indeed, the particles are to small and they stick very strong at the magnet.

And the coils wires are sooo fragile!

I will follow the suggestions from Bulgin and post the results. But I must find the silent moment to do such a job.

Allen: do we see us at next ETF in Holland?

Looking forward
Franz