Build Your Own

Jack

Bob & Bill-

Any chance you guys can post some photos of what you've worked up? You never know; you could end up being the next Big Guy. Even if you're not interested in making stuff for others, I, at least, would be interested to see what you've done.

Best,
Jack.

bill raymond

I can maybe dig up a few photos to post. Meanwhile, my good friend Pete Davies has just put up a new site with some step by step photos of his construction of his first Maccaferri (without resonator). Pete does really good work, and you can view his site at:

http://www.pluckandsqueeze.com/Mac%20pr ... roject.htm

Although it doesn't show in his photos, he even made the "compound cutaway" where the cutaway follows the edge of his tapered neck heel. The instrument he made is very fine sounding. You may want to take a look.

Bob Holo

The gent with the good pictures has done a better job of documenting the process than I have to date. He leaves out process information such as how to accurately cut the brace profiles and about camming the top & etc.. but from a "here's what the inside of the guitar looks like" perspective - he's done a really nice job. Let's see how Michael Collins' book looks and if it leaves some things uncovered maybe I'll toss a few posts up. I don't have an FTP server for pictures but mostly what is needed is a description anyway - look at a picture - think about the description of how its done - and the technique becomes clear.

A particularly interesting thing about Mac style guitars is that the top profile is not spherical. There are at least three styles I know of - and none of them are. One is bent (literally - 6 degree corner put in the top near the bridge... I saw Patrick Sassois' rig here recently and that is the style of his.. beautiful singing tone - great piece of tonewood with a band of rosy color running down the center. ) The other styles that I've seen / measured are varying shapes of asymetrical domes which more or less have their high points around the bridge. I'm sure that some of the variation I've seen has to do with the movement of the tonewood over decades... but ti's not as simple as buying a domed sanding dish from LMII and routing out 15' radius top braces. It is truly a combination of using the braces to establish an arch perpendicular to the neck and then one of (at least two methods) of establishing a domed arch parallel to the neck. I spoke with Josh recently at Jazz Alley in Seattle and he is using a few techniques he learned while studying violin making. I'm not sure how I'll solve this issue. I've started it twice and discontinued both attempts because they just werent "it". I'm looking into a couple of techniques used in making vioins, mandolins and some of the "wavy" cammed-top guitars of the 1920s. There are many ways to do something - I want to find one that makes me feel as though I am crawling around in Mario Maccaferri's head thinking his thoughts. It may take a while, but it's the fun part of the pursuit anyway

Speaking of wavy top guitars - did anyone play the one Shelley Park brought to DJfest? It was inspired by a 1920's Vega design. It may have been the nicest sounding "traditional" steel string guitar I've ever played. It was clear / penetrating / bell-like. Gobstopping work on her part - just fantastic.

Jack

Bob Holo wrote:

I don't have an FTP server for pictures but mostly what is needed is a description anyway

Bob, I might be misunderstanding you, but if not: Michael's made it so you can upload photos/files directly to the forum using the Add an Attachment button. Go nuts.

best,
Jack.

bill raymond

Bob Holo wrote:

A particularly interesting thing about Mac style guitars is that the top profile is not spherical. There are at least three styles I know of - and none of them are. One is bent (literally - 6 degree corner put in the top near the bridge... I saw Patrick Sassois' rig here recently and that is the style of his.. beautiful singing tone - great piece of tonewood with a band of rosy color running down the center. ) The other styles that I've seen / measured are varying shapes of asymetrical domes which more or less have their high points around the bridge. I'm sure that some of the variation I've seen has to do with the movement of the tonewood over decades... but ti's not as simple as buying a domed sanding dish from LMII and routing out 15' radius top braces. It is truly a combination of using the braces to establish an arch perpendicular to the neck and then one of (at least two methods) of establishing a domed arch parallel to the neck. I spoke with Josh recently at Jazz Alley in Seattle and he is using a few techniques he learned while studying violin making. I'm not sure how I'll solve this issue. I've started it twice and discontinued both attempts because they just werent "it". I'm looking into a couple of techniques used in making vioins, mandolins and some of the "wavy" cammed-top guitars of the 1920s. There are many ways to do something - I want to find one that makes me feel as though I am crawling around in Mario Maccaferri's head thinking his thoughts. It may take a while, but it's the fun part of the pursuit anyway

