new Regenerate build - M-Series 4-string lefty

[Rodent]

Documenting the first M-Series lefty build from genesis to completion …

Specs:
• Spanish Cedar body core with figured Maple top, Honeyburst finish
• AAA Birdseye Maple 4-string neck, zero-fret, 12”R fretboard, 34” scale, 21 frets, bone nut
• Nordstrand Big Singles pickup set
• Nordstrand 2-band preamp configured Vol (pull bypass) + Blend + Passive tone + Active Bass/Treble stack
• Hipshot Type A bridge, alum core, .75” string spacing
• Hipshot Ultralights with Y-keys
• Chrome hardware
• Dunlop strap locks

The rough kiln-dried Spanish Cedar 8/4 lumber was selected at a lumber yard about 4 hours drive from my shop during a vacation this past August. It’s been acclimating in my shop for several months now



After selecting the board for this build, I first shorten it to a workable length with a miter saw. Notice that I have shims at the ends so that the board will not drop (or worse – that the miter saw will suddenly tilt while the saw is still running!) once it’s been cut thru. I leave these shims just shy of touching the ends so as not to bind the saw blade while cutting



Once I have a workable size I square the edges with a jointer. The intended outcome is that I’ll have edges that are exactly perpendicular to the face and also perfectly level and smooth along the glue edge.



Before and after images of the glue edge



The Powermatic jointer I’m using has a helical cutter head, so the freshly jointed edge is significantly smoother than what a standard 2 or 3-blade cutter head will produce. This said, the edge fresh off of a jointer still needs to be hand detailed to remove all of the minuscule ‘cups’ the cutting blades leave behind. The cups from a helical head are pretty much non-existent, but they are there if you use high quality measuring tools to find them. The cups from a standard cutter head can be felt if you carefully run you finger down the edge, and will require more clean-up attention. One other key benefit of a helical cutter head is that is more forgiving of highly figured woods, causing less tear out on flame, birdseye, and burl figures

Once I have the glue edge detailed, it’s time to thickness sand the boards to within 1/32” of the final body core thickness. I will first cut the body core section into two pieces so I eliminate the potential for snipe. I’ll then alternate running each piece thru for a given thickness reduction, setting the board at a slight angle to help the sandpaper cut the grain easier. Spanish Cedar can get fuzzy if you run the piece straight on along the grain, and this will bog down the sanding drum. For this phase of the thicknessing I use 80-grit paper on the drum



It’s now time for a dry-fit to ensure the glue joint is tight and that the grain is aligned for a pleasing pattern. If I don’t have a perfect fit prior to adding clamping pressure I’ll detail the joint further until it simply disappears when lightly pressed against the mating piece.



Once I’m happy with the joint it’s time to apply an even coating of glue along the mating surfaces and clamp them together with even pressure from both sides of the body core. I like to use clamps from alternating sides so to help eliminate any clamping stresses that could arise from clamping just one side. I also want to see glue squeeze-out evenly along both sides of the entire joint



The body core blank will now sit to cure for 24+ hours depending on the wood species.

More to come in the next installment. Until then …

All the best,

R

[SDB Guitars]

An excellent start, sir!

Out of curiosity, where to you source your Spanish Cedar? That looks significantly nicer than what I see at my local Windsor Plywood...

Also, why do a bone nut if you are using a zero fret? I mean, doesn't the zero fret kinda make nut material irrelevant?

Thanks,

Shawn.

[Rodent]

I picked thru a large pile of 6/4 and 8/4 boards at Edensaw in Pt Towsend, WA. when I was there they even had a couple 8/4 x 13" x 12' Spanish Cedar boards available, but these are just a bit too narrow for my builds. with the exception of one board, all the Spanish Cedar they had in stock looked stellar

http://edensaw.com/products.asp?cat=1

I also have a couple 1-piece Spanish Cedar body blanks I purchased from Larry at Gallery Hardwoods. I'm saving these for a 5-string build that'll be starting early in 2011


I'm using a bone nut simply because it's what I have in stock, and my other preference of Ebony would have drawn too much attention (in a bad way IMO) on the brilliant white birdseye neck.

all the best,

R

[SDB Guitars]

Nice. Somehow, I missed that you're on the other side of the Sound...

That's good lookin' cedrela, though, that's for sure. I would have just about killed to have gotten my hands on that 13" wide stuff. I'm about to start building a LP Special for myself, and I'm aiming for super light weight... a one-piece body would have been stellar, and I'm even considering a neck made of the stuff.

