Ergonomic bass build "Twisted Sister"

[Slidlow]

Yes, but shipping to Japan only and price seems high. Just wanted a little more information.

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The ones I have were made by KTS in Japan. They still make titanium single acting rods but stopped the dual acting due to claimed stiff operation by some users. Probably had galling issues as they were all titanium and if not properly lubed could have issues. I have no info on Tatsuta and haven’t had a chance to try to investigate further.

 

[TFM94]

Yes, but shipping to Japan only and price seems high. Just wanted a little more information.

tatsuta Titanium Parts powered by BASE

Yes, that's where I ordered from. If you contact them directly via email, they'll ship it anywhere you want. Shipping to Finland was surprisingly fast and affordable. Of course they're more expensive than your average steel rod, but if you have them in front of you, you know why. The welds are clean and square, and the design is very compact. Even the adjustment nut fits into the 6mm channel, so there's no need to widen the channel at the headstock.

 

[TFM94]

The ones I have were made by KTS in Japan. They still make titanium single acting rods but stopped the dual acting due to claimed stiff operation by some users. Probably had galling issues as they were all titanium and if not properly lubed could have issues. I have no info on Tatsuta and haven’t had a chance to try to investigate further.

I was trying to get my hands on a KTS trussrod, but they were not available anymore. Now that you are mentioning galling, I hope this will not become a problem with the Tatsuta rod. Turning the nut feels a little stiffer than a normal steel rod, but it's still easy to turn. I've installed the rod already, so I cannot add lube anymore. I hope Tatsuta has put some on the threads.

 

[Slidlow]

I was trying to get my hands on a KTS trussrod, but they were not available anymore. Now that you are mentioning galling, I hope this will not become a problem with the Tatsuta rod. Turning the nut feels a little stiffer than a normal steel rod, but it's still easy to turn. I've installed the rod already, so I cannot add lube anymore. I hope Tatsuta has put some on the threads.

Likely the rods were not pre-lubed. Careful adjustment will probably be the course of action. If you find the threads getting stiff while adjusting then back it off and tighten again. May need to repeat to insure the threads don't lock. Absolutely all adjustments with string tension relaxed and you may have to help the neck bend physically while adjusting.

 

[MPU]

I don’t see string tension as a ”problem” with truss rod adjustment. Truss rod is foor keeping the neck in relief, not making the relief. I always bend the neck by hand when adjusting truss rod.

 

[TFM94]

Likely the rods were not pre-lubed. Careful adjustment will probably be the course of action. If you find the threads getting stiff while adjusting then back it off and tighten again. May need to repeat to insure the threads don't lock. Absolutely all adjustments with string tension relaxed and you may have to help the neck bend physically while adjusting.

I can live with that.

 

[TFM94]

All rods are installed and the filler strips are flush with the surface:

Who can guess where the trussrod access is?

 

[Jeff Siddall]

All rods are installed and the filler strips are flush with the surface:
View attachment 4559579
Who can guess where the trussrod access is?

Looks good!

Headpiece truss rod adjust?

 

[TFM94]

Looks good!

Headpiece truss rod adjust?

Yup, it will be on the end/side of the little headstock. And now it's official, I'll go with a little headstock instead of cutting it straight off. For modern styles the straight cutoff looks better, but with the rounded, ornate body shape, it has to be a bit over the top ;-)

 

[TFM94]

Fretboard ingredients:

The fretboard will be laminated from two layers of wenge and three layers of maple venner (0.5mm). The veneer is only there for adding thickness (about 6mm/just below 1/4" total), it will not be visible later on. I also prepared two strips of ebony as binding (3mm wide). Usually I don't like to use ebony for sustainability reasons, but these are offcuts from a friend's build project, and I don't want to see them go to waste.

On a normal straight neck build I would cut the fretboard to size, glue it onto the neck and then use it as a template to route the sides of the neck flush with the fretboard. Here I want to do the same thing, but it requires a few more steps. Here's what I'm thinking, please double check:

1. Laminate the veneers and wenge layers onto the twisted neck blank.
2. Then use a thin bendable piece of MDF (3mm) as a template to route the sides of the fretboard in the twisted jig. To compensate for binding, I'll rout it 3mm narrower on each side.
3. Glue the ebony binding in place. Now the fretboard has its final width.
4. Use the outside of the binding with a template router bit to rout the sides of the neck
5. Radius the fretboard using the twisted jig with a router base similar to the one used and described by @Bruce Johnson.

Alternatively, I could laminate the fretboard with a plastic film in between the fretboard and neck blank, so that I can take the fb off afterwards and add the binding. Then I could glue it on as a whole. The advantage would be that I could easily make another fretboard if I make a mistake, but otherwise this seems more complicated, right?

