Magnet failure and repair

Cliff -

I can easily see how a magnet could be broken into two pieces that would repel each other. For example, if the magnet is rectangular and thin, say 1cm by 2cm by 5mm, and is magnetized such that the largest faces are the poles, then if you snapped it in half you would get two

I doubt if it is repairable.

Regards, Tony

Not much idea of repairing this sort of thing, but I doubt an online search of car wreckers would reveal something as detailed as this. Certainly, going to my local car wreckers the only way to know for sure the status of parts like this is to go and look physically. The owner on the phone seems to know the status of every car on the premises in regard to panels, doors & light fittings etc, but things like you're asking well, come and look is the norm.

His PC is just for accounts records, certainly too busy to create an online listing of obscure parts for umpteen models.

Kevin Martin

Cliff, I doubt very much if repair is possible and running with 5 will not work at all well possibly burning out the armature even if you could get it to run for a while. I assume the car is out of warranty (>3 years old) but that does increase the likelyhood of finding one in a breakers. web forums such as FFOC for Focus/Max owners or relevant ones for your car model might be worth a look. Do they fit the same fan to other models. Ford cover quite a few other marques now eg Jaguar, mazda, Land Rover etc

Not looked recently but Exchange and mart used to list breakers by car model that they were breaking in the coming week Ebay could be worth a look rather for breakers specialising in your model than the specific part. There also online suppliers of genuine Fraud parts at less than list price. Maybe your local independant garage would buy it in trade price for you in exchange for a beer voucher.

Lots of ways to skin this cat and you should not have to shell out £300 if you are prepared to spend some time hunting.

Good luck

Bob

If the armature is undamaged I think there is a reasonable chance that this can be rescued - it's certainly worth a try. These are ferrite magnets and provided you can reassemble the broken bits to close to the original mechanical shape they will recover most of their original magnetic strength.

No polarity reversal has taken place - it is normal for like poles to repel so all broken pieces will try to resist being correctly reassembled! Your best bet is to carefully reassemble the broken magnet away from the motor using epoxy adhesive and LOTS of sticky tape to hold the bits in position - be very sure that this is a good setup and there's no chance of it slipping out of position while epoxy sets.

Once this is safely in one piece, epoxy both magnets back in place. Be sure that you haven't interchanged their positions the six poles should alternate NSNSNS.

Let us know how you get on.

Jim

Galaxy?

I have done this with an auto fan motor and it was successful. The only problem was overcoming the magnetic field and forcing everything tightly in place. Non-magnetic clamps would be nice. Be careful when reinstalling the rotor that you have it all well restrained or you will likely damage the rotor or magnets.

Don Young (USA)

You could say that It's a 1994 Granada Scorpio, one of the last Mk 3.

I thought the same until I started looking. Few of them were fitted with aircon, and of those that were all seem to have suffered the same condenser fan fault as mine, hence the need to repair.

Have tried all these avenues already unfortunately. Am also trying to contact the original manufacturer, Siemens.

Cliff.

Thanks, Jim. I feel the lure of Araldite drawing me to the workshop.

Cliff.

Ah well, my guess of it being a galaxy was well of the mark, and I thought ford only kept the extortionite prices for them!

Do you happen to know if ford were showing any in stock at the warehouse? Or what the current part number is?

No I don't know stock level. The Ford part number on the motor is 91 GB

Cliff.

Hey - I never knew it was that easy making a magnetic monopole. Keewl.

Just keep taking the tablets...

Regards, Tony

Maybe superglue might be better. Quicker to go off when holding in place against the magnetic repulsion and excess will not set and can be wiped off. Also dots of superglue to tack the completed magnets in place and once confirmed in place, use fillets of real mans slow cure araldite to make sure none of them come off. Hope your efforts pay off. Fraud are really taking the pi** at £300 for a new one.

Good luck

Bob

Chances are, if ford still had stock somewhere, they'd be trying to sell it of for next to nothing, but they only reflect that in the trade price. They don't change the retail price, and alot of dealers still use the retail less xx% for trade prices. So it's a case of who you know, and who you deal with that makes a big difference.

If I get time at work tonight, I'll see what our usual dealer can come up with. And that's not the actual part number ford use in their system. Although that's the full part number, which details the year it was designed (91), the component number (19C634), and revision version (AA), that gets put in the parts catalogue and it spits out a 6 or 7 digit FINIS number, which is used for parts ordering.

Thanks Moray. I would be delighted if you can find one, but I go on holiday for a week from tomorrow so if you do find anything I won't be able to reply until afterwards.

Cliff.

Well I glued all the fragments together, checked the rotor clearances, ensured it was free to rotate, and tested it today. At the first test the motor whizzed round for the second I had power onto it and I thought the repair had been successful. Unfortunately at the second test it only crept round and stated smoking within seconds. Damn!

Cliff.

Strange - I thought you had a good chance of rescueing it. It's pretty certain that the magnet is now OK provided you've put it back in the right place (NSNS sequence).

If it's not totally fried look very closely at the armature - there has to be a short circuited or broken wire somewhere.

Good luck!

Jim

Thanks for your help, Jim. I really would like to repair this motor just for my own personal satisfaction. Having opened it up again, all the windings, brushes and connections etc. look to be OK, and the magnets are intact and alternating NSNS. The exception is a cylindrical component about 10mm x 5 mm across the supply leads that has split during the test. It is black with a silver hoop at one end, would that be a resistor? I assumed, perhaps wrongly, that the polarity of the supply would not matter so I took no care which way positive and negative were connected. Have I ruined all the careful work of magnet reconstruction by connecting the motor wrongly?

Cliff.

reasonable

reassemble

slipping

workshop.

clearances,

thought the

intact and

wrongly?

Probably a capacitor, in which case most likely the silver band should have been +ve. Remove the capacitor and try the motor without it. You will find that the commutator sparks more without the capacitor, so source a replacement.

AWEM