Guitar build number three...

[Jim Becker]

Tele at heart when it comes to the metrics, but I wanted to do something that was "mine" to go with the neck/headstock design I had been noodling with. And what a nice way to leverage a 360mm wide hunk of sapele that I picked up last summer while at a sign-making training class down in Suffolk VA. https://www.tdpri.com/styles/default/xenforo/clear.png

So I came up with a double cut with a top contour that favors arm relief like a Strat and with a belly cut. Both serve for weight reduction, too. The cuts and contours were done using Vectric's molding tool paths that Alex Navaro featured in a video not long ago...a little easier than modeling them in 3D and faster, more efficient when cutting. This one is for humbuckers, but I can easily flip the design to Tele-style single coils. This is designed for two-sided machining.

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I cut the back side first which includes a slight round-over for the edge, the ferrule recesses, the control pocket and recess for the cover and for this design, the belly and horn relief cuts

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Then the top gets cut.

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It's important to note that the CNC is just cutting out the body in the same way one would do it manually. It still needs the same refinement and hand work to complete the job. The big advantage to using the CNC is it removes some of the drudgery work, adds consistency and most importantly for a "new" design, provides the ability to visualize things and work out details before a single piece of expensive wood gets touched.

I did a little sanding on the contours before releasing the body from the waste because it held things flat and stable. From there, all of the machining marks were removed from the top and bottom with 80 grit on my ROS. The body still needs to get the edges treated at the OSS once I have a large table project out of the way and then a whole lot more sanding to get it where it needs to be. But here are some photos that illustrate the design and contouring I ended up with this first iteration of the design.

(just wiped down with DNA, which is why there may be some color spots)

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[Jim Becker]

Control cover on the back fits nicely

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And here are views of the "package" with the neck mock up design

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I think this is going to look great when it's completed. Hopefully, it will sound nice, too. ;)

[Paul F Franklin]

Another winner Jim! What are your finishing plans?

[Jim Becker]

Another winner Jim! What are your finishing plans?

Still up in the air, Paul, but the sapele will be the feature. I may cut the neck from it, too, and I have some various types of rosewood as well as some interesting koa available for the fretboard. Still mulling things over. Whatever I choose has to also translate in the matching bass I have planned with the same body and headstock shape. :)

[Jim Becker]

I decided to go with sapele for the neck for this instrument and cut that today while I was waiting for glue to dry on another project. To add a splash of interest, I added a "skunk stripe" to the back of the neck. One thing I did different while cutting the back contour was to do the "finish cut" tool path across the neck rather than parallel to it this time. Oh my...major difference an increase in quality due to the way that ball nose bits become less efficient on the vertical sides of an object. There will be a whole lot less scraping and sanding required for the back of this neck!

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[David Falkner]

Another good looking build, Jim! How long did each take to cut - body and neck?

David

[Jim Becker]

David, I forgot to note the cut times, but they were surprisingly quick despite the molding tool paths. I'd say the back of the body took maybe 15-20 minutes and the front about 30 minutes and that was only because of the repetitive cutting of the contours at a 9% step-over on a .5" ball nose. Top of the neck took about 12 minutes to cut. The back of the neck took about 40 minutes. That last one is significant...it would take many hours to do the same by hand to the same point of finish.

[Jim Becker]

With the shop changes completed, stuff put away and my remaining client work out the door, it was time to get back on this guitar build.

To start off, I cut the neck free and removed the tabs so I could test fit it to the body. This neck is also sapele with a little maple skunk stripe on the back. The fit is fine and I'm seriously considering making this a set neck so I can do some further sculpting on the back side of the heel/body for even better access to upper frets. I really do like the body shape and neck design together.

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I will certainly think a little more about that. In the meantime, it was time to cut a fretboard. I scored a nice piece of east Indian Rosewood at Hearne a few weeks ago and I think that the darker fretboard will really look nice on this instrument. So I cut a hunk off and re-sawed and thicknessed two fretboard blanks and set things up on the CNC. The wood has a really spicy smell to it...quite interesting.

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This rosewood species cuts really nicely and after a bit of time and a few tool changes, it actually looks like a fretboard. :)

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The surface off the machine is much nicer than the maple I've cut with the same file. Once it's sanded/scraped, it's going to positively glow

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For those wondering...this is what the tiny cutter looks like that does the fret slots... .023", three flute running at 18K RPM, 20 ips, five passes per slot. This tooling is from PreciseBits (Tinker and Tinker) in Colorado.