[Rodent]

I'll make an attempt to remember to drop you a note a few weeks in advance of my next trip over (the ferry ride is pretty, and it's always fun to drive on the floating bridge) ... if you're in the market for some wide stock and they have it in the pile I'm sure we can work something out (unless you're just itching to visit there yourself)

they also had a great supply of Black Limba on hand, but all of the nice pieces were S2S 4/4 (the turtle guys were supposedly there a week or two earlier and grabbed all the fancy 8/4 and 6/4 stock)

all the best,

R

[SDB Guitars]

Yeah, I'm not likely to make a trip over there myself until next summer, at the earliest (all spare time and funds are going to the impending wedding in May )

If you decide to make a trip over there sometime soon, definitely holler at me, and maybe we can work something out, I can PayPal you some funds, or whatever...

Thanks!

[Larry Davis]

Robert Ruck came and bought all my Cedro last fall...part of my retirement warehouse reduction plan Had some 8/4 timbers 30" wide!!

Rod, when possible I utilize all material and see quite a bit of excess wood either side of your profile outline. I like to rip the excess off before chopping and use as neck stringers.

Cedro comes in all weights and quality...some hardly distinguisable from mahogany.

[Rodent]

I hear ya on the wastage Larry ... I was lazy on this body build, and simply didn't take the initiative to set-up the outfeed rollers for my bandsaw to make better use of what now will be wasted. o for the want of room for a tablesaw

all the best,

R

[Rodent]

time for another installment on this body build ...

after removing the core from the clamps, I used a card scraper to remove the glue runs prior to thickness sanding the core to its final target thickness. similarly, I also gave the bookmatched Maple top it's final thickness sanding. I use a dial caliper to measure the thickness so I can exactly meet my target on both the top and main core, and to ensure that I have even thickness on the entire piece

here's the top and body core ready for gluing (sorry, I forgot to snap images of how this bookmatched top was assembled, but the process is very similar to what I did for the body core)



it's important to use ample glue (but not too much!) and cover the entire surface of both pieces being joined. I use Titebond Original for most of my glue-ups, and spread it with a roller to ensure even coverage across the entire surface



once the glue has been applied to both faces I secure the location of the top laminate utilizing multiple pieces of tape. I mark the centerlines on each piece so it's easier to see if some glue is applied to it.

when everything is taped into position I roll out the vacuum bag, slide in a piece of breather material, carefully insert the body sandwich, add another piece of breather material to the top side, and clamp the end shut. the rest is as simple as connecting the vacuum hose and stepping on the on/off switch to start the pump



the sandwich will remain in this vacuum bag for roughly 24 hours so that the glue can completely cure.

until next time ...

all the best,

R

[roberthabraken]

Nice build, I like such a clean way of working . May I ask why you use the vacuum bag? Never seen it before...

[MPU]

Originally Posted by roberthabraken

Nice build, I like such a clean way of working . May I ask why you use the vacuum bag? Never seen it before...

I guess even pressure is the key here.
Marko

[stepswork4me]

I've seen this before on another build. It's used in lieu of traditional clamping. I know nada though.

[Rodent]

and here's the result - a body core with figured top where all of the glue lines are perfectly aligned



the next step in this process is to cut the neck pocket with a friend's CNC. sorry, per his request I'm unable to provide an image that would reveal his system and/or hold-down techniques. the next image will be of the body blank (with newly added neck pocket cavity) at the next step in construction

until then ...

all the best,

R

[Rodent]

Originally Posted by roberthabraken

Nice build, I like such a clean way of working . May I ask why you use the vacuum bag? Never seen it before...

sure. it's a common practice I've seen in use at many of the 'big guys', and also used at a number of the smaller custom builders as well.

vacuum clamping has a couple key advantages over the traditional method of endless clamps. here's the main ones that drove my decision to move to this method:

- ease of set-up. I simply need to apply glue to both sides of the laminates to be mated, flip them into position and carefully align the seams, tape the pieces together so that they do not shift, and then insert into the bag and suck the atmosphere out to apply the clamping pressure

- evenness of clamping pressure. since it's the earth's atmosphere providing the clamping pressure, I'm assured of even pressure all the way around resulting in superior glue lines all around. since moving to this method I have yet to experience a 'wiggle' in a glue line where one clamp was a little tighter than the one next to it. in cases where I'm laminating thin layers (less than 1/4" iin thickness) I use a caul to assist in providing firm pressure across the mid section

