Making Becky's "Bass"

Becky's Bass

 

I made an electric upright bass for my eldest daughter Becky. It has a variable scale length of 950-1000mm depending on where the bridge is placed. The body and neck are made from Port Orford Cedar from a tree that grew in the front garden. The body is covered in Sapele veneer front and back and the fingerboard is East Indian Rosewood. The tuners are Hipshots and it has a K&K bass pickup.

 


Here are most of the parts.


The beginning of the plans.


The East Indian Rosewood fretboard is glued to a piece of Port Orford Cedar to make a composite fingerboard thick enough for a radius to allow bowing as well as plucking but also light in weight.


Fish glue is used and other fingerboard blanks are used together with clamping cauls to keep the composite fretboard straight as the glue dries.


The fingerboard taper is cut and the initial radius put on the fingerboard. The final radius will be done with the strings on.


The fingerboard has the East Indian Rosewood bindings glued on the side and end using fish glue.


The scarfe joint is cut in the Port Orford Cedar neck blank and the two pieces glued together using hot hide glue in this jig.


Here's the neck blank after tidying up the joint.


The volute on the back of the headstock is shaped in the thickness sander.


Slots are routed in the neck for two 8mm carbon fibre rods.


The carbon fibre rods are fitted and a Port Orford Cedar cap glued on top - here's the first cap glued in.


With the second cap on the neck is clamped until the glue dries.


The Etimoe front headstock veneer is glued on using fish glue after shaping the nut edge to the correct angle.


The Port Orford Cedar body blank will be faced with Sapele veneers on the top back and sides. Here's the body with the top and back veneers.


The top and back veneers are glued on to the body using fish glue, cauls and lots of clamps.


The Etimoe rear headstock veneer is bent on the hot pipe to match the volute and glued on using fish glue.


Next the neck pocket is routed out.


Then the body is cut to shape.


The Sapele sides are thicknessed.


The sides are bent on the hot pipe and then glued to the body using fish glue.


The holes for the Hipshot tuners are marked on the side of the headstock and drilled using a 14mm drill.


The central slot is then routed out of the headstock. First most of the material is removed with a Forstner bit and then the sides of the slot are routed.


Here's the result - the ends of the slot will be finished using files and sanding blocks and the nut end ramped.


Here's the tidied up slot with the Hipshot tuners test fitted. The headstock has also been shaped.


The fingerboard is then glued on to the neck using fish glue.


The neck is trimmed flush with the fingerboard and a step cut at the fingerboard end.


The neck is tested for fit in the body.


Looks like an electric upright bass now.


The binding channels are routed on the body together with the top and back purfling channels. The Etimoe end-graft is then glued in.


The top Etimoe bindings together with black/pear/black top purflings are glued in using fish glue.


The back Etimoe bindings together with black/pear/black back purflings are glued in using fish glue.


The bindings are scraped flush and then the Etimoe end-cap is glued on using fish glue.


Here's the end-cap after shaping to fit the body.


The neck will be attached to the body using three M6 bolts and will be "adjustable" to change the neck angle and string action height under string tension. The three bolt holes are marked on the back of the body and the recesses for the bolt heads drilled with an 11mm drill.


The bolt holes are then drilled through using a 7mm drill.


The third bolt will act as a securing bolt - it will go through a threaded inserts and the end of the bolt will be tightened onto a brass insert in the neck. An 8mm hole is drilled from the top of the neck pocket for the threaded insert.


The threaded insert is then installed.


The other two bolts will go into threaded inserts in the neck - the middle bolt being "captured" in the body which is used to adjust the neck angle. The neck threaded insert positions are marked and drilled and the threaded inserts installed.


Here's the neck attached with the three M6 bolts installed. A brass cap will be installed over the last two bolts on the rear of the body "capturing" the middle one.


Here's a side view showing the neck angle.


Here's a front view.


The pocket for the cover plate is routed.


Here it is after tidying up with a chisel.


I decided to use an ebony cover plate rather than brass and it is drilled at each end using a 5mm drill for the brass M5 bolts that will attach it.


The central two holes for reaching the adjusting bolts are then drilled with an 8mm drill.


The two threaded inserts for the M5 bolts are installed in the body.


Given that the string tension will be 250lbs I decided to add a central bolt for the cover plate. Here's the cover plate is test fitted.


A piece of ¼" brass rod is epoxied into the neck where the stopping bolt is. When the epoxy dries it will be filed flush with the neck.


The string holes are marked on the body and drilled through using a ¼" drill.


The recess for the strings is then routed on the rear of the body.


Here's the result after tidying up with a chisel.


A piece of ebony will be used for the ball ends of the strings to rest on. This is glued into the recess using fish glue.


The string holes are then drilled through the ebony strip and are then reamed on the top of the body for tuner bushes to be fitted after the body has been sprayed.


The recess edges are then bound with Etimoe strips. Finally the ebony cover plate is bound with Etimoe.


The bass will be suspended on a stand for playing rather than using a spike and support bracket arrangement. The stand will be made from a heavy duty microphone stand and a speaker bracket. Threaded inserts are installed for the two bolts that will hold the speaker bracket in place.


The bracket is then bolted on.


The bracket drops onto the microphone stand and is secured with a set screw. The stand allows the bass to be swivelled from side to side and up and down.


Here's a back view.


Neck carving but not as we know it Jim - this is a big one.


Looks more like a neck now.


The stand wasn't quite stable enough so a 6mm carbon fibre rod was fitted into a cable tie on the stand with the other end locking into the string recess on the back of the body.


The bridge is made from mahogany with a curvature matching that of the end of the fingerboard. Two 18mm holes were drilled with a forstner bit between the strings. Here's the front view.


Here's a back view of the bridge. The bass was assembled to test the bridge with the K&K Double Big Twin's four transducers attached using double sided tape beneath each string. A wooden nut was fitted together with the D'Addario NS electric double bass strings for the first time.


Here's the test set up - the bass is plugged via an LR Baggs PADI into a Phil Jones Double Four Bass amp. A very basic recording was made from this set up using my Zoom H4N recorder using flat EQ on the preamp and amp. The bass holds up well to the string tension and the adjustable neck system works well under string tension. The best bridge position is at 1000mm scale length.


The body has to be sanded and pore filled using egg white, allowed to dry and then sanded back.


The body and neck are then sprayed with pre-catalysed lacquer.


When the lacquer is dried it is levelled and polished and the bass assembled. The K&K pickups are superglued to the bridge and a clip attached to the body for the end-jack. The strings are then fitted. The stand has a cable clip attached with a screw that holds the bow when not in use.


All it needs now is a name.


Back view.


Cases for electric upright basses are hard to find. I’ve seen snowboard bags used but these are a little flimsy so I decided to use a keyboard gig bag. Velcro straps are fitted inside to strap in the bass, bow and stand.


The gig bag is zipped up, folded in half and three velcro straps used to hold it in place.