Headstock with custom abalone-inlaid truss rod cover.
closeup of pickup rings
Once the finish was sufficiently cured, I spent an afternoon sanding and buffing it out. This part I generally dread as I’m always anxious about sanding through the finish. No matter how slowly I go, when you’re wet sanding, the finish usually looks fine until after you remove the sandpaper and dry it off. Only then do the dull or faded spots appear.
This guitar’s finish isn’t flawless, and I was unable to attain the mirror-like sheen all the way around as I wanted. If there were time before the big raffle I’d apply another few coats and buff this out again. That said, the instrument itself came out well and plays very well after I set it up.
As I’ve done for the past few guitars, I crafted the nut from a sample block of black Corian. This stuff really works great and polishes up nicely as well. This time instead of simply measuring for the strings, I used the CNC to cut me a string spacing gauge. Another great use of a CNC machine – tool making. Time to wire her up!
Just like the Double Cat it’s based on this guitar features a P90 in the neck position and a humbucker at the bridge. For controls it keeps things simple with a single volume control, tone control, and 3-way pup selector switch. I prefer it simple like this. On my personal Surfcaster build I added a push-pull switch on the volume control that flips from parallel to series wiring. This effectively acts as a booster and works really well. But beyond something like that, I’m all about the KISS principle.
I found a wiring diagram that purports to be for the Double Cat and decided I’d use this as my guide. It features 3 separate caps of different values and some interesting wiring of the humbucker. The results worked, though I’m a bit disappointed at the tonal variety — there’s not much difference between the tone in the first (neck-only) and second (neck+bridge) selector positions. The tone is great. I played for about an hour ranging from clean tones to metal and feel this guitar can cover the range nicely. I may however review the wiring and test out a few different capacitor options to see if I can get a bit more variety.
I managed to get some video (see below) of my son and the guitar player from my band testing out the Dragon. Not the best quality or their best work, but gives at least a sense of the guitar’s tone. You’ll have to take my word on the sound quality for heavier rock…definitely achieves a beefier tone when called upon.
After a quick trip to the photographer for its “glamour shots” it was time to bring this baby into the office and put it on display. Raffle tickets are on sale with the winner chosen from the stage at the Chicago House of Blues on December 14th.
Finished cutting, lightly sanded before removing from CNC
Sanding the pickup ring
Abalone inlay pieces cut out, waiting to be installed in the pickup rings
Completed pickup rings
Back when I first acquired the CNC, I also purchased some sheets of thin plywood, vinyl, and aluminum of varying thickness. My plan was to experiment with cutting these materials immediately after assembly to learn just what it could — and couldn’t — do. I instead wound up diving headlong into cutting wood and building guitar bodies. The aluminum sat idle in a corner for the better part of a year.
In considering the options for the Double Dragon hardware, I looked around at my stock of pearloid pickguard sheets, black and white acrylic, and wood, until my eyes set on the 1/8″ aluminum stock. After some time reviewing videos and reading articles on aluminum milling it was time to give it a go.
Dialing it in
I learned early on that aluminum is far touchier and less forgiving than wood. THe 1/8″ endmill was definitely up to the task, however my earliest cuts were too deep, resulting in poor performance and finally a broken bit. Subsequent attempts succeeded in making a usable part, however the bit pulled up long ribbons of material and generated signficant heat. I responded by slowing down my feed rate. Further research indicated this was probably the exact opposite of what was needed here to produce nice, small, heat-dissapating chips. I limped through cutting the pickguard with this process. The end result is solid, but it required significant sanding and cleanup.
The smaller pickup rings required more precision to get the inlay edges right, so I would need to get this process a bit more refined. In the end I found that I could get much better results with very shallow passes — around .002″ or less — at a high feed rate (sorry, don’t have the rates I used handy). The 1/4″ 2-flute bit used for final cutout did an amazing job at ejecting nice aluminum chips and leaving a clean and shiny cut edge. The 1/8″ bits weren’t quite as perfect, but the results I managed with these bits was ultimately safisfactory.