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Here's the fretboard with the edges cleaned and ready for assembling to the neck when I'm ready to do that task. It's cut slightly long at the headstock end so I can precisely trim it before blending into the sweep up from the headstock to the neck surface.

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Yea, I like this. A lot.

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[Jim Becker]

I decided to re-cut the neck for this build today...there were some things I just didn't like at the interface to the headstock and I wanted to move the break at the heel a little closer to the end of the neck pocket since I'm considering making this a set neck. The one I already cut will not go to waste as I have another body I'll likely mate it with where the things I don't feel work with this body will be less of an issue for me.

It was the same "put in the stripe"..."flip it and cut the top"..."flip it and cut the neck contour on the back" thing as last time. There was a slight onion skin because of a minor variation in thickness, but that sanded out while I was cutting it free from the blank.

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[Phil Mueller]

That’s going to look great, Jim. Kudos for the “redo”. It’s always a bit of head scratching for me to try to make something work without a redo...but once I get over it, I’m always happy I did.

I’m not familiar with CNC bits. Are small straight cutters like you show all “down cut”. The fret groove edges look pretty darn crisp.

[Jim Becker]

That’s going to look great, Jim. Kudos for the “redo”. It’s always a bit of head scratching for me to try to make something work without a redo...but once I get over it, I’m always happy I did.

I’m not familiar with CNC bits. Are small straight cutters like you show all “down cut”. The fret groove edges look pretty darn crisp.

I use both up cut and down cut tooling, depending on the job and the depth. I also use compression cutters which have up-cut at the tip and are otherwise downcut. These are ideal for sheet goods for clean edges and I also use them for pocketing boxes so that the top edge stays pristine while the swarf from the bottom of the cut gets moved upward enough that the dust collection can grab the chips without them getting packed in like they would with a down-cut. The tiny tooling for the fret slots is up-cut. The first pass is so shallow that the edge stays fine and would be hidden anyway by the fret wire, and you don't want to pack chips into the slot for something so delicate.

[Jim Becker]

Today I finally got the "dot" inlays into the fretboard for this build. They are "pearloid" (fake pearl) and look great. I used black CA which pretty much made the intersection between the inlays and the Indian Rosewood disappear. The fretboard was then "final" sanded and is ready for fretting. Interesting that this wood has a "cinnamon" smell do it while sanding, too.

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Oh, and to add a little bling to his instrument...I'm using gold fret wire. :)
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[Bruce Page]

It looks like the new bench is working out well. 20 ips? The .023 cutters are scary.

[Jim Becker]

It looks like the new bench is working out well. 20 ips? The .023 cutters are scary.
Yes, used it for the first time yesterday, although I had to flip around to the main bench for awhile because of sun coming in at a low angle through the slit window over the guitar bench. It's that time of year...and with the leaves gone, it can be blinding! The ~1000mm bench height is really perfect for this work, too. No back strain.

I was really surprised about being able to go 20 ips+ with that tiny cutter, but Ron at PreciesBits went over the math and he came up with 24 ips as reasonable for the bite I was taking at 18K rpm. I've become less conservative with some of the other small cutters I use for inlay pockets for a client now, too...

[Bruce Page]

I never would have thought that it could handle a feed rate that fast. The smallest I've used was 1/16 single flute when I had to cut a .100 deep X 4' long slot. I probably could have done it in 1/4 the time it took me.

[Jim Becker]

It's a balancing act between pushing too hard and causing lateral stress leading to breaking them off vs achieving proper chip load to throw off heat because as you know, heat kills cutters "reliably".

[Zachary Hoyt]

Is that EVO fret wire or something else? I've been using EVO for a while on most of my banjos because it matches the brass hardware and also is supposed to last a lot longer before having to be worked on, but I've never played an instrument enough to wear out any kind of fret wire so I don't know for sure that it really is a lot more durable than nickel-silver.

I'm always surprised that fret slots can be CNC cut at all without breaking the bits, but it seems to be a widespread thing nowadays. I'm extra surprised that you can go that fast. How many passes does the machine make to cut a fret slot the full depth? I am a dinosaur and still cut my slots with a small circular saw blade so I have no idea.

