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http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=7990		 Page 1 of 2
Author:  Sam Price [ Mon Aug 14, 2006 7:30 am ]
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I was advised to measure twice, cut once...in my case, it's measure ten times, run away scared with a coffee and do something else, then return to measure another five times...

Yup, I've run away again, and seek the wisdom of the Luthiers...

When a book says "measure 11-3/8" from the neck end of the guitar" (with regards to bridge placement), do I measure from the top of the guitar at the neck end, or from the routed mortise of the neck block??

If I measure from the top of the guitar, shall I place something over the mortise to measure from, as I will be placing the straightedge against the centerline of the top.

Sorry, if this didn't make sense!!
Author:  RussellR [ Mon Aug 14, 2006 7:44 am ]
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Hi Sam

If it is to locate the bridge I wouldn't recomend this method, I would put the neck on with the fingerboard attached then assuming you are not compensating the nut, measure down the center line from the nut end of you fingerboard to the center of the 12th fret, double this and add your compensation (allowance for the bend in the string when fretted, I use a compensation of 2.5mm on a 24.9" Scales or 3mm on 25.4" Scale).
Then measure down the center line again from the end of nut end of your fingerboard and this point should be where the center of your saddle falls.RussellR38943.698587963
Author:  Sam Price [ Mon Aug 14, 2006 7:45 am ]
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Hesh.....

THANKS!!!


Right then, back to work...

I always err on the side of caution with my guitar build. It is bizarre that I am pretty impulsive and "go for it" with everything else!!!
Author:  Larry Davis [ Mon Aug 14, 2006 7:45 am ]
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post movedLarry Davis38943.8626736111
Author:  Sam Price [ Mon Aug 14, 2006 7:48 am ]
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[QUOTE=RussellR] Hi Sam

If it is to locate the bridge I wouldn't recomend this method, I would put the neck on with the fingerboard attached then assuming you are not compensating the nut, measure down the center line from the nut end of you fingerboard to the center of the 12th fret, double this and add your compensation (allowance for the bend in the string when fretted, I use a compensation of 2.5mm on a 24.9" Scales or 3mm on 25.4" Scale).
Then measure down the center line again from the end of nut end of your fingerboard and this point should be where the center of your saddle falls.[/QUOTE]

Ahh, Is this based on the assumption that the original plans and measurements may not match up with the guitar body due to how the carcass was assembled???...say for example the dreadnought is 20" long, it may be something like 19-5/8 which would render the printed measurements as useless.

Thanks very much for this information.Sam Price38943.7029282407
Author:  MSpencer [ Mon Aug 14, 2006 7:52 am ]
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Sam,

get yourself a Saddlematic from StewMac, does it all correct and accurate, cost about 30.00 as I recall.

Mike
White Oak, Texas
Author:  Mark Tripp [ Mon Aug 14, 2006 8:05 am ]
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I agree with Russell - measuring by his method will be more accurate. Even better, get the Saddlematic Mike mentions. I thought I saw a pretty slick homeade version on the forum, but couldn't find it. Might have been a different forum. I did find another thread on OLF that might be helpful. You can find it here.

Hope this helps Sam. Good luck!

-Mark
Author:  RussellR [ Mon Aug 14, 2006 8:09 am ]
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Hi Sam

Not so Much that the body could be different, but that the method you describe relies on the center of the 12th or 14th fret falling exactly on the line of the front of your guitars body, by the time you have fitted your neck to the body and got a good angle and clean fit this may not be exactly the case, and even 0.5mm can make a lot of difference to the inotation.
Author:  Sam Price [ Mon Aug 14, 2006 8:16 am ]
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/\ Okay, i need to go and re-think..I did not consider any other method, so the old brain has seized up...

Do I measure for bridge placement, using the more accurate method, AFTER I have set the neck angle?

I only ask these questions, for it's imperative I get it RIGHT!!!Sam Price38943.7202893519
Author:  RussellR [ Mon Aug 14, 2006 8:22 am ]
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Sam

Yes I would do after the neck is in its final resting place, normally I wouldn't final fit the bridge until the whole guitar has it's finish on and the neck attached, if you want to mask off the bridge area before you finish the body then you can fit your neck position the bridge then remove the neck again.

Don't worry about asking questions thats what the forums for.RussellR38943.7259722222
Author:  Joe Beaver [ Mon Aug 14, 2006 10:43 am ]
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I'm with Russell on this one. Get the neck the way you want it then do your measurments from the zero fret position (up against the nut)down the center line of the neck. Then be sure you align the bridge with the center of the sound board and square with it.
Author:  CarltonM [ Mon Aug 14, 2006 11:15 am ]
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Sam,

If I'm understanding you, it looks like you're concerned about checking your neck angle against your bridge? If so, the bridge placement isn't critical for that purpose--just tape it down, making sure your center lines are matching. To find your general bridge location, measuring from the body's top edge would work, but you'll still get the best results, I think, by dry fitting your neck and measuring half your scale length from the center of the 12th fret slot. Once your angle is set and your neck is permanently glued (or bolted), that's when you'll need to make your critical scale-length-plus-compensation measurment from the 12th fret center.
Author:  Sam Price [ Mon Aug 14, 2006 6:18 pm ]
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Thank you all, for your replies.

It's a great idea to buy the Saddlematic, however this will be the only guitar I'll make in the forseeable future ...the guitar I am making at the moment is taking a considerable amount of emotional energy and time I feel is jepoardising my young family.. (quality time!!)

