If it's not a compound curvature, I think starting with a straight beam in the direction where a straight beam will work (perpendicular to the curvature and marks) would do a better job of leveling the router marks. Then you might switch to other means.
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If it's not a compound curvature, I think starting with a straight beam in the direction where a straight beam will work (perpendicular to the curvature and marks) would do a better job of leveling the router marks. Then you might switch to other means.
I've used a curved and straight, narrow sanding blocks with 80 grit paper to sand those router marks. Curved block has the same radius as the back and is about 1.5 times longer than the body width. Across the back with curved, along the neck with straight. Then ROS. That way I got even, straight curved back.
This week was all about routing the top of the body for headless bridges and tuner access.
Until now the center beam of the body was just following the twist of the neck, so I needed to rout a flat area to mount the bridges on. I used a simple MDF template that is supported by two strips of MDF that have opposite taper to account for the twist. Luckily I didn't have to rout too deep to get everything flat, so the bridge height should work without a baseplate. An important note is that due to bridge height at an angle, the bridges need to be mounted offset toward the treble side.
And then I used a similar jig for routing the finger access fo the tuners. There was a cavity left from when I thought I would go with the Alembic-style horns, so I needed to fill that back in. It's not perfect, but will mostly be covered by one of the bridges anyway.
Next up is refining the heel shape and making the roundover on the concave back. Does anyone know a trick to do that with a router? Otherwise I'll do it by hand with rasps and files.
Until now the center beam of the body was just following the twist of the neck, so I needed to rout a flat area to mount the bridges on. I used a simple MDF template that is supported by two strips of MDF that have opposite taper to account for the twist. Luckily I didn't have to rout too deep to get everything flat, so the bridge height should work without a baseplate. An important note is that due to bridge height at an angle, the bridges need to be mounted offset toward the treble side.
And then I used a similar jig for routing the finger access fo the tuners. There was a cavity left from when I thought I would go with the Alembic-style horns, so I needed to fill that back in. It's not perfect, but will mostly be covered by one of the bridges anyway.
Next up is refining the heel shape and making the roundover on the concave back. Does anyone know a trick to do that with a router? Otherwise I'll do it by hand with rasps and files.
I think the trick is to make a router base that has a convex surface to match the concave of the body. You don't want to let the router wobble side to side.
Can you set it up again in the jig you used to produce the concave back? That will present the round-over bit perpendicular to the back surface, and at a constant distance to the back surface, at all points along the perimeter. That should be 90% of the battle won.
Before we get started: This post is a bit more flashy than I intended. There are still a lot of rough spots on this bass, a lot of shaping, sanding, fretwork etc. It will still take a few weeks to sort it all out.
However:
I decided to get all the hardware mounted, rout the pickup cavity and check the geometry of this bass. This means putting strings on it and see how it plays. If there are any issues, this is the time to fix it.
So, here we go. First I got started on the nut and mounted the headpieces:
The retainer for the lowest string needed to be drilled out. I decided to tune this bass one octave below my Supersymmetry baritone guitar, which is in drop Ab, with a 150 gauge for the bottom string.
After mounting the bridges I could align the pickup routing template with the strings. The template is resting on two MDF strips just like the previous jigs.
And everything put together:
The last pic is together with an Ibanez 1005 MS which served as inspiration for this bass.
Playability is ok, some frets are a bit buzzy but nothing that you wouldn't expect before fret leveling. It's good enough for now, so I can move forward with fretwork, sanding and finishing.
However:
I decided to get all the hardware mounted, rout the pickup cavity and check the geometry of this bass. This means putting strings on it and see how it plays. If there are any issues, this is the time to fix it.
This trick worked quite well, except for the lower bout where the sides are not perpendicular to the back. It got me about 80% there, the rest is easy to blend in with files and sandpaper.
So, here we go. First I got started on the nut and mounted the headpieces:
The retainer for the lowest string needed to be drilled out. I decided to tune this bass one octave below my Supersymmetry baritone guitar, which is in drop Ab, with a 150 gauge for the bottom string.
After mounting the bridges I could align the pickup routing template with the strings. The template is resting on two MDF strips just like the previous jigs.
And everything put together:
The last pic is together with an Ibanez 1005 MS which served as inspiration for this bass.
Playability is ok, some frets are a bit buzzy but nothing that you wouldn't expect before fret leveling. It's good enough for now, so I can move forward with fretwork, sanding and finishing.
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Thanks! I totally get it, I've been working on this thing on and off for two years, and it still looks weird to me. The good thing is that during the first playing test it was very intuitive and not weird at all. I was afraid that there would be an acclimatization phase but no, it plays exactly the same as my other 5-string.
