Why did USA 7' singles have large hole.

Subject: Why did USA 7' singles have large hole.
From: Dita
Date: 19 Mar 06 - 05:26 PM

I've always wondered why the central hole in USA singles was so large.
I know that size was juke-box standard, and in the UK the singles had a "push out" middle to allow for the larger spindel.
However in both countries LPs have the same small hole.
Why did USA decide a different industry standard for 7" & 12" records.

cheers, john.

Subject: RE: Why did USA 7' singles have large hole.
From: The Fooles Troupe
Date: 19 Mar 06 - 05:33 PM

The 45s were used in the juke boxes, the LPs were not.

Aussie sold domestically 45s had an insert to fit the large hole.

Subject: RE: Why did USA 7' singles have large hole.
From: pdq
Date: 19 Mar 06 - 06:11 PM

Everybody knows the answer to this one.

It's so the average gum-chewin' teenybopper could carry around a stack of 'em on her thumb while boppin' down the halls of her junior high.

Next question.

Subject: RE: Why did USA 7' singles have large hole.
From: frogprince
Date: 19 Mar 06 - 06:13 PM

Or so a horny teenage boy could carry a stack of records and keep his hands free...

Subject: RE: Why did USA 7' singles have large hole.
From: treewind
Date: 19 Mar 06 - 07:15 PM

I read somewhere it was a misguided attempt by RCA to gain a monopoly of the market. They thought if they made records with a different sized hole and speed then they'd make lots of money selling the players for them.

Of course the other record player manufacturers adapted in about 5 minutes....

Anahata

Subject: RE: Why did USA 7' singles have large hole.
From: Sorcha
Date: 19 Mar 06 - 07:23 PM

Because they could?
Because they wanted to???
Who knows?

Subject: RE: Why did USA 7' singles have large hole.
From: pdq
Date: 19 Mar 06 - 07:53 PM

...from RCA in June of 1949...

"All record changers require a selecting mechanism of some sort to separate individual records from the stack. With records of constant thickness, all practical designs of selecting means cause some damage to the edge, body, or center hole area since the records have to be forced apart or slid one against the other to effect selection. With a small center hole and the heavy records commonly used, high stresses occur around the center hole and record damage results. A small center hole does not permit record stability on the spindle without edge support or complex spindle mechanism. Further, the small hole makes loading difficult."

Subject: RE: Why did USA 7' singles have large hole.
From: mack/misophist
Date: 19 Mar 06 - 08:23 PM

I clearly remember rhat many - though not all - records were extra thick in the label area to help protect the grooves. Come to think of it, this thickness would require a thicker spindle to ensure stability. That would have been mostly 45's. I reckon.

Subject: RE: Why did USA 7' singles have large hole.
From: Gene
Date: 19 Mar 06 - 08:52 PM

NAW! It was simple economics...

by making the hole bigger, they could produce more 45's per
1000 pounds of plastic material...

Subject: RE: Why did USA 7' singles have large hole.
From: Peace
Date: 19 Mar 06 - 09:29 PM

http://www.straightdope.com/classics/a1_258b.html

Subject: RE: Why did USA 7' singles have large hole.
From: JohnInKansas
Date: 20 Mar 06 - 02:44 AM

Peace -

While your link touches on some things that influenced the development of the 45 RPM record, it ignores the documentation that supports that it was developed to make automatic changers for single tune records more practical - at a time when changers were clumsy, expensive, and prone to damaging the records.

The large hole made it relatively simple to build a selection, holding, and release mechanism directly into the spindle. In typical home players/changers, you just piled a bunch of records on the spindle. The mechanism dropped the bottom record, but it also had to keep the remaining records from dropping. Previous record types generally had constant thickness, or the label at the center made the thickest part of the record at the center hole, so that at the center, there was only a tiny "crack" between records.

