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Schmitz
05-27-2011, 02:23 PM
Hello,
could someone please advise where to buy those three mounting nuts for the 288C drivers, they were not supplied with mine drivers.
Great plains audio did not reply to my request.
Thanks, Uwe

rgwalker
05-27-2011, 07:35 PM
Hello,
could someone please advise where to buy those three mounting nuts for the 288C drivers, they were not supplied with mine drivers.
Great plains audio did not reply to my request.
Thanks, Uwe

The nuts are 1/2" fine threaded and should be available at any decent hardware or online if the local Home Depot doesn't stock them.

However, the thread in the driver is 1/2" coarse and you can use regular bolts to mount the horn to the driver.

Bob W


Bob W

hjames
05-27-2011, 07:43 PM
The nuts are 1/2" fine threaded and should be available at any decent hardware or online if the local Home Depot doesn't stock them.

However, the thread in the driver is 1/2" coarse and you can use regular bolts to mount the horn to the driver.

Bob W


Bob W
Not to be mean, but ...
They gots Home Despot in Germany? :)

rgwalker
05-27-2011, 11:30 PM
Not to be mean, but ...
They gots Home Despot in Germany? :)

Ha ha.....I didn't even notice that. Also, the bolts are 3/8" and not 1/2".

Schmitz: If you can't find US Standard nuts or bolts over there let me know what you need and I'll mail it to you.

1" long is fine for an Altec 311-60 horn but I had to use washers as shims with an EV HR60.

Bob Walker
[email protected]

Schmitz
05-28-2011, 03:56 AM
Hello,
no home despot shops at least in this area of the world!
Will those be the right ones?

http://cgi.ebay.com/Hex-Nuts-3-8-24-SAE-Fine-Thread-Zinc-Plated-/370513221415?pt=LH_DefaultDomain_0&hash=item56444f1727

I bought 3/8-16 already, but the thread doesnt fit.

Thanks, Uwe

1audiohack
05-28-2011, 07:13 AM
A thread diameter question;

Is the threaded section of the fastener really 1/2" in diameter or is that the size of tool required to turn the fastener?

I would suspect that the thread and grip diameter is 5/16", very close to 8mm, the female thread in the driver would be 5/16"-18 threads per inch and if studded, the nuts needed would likely be 5/16"-24 thread per inch. Some studs are the same thread pitch on both ends and some are course to fine.

rgwalker
05-28-2011, 09:38 AM
Hello,
no home despot shops at least in this area of the world!
Will those be the right ones?

http://cgi.ebay.com/Hex-Nuts-3-8-24-SAE-Fine-Thread-Zinc-Plated-/370513221415?pt=LH_DefaultDomain_0&hash=item56444f1727

I bought 3/8-16 already, but the thread doesnt fit.

Thanks, Uwe

Did you get nuts for the fine thread that's exposed or did you get coarse threaded bolts to screw into the driver? I'm not familiar with the '16' number designation but I can find out if the correct thread has one. Otherwise, send me $20 through PayPal using my email address and I'll ship what you need and refund the difference.

Just let me know whether you need fine threaded nuts or coarse threaded bolts with the length and how many.

Bob W

Earl K
05-28-2011, 10:32 AM
Hi,

Here's a good pdf document from Altec . (http://www.altecpro.com/pdfs/vintage/SpeakerAndMics/drivers/288-8L%20288-16L%20HF%20Driver.pdf)

- It clearly shows that the 288 driver is threaded to receive 3/8"-16 UNC bolts down to a maximum depth of 1/2" ( before one meets ceramic magnet in the case of the newer 288K or L type ) .

- You've said that your 3/8"-16 UNC bolts did not fit / they should, if the bolts' threads move in the correct direction . They need to be standard Right-Handed threads .
- Maybe yours are a left-handed thread ( or maybe there's some paint within the threaded portion of the driver ) .

http://www.sizes.com/tools/images/Handed.gif

- See this article (http://en.wikipedia.org/wiki/Screw_thread)for a more thorough explanation . Also read, this link. (http://www.sizes.com/tools/thread_screw.htm)

<> EarlK

Oh OK, I see you are looking for the nuts . If you have bonafide Altec studs, then the correct thread size for those is ;
3/8"-24 UNF ( fine ) .

Schmitz
05-28-2011, 11:48 AM
ok, I have to give up.
The only thing I know is that my 100 pcs. of 3/8"-16 hex nuts doesnt fit. Whether right or left threaded, fine threaded, UNC or not, the thread isnt right to fit, otherwise right diameter.

Bob, thanks for the offer. I will send you the money on monday, it would be great if you could send me 10 hex nuts to mount my horn on this fine driver.
Maybe next seller is as much intelligent as this one and will sell without the nuts.
Great problem here in germany.

Thanks to all for this help and fine information,
Uwe

rgwalker
05-28-2011, 04:20 PM
ok, I have to give up.
The only thing I know is that my 100 pcs. of 3/8"-16 hex nuts doesnt fit. Whether right or left threaded, fine threaded, UNC or not, the thread isnt right to fit, otherwise right diameter.

Bob, thanks for the offer. I will send you the money on monday, it would be great if you could send me 10 hex nuts to mount my horn on this fine driver.
Maybe next seller is as much intelligent as this one and will sell without the nuts.
Great problem here in germany.

Thanks to all for this help and fine information,
Uwe


The bolts are double threaded with the thread inside being coarse or as we've discovered #16. The exposed part of the bolt that the horn is tightened to has a fine thread. I don't see a logical reasoning for this and the easiest thing to do is to remove the OEM bolts and use #16 bolts to mount the horns into the drivers as opposed to tightening them to the driver with nuts. If this is confusing I'll take one apart and post photos. I have to locate some fine threaded nuts myself and if they're readily available I'll have some on Monday.

rgwalker
05-28-2011, 04:26 PM
Hi,

Here's a good pdf document from Altec . (http://www.altecpro.com/pdfs/vintage/SpeakerAndMics/drivers/288-8L%20288-16L%20HF%20Driver.pdf)


Oh OK, I see you are looking for the nuts . If you have bonafide Altec studs, then the correct thread size for those is ;
3/8"-24 UNF ( fine ) .

I have a hard copy of the same document and I didn't even think to look. I think that's what he needs and I'm getting some for myself on Monday and can send some to him.

Altec Best
05-29-2011, 04:05 AM
DO NOT USE EMAIL ! When contacting GPA use the telephone.Bill will send them right out to you.

405) 789-0221 ;) Instead of going to eBay