It's all looking great, good for you.
Zach

[Jim Becker]

Yes, that's Jescar EVO Gold, medium pre-radiused from Philadelphia Luther Tools and Supplies. Their prices for the pre-radiused stuff is far better than StewMac, etc., and it's never a problem finding enough stuff to quality for free shipping. LOL . My understanding is that this wire is a bit more durable and consequently a little harder to initially setup, but there's no harm in a challenge. :)

I'm doing the fret slots in 5 passes for 2mm depth...just faster than I was before having that conversation with the dude at Precise Bits that I mentioned. You can probably do a board faster with your circular blade setup if it's indexed, but I can do something else while my machine is cutting them. :) :D

[Zachary Hoyt]

It takes me about 5 minutes to mark the fret locations and another 5 to cut them, so I imagine that your CNC is faster than that, besides the advantage of not having to do it yourself. My slotting system isn't indexed, it's sort of like a miniature sawbuck, but that works better for me because I routinely am using several different scale lengths. I used to buy EVO from LMII but I found out that it's much cheaper to buy it directly from Jescar, at least in quantity. My last order was for 300 feet as I recall, and it should last me for another year or two. I would prefer to get it in straight lengths but it comes in a roll, about a 12" radius or so. Most of my banjos have flat fretboards and get EVO, which I have to flatten, and when I build guitars they get nickel-silver because I still have a lot left in a guitar size, but it's in flat 2' pieces and I have to radius it before putting it in.

[Jim Becker]

The machine cut is longer than ten minutes but not excessively so. And as I noted, I can be working on other things while it works. Since I'm not building in volume, I'm fine buying the pre-radiused cut fret wire for now, but if for some reason I start to build necks with any frequency, I'd probably get some form of radiusing tool and buy the wire in a roll.
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After spending the morning on design work for a client, I got a little bit of time in the shop this afternoon to work on this build. The short version is...fretted, dealt with the ends of the frets, did a lot of sanding on the neck and then glued the neck to the body. :D https://www.tdpri.com/styles/default/xenforo/clear.png Definitely looks something like a guitar now. LOL

Sinking them home...this went a lot faster and easier as "this time" the fretboard radius was dead-nuts on. I bought an appropriate radius sanding block which removed any variation while I was knocking down the dots. The fret press head is a knock-off from EBay (Elmer brand) and works extremely well for this.

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Nipped and abraded even to the edge of the fretboards...

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Taped and then dressed the fret ends...easier to do that while the neck was still free of the body, although they will probably need a little more refining.
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Final test fitting before glue...

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And....glue up. It was easiest to start here at the vice so I could have two hands available to insure it was seated exactly right while tightening the clamp with the other hand.
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After it set for about 45 minutes, I inverted it and cleaned off any glue squeeze out while it was still pliable
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Next steps include a whole bunch of finish sanding before coating this with a bunch of things to make it prettier.

[Phil Mueller]

Thanks for the follow along, Jim. Not sure a guitar build will be in my future, but appreciate seeing how it all goes together. Looking forward to seeing the finish on that wood...as I’m sure you are as well.

[Zachary Hoyt]

It looks great. I didn't realize that solidbody guitar necks were glued on. What kind of joint is used? I had had the impression that they were mostly either bolt-on or through necks, but I don't know why I thought that.
Zach

[Jim Becker]

It looks great. I didn't realize that solidbody guitar necks were glued on. What kind of joint is used? I had had the impression that they were mostly either bolt-on or through necks, but I don't know why I thought that.
Zach

Some necks are set (glued) and some are bolt on. Fender designs are primarily bolt on and Gibson designs are primarily set necks..."in general" and there are exceptions, especially on the Fender side. There are a lot of folks in the Fender world who swap necks around...Clapton's Telecaster with a Stratocaster neck is one noteworthy example. It is actually an advantage to the design beside the simple "no neck angle" metrics. This is no special joint for my project...it's a Fender design with a precise pocket. I decided to glue instead of bolt so I could sculpt the join of the neck to the body, particularly on the bottom horn side where one would be reaching for the upper frets. It gives more hand clearance. I'll be looking at the flex when I take it out of the clamp today and if I feel uncomfortable, I can always put a few hidden screws in...but PVA glue on a well fitted joint with a lot of aligned woodgrain surfaces makes for a very strong joint.

I'm thinking about doing a through neck at some point, but I want to take the time to properly figure out the cutting design to do it with the CNC. I'm not squeamish about adding complexity and challenges here! That's why I'm doing this...I really cannot play guitar very well at this point because of surgery on my left wrist a few years ago, not that I ever could play "well". (merely adequate to meet a need in a band I was in back in the 1980s and the same for bass in a summer band I was in during my collage years...I'm a keyboard person generally)

[Jim Becker]

I did a little more work today on this build...a LOT of sanding plus a little more attention to the fret ends as I was not happy with a few of them, drilling for the jack, masking off and then doing the first coat of Z-Poxy for grain filling the sapele.