I thought it would be a nice touch to add some “bling” to these pickup rings. As usual, I used doubled-up lengths of blue 2″ masking tape on the waste board and then CA glued the abalone to that. My 1/16″ coated Kodiak endmill has no trouble cutting shell in the past and this time was no exception. Once these were cut, they were glued into place with thin CA and the assemply mounted to a jig for sanding.
At first I was thinking I might powder-coat the aluminum. I bought a poweder-coating system several months ago and was looking for a project to try it out on. However, I couldn’t find a color I liked. Chrome seemed a good option, though maybe too shiny for the pick guard. I decided to sand these down with ever finer grits of sandpaper and basically stop whenever I liked the result. 1500 was the winner — it resulted in a very smooth and clean, yet matte, finish.
I applied a few coats of spray poly for protection and set them aside until it was time for installation.
Once the guitar was out of the clamps with the neck permanently secured, it was time for finishing it up. The neck joint was flushed with scrapers and sandpaper, and the entire guitar was given a good sanding down to 220. I’d already applied some finish to the inside of the sound hole and so this area was stuffed with paper to prevent any dye from dripping inside.
I spent a long while contemplating the finish on this guitar. Duesenberg offers the Double Cat in a Fire-burst (yellow-red) and black gloss paint finish. I considered red for this guitar, but was thinking I wanted something a bit different. Originally I tried a blue-green burst, but I couldn’t get it quite right.
Ultimately I settled on a yellow-green “dragon’s breath” finish ala PRS. I wound up applying, sanding off, and reapplying a few times until I was reasonably satisfied with the result. As anticipated, the Maple neck proved the most troublesome as Maple tends to blotch. I considered keeping the neck natural, but I didn’t think that would look right either. I’m not sure I’d repeat this finish without some additional experimentation and tweaks. In the end, however, after much fussing, I was happy with the back and satisfied with the cap.
Tru-Oil vs. Formby’s
For my last 3 or 4 guitars, I’ve hand-rubbed around 20 coats of Homer Formby’s “Tung Oil Finish”. I’ve been reasonably pleased with the results. However I haven’t seen or met any others using this finish. Almost to a person they’re using Tru-Oil. I decided for this guitar I would give it a try. It’s slightly cheaper than Homer Formby’s and readily available.
Once the dye had sufficiently dried, I began hand-rubbing on layers of Tru-Oil. As usual, I applied roughly 15 coats of finish to the guitar. Here’s where I should’ve read the directions. I rubbed it on similar to how I’ve used Homer Formby’s in the past. What I failed to do with this one is to apply a very heavy first coat and wipe it completely off the surface. Instead I wiped thin coats on, allowed them to dry, and scuff sanded between.
In the end this required significant wet sanding to level everything off. The Tru-Oil didn’t seem to sand as well for me as the Homer’s. I was able to buff out the back fairly well, but spent considerable time again fussing with the top. The end result is more of a semi-gloss finish than the high-gloss I was aiming for. However I was concerned that I’d wind up buffing through if I continued, and this guitar is on a tight deadline. If I’ve some time before the big give-away, I’ll work on rubbing in another coat or two of finish.
For now, its time to let this one sit for a bit and then install the hardware and hear how she sounds!
The CNC cut a 3-degree angled neck pocket on its final pass. The bottom of the pocket came out great. Unfortunately I screwed up the top edge, which came out rough. Thankfully this wasn’t a huge issue – I pulled out my neck pocket routing jig and manually cleaned up the top. CNCs are great tools, but they’re not “drop the wood in and press the button” easy…there are still plenty of ways to wind up with firewood.
