Hello, dear friends of the Felder Group As promised, today we will show you another, very special application example of the new HAMMER CNC router. The professional production of a real "base guitar" that makes the heart of every musician beat faster. This wonderfully crafted piece, made by our master carpenter Helli, already had its premiere at a professional live performance. Professional in this context also means building the guitar itself. Why is professionalism so important? Firstly, we entrust the machine with a very expensive material such as ebony and curly maple and secondly, during the entire manufacturing process, the precision and repeatability are of enormous importance for a perfect end result. Even the slightest twists on the machine produce errors or inaccuracies and would lead to costly corrections – in many cases even to the complete destruction of the workpiece. This is particularly fatal when the processing steps, as with our guitar, build on one another, ie take place step by step.
And thirdly, the more precisely the machine works, especially with surfaces and curves, the less reworking, such as sanding and polishing, is. Take a look at how perfectly the production works – simple, uncompromising, solid, a masterpiece. The design of the base guitar and the processing of the cutting paths were created with the FUSION 360 software. The preview assists in creating a workflow concept that builds up in the most logical way possible and helps to identify and avoid errors. The finished "G-Code" was then imported into "EDING-CNC" which is the control software of the Hammer CNC router. The center point is marked, the end points at the sides result from glueing, since the guitar body is book-matched, meaning it is glued together exactly mirrored. The workpiece is moved into position in such a way that the cutter is positioned exactly above the center line. The tool zero point is located on the material underside during ALL work steps, preventing errors caused by changing zero points.
First, the cut-outs for the pickups are done. For this work step we recommend a depth adjustment of 2.5 mm per cycle. This value has proved to be best for cutting the tough flamed maple material. A depth adjustment of 2.5 mm is also used when cutting out the electronics pocket. Now the neck pocket is being cut. During all pocket milling operations, the machine runs alternately in synchronous and reverse mode. These results in the fastest processing time. The body outline is created, the classical jazz base shape is now visible for the first time. Milling is done up to the center of the material A very important working step: The reference holes for offset-free machining of the backside of the base guitar. These are molded into the 4 corners of the corpus. Here you can already see a part of the finishing touches. The outer rounding is machined with an 8 mm radius cutter.
This can also be done with a hand held router. However, with the HAMMER portal router, you can also mill the rounding on the armrest in 3 dimensions. The result: absolutely perfect – time-consuming rasp work and reworking are thus completely eliminated. For easier positioning of the hardware later, the screw connection positions are already slightly pre-drilled at this stage This saves tiresome measuring and positioning during assembly. In order to be able to work on the back of the guitar body, it must be repositioned exactly as before. For this purpose, 4 reference holes are first drilled into the MDF protective panel. The dowels help to position the workpiece precisely The reference holes previously machined on the corpus now allow for absolutely precise clamping on the backside.
We start with pre-milling the rib arch, which is also known as beer belly milling among guitar players. Since the back is made of alder wood, we apply an infeed of 3 mm per cutting operation. Rear holes for mounting the guitar neck. And now the body outline is cut out. You can clearly see the 4 bridges in the cutting path. These hold the workpiece in place and are later cut out manually. Using an 8 mm radius cutter, the rib arch recess is now fine-milled in 3 dimensions. Generally we recommend ALWAYS a tool length sensor for all height settings. Measuring errors are almost as good as certain and would lead to damaged tools, materials and machines.
Thanks to its solid build the Hammer CNC router provides an extremely high surface quality. Machine vibrations would otherwise be immediately visible here. The outer rounding on the back is also 3-dimensionally shaped. The 8 mm radius cutter therefore follows the previously defined contour exactly, even in depth. Master carpenter Helli is satisfied with the performance of his Hammer CNC spindle moulder. Out of an idea, a drawing, and a program, a perfectly shaped workpiece was created. Ready for the finishing touches. A template for the guitar neck is now made. The long neck of the base guitar only fits on the machine if it is worked diagonally. This is no problem for the Hammer CNC portal router. First the template mounting holes must be drilled. In order to be able to position these perfectly diagonally, the position was marked with a lettering cutter Because 2 holes are just outside the machining area we use a little trick.
First, we clamp the template in an assisted position so that the machine can reach all parts. The mounting holes fit "CNC Made" one hundred percent. For the processing of the neck, the template is now rotated into the machining position, which in turn has been marked beforehand with a lettering cutter. This "trick" enables the template to be screwed onto the groove table and all further processing steps on the neck. The machining steps have all been programmed in "FUSION 360" as normal, ie straight, and can now be rotated as needed on the machine. To avoid unnecessary cutter changes, the template has to be edited. The finished fingerboard will later be placed into this recess. In the first of 3 working steps the guitar neck is screwed on the template. An important work step – the reference holes for the fingerboard are drilled. These are located exactly above the holes previously milled into the template. This is particularly helpful for accurate clamping during all subsequent work steps.
First the groove for the neck tension rod, also called truss rod, is cut with a 4 mm finishing cutter. To ensure that the fingerboard can be glued on without slipping, we use additional auxiliary holes. The tension rod is simply inserted into the precise fitting slot. Important: the tension rod must not be glued to the fingerboard. It has to be able to move freely. 8mm / s dowels secure the fingerboard against slipping during gluing. We have already cut out the maple inlay dots. These create a very nice contrast to the ebony fingerboard. After the glue has dried, the neck glued to the fingerboard is put back on the machine. The reference holes now enable exact positioning.
Precision is extremely important when working on the neck! Even the most precise machine is useless if the workpiece is not positioned correctly in between the work steps. Next, the bridge, also called the "bone" and the holes for the dots are cut The maple dots are simply knocked out of the block and glued into the milled holes. "Express glue" is best suited. This reduces the waiting time to virtually zero. While the glue is drying, the head plate can be worked on with an 8mm / s finishing cutter. The holes for the mechanics are made here. Traditionally with a diameter of 17mm The fine cut is done with the 8mm ball cutter.