Ladies and Gentlemen, it's done!
It's been a long journey and this bass has been in an "almost finished" state for way too long, so I took the time to do the chores and get this project over the finish line. First off, I want to thank everybody who supported this build with advice, tips, or reassuring comments. In particular, @Bruce Johnson, @MPU and @Jeff Siddall have been of great help throughout this project.
The last steps were sanding, finishing with tru oil, fretwork and electronics. For finishing I applied four coats of tru-oil to get a natural feel, but still some protection. In my experience Wenge surfaces feel the best with minimal finish, and for me it doesn't need to be super glossy anyways.
Fretwork was a bit tricky for many reasons.
1) After applying tru oil to the top I didn't like the look of the oiled wenge top and unfinished wenge fretboard, so I applied a few coats of oil on the fretboard as well. The result: Some frets popped up and the first fret fell out completely, so I re-pressed all the frets with superglue.
2) I did some math and came to the conclusion that a round sanding beam (aluminum tube) does not create a flat string path unless its diameter is very small. It might work ok for a low amount of twist, but at 35 degrees it would take off too much in the middle. What I did instead was putting the hardware and strings on and setting it up with fairly low action where it just started buzzing. Then I could see where it buzzes and where it doesn't. If it buzzes on the 7th fret, but not on the 8th, then the 8th is too high. With my fret crowning file I can file down the high fret a bit and try again. I did a few iterations of this and now it plays very nicely.
The electronics are really simple. The pickup is a Nordstrand BigRig wired in parallel with a volume and tone control. The trickiest part was the input jack, because the body is very thin at the edge. I chose a barrel jack, but I couldn't screw it in normally, so I glued it in place with hot glue. It's stronger than it looks.
Now for the glamour shots:
I will also make a more condensed NBD post with all the specs about this. I hope you enjoyed this build.
It's been a long journey and this bass has been in an "almost finished" state for way too long, so I took the time to do the chores and get this project over the finish line. First off, I want to thank everybody who supported this build with advice, tips, or reassuring comments. In particular, @Bruce Johnson, @MPU and @Jeff Siddall have been of great help throughout this project.
The last steps were sanding, finishing with tru oil, fretwork and electronics. For finishing I applied four coats of tru-oil to get a natural feel, but still some protection. In my experience Wenge surfaces feel the best with minimal finish, and for me it doesn't need to be super glossy anyways.
Fretwork was a bit tricky for many reasons.
1) After applying tru oil to the top I didn't like the look of the oiled wenge top and unfinished wenge fretboard, so I applied a few coats of oil on the fretboard as well. The result: Some frets popped up and the first fret fell out completely, so I re-pressed all the frets with superglue.
2) I did some math and came to the conclusion that a round sanding beam (aluminum tube) does not create a flat string path unless its diameter is very small. It might work ok for a low amount of twist, but at 35 degrees it would take off too much in the middle. What I did instead was putting the hardware and strings on and setting it up with fairly low action where it just started buzzing. Then I could see where it buzzes and where it doesn't. If it buzzes on the 7th fret, but not on the 8th, then the 8th is too high. With my fret crowning file I can file down the high fret a bit and try again. I did a few iterations of this and now it plays very nicely.
The electronics are really simple. The pickup is a Nordstrand BigRig wired in parallel with a volume and tone control. The trickiest part was the input jack, because the body is very thin at the edge. I chose a barrel jack, but I couldn't screw it in normally, so I glued it in place with hot glue. It's stronger than it looks.
Now for the glamour shots:
I will also make a more condensed NBD post with all the specs about this. I hope you enjoyed this build.
Wow!....A truly beautiful instrument! Art, Engineering and Craftsmanship all together at a high level. You did it. You worked out all the problems one at a time, and stayed with the artistic vision.
Thanks! The body has a quite radical profile with less than 0.5" at the top edge and 2" just below the bridge. The weight is 3.6kg/7.9lbs, which I think is not too bad for a 5-string. There is no chambering in the body, just a rather big control cavity.
Working on it!Yeah, perfect weight.
So when do we get to hear some sound samples??
Meanwhile, here's the NBD post with full spec list: https://www.talkbass.com/threads/nbd-ergonomic-bass-twisted-sister.1646483/
That turned out amazing! 
Congrats on what I know was a particularly tricky build.
With spring officially here (the 20 cm of snow we got yesterday notwithstanding) I need to get the CNC fired up again and get on with finishing mine.
Congrats on what I know was a particularly tricky build.
With spring officially here (the 20 cm of snow we got yesterday notwithstanding) I need to get the CNC fired up again and get on with finishing mine.
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Curious what the percentage of bass players use rounds vs flats is.- Latest: 5StringBlues
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