Neck and fretboard
The neck blank was glued-up while the body was being cut out, and so it was time to cut the matching tenon. I’ve never had great luck with getting perfect alignment here, definitely requires patience, planning, and the right touch. For this guitar, the tenon fit snug – requiring a bit of scraping to fine tune. I was left with a small gap on the bottom angled toward one side. I fussed a bit with the tenon, but in the end resorted to gluing a shim in place to close the gap. Hopefully I’ll get this perfect on the next one. Thankfully it’s merely cosmetic and won’t effect the durability, playability, or tone. Once dyed it should be barely noticable by a careful observer.
I let the CNC cut the fretboard and route out the inlay pockets and matching mother-of-pearl. I’ve done this by hand before, and while the pockets aren’t that bad, hand-cutting tiny MOP pieces is a major headache. Cutting the stuff with a jeweler’s saw is pretty easy; holding onto the tiny pieces during and after is the hard part. I’ve successfully cut numerous tiny bits of abalone and pearl only to lose them in the sawdust on the floor afterward. All it takes is a poorly-timed exhale and the piece is lost forever. Frustrating!
Next it was the usual – route out a channel for the truss rod, press in the fret wire, and glue the fretboard in place.
Carving the neck profile
Now for the fun bit, and the part that I feel has the greatest impact on playabilty — carving the neck profile. This neck is significantly different from the previous 3 bolt ons. This neck features a curved heel and a quasi volute. First step was roughing out the blank on the bandsaw.
From there it was all hand tools — gouges, chisels, rasps, files, and cabinet scrapers. I own a spokeshave, but have never really had much luck with it. I typically will mark the center line and then use a course rasp to make a shallow “V” profile from the center to the edge. Once I manage to work all the way down the neck, from the center line to the fretboard, I’ll switch to a finer rasp, file, or scraper. I’ve used a small hand plane as well with mixed results.
In this case, I also needed to carve out the heel. Carefully following the pencil line, I used a “V” gouge to define the heel curve. Then a combination of gouges and rasps to get the basic shape right.
This past summer at GAL 2017, I attended an interesting talk by Stephen Marchione on shaping necks by hand. One key takeaway was the measurement he uses for neck thickness at the first fret. It was mainly geared towards acoustic guitars, but according to Stephen, the ideal measurement at the 1st fret is 22mm. He claims that this is a key to a neck that pretty much all players will like. I’ve used 19mm before on my favorite Telecaster build and that feels great to me, so I figured I’d essentially split the difference on this one.
Once I get past rasps and into scrapers, and finally sandpaper, I begin a process of frequently unclamping the neck and “trying it out.” There’s no better way than to guage the feel of a neck than actually running your hands up and down it. You can feel the smallest bumps and irregularities that may be difficult or impossible to see. I think this is where being a player can make a big difference.
Binding the body
Before mating the neck and body, the body binding needs to be installed. For this guitar I selected a faux abalone celluloid binding 5/16″ wide by about 1/16″ thick. I’ve been using Stewmac’s Bind-ALL for this purpose fairly successfully, though I’ve been considering trying plain acetone as I’ve seen other luthiers use.
The acetone is a solvent for the celluloid and effectively melts the surface which welds it into the wood. However, it takes longer to adhere and requires more tape and a closer eye on the process as I can imagine the binding shifting behind you as your progress. However, excess Bind-ALL can soak into the wood and make it very difficult to get a good finish. If you don’t wipe, scrape, sand off ALL of the cement, you wind up with nasty splotches near the binding that won’t accept any stain or finish. Ask me how I know.
The stuff’s also very messy to work with. Ultimately though, I chose the Bind-ALL once again for better or worse and will be diligent in removing any and all squeeze-out.
Body, meet neck
The glue-in process was pretty straightforward — apply glue, slide the neck into position ensuring a tight, close fit, then clamp. Time for some sanding, finish work, and the electronics.
Body blanks glued up. Ash in the fore is for the Double Cat. Upper left is the blank for the all-Mahogany Double Cat. The upper-middle piece is Alder for a Telecaster body I cut for a coworker.
