Center hole sizer

Another Johnson

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Jan 13, 2022
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The spindle on my LP12 is 7 mm. Nearly all records drop on without force other than gravity.

But the spindle on my Clearaudio Master Reference is 7.3 mm. While most records drop on with just gravity, a few hang due to slight interference. Clearaudio sells a tool to enlarge the hole to 7.3 mm for $50 in the US.

Or, you can make your own.
1. Buy a 7.3 mm bit (Amazon resellers offer them for less than $7).
2. Buy a wooden file handle. Another couple of bucks from Amazon. I had some extras in my tool box, so I did not have to buy one.
3. Use the bit with your electric drill to drill out the handle.
4. Press the bit into the handle.

Voila!
image.jpg

Works great!
 
The spindle on my LP12 is 7 mm. Nearly all records drop on without force other than gravity.

But the spindle on my Clearaudio Master Reference is 7.3 mm. While most records drop on with just gravity, a few hang due to slight interference. Clearaudio sells a tool to enlarge the hole to 7.3 mm for $50 in the US.

Or, you can make your own.
1. Buy a 7.3 mm bit (Amazon resellers offer them for less than $7).
2. Buy a wooden file handle. Another couple of bucks from Amazon. I had some extras in my tool box, so I did not have to buy one.
3. Use the bit with your electric drill to drill out the handle.
4. Press the bit into the handle.

Voila!
View attachment 140975

Works great!
Pocketknife works great.
 
Pocketknife works great.
A slightly tilted 9/32” bit with no handle works too.

Best would be a 7.3 mm reamer. We’re talking about shaving a hair’s worth of vinyl.

You can even just press the record down. That’s free.

I like Linn’s approach. Just make the spindle 12 thousandths of an inch smaller than the nominal hole size. But … you know how precise turntable tweaks can be.

Now if we could get the hole centered we’d have something. Calling Nakamichi, need centering on aisle one. :rolleyes:
 
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I've used a 20th century relic ... a letter opener.
That’s the “dull pocket knife” solution, and I’m sure it works.

I’ve gone several decades not needing this tool. I can’t think of ever needing it on the LP12s.

When I got the MW-1 RCM, its spindle was tight on some records, so I grabbed a 9/32” drill bit and used it as needed. But when I got the Clearaudio Master Reference, sometimes I had to redress tight holes. That’s when I noticed the $50 Clearaudio tool.

I like tools. So I had one in my cart to buy it. But something told me to check and see if a 7.3 mm bit was available… and it was. I was going to make a handle for it from a hardwood dowel, when I noticed that one of the extra file handles I had would serve. Hence my little project.

This tool doesn’t roll off the table when I set it down. And it looks “finished.”

Obviously there are many ways to enlarge a hole. This one is fairly precise. YMMV
 
It's not cheap (about US$43), but the Elusive Disc Vinyl Center Hole Reamer is a classy thing to have on your shelf and works very well.

<Edit: It's actually made by Stable 33.33 and available at several online sites>
 
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It's not cheap (about US$43), but the Elusive Disc Vinyl Center Hole Reamer is a classy thing to have on your shelf and works very well.

They say the spec is .286 +.001/-.002 inches. Clearaudio says 7.3 mm which is .2874”. So the 7.3 mm size should always “work.” They do not give the reamer specs, but I’ll bet it’s .287” and I suspect it will always work too. That’s a nice solution too.
 
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The Stable 33 reamer works great and you get a perfectly perpendicular cut. Seems like with a long bit you’d risking a wonky cut unless you can hold it exactly at 90 degrees.
 
The Stable 33 reamer works great and you get a perfectly perpendicular cut. Seems like with a long bit you’d risking a wonky cut unless you can hold it exactly at 90 degrees.
You don’t need a long bit. The interference is cleared with minimal insertion. And once cleared, anyone with reasonable hand eye coordination can withdraw. If one isn’t comfortable with the long bit, just enclose the bit in a longer handle so that a small amount (say .2” to clear .180” vinyl) protrudes.

This isn’t rocket science. The Clearaudio tool has a relatively long bit compared to the one sold by Elusive Disk.

