Repair Altec 291-16K

[KBergsson]

Hi I received a pair of Altec 291-16k in bad shape. Partly due to shape before postage + inadequate packaging for international shipment.
I think I can fix one of them easily by realigning the voice coil gap with some wood distance pieces.
The other one was in worse shape as the pole piece ( the one with the tangerine phaseplug ) which is supposed to be glued to the end piece ( magnetic return pot ) had come loose/unglued. I managed to dissasemble the top plate including the magnet and remove the pole piece (not easy because of the powerful magnet) and now I need to glue the polepiece to the end piece and find a way to assemble again probably with some wooden spacers due to the strong magnetic forces.

I have some two component araldit epoxy glue. Is that usable or do I need some special glue for the polepiece?
Does someone on the forum have experience in assembling those big drivers tha can advice me?
Best regards
Kjartan

image.jpg
image.jpg
image.jpg

[KBergsson]

As you see on my pictures the end piece bolts are sheared off. I managed to get 3 of the stubs out. Probably need to drill the last one out. The magnet seems to be glued to the magnet end plates, how do
I separate the rear end plate from the magnet? ... Screwdriver, hammer and brute force?
Regards
Kjartan

[bowtie427ss]

I had to do a double take, 604's in the background, Stoeger's on the workbench, that could be someplace very familiar to me.

Sadly, i have no advice for removing the ferrite from the plate. That stuff is all assembled before they're magnetized, and supposed to remain that way "forever". I think you'll have to fashion some sort of jig/fixture that's strong enough to align the parts while the magnet is charged.

I think you risk too much breakage of the ferrite in trying to remove it from the plate.

[KBergsson]

I had to do a double take, 604's in the background, Stoeger's on the workbench, that could be someplace very familiar to me.

funny coincident I was thinking of buying a used shotgun a couple of days ago
Regrettably I think one of the units is totally shot. You need to remove the plate from the magnet to be able to bolton the end piece (its actually the front piece that bolts to a horn). I will see if I can salvage the other unit. But if the magnet endplates are fixed ( glued as well as bolted) to the magnet there is nothing to adjust and that unit is probably shot as well.
Bad day .. as Neil Young and Crazy Horse tour was also cancelled today. Me an my two younger teenage kids had tickets for the consert on saturday in Bergen
Regards
Kjartan

[Altec Best]

Agree that trying to pull the ferrite magnet apart from the glue,will most likely end in breakage.Ferrite magnets are very brittle..If you can repair them you may want to try using plastic shims for aligning the gap instead of wood however..

Professional Voice Coil Shims for Reconing Speakers | eBay

[Audio_by_Goodwill]

If all else fails, send the parts to Bill at GPA.

[KBergsson]

If all else fails, send the parts to Bill at GPA.

Problem with that is that the cost of sendig the pair to US and back to Europe is same as cost of one new GPA driver.
But once I have got a conclusion from the ebay seller and depending on that conclusion I could phone GPA and hear if there is a possibility of me fixing the drivers myself, with parts from GPA.

[Old Guy]

Is it possible to discharge the mags, assemble then recharge? A conversation with a good remagger may be in order...

- - - Updated - - -

But once I have got a conclusion from the ebay seller and depending on that conclusion

At eBay you can file a 'not as described' claim. You would get a refund but have to pay return postage...might be best...

If the seller is willing to do a partial refund, enough to cover repair, then it's a tossup.

[KBergsson]

These are ferrit drivers not alnico. Arent the ferrit magnets permanent magnets?
If I could remove the rear "magnet" plate from the magnet, without breaking the magnet, I beleive they are repairable.

[Audio_by_Goodwill]

Problem with that is that the cost of sendig the pair to US and back to Europe is same as cost of one new GPA driver.
But once I have got a conclusion from the ebay seller and depending on that conclusion I could phone GPA and hear if there is a possibility of me fixing the drivers myself, with parts from GPA.

I didn't realize that you are in Europe, although, I see you did mention international shipping. If this was a case of bad packing/shipping, it would have been better to leave them as is, and not take them apart. Now the seller and shipping company have grounds to say that you simply disassembled them.