Maple burl cap bookmatched pieces glued up.
Foam carved on CNC to test model
Cutting the Ash body blank
Selecting the cap grain
After a summer-long hiatus, it was time to get back into the shop for the next guitar project. I needed to build the next charity guitar for our 4th annual guitar raffle to benefit Make-a-Wish. The first of these was a copy of a Gibson SG Junior in 2014. Last year’s guitar was a Charvel Surfcaster dubbed the “Wishcaster.” Including a generous company match, we’ve raised and donated $18,000 to Make-a-Wish Illinois. This year I’m hoping we can double our previous 3 year total.
I keep a couple guitar “encyclopedias” at my desk at work that I like to peruse on occasion, looking for interesting designs to either copy or inspire my own custom work. Over the summer I discovered Duesenberg guitars’ “Double Cat” and fell instantly in love with the design. If you’ve seen my recent stuff, you’ve no doubt noticed I have an affinity for semi-hollows. This is mainly for the visual aesthetic – I just love the look of this style. And the Double Cat is a real looker. I assume it derives its name from the combination of the double cutaway body and the single cat’s eye sound hole in the upper bout. Naturally it’s a semi-hollow. But I was also drawn to the Bigsby-style tremolo and the combination of P90 neck pickup with a humbucker at the bridge. What unique tones this thing must produce!
The trickiest bit to this build would definitely be in the neck/body joint. It would need to be angled due to the tune-o-matic style bridge. And the double cutaway style means there’s a relatively long tenon that would need to be cut SG-style, with a long shoulder extending from the 19th or 20th fret to the 16th fret.
Unlike last year’s Surfcaster, I was unable to locate any measured drawings online for this guitar. Instead I used photos, the largest I could find with the most direct top-down view. Importing this into CorelDraw, and taking note of the advertised 25.5″ scale length, I was able to scale the drawing and adjust as much as possible for distortion. This was digitally traced, manually cleaned up, and finally tweaked until I was happy. The hardware was placed appropriately in the drawing to locate the holes and everything was organized into layers to be imported into Cut2D for generating the toolpaths for the CNC.
Because this is a semihollow, I also added reference holes in each corner to allow me to both flip the part over and cut the top and base independently. Dowels are inserted into these reference holes on the waste board, main body blank, and Maple burl cap to keep everything properly positioned in relation to the CNC home coordinates.
Cutting it out
Once I was satisfied with the model, a full-size version was cut from stiff insulating foam to confirm. At this point the waste board is attached to the bed, reference holes cut, and then the prepared body blank cut on the CNC. The Ash body for this guitar is fairly heavy, so an additional chamber was cut on the lower bout for extra weight relief. I cut an acrylic template of the top to aid in selecting the best grain orientation of the maple burl cap. One of the coolest things about having a CNC is how easy and fast it is to make a perfectly accurate template like this.
I married the Maple cap to the Ash base, and once the glue dried, brought the entire assembly back to the CNC for a final route. The CNC was used to cut the pickup and electronics pockets, plus the holes for the bridge posts. It cut the channel for the binding as well. Finally, the neck mortisse was cleared out at a 3-degree angle.
While I was at it, I repeated the process with a solid Mahogany version. Next up: binding the body and start on the neck.
We have an annual tradition in our house of making a “summer fun list.” Towards the end of the school year, we all sit down and take turns coming up with activities we’d like to do during summer vacation. The list usually includes stuff like “Picnic” or “Christmas in July” or “Sundae Sunday.” This year two of the ideas listed were “Build a Guitar Day” and “Wacky Instruments Day.”
Now shop day is a common thing in our house – on a rainy weekend day when the shop’s fairly clean and not packed with half-completed projects, the kids and I will dream up a project or two and work on them together. We’ve used this time in the past to build simple musical instruments like cajons and “canjos.” This time I figured we’d cross both items off and work on a “wacky guitar” together in the shop. Originally I had assumed we’d do something with PVC pipes or other atypical material. But after some discussion, we decided that what our basement music room really needed was a lap steel guitar. So we decided to build a “wacky” one.