The big surprise is that the interference is typically in the range of less than three thousandths of an inch. If you feel a .001, .002, and .003” feeler gauge, you quickly see just how quickly the hole changes from an interference fit to a running fit.
 
I own ~2,000 LP's that I've acquired since ~1970, and I could count on one hand the number of discs that had tight fit issues. Recently I started buying a bunch of 45 rpm "fancies" from Acoustic Sounds, and I have to touch up the center hole on half of them. Plus they have extra vinyl slag/flash attached to the hole - - just sloppy manufacture! Even on their $150 sets. Geez.
 
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J. Gordon Holt described a workable approach to correcting off-center LP's: spin it on the deck and observe the rotational point with the greatest outward movement of the arm as it tracks the eccentric grooves, and mark this on the LP's label with an arrow pointing inward. Then file the center hole into that direction a bit, register the spindle against this filed location on the LP (that you marked!), and try it again to gauge your success. Iterate as needed to get things nice and even. Then just always register your LP against the mark, and you're good. Sure, it's a bit anal retentive, but what else is new for a vinyl enthusiast?
 
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You don’t need a long bit. The interference is cleared with minimal insertion. And once cleared, anyone with reasonable hand eye coordination can withdraw. If one isn’t comfortable with the long bit, just enclose the bit in a longer handle so that a small amount (say .2” to clear .180” vinyl) protrudes.

This isn’t rocket science. The Clearaudio tool has a relatively long bit compared to the one sold by Elusive Disk.

The big surprise is that the interference is typically in the range of less than three thousandths of an inch. If you feel a .001, .002, and .003” feeler gauge, you quickly see just how quickly the hole changes from an interference fit to a running fit.

That’s exactly my point, you don’t need a long bit, but you seem to be using one. The Stable 33 tool is money well spent for a foolproof purpose built solution.
 
That’s exactly my point, you don’t need a long bit, but you seem to be using one. The Stable 33 tool is money well spent for a foolproof purpose built solution.
Let me explain what I get out of reading the various contributions to this thread.

1. The problem is rare, but may be more common with some record manufacturers.

2. Some turntable manufacturers have larger diameter spindles than others, so this affects whether or not you might need a solution.

3. Many people have improvised solutions. Knives, files, letter openers, drill bits, perhaps others.

4. Clearaudio and Elusive Disk sell tools. Clearaudio’s is the one I’d seen before someone shared the other. My solution is a knockoff of the Clearaudio tool, and I do not intend to sell it. It is strictly DIY.

5. You prefer the tool offered by Elusive Disk. You would be uncomfortable with the other solutions out of fear that you couldn’t control them and would end up with janky holes.

Well, as always, YMMV. You should use the tool you prefer. Mine could be easily constructed to have a very short protruding bit if one were worried about your issue.

As I noted (by liking the post about it and providing a link to the Elusive Disk offering), I think that little reamer is very nice. But … I don’t need another solution at this point. I can control mine, and it works great.

If I were still thinking about buying a tool, I might choose that one, but in general, I am partial to the Clearaudio tools.

Thanks for your critique.
 
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I use a round tapered file for different sizes.
What we call a rat tail file over here. At least, that's what my dad used to call it. :) Shove it in the hole in the record, rotate gently a couple of times. Job done.
 
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J. Gordon Holt described a workable approach to correcting off-center LP's: spin it on the deck and observe the rotational point with the greatest outward movement of the arm as it tracks the eccentric grooves, and mark this on the LP's label with an arrow pointing inward. Then file the center hole into that direction a bit, register the spindle against this filed location on the LP (that you marked!), and try it again to gauge your success. Iterate as needed to get things nice and even. Then just always register your LP against the mark, and you're good. Sure, it's a bit anal retentive, but what else is new for a vinyl enthusiast?
It sounds logical at first—like a solution anyone could find for a small problem. However, being off-center is typically associated with only one side of the LP. Other side may or may not be off-center or off-center on different direction or at different amount. Sides are independent from each other. Enlarging the center hole to perfectly center that side may actually worsen the other side’s alignment, often ruining its eccentricity. Therefore, it’s not a viable solution.
 
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