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Hey Yall,

I have five guitars under my belt here and I'm planning the sixth. One of the greatest challenges I'm facing is getting the angle of the neck to coincide with the top under the fingerboard. So far I have been building in the style of the Cumpiano book which doesn't detail this point in the build to the best of my knowledge. I have read a bit about it and have checked out John Halls videos and Im considering using his methods in the hopes I can overcome this problem. I have only just learned about the slight slope needed in the rim of the top to compensate the angles. My question is it seems like a lot of things I don't have to make this happen, molds, radius dishes ect... Can anyone advise in the style that I have been building in so far? Do you think its worth the switch spending the extra money to gear up for mold building? Do you find building in molds to save time?

Thanks

Wes

Yes and Yes on your last 2 questions. I personally have found that once I got my current method dialled in neck angles are working out very well. It costs little $ to build a mold and not a whole lot of time.

I have built 4 guitars and had various levels of success from #1-3. I tried a couple of methods I fond on the interweb and found some a little unclear, and some so precise as to be cumbersome. Before I built #4 I found a page on Hesh Breakstone's site on his method and it worked perfectly.

Understanding that not all neck/body angles are the same, and not all doming of the top is the same, this method will work within a broad range of conditions.

Once the rim is done, flip it over so the flat edge of the top side is down. Place a sheet (or 2) of sandpaper under the upper bout from the neck block to the waist. Put a 1/8" shim under the heel block. Move the rim over the sandpaper so that it removes material starting at the neck block until the sanded portion hits the waist - voila. Might help to lower the neck block almost a bit with a wood plane to make things go a little faster.

I think you should be able to do this without a mold if you can find a way to hold the rim a bit rigid - perhaps a stretcher in the upper bout with a bar clamp on the outside to press against the stretcher.

The link I saved 4 months ago to this page does not work, and I just looked on the Ann Arbor Guitars website and it is stuck on the home page with no place else to go. If you find the multiple "tips" that Hesh has (had) up you will find it.

Ruby: This what you are looking for? viewtopic.php?f=10117&t=25931
Tom

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A person who has never made a mistake has never made anything!!!

Wes Ken Cierpilowski sells a mega mold that adjusts to any guitar body shape and has a bar designed to do exactly what your looking for. Check it out at KMG guitars.


Sent from my iPhone using Tapatalk

I just completed my 3rd guitar, but it was my first "solo" build. I built my first two in one of Frank Finocchio's classes that he does. We used molds on both builds and I used a mold for the dred I just made. I gotta believe it makes the whole process SO much easier, like when you radius the rim in the sanding dish, you are just assured that the sides are secure and not moving around on you which would impede accuracy. And, using the technique that Ruby describes which is the same one Frank and I believe John Hall use maybe Hesh too, the mold really helps you get the angle you want. I put a little chalk on the neck block and the top of the rim sides down to about the waist so you can see how it progresses as you sand. In all cases, my neck angles have been right on and it really helps the fingerboard transition to the body when you have the correct angle, and this area is flat. Check out John's YouTube channel, I think he even demos how he does it.

Kurt

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Kurt Thomas

"There's a first time for everything even if you do it by mistake."

Wes.... I'm still working on my first, but gosh the process you describe was a breeze using the radius dish and form. !/2 hour and i was done with both sides. It makes sense to sand in the same dish that you used to dome the top/back. It has to be a perfect fit... or am i missing something?
Pics from my build are here... 3rd & fourth from the bottom... [url]http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=41876&start=25
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Ruby... i am not sure (pardon my inexperience!) why all domes are not the same... if you build in a radius dish shouldn't they all be the same? Isn't that why someone would use the radius dish? I must be missing the point. Sorry!

Tom West - thanks for the archive - this info used to be on his website but it appears to be gone - I have bookmarked that page.

Robert - there is no set-in-stone radius for a guitar top. There is a wide range of them, and as mentioned in Hesh's procedure, some even radius the part over the upper bout but make a flat spot in the middle where the fretboard extension rides. Good luck on #1!

Ed Minch

Thanks for all of the tips fellas!!!!! I have enjoyed the open building process and am pleased with what I have built so far, the obvious part being getting the last part of the fretboard on a perfect plane with the rest and refining speed, repeatability and accuracy in the process is my aim. I don't see making molds to be to hard but what about the radius dishes? Do you guys buy them or make them?

