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12-08-2007, 09:33 AM | #1 |
Your Bartender
Join Date: Jan 2002
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Screw Me
Miss Dallas' cello has machine tuners at the top. (The kind normally found on string bases, as opposed to just plain pegs, which are more common on cellos.) One of the screws fell off, and we need a replacement. In my naievety, I thought I could take a sample down to the hardware store and get a replacement.
Since I'm posting this, I'm sure you can already guess that everything was either too small or too large. After consultation with a handful of string instrument repair experts (one of whom actually laughed at Mrs. Dallas on the phone--way to make friends and earn future business from a family with a violinist and a cellist), we've learned that such screws are actually custom made, and that we can get a replacement made for $100-$200. Now, this screw is not structural or functional--I mean in the sense that it affects the tuning. There is a gear that adjusts the string tension, and these screws only serve to hold the gears onto the side of the pegbox. So, thoughts? I figure surely somebody here knows where I can have a simple machine screw like this duplicated for less than $100. (I forgot to include something for scale... the size is somewhere in between 10-24 and 1/4-20.) |
12-08-2007, 09:41 AM | #2 |
Glutton for Gluttony
Join Date: Oct 2007
Location: Tampa, FL
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What about the manufacturer/artist that made the cello? Is there any way to contact them and see if they have any spares?
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12-08-2007, 09:43 AM | #3 |
barely disguised asshole, keeper of all that is holy.
Join Date: Nov 2007
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Any chance its just the threads that are off & not the actual diameter of the screw? Perhaps a metric size might work. What type of material is it going into - brass, steel, wood...?
You may be able to tap out a slightly larger diameter and use a standard sized screw. |
12-08-2007, 09:44 AM | #4 |
barely disguised asshole, keeper of all that is holy.
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Oh and the Lowes near me has a pretty good assortment of furniture hardware that has some goofy sized screws that might fit.
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12-08-2007, 10:51 AM | #5 |
Radical Centrist
Join Date: Jan 2001
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Is the intent to preserve the instrument so as to maintain its worth, or is the intent to make it securely tunable and playable, no matter what has to be done? (i.e., would you accept puttying/gluing and re-threading the hole? that could be done on the cheap)
Why would somebody craft a screw that's more like a machine screw, than a wood screw, to securely hold something to wood? Seems like it's a design failure if it came out. Was this an older instrument or was it bought new? |
12-08-2007, 10:54 AM | #6 |
i am myself
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the assembly is surely brass. can you not simply replace the entire tuning mech section? they sell them for acoustic guitars....gear and all. oh. and my next door neighbor has a machine shop in paoili, but he's a nutter.
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12-08-2007, 01:00 PM | #7 |
NSABFD
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If it screws into metal get Loc-tite
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12-08-2007, 04:05 PM | #8 | |||
Your Bartender
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Quote:
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It's an interesting idea, but I'm not sure it could be done and still let the gears turn. Here's what it looks like. |
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12-08-2007, 04:30 PM | #9 |
NSABFD
Join Date: Jul 2004
Location: MS. usa
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SD Maybe just use a drop on threads and be sure and keep off moving parts. They make a thread thing, e-zcoil, I think to replace things with. Someone else will have to comment on that.
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12-08-2007, 08:23 PM | #10 | |
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Quote:
Try McMaster Carr or Reid Tool and Supply. They have a large selection of fasteners. This link has two sizes "somewhere in between 10-24 and 1/4-20." One final idea, you work at a college, right? There must be a machine shop somewhere in that place that could help you. Many physics departments have machine shops. |
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12-08-2007, 10:04 PM | #11 | |
Vicariously, I live...
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Oh, what? Sorry...habit.
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12-08-2007, 11:58 PM | #12 |
The future is unwritten
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A 10 screw would be about 0.190 diameter.
A 12 screw would be about 0.215 diameter. A 1/4 screw would be about 0.245 diameter. What is the pitch? How many threads per inch? Just count the number of threads along a ruler. If it's not an inch long count the threads in a half inch and double it. Don't count the thread you start from. But, being old and German, everything above is probably moot. How does it work? Do you have to loosen the screw before adjusting the string tension? If not, Green loc-tite will fill up to 0.015 gap and hold with a death grip. Red loc-tite won't fill much gap, but will hold tight and be removable, if the threads are fairly close. Blue loc-tite will keep fairly snug threads from moving.
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12-09-2007, 12:52 AM | #13 |
trying hard to be a better person
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What about trying to find an old cello of the same kind and taking the screw out of that? who knows, you might get lucky. Maybe try instrument refurbishers. I think that's your best bet.
What sort of cello is it?
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12-09-2007, 09:53 AM | #14 | |
Radical Centrist
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12-09-2007, 09:56 AM | #15 |
barely disguised asshole, keeper of all that is holy.
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You may be able to tap out a slightly larger diameter hole and use a standard sized screw.
This is still the only idea i can come up with - sorry. |
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