Off to the shop…
The kids and I selected a nice Ash board, some leftover guitar parts including a humbucker pickup, fender-style bridge, 6 inline tuners and set to work. The concept was “Pegasus” – though as you can see it’s more impressionist than realism. They drew the outline together and each child selected one bit to paint.
I was seriously impressed at the way they worked together on this with very little conflict or disagreement. And the end result is a true work of playable art!
I can’t wait for our next group project.
pickup and electronics cavities routed
Nate taking a turn at the sander
They collectively decided on a design and then divided the painting duties up into sections for each to paint
After a few false starts, first with the headstock finish, next with the body, I finally managed to wrap this project up. I’ve been playing it for a few weeks now at rehearsal and plan to play it in my next gig. Here are the glamour shots fresh from the photographer.
Body: Sapele base with Maple Burl cap; black binding on top of body and sound holes.
Neck: Maple, hand carved profile; 25.5” scale length
Fingerboard: Birdseye Maple with Abalone fret markers
Finish: Black/Yellow/Red dye with hand-rubbed high gloss Tung Oil top coats
Pickups: Fender N3 Noiseless
While the finish was curing on my latest guitar project … and while I worked out how to fix some issues with inadvertant overspray … I turned my attention to another interest: electronics.
The kids and I have been playing around lately with Arduino. OK, well mostly me, but I’ve managed to catch the interest of my 10 year old son, with whom I prototyped a rudimentary “guitar tuner” using a nano, piezo, and several push buttons. My 11 year old daughter’s caught the bug as well, or should I say the mouse as we’ve been working on an analog project “Mousey the Junkbot,” though thus far without much success.
In any case, I’ve been itching to try out PCB engraving – or “isolation milling” on the CNC machine. If you’re not familiar, this is basically the process of creating a circuit board from raw copper clad board by removing the negative bits between the traces you want, thereby isolating the lines you need from one another. This may be done on a CNC machine with a very fine engraving bit – many sold specifically for this purpose.
Being a newbie to PCB design and fabrication, I naturally turned to the Internet for advice. I found numerous options and tried several of them. In the end I managed to cut a few good boards, with some headaches and false starts along the way.
This is one of the first programs I discovered while learning Arduino. It’s free and boasts an attractive UI. My initial design for the circuit used a 2-digit 7-segment display, which wasn’t available in the Fritzing parts inventory. I attempted to create one of my own and found the process frustrating. I also experienced some UI issues with the parts library dissappearing and overall sluggish program response. I was also hoping to find a way to simulate my circuit so I could work on it while I was on vacation or simply commuting between work and home. And so, I kept searching.
Next I stumbled upon this pretty amazing site by Autodesk. Here you can virtually prototype and simulate your circuit designs. It even allows users to develop Arduino code that executes in the simulated environment. I was able to build my prototype circuit, test out the code and ensure I wasn’t going to blow things up. While this all works well, there are still some issues. First, the site is sloooooooow. I realize it’s doing a lot, but at times it’s completely unusable, especially when I’m mobile. The inventory of available parts is also fairly limited. Considering the fact that every part in the system needs to be coded to work within a simulation, this isn’t surprising. However, I found it odd that there was a common anode 7-segment display, but not a corresponding common cathode version…which is basically the same thing but in reverse. This was very inconvenient as I had common cathode displays on hand and wasn’t about to purchase a replacement just because it wasn’t simulatable within circuits.io. I wound up designing and testing the circuit on the website using the common anode version of the part, and then cloning the project and reconnecting the common pin to ground in order to design the PCB board. I also ran into a few odd bugs – one of which necessitated deleting the project at one point and starting over. My posts to the support site to this day have remained unacknowledged. Sigh.