Not only do molds save time, it's the only way to make a guitar straight and symmetrical. About all you need to make molds is a bandsaw, router table, spindle sander, some good baltic birch and glue.
Same with radius dishes, you can make a radius carriage to hold the router and rotate or move the carriage. I bought a couple of radius dishes early on, then re-routed them later to 10' and 12' and made a 10' cylindrical "dish" that I use for tops.

Click on slide #27 and you can see how I used a saber saw, a drill-press mounted sanding drum, and router and pattern bit to make perfectly adequate molds.

https://www.flickr.com/photos/ruby1638/ ... 029319394/

A mold really does make things easier and takes less than 2 hours to make

Then 5 slides after the mold I use a sanding bar instead of a dish to do all of the doming - very easy.

Ed

I should have added that it does not matter what type of plywood you use, but 3/4" is a good size. I happened to have this nice stuff from a furniture project, but exterior grade sheathing would work just fine. Also, I have built 4-7/8" deep bodies just in this type of 3" deep mold with nor problems - sides end up nice and square. And the sanding battens are just 2X4's that I had in the shop for a while so I was pretty sure they weren't going to move around, and they haves stayed true for 2 years now.

Good luck and keep us posted.

Ed

I build in the open workboard fashion...similiar to Cumpiano....although I learned it directly from Michael Millard. I have also previously , starting out..... worked with the molds / forms, and now prefer the open plan. Since my time with Mr. Millard....I've changed a few things. I've built this way, with the top of the rims sanded flat, and the braces radiused to 25 ft. r....and with the top of the rims / sides radiused to 25' r. Both ways...preferring to use the flat top sides / radiused braces. No problem with neck angle ...either way really. Where I depart from Millard / Cumpiano , is I employ the radius dish to put the radius, on the back plane (16 ft. r.)....and the top (if and when I do radius the top rims) I modified the centre hold down clamp to have a central post that accepts the radius dish in the desired position. Saves me time, and I like the consistency I get, rather than and plane by eye at each radius operation.

I apologize for the huge reply size...not sure why it's happened ,or what I did wrong. Loader doesn't auto resize photos of a proper fit?

Another option is the Fox type adjustable mold. I started with that because I took his course many years ago. I also use a rigid mold for some models. Both approaches have some good points and issues you have to work around. I do use the adjustable mold for 80% of what I do. Not because it's necessarily any better than a rigid, I've just gotten used to it and developed techniques to get around it's weak points.



As far as angling the upper bout with the adjustable mold-- after I radius sand I place a cross piece at the bridge location that is roughly the thickness of the bridge. (the actual angle that works depends a lot on how much the upper bout of your guitars moves on string up. You may not want it exactly co-planar with your desired neck angle unstrung in order to have it right under tension.). A sanding board with a 1/4" piece of plexiglass on the bottom to represent the fretboard pivots on that cross piece and angles and flattens the upper bout.

The Fox Paddle helps fine tune things after the top is on. For me the pivot point is about bridge height.

I used to glue my top brace flat as well but now put a very slight radius (50') in it. It has definitely helped stabilize the upper bout.







The amazing thing about lutherie is how there is no one "right" way to do things. I think the important thing is to pick an approach and become comfortable with it. They all have issues you have to deal with. I love threads like this that show how very different techniques can all lead to the same desired outcome.

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Well said Terence and so true.

I built 'free hand' for a long time, and had issues with things like neck angles to varying degrees. I started using outside molds when I began to teach, as much for the students' sake as anything else. Recently I've been using a 'solera' from time to time, mostly with Classicals and harp guitars. As has been said, every method has it's advantages and drawbacks.


The big advantages of the 'horse collar' mold are repeatability, consistency, and time saving, particularly in making the box. I've found that making a horse collar mold and bending form to use with a heat blanket saves more time than it takes to make them. I like to cut the half pattern for the mold out of 1/4" Plexi: it's easy to scribe a line over the drawing and trim right to it, either with files or a sanding drum. Rough cut the plywood to shape, pin the pattern to the pieces and trim them with a router one at a time. If you're careful making the pattern you can join the pieces in the middle and end up with a nice symmetric mold.