The glue-up really went well and after sitting overnight. Solid.

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There was also that little operation to deal with where the jack goes before I proceeded to finishing steps. We'll start there. I'm using the nice looking metal inserts to hold the audio jack. The outer rim is 25mm/1", so the first step was to use a 25mm forstner bit to create a recess so that the rim sits flush with the body.

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This also provided the pilot point for running the 7/8" drill through to the control cavity...not shown.

After some more final sanding...and some more final sanding....oh, and a little more final sanding, I masked off the fretboard and the various recesses and holes in the body in preparation for finishing.

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And then slathered on the first coat of Z-Poxy to grain fill the sapele and start things on the way to what will hopefully be a very nice finish. The body and headstock will likely get at least one additional coat of Z-Poxy after it's sanded back, but I'm not going to do that on the back of the neck as I don't want to build that area up too much. The Target Coatings sealer will be more than enough in that area without additional resin. Since I did coat all the surfaces, I hung the instrument for the resin to cure. Any subsequent applications will go on "flat" so the resin can settle down on the faces. That will take more time because of waiting between front and back, but should result in a better surface. Dat color though... https://www.tdpri.com/styles/default/xenforo/clear.png https://www.tdpri.com/styles/default/xenforo/clear.png:) :D

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[Zachary Hoyt]

The finished wood is very pretty, and thanks for the explanation about necks. It seems like the neck-body joint would be quite strong the way you've made it, and the thick wood of a solid-body guitar should be much more stable than the box made of very thin wood and bracing so I would think that as long as the neck is firmly attached at the heel there's nothing else to have to worry about.
Zach

[Jim Becker]

Yes, it's really solid, Zach.
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Mucho sanding later, the Z-Poxy is flat and the grain is filled really nicely. The downside to a heavy coat is the amount of sanding, The upside is that I don't need to do it a second time, at least on this instrument. I got lucky for sure. I'm happy with the results...

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After a through cleaning, I shot a very light coat of de-waxed shellac to be able to confirm visually that everything is filled to my satisfaction. I'll hit that with some 400 or 600 to knock off any nibs or whatever and can then start on my clear coats.

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[Jim Becker]

Started shooting water borne "clear" today after going over the whole thing with 600 to knock off any nibs or dust from the light coat of wax-free shellac I put on last night to check things over. Target Coatings EM1000 sanding sealer is my first step here.

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I'm reasonably happy with that but I want to liven that sapele up a bit on the front of the guitar, so since I also was applying the same product on another body heavily tinted with Honey Amber dye as a first step to a burst, that got the nod on this guitar, too. Amber can really kick things up for mahogany and mahogany like species like sapele and is a common finishing step on some traditional furniture types that tend to be built from these species. It really brings out the special character of this wood. And yea...now I like it a whole lot!

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I'm going to do the same on the back and sides, but with a far darker effect...I don't want a "burst", but I want the front faces to stand out from the edges and back side. There will barely be some feathering at the edges if things go well.

[David Falkner]

The color is beautiful, Jim - beautiful!

David

[Jim Becker]

Got the back and sides toned darker and I really like how this is heading...

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And the logo applied...while I plan on doing these using brass inlays in the future, this one is painted using a mask

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[Phil Mueller]

Jim, the color is really nice. I look forward to the rest of the finish schedule. I assume it will be wet sanded/rubbed out at the end?

[Jim Becker]

Thanks, Phil. The Sapele is really looking nice, IMHO. I will say that finishing a guitar with a set neck is a lot harder than a bolt-on! As to your question, yes, once the finish settles down, it will be leveled and brought up though all the levels of micro mesh before buffing. The back of the neck will get knocked back from gloss to something more matte which is what most players prefer...gloss is too "sticky" for the back of the neck.

[Jim Becker]

I have all my clear coats on at this point...it will be "resting" for awhile and then it will be time for some "elbow grease" to level and refine the finish with Micromesh before buffing it out. So I'll be hanging it out of the way tomorrow to hopefully avoid any accidents between now and then. I also have most of the clear coats on the "refinished" build number two (burst) that did get damaged. I'm spraying the same finish on some boxes for a client's holiday order, so that body will be ready for micromesh and buffing at the same time as this guitar.