The track spacing is 0.4mm, which means that the surface virtually requires no post-processing. The glue has dried and now the dots can be pre-trimmed with the Japanese saw. The fingerboard radius is now milled on the ebony fingerboard. Ebony is one of the heaviest and hardest woods in the world. With 0.3mm track spacing the Hammer CNC portal router produces an almost polished surface. The dots are milled perfectly to the contour of the fingerboard. No further processing is necessary. A 0.6 mm router bit is used to cut the fret slots. The machine works with a depth adjustment of only 0.2 mm in extremely hard ebony! The machine has to work absolutely precisely here, otherwise the guitar will sound out of tune – or the thin router would break off immediately in case of imperfections.
Finally, the outer contour of the fingerboard is cut out. For best surface quality, it is recommended to operate the cutter in climb milling mode. The top side is finished. Now we turn the workpiece. Due to the fitting holes, this is done with absolute precision. The fingerboard is placed in the previously milled pocket. The neck profile emerges. The first work step here is to prepare the surface with the 8 mm router bit. and then fine milling with the 8 mm-s radius cutter. Here, too, the robust design of the machine is important. Vibrations would immediately become visible in the wood and make reworking more difficult. The neck pocket is now cut out with the 8mm finishing cutter. Please pay attention to the bridges that hold the workpiece in place.
The same applies to the head plate. Reference holes for the mechanical parts facilitate later installation. And this is what the finished guitar neck with fingerboard looks like. Now it is time for the nut. This small component is clamped on a machine vice which is fixed in the T-slots on the table. Using 2 wooden clamping jaws, we cut the support for the so-called "bone". We set the zero point for cutting exactly in the middle of the clamping jaws. In this case, the cutter height is zeroed on the upper side of the clamping jaws. Small and tiny components are usually very difficult to clamp. With the Hammer CNC you can design and also produce individually adapted clamping aids yourself. The synthetic bone can be processed very easily with standard tools – no special cutters are required. Usually the nuts are manually shaped with special nut files.
With the hammer CNC machine and the appropriate tools, this work is no longer necessary. The CNC made nut fits immediately! CNC made meets MANUAL work, now it's time for manual work and the CNC machine takes a break. The easiest way to cut the bridges is with a Japanese saw. Our recommendation: It is better to leave a little more distance to the component and saw again afterwards. Sanding is only done by hand. We start with grain size 150 and work our way up to 320.
For better handling we have bolted a temporary handle to the body. Soaking the wood in lukewarm water erects the last remaining wood fibers. After sufficient drying time, these are trimmed with new "sharper" sandpaper. A perfect result !! Master carpenter Helli is happy. Last check – before painted black. For staining we use ordinary water based stain. The stain is generously applied with a sponge. The flamed structure of the maple absorbs the stain differently. This creates the 3-dimensional wood grain effect. We let the stain dry overnight. Only the best for our base guitar. The local car paint shop was delighted to receive the order and was happy about this special change. Now it's time for fretting. For this purpose, we have made a quite handy fretting aid with the Hammer CNC.
A wooden block with the exact shape of the neck profile. This is used to hold the neck while the frets are hammered in. The fretwires are pre-lengthened with a little oversize – and hammered into the exactly fitting slots with the fret hammer. The protruding ends are simply pinched off with a pair of fretting pliers. remove the last excess with a file – first straight … .. and then with an approximately 45 degrees angle To avoid the precious neck from scratching and soiling during the final works we tape it with painter's tape. best is to cover the complete neck – up to the frets for clean fret ends it is best to file the edge with a mini flat file Polishing with a felt disc and polishing paste gives the frets a "high gloss" finish.
The complete neck is covers with linseed oil varnish. This provides sufficient protection and gives the wood grain of the flamed maple a particularly beautiful look. In addition, playing feels better because the hand can slide better. Painted necks, on the other hand, often feel a bit sticky. The neck is now complete. A clean job. The body is now back from the paint shop, a quick check in the sunlight – perfect. Before the components can be installed, several holes must be drilled in the body. To ensure that nothing can go wrong, we have built a template. The felt coating protects the painted surface from pressure marks and damage.
With a long 5 mm drill bit the holes for the wiring are drilled. Shielding varnish is used to prevent unwanted noise later on. The reference drillings are now paying off. All mechanisms can now be mounted with absolute precision immediately. The nut is held securely in place with a little super glue. Finally the moment has come: The marriage of body and neck. Due to CNC precision the neck fits perfectly into the neck pocket. This is particularly important for good and above all consistent acoustics. The neck must neither be too loose nor too tightly wedged in.
Now all that is missing is the electronics. Here too – the assembly – without having to be re-measured – it fits perfectly. We have already prepared the electronics. Ground and pickup were soldered and are now being installed. Stringing is only a routine job. Last but not least the two strap buttons. The first sound that our bass guitar produces – when unplugged – already sounds very promising. We have come up with something very special for the final work step. The Hammer CNC portal router not only processes wood, but also non-ferrous metals of all kinds, for example brass. First the brass block is face milled with an 8 mm-s router bit.
Then, a 60 degree V cutter is measured exactly to length. When milling brass, the rotational speed and the feed rate are particularly important Our self-milled branding iron is finished. The culmination with our own label. A challenging project has come to a perfect end. It shows that creativity and versatility are almost limitless. And one of the most important things is: You can count on the performance and precision of the Hammer CNC portal router 100%. The perfect workmanship of the design and material of our HAMMER J-Bass convinced a professional bass player spontaneously and was rewarded with a successful performance at a concert. A big compliment for our work. Have a listen and let yourself be inspired!.