- no slippage while clamping. I am able to carefully align the seams so that they're dead-on then merely tape them into place. gone are the days of everything slipping all over the place while tightening all those clapms. gone also are the nicked router bits that accidentally caught one of my alignment pins buried in the sandwich

- and finally ... LESS STRESS during glue-up! my blood pressure no longer rises while gluing a complex body sandwich, and I no longer feel the need to quarrantine the shop just before starting a glue-up. unless I'm a careless idiot when inserting the core into the vacuum bag, everything stays exactly where I put it ... including my blood pressure I am actually beginning to enjoy the glue-up process once again

I can say that utilizing the vacuum bagging approach has revolutionized the build process more than anything I've done in the past 2-3 years. it has allowed me to significantly increase my quality while simultanoeusly decreasing my stress levels. once I begin sucking out the atmosphere from the baggie, I can quickly move on to another project without the need for an extended breather and time to decompress before doing anything else

I'm also in process of making several cauls that match my headstock transition radius. with these, I'll also be able to start offering a matching headstock veneer on my M-Series builds.


let me also toss out this caution: vacuum bagging isn't going to solve issues associated to poor build practices. you need perfectly prepared glue faces if you want clean glue lines - this is true for whatever method you use to apply clamping pressure. surfaces that look like they where made planer with a cheese grater will result in ugly lines. so will gaps. if you've become accustomed to utilizing extra clamping force to eliminate waviness in your mating pieces, this is not a clamping method for you

there's no shortcut to good, solid prep work

all the best,

R

[roberthabraken]

Thanks for the thorough explanation, it sure does sound a whole lot better than clamping! I've had a lot of stress during glueing the fretboard in place, and I spent a lot of time building a jig to align the top on the body, without having it slipping all over the place.

I would never have thought a vacuum bag provided enough 'clamping' pressure. If I ever get to build a guitar more than once a year (or two), I'll have to keep this neat trick in mind.

[Rodent]

this is the beauty of a well detailed pair of mating surfaces and the right amount of glue. it doesn't take 200 tons of pressure to make the glue line disappear

here's a sandwich I assembled earlier this year. it was a two step process worked over the course of two days, with one outer Redwood panel and accent line added to the flame maple core in each session



about two weeks from now this Redwood/Maple sandwich will start the steps into becoming a real 5-string body

all the best,

R

[Greenman]

Originally Posted by Rodent

and here's the result - a body core with figured top where all of the glue lines are perfectly aligned




R

I've seen a lot of nice joints in my life and that is a smoker.

[pilotjones]

Originally Posted by Rodent

this is the beauty of a well detailed pair of mating surfaces and the right amount of glue. it doesn't take 200 tons of pressure to make the glue line disappear

here's a sandwich I assembled earlier this year. it was a two step process worked over the course of two days, with one outer Redwood panel and accent line added to the flame maple core in each session



about two weeks from now this Redwood/Maple sandwich will start the steps into becoming a real 5-string body

all the best,

R

That's a right pretty cross section.

[Rodent]

back from the CNC shop ...



not only is the neck pocket cut with exacting precision when utilizing a CNC, but I can also compensate the bottom pocket face to include the slight angle that is usually accounted for by adding a neck shim. it's far better to account for this when machining the neck pocket, because I can ensure that the neck is mounted flush into the pocket and that the energy transfer is not disrupted. the physical amount equates to around 1/64" difference front to back ... small enough that it's difficult to consistently cut to exacting tolerances utilizing just a hand-held router and templates

now it's time to get busy on the body outline, pickup & control cavities, and forearm & gut-cut contours


for some time now I've been leaning towards this body Honeyburst, but Cherryburst and a Vintage 2-tone burst are beginning to run fairly close behind

all the best,

R

[Rodent]

more progress ...

body contour has been rough cut with a bandsaw, keeping within about .06" excess to be sanded in the next step



then it's over to the oscillating spindle sander for a game of chase the line the idead is to take light passes over a long length to work your way to the center of the body contour outline. a millisecond too long in one place or too hard of a push and you get small cupped spots



these cupped spots are only a couple .001" deeper than the surrounding wood, but you can feel them when you quickly run your fingers along the edge. rubbing the edge with chalk and then hitting the high spots with some sandpaper hepls to reveal where these cups are. I use a semi-flexible sanding pad to hand detail the body edge to eliminate any cupping ... I also will pass my fingers along very quickly to identify any unevenness or flat spots in the outer contour



once I have the outer contour fully detailed, the body can be moved onwards to the next steps. here's a peek at how this body is starting to look like a bass and no longer like just a bunch of wood



all the best,

R