 

[TFM94]

Today i made the radiusing jig that I'll use once the fretboard is glued on. It utilizes the same jig that I showed in my first post, but I can exchange the straight rails on the router base with these curved ones:

I made the curved pieces with a simple circle-cutting router jig with the desired fretboard radius (16"). The router base rests on the jig on three points, two on the left rail in the picture and one on the right.

 

[T_Bone_TL]

Today i made the radiusing jig that I'll use once the fretboard is glued on. It utilizes the same jig that I showed in my first post, but I can exchange the straight rails on the router base with these curved ones:
View attachment 4563794
I made the curved pieces with a simple circle-cutting router jig with the desired fretboard radius (16"). The router base rests on the jig on three points, two on the left rail in the picture and one on the right.

Note that if the router bit is not the same height as your curved rails, the radius won't be 16"

 

[TFM94]

Note that if the router bit is not the same height as your curved rails, the radius won't be 16"

That's true, thanks for the heads up. The router bit will have to stick out a few mm below the rails and reduce the radius, but that doesn't really matter. It is still a consistent fretboard radius, and with the fanned fret design the actual fret radius will be different for each fret anyways.

 

[TFM94]

A random assortment of parts arrived today. After I dug my car out of the deep snow I could finally get to the post office and pick em up. Life is hard.

Here we have:
- Nordstrand bigrig neck PU with custom 18mm spacing
- ABM headless bridge and single headpiece in gold (x5, the others are still in the box)
- gold Schaller S-Lock buttons
- a jack plate
- a switchcraft jack socket
- a dpdt mini toggle switch, which is intended for Series/Parallel/Single coil switching
- an XL tusq nut

It's good to have everything ready to go. No more excuses!

 

[TFM94]

I've made some preparations for the fingerboard glue-up. In my opinion there are two ways to clamp the board:
- A clamping caul with the corresponding twist, routed in the same jig as the neck, or
- Vacuum clamping.

Since I get to borrow my dad's vacuum pump, I decided to clamp it in a vacuum bag. During the last days I have made some changes to that setup and now I can achieve a proper vacuum pressure now (around 0.25 Bar/3.6 psi).

This is the pump I'm using. It sucks, but here that's a good thing.

I use a tubular vacuum bag, about 15" wide and 5' long. It's open on both ends, so I had to come up with a proper seal. I hate to use silicon or tape for this, so I went to the hardware store, bought a 1" PVC pipe for two bucks, cut it in two pieces and cut a slot into one of them. Now they have a very tight fit, almost too tight, and seal the bag.

Now I will cut the fretboard layers to size and prepare some locator pins. Glue-up is planned for this weekend, I'm pumped!

 

[TFM94]

There's some good vacuum clamping action going on this morning!

I glued the fretboard on, 5 layers in total. This was one of the more stressful glue-ups, but thanks to 4 pins to locate the fretboard it went ok. I was quick and sloppy with the glue, because I wanted to get it into vacuum as soon as possible. There's probably a bit too much glue as you can tell from the squeeze out, but I think it's gonna be ok. I just hope that none of that makes its way into the trussrod channel. Now I'll keep the pump running for a few hours.

I'm excited to see how this turns out!

 

[TFM94]

Quick footnote about today's glue-up.

There was a lot of squeeze-out. So much, in fact, that it wouldn't dry in several hours and I had to take it out of the bag, scrape off the excess glue, and clamp in vacuum for a few more hours after that. Since Titebond is a water-based glue, I suppose it dries slower in vacuum.

Still, I think it turned out quite well.The trussrod can still move, and there are no visible gaps. I'll let it air out for some more time. Next up is routing the fretboard edges straight to accept binding. I'll probably get to that later this week.

 

[TFM94]

Ladies and Gentlemen, we have a fretboard.

After glue-up, I routed the fretboard sides in the twisted jig to accept binding:

Gluing the binding in place. Once again it was difficult to clamp, because the binding slot ist twisted. Vacuum clamp wasn't an option this time, because the neck blank is still full width. I made some MDF pieces that wedge in place and act as little C-clamps:

And after some cleaning up we have a bound fretboard in wenge and ebony.

Now I have to decide whether I want to first rout the sides of the neck using the fretboard as a template or radius the fretboard first.

 

[Beej]

So you're not only building a torzal bass but you've also now bound the fretboard? I feel like your lutherie is making fun of my lutherie.

 

[RichterScale]

Yeah, there's a lot of winning going on in this thread.
I don't have much to add. Just watching intently.