Simulating a 2-digit 7-segment LED circuit
That said, I did manage to design a PCB board, export the Gerber files for it, and upload these to OSH Park. I immediately ordered 3 boards from there for <$20 and, while awaiting these, continued my tool search to see if I could find a tool I could use to mill my own boards.
There is an option on the circuits.io site to “Export Eagle Board,” however it never actually worked for me. No matter which design I used (and I tried some very basic ones), the site gave me an error saying it was unable to connect to the service. Clearly this feature is broken and there doesn’t seem to be any urgency to supporting this site. I searched around instead for a way to convert the downloaded Gerber files into usable CNC gcode. For this I found pcb2gcode and pcb2codeGUI.
My first try looked very pretty but suffered from some incomplete traces. I was also struck by just how tiny it was! Looking at it on screen for a few days I never got the sense of just how tiny these lines were. But once cut into a PCB I required magnifiers to verify the traces. I had set the depth a bit too shallow and hadn’t compensated for variations in thickness/level of the board on the CNC. I tweaked the gcode Z value and tried again. This time the board looked good, but the traces were too narrow in spots and there were incomplete routes. I also wasn’t sure how I could solder these connections. The traces passed so close to the connection points that I didn’t feel I could keep my solder work from shorting some of them out. I tested this out anyway and decided I really did need to make myself some more room.
After several attempts at getting this right using circuits.io and pcb2gcode, I decided I should invest some time reviewing and hopefully learning “Eagle.”
Another Autodesk product/acquisition, Eagle is the old dog in EDA (Electronic Design Automation) software. It was developed in the late 80’s and the UI hasn’t apparently seen many changes since. Wherever I looked around for info on circuit design, Eagle kept appearing. Clearly this was one of – if not the – industry-standard EDA tool available today. It took a bit to get a feel for the rather clunkly and clumsy UI, but once I managed to get the hang of it…well, so I still haven’t totally gotten the hang of it, but I am many times better with it now than when I initially picked it up. It really would benefit from a major UI overhaul by Autodesk, though I imagine they’d need to maintain some degree of backward compatibility for those with years – if not decades – of practice with the existing interface.
Circuit design for 2-digit display module
I really liked the schematics I was able to produce with this tool. There are also libraries avialable for just about any part you could want. Many of them contributed by users and posted to Github. Most of the “maker” retailers have made their components freely avaialble as Eagle libraries as well. I drew up the schematic based on the simluation circuit from circuits.io (so I knew it would work) and switched to the PCB view.
PCB design for 2-digit display
I played a bit with the autorouter, which helped me visualize some routing options. However, in the end I wound up routing nearly all of my own traces. There are some idiocyncrasies with routing that continue to bug me – like how sometimes it wants to snap to odd paths when there’s definitely enough clearance to go the more direct route. I’ve wound up fighting the tool on more than one ocassion. After a few scrapped designs, I was able to create a pretty decent looking board.
The next step was to turn this into usable G-code for my CNC. The plugin that kept turning up was “pcb-gcode“. This ULP (user level program) runs within Eagle and provides a GUI that you can work with to produce g-code appropriate for your particular machine. After some toying around, I managed to export some gcode that looked pretty good in the UCCNC software used by my stepcraft CNC machine.
At this point I’m on my 5th or so board and have been getting fairly consistent results with trace widths of 1.27mm and a z-depth of .03mm. It’s still somewhat challenging to solder some of the connections due to the proximity of the traces, but with some patience I’ve been able to get them to work properly.
So far I’ve assembled 4 2-digit boards – 3 using the OSHPark factory boards and 1 with my own shop-milled PCB. I’ve also successfully milled the main controller board and have tested the final assembly with a simple counter program. It works!
Design lead Matty Martin providing demonstrations and usage tips to visitors.
Shaper HQ in SF
The unit I was able to try out.