The biggest drawback of the horse collar is that you're left with fitting the neck freehand. This is always the biggest issue for my students now. I've worked out the height of the neck surface projection at the bridge location and use that to get the angle. I use a single tapered tenon on the neck, and rout the mortise to start, after making sure the upper end of the box is smooth with no bumps, dips or fall-off at the edges. I usually just cut the tenon cheeks at a right angle to the neck surface, and then fit them from there. The actual angle will, as has been pointed out, vary a little depending on the way you dome and fit the top, and the projection has to be exact.

The most important thing about fitting the neck tenon is what I call the 'koan of lutherie':"The slower you work the faster you finish". You'll need a REALLY SHARP chisel, that can remove a shaving that's little more than dust from the end grain. When you make a big cut there's always the chance of over shooting even if you cut in the right place, and, of course, if you made the wrong cut you're even further in the hole. With a fine cut you don't advance fast, but you don't screw up big either. Sometimes the trick is just to avoid screwing up... I use chalk and the 'sandpaper flossing' method to get things right.

Also, as with anything complicated, it helps to break it down. In this case that means getting one thing right at a time. I get the tenon trimmed until the neck is almost, but not quite, bottomed out (say, 3-5mm proud), then trim the shoulders to get the center line lined up, and work on the back angle last. Then I finish dropping it in by trimming the tenon. It helps to do this with the neck shaft wide and before you put on/cut the head. Once you get the neck joint fitted you can pin the fingerboard on with the 12th or 14th fret at the edge, and figure out where the head is going to be. Leave the heel over size too, of course.

The big advantage of the solera is that it takes care of all of those neck angle issues PROVIDED you do a careful job of making the fixture to begin with. If you use a uniform radius, like the common 25' for the top, you can make it to accommodate a range of shapes as well. A couple of my students have combined the solera with a horse collar mold. I generally cut the top 2mm small all around (the thickness of the sides) and push the sides in against it to get the shape. It's not as precise in that way as the horse collar, perhaps, but so long as the guitar fits the case and looks good why worry?

It's possible to make a guitar on the solera and have the neck removable as well. Simply start by fitting the neck tenon into a piece for the block, without worrying too much about the exact angles. When you get the tenon the way you want it attach it however you like (bolt, glue, whatever) so that there's a 2mm gap between the shoulder of the tenon and the face of the block (I use plastic spacers). Treat the assembly as if it were a one-piece neck from there. You only have to remember to cut away the wood of the top over the end of the tenon, so that the neck can be removed later in the usual way. One advantage of this method is that the slot is better. The shoulders of the tenon and the end of the block can be made much smoother than you usually get them when you saw the slot, the gap can be more exact (you can even chalk fit the surfaces) and you can size any end grain with hide glue before assembly, which should make a stronger joint.

Just a couple of the many good ways to do things.

Was Hesh saying in that thread that he uses a go bar deck to glue the top and the back on?

Great advice all around!! I do like to look at as many methods as I can and settle on the one that make the most since to me. Can someone explain the position for the pivot when using a radius disc? Is it just dead center to the X brace?

Thanks for the pics Ruby!!!! I like your radius sanding method, it seems simple to setup I also noticed that your mold doesn't split in half as a lot them do. are there any advantages to having one that does?

Thanks for the link to the Hesh thread thats very usefull.

yes just center right left fore and aft.

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John Hall
blues creek guitars
Authorized CF Martin Repair
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Go bars are a great way to glue the plates.

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Wes Paul:

My mold DOES breakdown. the two halves are held together with C-clapmps and I find I only take it apart one or two times until I am done with the mold, so I saw no need of buying specialized clamps to hold it together.

Look at the pictures starting here:

https://www.flickr.com/photos/ruby1638/ ... 1029319394

to see the clamp at each end.

Ed

Wow that's cool glueing the plates with the go bar deck I have to make one of those!!!' Where do you get the go bars at?

The original --- Does all of the about and more

http://www.cncguitarproducts.com/kmg-me ... xture.html

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Ken Cierp

http://www.kennethmichaelguitars.com/

That's a sweet mold very functional. How do you normally figure out the profile to cut on the sides before bending?