Official Luthiers Forum!

I figured I'd start a new thread for this rather than tag on to the end of the old one...

GD Armstrong sent Bruce Dickey a tracing of a 1937 Martin 0-18, 14-fret (Not to be confused with the more common 12-fret, which is a different body shape). Bruce forwarded it onto me, and I scanned it and traced over it in Autocad to make a nice repeatable (and online-sharable) copy of it. Nothing too fancy, just the outside pattern. I also offset a line 1/8" so it could be used to make an inside bending form.

Here's a little preview:


So here it is in various formats. You'll probably want to right-click and save-as if you're using Windows.

Acad2000 dwg version

EDIT: Acad R14/LT97 dwg version

DXF version (about 1 Meg, big file)

PDF version - This is set so you can print out a half-pattern on letter size sheets, there are matchlines so you can tape it together after you print. Remember to uncheck any print options that involve shrinking or expanding to fit the page.

Hope this is helpful to someone. Feel free to copy and share as you like. Thanks, George and Bruce!


UPDATE!
The Acad2000 DWG and the DXF links above now include the side profile tracing, and they also include the original scale tracing before I scaled it up to be exactly 18-3/8" according to spec. The side profile is non-scaled, I didn't really have any definite reference points to adjust to scale. It appears from the tracing that the top didn't have a radius, at least around the perimeter of the sides.

Here's a PDF of the side profile that can be printed out on letter size sheets and taped together:
PDF version of side profile

UPDATE AGAIN!
Here's a PDF version of the CAD version sized as George traced it, which was slightly smaller than published specs. The PDF posted above was scaled up slightly to meet published specs. The body length on this one is a little less than 18-1/4" (18-3/8" is spec size).

PDF version of original, not scaled up to published spec
letseatpaste38938.5077777778

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Jonathan Kendall, Siloam Springs AR

Neat Jon! Thanks for sharing.

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Joe Breault
Merrimack, NH
Perpetual novice

Thanks Jon, great sharing.

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Thanks Jon, i appreciate it!

Thanks.

I wonder if Lance or Brock could make an area on the OLF to store files like this?

Jon,
Wow, that is great. Is there anyway I could talk you into posting an Auto-Cad 14 version of this file?
I'm a little behind the times.

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

Thanks for converting that, Todd. I also went ahead and made an R14 version and added that to the original post above in case anyone else wants that... I think that's as early as I can go on Autocad file versions, I have Acad2002 installed at home and 2006 at work. The dxf is supposed to be R12 compatible, but that hasn't always worked before when I've tried to save files for a friend of mine still on R14.

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Jonathan Kendall, Siloam Springs AR

Jon, excellent work. I'm making a template today. Just printed out the PDF file and compared it to the tracing still on my back sliding door. I was amazed at how close it is to the original.

For those using the pattern, here are the original numbers I found somewhere for comparison.

1937 Martin Concert Guitar, 0-18 14 Fret, 24.9 scale

Body Length 18 – 3/8,
Upper Bout 10
Lower Bout 13 – 1/2
Tail Depth   4 – 1/4

Just to give you an idea of how much interest this drew, there were 373 Page views to the other post. Thanks again to those who offered tracings. There should be a 12 Fret version enroute.

The tracing I got was just shy of 18-1/4" long, and the lower bout was a little small, too. I scaled it up so the body length was exactly 18-3/8", and then the resulting lower bout was just about dead-on 13-1/2", so I feel pretty good about scaling it up that little bit. Some of that may have been because I tended to stick to the inside line of the tracing when drawing the line, so I may have erred on the small side when I traced. You'd be surprised how wide a pencil line looks when you zoom way in :)

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Jonathan Kendall, Siloam Springs AR

Don't suppose you could do a side profile and a bracing pattern for that "O"?

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

Yes, upon comparison to George's tracing the length was 18 1/4. Yours hit dead on 18 3/8 so I figured you went to the stated measurements which came from a compilation of Martin Measurements I got somewhere.

I checked the six inch ruler on the printout and it was perfect. All in all a very satisfactory job, and in three formats too, wow. Thanks George and Jon.

I have a copy of the side profile that George traced, I didn't do a CAD version of it because I figured it would change depending on top and back radius, and I didn't know what the original radii were anyway.

I don't have any bracing info, soundhole location, etc...

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Jonathan Kendall, Siloam Springs AR

Nice! Thanks for going through the effort to do us all this service.

I'll probably be making a CAD file of the side profile that George traced... It may be a week or so, as I recently resigned my job and this is my last week, and I need to finish some projects so I can finally get out of here. :)

So what would be a typical top and back radius for something like this? I'm toying around with the idea of eventually figuring up a side profile in CAD, just because I haven't done that before.

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Jonathan Kendall, Siloam Springs AR

Thanks a lot Jon. My copy is exactly 18 3/8 long. This will help me a great deal . How about some more sizes?

I added an update to the original post: The CAD drawings now feature the traced side profile, and also the original scale tracing before I scaled it up to an exact 18-3/8" body length (it was slightly under 18-1/4" on the tracing). I also included a pdf for the side profile.

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Jonathan Kendall, Siloam Springs AR

I took the PDF file today which I printed yesterday and tape it to a nice piece of flamed redwood for a pattern. Then I bandsawed it out just inside the line, but not to the 1/8th inch line.

A couple coats of shellac and a hole at the top and I have my template hanging on a nail. Ready for business.

The power of an idea and the internet.... really cool.

About the side profiles I always add 3/4" - 1" on each end when tracing older instruments so there will be a bit to trim for clean joints so that side is a bit long.
I've found that older Martins can vary as much as 3/8" both in length and width from the stated sizes.
I've got some other tracings of pre-war guitars that I'd be happy to share. I'll have to sort through them to see what all I've got.

I was wondering about that, how often they strayed from the stated size. That's why I figured it would be a good idea to go back and add the original size.

George, I'd be happy to give any of your other tracings the same treatment so it's easily sharable online. If you've made any other measurements or notes on these and you wouldn't mind, I could incorporate those, too. Do you own these instruments, or are these ones that have come through your shop? It's very generous of you to share, thanks again.

I've got a 1955 00-18 14-fret that I'd like to trace pretty soon and I'll put that up. I may go nuts and make a whole plan based on it.

Since I'm leaving my job, it'll be another month or so before I have ready access to an 11x17 scanner and Adobe Acrobat and stuff. I'm thinking I'll probably put up a web page so there's a more permanent place to post these, a library of sorts.

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Jonathan Kendall, Siloam Springs AR

I just read that there were only 30 0-18's produced in 1937.....Terry Stowell38938.3692013889

Wow, only 30? I didn't even know there was a 14-fret 0-size until Bruce started that original thread looking for a tracing.

Here's a 1940 0-17 14-fret

And here's a 1936 0-17 14 fretter

That Gbase.com site has a lot of nice vintage Martins to look at.

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Jonathan Kendall, Siloam Springs AR

Thanks Jon, I have my copy.

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Horton, MI

thanks for the gbase site tip. Never seen it before. I get my Martin info from the Martin book by Mike Longworth

Thanks George, Bruce, and Jon.

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Don Atwood
Arlington, VA

Very cool. Thanks for all of the formats, works for everyone that way.

Donovan