When I was first searching for a CNC to add to my shop, I ran across an odd tool called the Shaper Origin. The tool was in essence a self-correcting router that works like a hand-held CNC machine. I spent some time watching the videos on their site and reading through the blog. It was a novel idea, though it wasn’t quite ready to ship (as I write the the first batch is slated to ship Fall 2017) and not really what I wanted/needed for guitar work. Still, it seemed absolutely incredible. Unbelievable really. Could such a thing really work?
These weren’t the sort of directions I was looking for, but I decided it best not ignore the advice of a beat cop.
Fast-forward to late February when I receive an email invitation (I had signed up on their mailing list, natch!) to come see a “private demo” and get a chance to actually try out the tool in their San Francisco HQ. Because I live in Chicago, this normally would have been filed away with a sigh. However, as luck would have it, I was signed up to attend the Strata + Hadoop World conference in San Jose that same week. To top it off, the demo was scheduled for 6pm on the last day of the conference (which ended by 5pm).
Done deal…sign me up!
On Thursday, March 16th, I rushed out of the conference a bit early to catch one of the evening express Caltrain’s up north to SF. Following advice I’d requested and recieved via email from the fine folks at Shaper, I transferred to a BART at Millbrae, taking that train up to 16th Street Mission station. I emerged from the BART via a fairly formidible flight of stairs, and immediately noticed a pair of SF’s finest watching over the active plaza.
“Can you tell me where Shotwell is?,” I asked. The initial look on their faces left me a bit uneasy. “What’s on Shotwell?” the male officer queried, shooting a sideways glance at his female partner. “Umm…a tool company” I replied.
Pointing down the street over my right shoulder, he proceeds to inform me it’s a couple blocks “that way” and that I should be sure to keep both straps of my backpack over my shoulders and not to walk around with my phone in my hand. These weren’t the sort of directions I was looking for, but I decided it best not ignore the advice of a beat cop.
Shotwell street – this block anyway – is basically industrial and not really intimidating. There’re typical buildings and a fenced-in parking lot across the street from Shaper HQ. Following a simple note taped to the door at 274 Shotwell, I walked on a bit until coming upon a small open garage bay. Inside were a handful of folks milling about (it was a bit before the 6pm start time – at least I think it was as I didn’t dare take my phone out of my pocket to look.)
I quickly slide the machine to the side to get a closer look at the point where the start and end of the circle met. My eyes and fingers couldn’t find any variation.
The shop is small and very cool. Next to a couple metal buckets of beer sat a table hosting the history of the Shaper Origin from initial prototype to its current inception. In the middle of the shop a live online demo was taking place. I watched the tail end of this before moving closer to the main work bench where Matty started putting the machine through paces.
Wow. It really did seem to work like their videos. He cut pockets in the form of some basic numerals – something like you might see on a mailbox or sign. We were then invited to give it a try. Someone cut the state of California. Another cleared out a pocket. When it was my turn, I opted to do something simple – a circle. Matty assisted with navigating the menus and I was able to set the diameter by clicking on the screen and dragging the tool outward until it reached the desired size – which was also displayed in decimal inches in the corner of the display.
The thing that struck me right away was the display also remembered all the other shapes that had recently been cut for earlier demos. These were outlined on the screen and couldn’t be missed. So I was easily able to specify a circle that would inscribe the various bits that had already been more or less randomly cut on the board. I could easily guarantee I wouldn’t run into a line at any point on my circle. Very very cool.
To operate I just turned on the trim router, (I was told the shipping version boasts a custom spindle with switched power from the unit itself), pressed the green button on the right handle, and followed the path on the screen. I purposely pushed it a bit, seeing just how fast I could comfortably cut with this thing and still track close to the line. In fact, I found myself playing a little game in my head – just how close could I track?
I closed the circle, pressed the red button to stop the machine and turned off the spindle. I quickly slid the machine to the side to get a closer look at the point where the start and end of the circle met. My eyes and fingers couldn’t find any variation. They appeared to meet perfectly, or at least close enough for any woodworking job I’d ever do.