The 45s, at least in earliest production, actually had a thinner area at the hole, so that there was a built in "gap" between records that a "blade" on the spindle could enter without damaging the hole to separate the stack from the record about to be dropped, instead of the "stop" for the next record having to force its way into a nominally zero width crack - and chew a hole in the record big enough for it to fit.

Evolution in changer mechanisms made most of the more subtle features of the original 45s mostly unnecessary, but at the time of their introduction they made it a whole lot easier to design a juke box.

John

Subject: RE: Why did USA 7' singles have large hole.
From: GUEST,Dave
Date: 20 Mar 06 - 12:14 PM

I always thought Jamaican 7-inchers were like this so a DJ could easily slip on a new record in a dark chaotic dancehall, over a cone-shaped adaptor in the middle of the turntable. That doesn't answer why 10 & 12" singles didn't have the large hole, however ...

Subject: RE: Why did USA 7' singles have large hole.
From: Bee-dubya-ell
Date: 20 Mar 06 - 12:40 PM

Silly me. I thought it was just an easy way to distinguish between 45 RPM and 78 RPM records so all your music wouldn't sound like Alvin & the Chipmunks.

Subject: RE: Why did USA 7' singles have large hole.
From: Dita
Date: 22 Apr 06 - 07:51 PM

Thanks for the input.I forgot to put a trace on the thread and have just managed to find it. Peace, your link helped a lot.

In the UK both 45s & 33s were made with the small hole. To allow juke-box use, a much smaller market in the UK, in the 50s and 60s they were made with a punch out centre. In the late 60s Polydor and related labels (ie Track) came with an USA sized hole, with a plastic adaptor. By the late 70s they were one solid centre with the small hole only, and had to be machine cut for the juke box. I presume this latter development was to ensure that the discs used had to be those provided by the supplier.

Belated thanks once more, John.

Subject: RE: Why did USA 7' singles have large hole.
From: JohnInKansas
Date: 22 Apr 06 - 08:29 PM

There actually were several other record formats, including a couple of 7-inch ones used some in the US with the small hole. The 45 rpm was the only "small" format that was ever popular in the consumer market, but 16.5 rpm disks, 7" with small hole, saw significant use in studio recordings and in "educational records" used by a number of public schools. (Maybe the educational ones came from the Brits?) I think (dangerous thing, I know) that there was a brief appearance of a 22.5 rpm format that was in the 6 - 8 inch diameter range, with standard(?) small hole; but I saw so few of them that I can't really be sure I remember what they looked like.

Many 50s - 60s era "changers" came with the small spindle for 78s and 33-1/3 rpm records, and had a larger spindle that slipped over that one for the 45s. The "change mechanism" for the small spindle worked/connected inside the larger spindle and actuated a pair of "flippers" to drop one 45 at a time.

"Plugs" that fit into the large hole were also available for purists who used a "real turntable" instead of a changer, and it was surprising to me - at that time - that quite a significant percentage of people who played lots of records insisted that "changers eat your records" and refused to use one. Even then, I'd observed that lots of the small-hole records had chunks eaten out of the hole by being used on changers, but I don't recall ever seeing a 45 (large hole) damaged by a changer.

John

Subject: RE: Why did USA 7' singles have large hole.
From: Bert
Date: 22 Apr 06 - 11:00 PM

I'm surprised that nobody has considered tha fact that it may be because Americans are "Big Pricks" *HEE HEE*

Subject: RE: Why did USA 7' singles have large hole.
From: frogprince
Date: 23 Apr 06 - 07:39 PM

Why did it take this long to notice that the thread is about USA 7 foot singles? Unmarried basketball players?

Subject: RE: Why did USA 7' singles have large hole.
From: Bill D
Date: 23 Apr 06 - 09:36 PM

LOL...good eye frogprince! (I'll bet those 7 foot turntables were fun to ride on!)

Subject: RE: Why did USA 7' singles have large hole.
From: GUEST,Joe_F
Date: 23 Apr 06 - 09:37 PM

And that, of course, leads straight to the answer: they are sized in proportion.

--- Joe Fineman    [e-mail]

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