Bob,

There's a photo in François Charle's book of the joining jig Mario used. It appears to be a cast iron frame that holds the two sides of the top together while holding them in the "domed" shape. The top was scored lightly with a knife at the "pliage" then bent over a hot pipe, then joined using this jig. The two short longitudinal braces beneath the bridge help to maintain the pliage, and the transverse braces are arched--you can use a spline curve or a section of a circle for the brace arching, it doesn't really matter much. I made a copy of Mario's jig in wood, and using the traditional rope and wedge method of clamping the top. I believe that there are photos of the jig in the archives at www.mimf.com . You'll have to join (it's free) to access the archives, but there are also photos in there of Al Dodson's bending the top, and discussions about the shape and methods of producing it. Unfortunately, the only photos I have at hand of my jig show it all clamped up, so it's hard to see any detail. However, if you'd like, I could take some more photos and post them. I hope this helps.

Bill

P.S sorry I didn't get the "quote" to look right in the post.

MichaelHorowitz

Bob...you have to end the quote with [/qoute]


The easiest thing to do is to just select the text you want to quote and then just hit the quote button. It'll do it for you...


'm

Bob Holo

(this time posted in the right place... I'll try to go erase the other one...)

Go nuts?

Well - it's too late for that, I've been certifiably nuts for many years...

I haven't done a very good job of documenting the build process but I found the following pictures - shrunk them - tossed them on a black background... so I'll try this to see if it works. Maybe I'll start taking pictures

Roughly, they're

Soundboard w/ Rosette installed & a test piece of bent rosewood/maple binding
Back Wood (before thicknessing - during which the pattern really clarified!!)
Me - playing Chez Jaquette on the 3" thick plywood Solara (building board)
Truing the scarf joint prior to gluing
glued / trimmed scarf joint ready for thinning
Drafting the Maccaferri Plans - wound up building the Charle Selmer first
My Fox Bending Jig sans cutout attachment - it took a long time to build this!

Bill - I just read your post - thank you. I hadn't checked on MIMF - I'll go do that. Scoring the Pliage gives me the willies... cutting tonewood fiber... I get what they're doing but wow... I wonder how Mario shaped his kerfing to accept the top with the proper angle which varies between 2 degrees and 4 degrees sloping away from the pliage in all directions once the top is in its fully domed position. He was a classical player and probably initially was predisposed to tentalones but he chose a bent kerfing (actually, that term is an oxymoron but you know what I mean) I can't help but think that his decision to use bent kerfing had something to do with the significant forces on the soundboard from the domed structure.

bill raymond

Bob,

What you have referred to as "bent kerfing" are "bent lining strips" or "linings". I can't know how Mario and his band of workers shaped the gluing surface to accept the top, but I can tell you how I've done it: A long "sanding stick", i.e. a batten (piece of 1 x 2 or 1 x 4 will do) long enough to span the length of the body with sandpaper fastened to one end, and spacer blocks of appropriate thickness rested on the top of the sides at the other. For instance, if the pliage is ca. 10mm elevated over the surface of the sides at its high point, you can rest a 10mm thick batten across the sides just where the pliage will lie and sand the angle at the butt. A 20mm thick block resting on one side about where the pliage is located will help sand the angle in the opposite side. Just keep doing it section by section, using appropriately thicknessed spacers. Remember, you don't need to be exact, and an angle that is slightly too steep will assure the top (or back) will contact the linings all the way around on the inside where you can't see during the gluing process, and the glue squeeze out will be on the outside where you can clean it off.

djangology

testing image. it turns out you just attach the image in the bottom attachment dialog and it just shows up like this. Interesting... i just noticed that I cannot delete a post any longer.

Bob Holo

Hah!

Great minds think alike

What I was thinking about - was to have an axle sticking up - dead center of the pliage... with a sanding stick hinged to it... so you can raise/lower the axis in the "Y" plane and spin it 360 degrees to sand that angle in the "X/Z" planes. Sure, there would be some error because what you're doing is approximating the tangent to an arc as the angle between the hypoteneuse and the opposite side of a triangle... and because the sanded area is a straight angle and not arched. (but over 3/8" it's almost irrelevant)

I've been meaning to do some calculations to find out what kind of error this would amount to... (.01 or .001 or .0001) and even then, the error could be reduced by figuring out what the average error is over the relevant distances at the relevant pliage heights and putting some small amount of arc in the sanding stick to mitigate the error from non-arched sanded surface and force the average angle error (hypotenuse vs tangent) to zero. Once you get to the point where the error from wood expansion is greater than the error from the sanding system - you're good to go.