This thing rocks
In conclusion, this machine really, really, works. I mean, it feels great, it cuts smoothly, the screen is responsive and bright, and it feels rugged enough for real use in a real shop. I could see myself using this to cut down large sheets of plywood in the garage to maximize yield while minizing strain of hauling them to the table saw.
And for any simple shapes you want to cut quickly, damn this would be incredible. I could cut out 10 perfect circles of varying sizes faster than I could find, install, and setup my circle-cutting jig on the router or band saw. And then there are the oddball polygons, curves, etc. For making fast jigs this thing would rock. If the price is right (and right now it’s rather pricey), this tool seems poised to launch a revolution in the average weekend warriors’ shop. If they can get the volume up and costs down to under $1,000 I could see this being the only cutting tool an average homeowner would need to have in their shop for common household stuff. Heck, for $1,000 I’d buy one to have on hand even though I’ve already got a shop full of tools and decent CNC.
I shot some video of Matty from Shaper guiding one of the visitors as he put it through paces:
Closeup of the back of the headstock after carving
The completed fretboard
Closeup of the binary inlays
For this guitar I wanted to do something a bit different for the fret markers. Though I considered a somewhat elaborate inlay like the previous two, for this one I was thinking of something a bit simpler and unique. As I’m in software engineering I’d been toying with the idea of essentially labeling the fret markers with their binary equivalents. For example, in binary the number 3 would be represented as ‘0011’, the number 5 is ‘0101’. I didn’t want anything quite that blatant — in fact the goal was to do it in a way that you’d never realize it was binary unless you were told.
After a couple hours sketching on the computer and playing with several ideas, I had a basic design. I used circles for 0 and rectangular shapes for the 1’s. To keep this looking good I would use only the left-most 4 bits (a nibble) and trim leading 0’s. For fret markers above 12, I decided for aesthetic reasons to recycle and use 5 for 15, 7 for 17, though upon further reflection perhaps it would have been more appropriate to start with ‘3’ again since this is a new octave? Either way I think it works very well.
This was the first time I used the CNC to cut shell, and it turned out to be easy, fast, and of course accurate. I purchased some cheap Chinese Ti-coated 3/64″ “rotary burrs” which looked like they’d do the job. I first tried holding the small 3/4″ square pieces of shell down to a scrap of MDF with CA glue and a slip of white paper between the shell and the MDF. The cut went great but removing the cut pieces turned out to be problematic – a couple of the pieces broke as I attempted to pry them off. Next I tried 2 layers of blue masking tape laid on top of the MDF and CA glued the shell to the tape. This worked perfectly. It held solidly in the machine and when done I was able to peel back the tape and remove the shell. I gave the pieces an acetone bath which freed them from any remaining tape. This will save tons of time and frankly make it possible for me to cut these very small shapes that I otherwise haven’t been able to do by hand.
The rest of the process went smoothly — sanding the 9.5″ radius, installing and filing the frets, etc. Once again I carved the neck, starting with a course file and progressing gradually down to finer files, card scrapers, and ultimately sand paper. The neck measures about 19.36mm thick at the 12th fret and is about as consistent as I can make it by hand, varying well under 1mm. This is nearly 1mm thinner than the example Fender Squier strat I was using for reference — though ultimately my reference is feel. As it gets down to the approximate final shape and size I tend to stop frequently and test fret positions for feel until I’m satisfied that it will play comfortably.
At some point I’m expecting to cut some profile templates to use for reference instead. These would be primarily for shaping necks to client specifications rather than to my own personal preference. But for now, this ‘by feel’ method has produced happy results based on feedback from other players, so I’m sticking to it for the time being.
I managed to complete 20 coats of hand-wiped poly clear coat on the body while finishing up the neck. Next up is sanding and polishing it up before final assembly and setup.
This one’s nearly in the books and ready for its first gig!