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Anyone have Gibson AJ plans? Diff between AJ and J-45?
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Author:  ScooberJake [ Wed Feb 13, 2013 10:55 am ]
Post subject:  Anyone have Gibson AJ plans? Diff between AJ and J-45?
I am looking to build my first guitar as part of the New Builder Challenge! bliss Very excited. But I would like to build something like a Gibson AJ and I can't find any plans online. Does anyone know of a set?

If not, I figure I will start with J-45 plans and change as necessary. From info I found mostly on Gibson forums, here are the main differences:

AJ v. J-45
Rosewood v. mahogany
25.4" scale v. 24.75"
Bracing

For the bracing, I found an article on the Stew Mac "trade secrets" page that explains how to take a plan for (standard?) Martin bracing and make it "forward shifted". Can I just do the same for the Gibson J-45 bracing? Of course this may not mimic the AJ bracing exactly, but I expect that it will get me close. Will it work? Any pitfalls I need to be aware of?

Then on the scale, does this just amount to shifting the bridge (and bridge plate) aft by the difference in scale length? Anything else I need to consider?

Thanks in advance for helping a new builder. [:Y:]
Author:  Tom West [ Wed Feb 13, 2013 2:50 pm ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
Jake: Be aware that you lose about half of the difference in the scale lenght in the neck.
Tom
Author:  ScooberJake [ Wed Feb 13, 2013 3:42 pm ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
Todd Stock wrote:
The second edition of 'Fabulous Flattops' has some additional details, and you might try the UMGF Vintage Corner and the Technical forum for bracing info. The OLF AJ plans may still be floating around, but I have no confidence that they are anything more than an interpretation.


Thanks, Todd. I will check into UMGF. Does "Fabulous Flattops" have enough information to figure out dimensions of the neck, bracing, etc? Also, any idea who I should talk to about the OLF AJ plans?

Tom West wrote:
Jake: Be aware that you lose about half of the difference in the scale lenght in the neck.
Tom


Thanks Tom, didn't know that. This is exactly why I would prefer to find plans rather than "wing it".

EDIT: Wait, I think I actually understand that. If you assume the body still joins at the 14th fret, then that point is stationary, so a little over half of the change in scale length would come from the neck side of the fret (since the 12th fret is halfway), the rest would come from the fingerboard extension. Right?
Author:  Tom West [ Wed Feb 13, 2013 4:01 pm ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
Jake: Your there. It's quite easy to think that you just have to move the difference in the scale lenghts on the top itself.
Tom
Author:  meddlingfool [ Wed Feb 13, 2013 4:32 pm ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
One thing about the AJ's, the bracing is shoved so far forward that there is only 19 frets. I took a tracing off mine and built one from it. Sounded nothing at all like a Gibson, but very nice. Also the top on mine is about .155 at the soundhole, which is quite thick. I ignored that detail and built as normal. There is also no Popsicle brace due to the utb being so close to the block.
Author:  ScooberJake [ Wed Feb 13, 2013 6:59 pm ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
meddlingfool wrote:
One thing about the AJ's, the bracing is shoved so far forward that there is only 19 frets.


I read a discussion of the dimensions of AJ's and J-45's on a Gibson forum. Of course being Gibson, the dimensions are all over the place. But I did read one poster who said the soundhole on an AJ is 3/16" further forward, presumably so the bracing can go farther forward. This might eliminate a fret.


Todd Stock wrote:
Not enough info to put a bracing plan together - more development and discussion of variants.


Thanks, Todd. I guess I'll contact Lance to see if he can find the OLF AJ plans.
Author:  Jeff Highland [ Wed Feb 13, 2013 7:46 pm ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
Based on the one AJ I have examined, you need to have one of the X braces fully flatsawn and the bridge wings lifting to get that Gibson sound :roll:
Author:  ScooberJake [ Wed Feb 13, 2013 11:16 pm ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
Jeff Highland wrote:
Based on the one AJ I have examined, you need to have one of the X braces fully flatsawn and the bridge wings lifting to get that Gibson sound :roll:


Then it must be a good choice for a first time builder, eh? [:Y:]
Author:  guitarjtb [ Wed Feb 13, 2013 11:42 pm ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
This may help a little. Imagine that the JB Weld is not there.

Attachment:
ajtopbr4.jpg

Attachment:
ajtopbr1.jpg

Attachment:
ajtbar4.jpg

Attachment:
ajbkbr2.jpg

Attachment:
ajxbr1.jpg



ScooberJake wrote:
I am looking to build my first guitar as part of the New Builder Challenge! bliss Very excited. But I would like to build something like a Gibson AJ and I can't find any plans online. Does anyone know of a set?

If not, I figure I will start with J-45 plans and change as necessary. From info I found mostly on Gibson forums, here are the main differences:

AJ v. J-45
Rosewood v. mahogany
25.4" scale v. 24.75"
Bracing

For the bracing, I found an article on the Stew Mac "trade secrets" page that explains how to take a plan for (standard?) Martin bracing and make it "forward shifted". Can I just do the same for the Gibson J-45 bracing? Of course this may not mimic the AJ bracing exactly, but I expect that it will get me close. Will it work? Any pitfalls I need to be aware of?

Then on the scale, does this just amount to shifting the bridge (and bridge plate) aft by the difference in scale length? Anything else I need to consider?

Thanks in advance for helping a new builder. [:Y:]
Author:  meddlingfool [ Thu Feb 14, 2013 2:56 am ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
I can verify the lifting bridge wing. Mine came equipped with one stock....
Author:  ScooberJake [ Thu Feb 14, 2013 10:31 am ]
Post subject:  Re: Anyone have Gibson AJ plans? Diff between AJ and J-45?
James Burkett wrote:
This may help a little. Imagine that the JB Weld is not there.


Thank you very much! That will help. Knowing that the lower bout is roughly 16" I can scale the layout of the braces off that picture. The height and profile of the braces will be a little tougher, but this is way better than nothing. Thanks!

I assume the ruler in picture #5 was aligned with the edge of the soundhole? From the picture it looks like it is a touch off, but that may just be the perspective.

Also, did you just decide to tear your AJ apart? eek
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