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Photos after overnight cure and masking removal...

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[Carl Beckett]

Jim, I am wondering what gun you are spraying with? HVLP gun?

Your work is always fantastic and this looks like a fair bit of orange peel on the finish. Am wondering if that is by design, but since you mentioned sanding and buffing it out by hand I am not sure. I bet you could get a smoother finish to start if desired.

[Jim Becker]

Carl, in the past year, encouraged by John T's positive comments, I upgraded to the QualSpray AM-6008 HVLP with the 3M PPS system. The latter provides a pressurized disposable container for the finish which in turn allows the gun to be held in pretty much any position including up-side-down. The "orange peel' is partly because of my aggressive use of the finish to build it up and my inexperience. It looks like more than it is, however, due to reflections, and it will be gone relatively quickly when I hit it with 800 and then work up through the micro mesh before buffing. I do believe that I'll eventually get to a better result "off the gun", but even so, it will still not eliminate the need to "finish the finish".

[Jim Becker]

Well...long time no visit with this one. CNC was cutting chair seats for a client, so I took the opportunity to FINALLY do the micro-mesh dance with this build. I'm pretty pleased with the end result, too.

I had a small amount of orange peel, so I started out with some 600 wet and dry (wet, of course) to level that away and provide a smooth surface to polish up with the micro-mesh.

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Let's just say that after this step, it's smooth but no longer looks as impressive. LOL And then we "do the thing"...from 1500 up to 12000.

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And end up with this...

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I'm liking that...

[David Falkner]

Looks great, Jim! Will you buff it out from where it is or leave as is? Personally, I like the sheen a bit less than the full on super high gloss but that super high gloss really catches your eye. Really nice figure in the body, too.

David

[Jim Becker]

I'm still debating on doing a polishing or not.

[Jim Becker]

I polished... :)

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[David Falkner]

And a fine job you did, Jim! Looks nice. What's next on this one?

David

[Jim Becker]

And a fine job you did, Jim! Looks nice. What's next on this one?

David

I had to order a different bridge for this build due to a miscalculation on the scale when I designed it...I now need a top-loader. Once that's here, I can do the final work on this instrument and hopefully, it will sound like a guitar. :) I have another build currently in progress that I haven't posted about..."brotherhood build" event in the TPDRI forum...a taste:

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[David Falkner]

Now THAT is going to be gorgeous!!

David

[Jim Becker]

Thanks, David. It's a clear white pine core capped front and back with Koa that I scarfed out of the $2 a pound bins at Hearne Hardwoods last fall. Double bound with black binding. And the body came in at an extremely light 3.155 lbs. (interior relieved)

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[David Falkner]

Not too bad at all, Jim. I just love Koa; my Takamine that I play in our Praise Band is an all Koa guitar and it's gorgeous.

Will this remain stable with the White Pine core? It's going to move differently than the Koa, I would imagine.

David

[Jim Becker]

The Koa is only 3mm thick "veneer". No worries.

[Jim Becker]

I have a bunch of setup work to do, but otherwise, this beast is built. Lined it with copper foil, replaced the jack with a Switchcraft that threaded into the Electrosocket jack mount properly, installed the tuners and got it strung up. Wow...I love locking tuners. Easiest I've ever had to go from unstrunk to in tune (prior to stretching) ever! Once I do the setup stuff, I'll get the "beauty shots" that the folks on the TPDRI guitar forum appreciate and will also post them here, too.

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[David Falkner]

Looks great, Jim! Nice guitar bench, too. So what does the copper foil do? My assumption is shielding but I'm an acoustic guy all the way so very little knowledge on this side of the fence.

David

[Jim Becker]

Yes, RF shielding to make things quieter. Even though the pickups on this particular build are "humbucking" designs, there is always the possibility for injecting noise. Shielding paint or foil tape with conductive adhesive helps deal with that. For instruments with single-coil type pickups (more traditional for Fender designs, for example) shielding is not optional in most cases. I have both the conductive paint and this foil product...this was the first time I tried the foil.

BTW, I have this instrument reasonably setup at this point with a little more fine tuning (pardon the pun) to go.

[Mark Rainey]

Gorgeous guitar Jim! Reminds me of a Paul Reed Smith guitar Carlos Santana plays. That should be a joy to play!

[Jim Becker]

Finally got a couple of outside photos of this build...

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[David Falkner]

That looks really nice, Jim! I like the small waist, too. But since I don't play electric that may be common...

David