The current Chickenpox outbreak with my kids has afforded me quality time with my build!!!

Needless to say it is an incredibly enjoyable journey, with a lot of the techniques seemingly instinctive...

*sigh* Luthierie is a beautiful art...Sam Price38944.1386226852
Author:  Colin S [ Mon Aug 14, 2006 7:28 pm ]
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Sam, the only thing I would say is listen to what Russell says, he builds the best sounding guitars you'll ever hear.

Colin
Author:  RussellR [ Tue Aug 15, 2006 7:03 am ]
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Hi Sam

Totally understand, this guitar making can be all consuming, I think it gets easier once No.1 is complete.

I actually use a device that John Hall makes which is similiar to the saddlematic, but there is no reason why you can't use an ordinary 1m rule.
Author:  RussellR [ Tue Aug 15, 2006 7:05 am ]
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Hi Colin

Great to see you on the forum , hope all is well with you, and that your Mum is making good progress.


RussRussellR38944.6708680556
Author:  RussellR [ Tue Aug 15, 2006 7:09 am ]
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Sam

I should have added, I still check by measuring after anyway.
Author:  Sam Price [ Tue Aug 15, 2006 7:40 am ]
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Okay, step by step...how many times have I measured already???

I am currently setting the neck..I have approximated the bridge (will check with more accuracy once the neck is set...)

The measurement of the bolt on tenon is the same depth as the neck mortise...I checked, after discovering a thread regarding Stewmac neck tenons being too long for the socket...

It was a little wide...the tenon stuck, and it couldn't go all the way down flush with the guitar sides...therefore I carefully filed away around the tenon for a more comfortable fit...

However the fretboard end of the guitar is pretty flush one side and not the other...and the heel end doesnt' go all the way down into the mortise...

Lots of questions.. Do I gently file away at the joint until it is pretty flush with the sides then file to set the angle, or do it whilst in this awkward position?

Quesion number 2...I have mocked up a laminated block, the thickness of the center of my bridge plus 1/16 compensation and taped it where the hypothetical saddle would be...is this okay?

Question number 3: I drew a centerline down the fretboard before cutting to shape and sticking to the neck...would this be a good gauge to match with the centerline I penciled in on the guitar top, at the upper portion of the rosette?

I seem to border on paranoia with this kinda stuff...I learn a bit, dry run, sleep on it, then try again the next day with more acquired knowledge...I learn through my hands!!!
Author:  RussellR [ Tue Aug 15, 2006 7:32 pm ]
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Hi Sam

In question one, are you saying that the tennon is preventing the neck cheeks from seating against the guitars sides ?

If so you need to get the tennon fitted so it is seated right the way round.

You then need to set your angle and get a good fit, Campianos Book which you have has good instructions on setting the angle. For the final fit to the sides i would recomend you undercut the material between the outside of the neck cheeks and the tennon leaving about a 4mm wide surface all the way down the outer edge of the neck cheeks and then you can put sandpaper between the joint and the body and floss the joint (From memory I think the stewmac instructions explain how to do this or search the achives here as I know its in there somewhere. If the fretboard is not sitting down flush, either the neck block is not in quite square, in which case the tennon is preventing it from going down square, inwhich case the solution is to remove a little material from the sides of the tennon so it can sit over (you may need to relieve the bolt holes too, in fact it may be them that are preventing the neck from seating), or you have a slope on your top, If you check the lay of your neck with a straight edge along the paths of the two E srings the gap between the staight edge and top should be the same assuming an even dome to the top.

Question 2

Compensation is the amount you add to the scale length not bridge height, so you want your mock bridge to be the same thickness as your actual bridge. Unless I am misunderstanding your method.

Question 3

The critical factor here is that the center line of you Fboard hits the dead center of your bridge pin holes, ideally with you bridge positioned so that its centre matchs the centre line of the body. I usually put a piece of low tack masking tape down the centre line of the body at the approx bridge position and use this to align to. RussellR38945.1913773148
Author:  Sam Price [ Wed Aug 16, 2006 4:02 am ]
Post subject: 
Hesh: I have that manual in my possession, however, there have been times when I have needed the Cumpiano book and certain internet references to "fill out" the process of the guitar build. The Stewmac manual isn't comprehensive enough, and the video is in NTSC!!! We don't sell guitar kits in the UK....

Russell, to quote from Cumpiano..

"if that airspace measurement is equal to the thickness of the bridge at it's middle plus (no more than) 1/16 inch or (no less than) 1/64 inch, we can expect to end up with an 1/8 inch tall saddle and medium string action after the guitar has been strung up and "settled in"--an optimum situation.....we allow a greater airspace if we expect the guitar to flex a greater amount under tension..."

I am expecting my guitar to flex. Sorry Russell if I used the wrong terms. Of course it isn't compensation, my bad.

Wish me luck, I'm going to start hacking away tonight!!! Sam Price38945.5444560185
Author:  RussellR [ Wed Aug 16, 2006 4:56 am ]
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Good Luck Sam

Author:  Sam Price [ Wed Aug 16, 2006 6:32 am ]
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Ok, so far...after some filing, I managed to get the neck to look like this...that is as far as I can get it to the top sides of the guitar before I have a nervous breakdown..







Measuring the airspace between the top of the bridge and the straightedge yeilds a 17/64....yeah, noob, aren't I? Either a lot of chipping off wood or creating shims to shore up the heel is needed...I dunno...my head feels like it's gonna blow..

Somebody said it was really easy...I must therefore be mad.Sam Price38945.650625
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