DIY Headless Bass Tuner (Open Source)

[rudy4444]

Those who want to do a simple inline tuner design for headless bass use may want to check out the detail photos for Dave Weir Guitars tuner designs. They use a bearing under the tensioning screw that bears against a pivoting plate to present a straight pull to the saddle.

Dave Weir Bass design on The Gear Page Forum

Dave Weir Tuner Details

 

[KidAmnesia]

I have a headless bass I built a while ago with an extremely simple tuning system I designed with a machinist. I had designed something similar to your system (without fine tuners) with a thumbscrew and a threaded block; but the machinist suggested that the screws were soldered into the blocks with a knurled nut I can turn with my fingers on the other side. That way, the block can be smaller and requires less space behind the saddle, and the nuts can be bigger than your usual thumbscrew and provide smoother adjustability.

Iirc the screws are M4 brass and the blocks have 12 mm of travel. It's proven to be enough travel with all the strings I've used; I pull the string form the other end before clamping it at the nut to get as little slack as possible and then tighten the tuners and ussually about 8 mm are enough to bring it to tension; I never maxed out a tuner.
It's really stable and it has worked reliably for about 8 years now.

I don't have any pics of it right now, but can upload some later.

 

[Will_White]

I have a headless bass I built a while ago with an extremely simple tuning system I designed with a machinist. I had designed something similar to your system (without fine tuners) with a thumbscrew and a threaded block; but the machinist suggested that the screws were soldered into the blocks with a knurled nut I can turn with my fingers on the other side. That way, the block can be smaller and requires less space behind the saddle, and the nuts can be bigger than your usual thumbscrew and provide smoother adjustability.

Iirc the screws are M4 brass and the blocks have 12 mm of travel. It's proven to be enough travel with all the strings I've used; I pull the string form the other end before clamping it at the nut to get as little slack as possible and then tighten the tuners and ussually about 8 mm are enough to bring it to tension; I never maxed out a tuner.
It's really stable and it has worked reliably for about 8 years now.

I don't have any pics of it right now, but can upload some later.

That's a great idea, you could do it as a pinned together flat with a square head bolt for ease of getting it machined.

 

[Smilodon]

Yes, it's a fair point about the bolt not being near its limit, so it won't be stretching very much. On the other hand, the female thread in brass is very definitely near (or beyond) its limit, so that component will deform, which I think will cause the same effect of diminishing returns with additional threads. I could well be wrong, though.

But we are definitely talking about failing the threads in the brass block, as @Jeff Siddall's excellent test demonstrated recently.

Ah, i see my mistake now. I just didn't understand why @Jeff Siddall had issues while I didn't in more or less the same situation. I missed the part where Jeff used fine M3 threads.

 

[KidAmnesia]

I have a headless bass I built a while ago with an extremely simple tuning system I designed with a machinist. I had designed something similar to your system (without fine tuners) with a thumbscrew and a threaded block; but the machinist suggested that the screws were soldered into the blocks with a knurled nut I can turn with my fingers on the other side. That way, the block can be smaller and requires less space behind the saddle, and the nuts can be bigger than your usual thumbscrew and provide smoother adjustability.

Iirc the screws are M4 brass and the blocks have 12 mm of travel. It's proven to be enough travel with all the strings I've used; I pull the string form the other end before clamping it at the nut to get as little slack as possible and then tighten the tuners and ussually about 8 mm are enough to bring it to tension; I never maxed out a tuner.
It's really stable and it has worked reliably for about 8 years now.

I don't have any pics of it right now, but can upload some later.

Here it is. It's a bit crude, but works great.
Now I see it's a bit more than 12 mm travel.

 

[eddododo]

Have you looked into differential screw threads? They are basically two "coarse" threads with slightly different pitch on the same screw. This can give you very fine linear movement with relatively coarse threads.

You could also try to find a way to increase the diameter of the tuning knobs. That will give you more leverage as well.



This. You'd be surprised how much of a difference a bearing will make in a system like this. Thrust bearings are relatively cheap and easy to implement.


For what it's woth, in the headless systems I have made I used M3 screws (IIRC). That seems to work pretty well. Just make sure you have enough threads to prevent wear on the threads under load.

Here is one of the build threads if you are interested: Project Bloodline

These are very interesting; I love when a technology is eye-opening

 

[Will_White]

Here it is. It's a bit crude, but works great.
Now I see it's a bit more than 12 mm travel.

View attachment 5094996

How are the strings retained?

 

[KidAmnesia]

How are the strings retained?

Once again, not very pretty but functional. I realized I wasn't capable of actually doing something more complex at the time. Srings pass through a hole behind the 0 fret and are clamped with those machine screws. The clipped string ends on the other side tend to mess with gig bags.

 

[Videojunkie]

That's going to be other thing to figure out is the best and easiest way to clamp the strings on the other end.

 

[Bruce Johnson]

That's going to be other thing to figure out is the best and easiest way to clamp the strings on the other end.

My quick advice on headless head blocks:

Run the string through a hole and clamp it with 2 setscrews per string. Drill a slightly deeper pocket under the second setscrew. The first setscrew holds the string down against the bottom of the hole. The second setscrew bends the string into a small kink that hooks onto the step in the block. This greatly improves the security of clamping the string end.

Clamping the string by simply squeezing it with one setscrew isn't that secure. You need more than that.

 

[Will_White]

View attachment 5096022

Once again, not very pretty but functional. I realized I wasn't capable of actually doing something more complex at the time. Srings pass through a hole behind the 0 fret and are clamped with those machine screws. The clipped string ends on the other side tend to mess with gig bags.

I meant on the bridge side, I'm not seeing what holds the string ball in.

 

[KidAmnesia]

I meant on the bridge side, I'm not seeing what holds the string ball in.

Oh, sorry. The hole in the block is angled back a few degrees (and the whole tuning system too, to get a better break angle over the saddle).

 

[Spiky_Bassist]

I know Steinberger is the OG in the headless bass tuner world, but anyone ever played/looked at Strandberg? My Boden Prog 5 has a pretty good bridge/tuner setup. It doesn't ever slip and the biggest complaint I have is that you need a good amount of finger grip strength to turn it once you have tension on it.

[Invalid or Expired Link Removed]

[Invalid or Expired Link Removed]

I think the thread issue is pretty well solved in that there's plenty of travel for pulling on the string and the threads are coarse enough to be strong so they don't pull out (anodized Al, not brass, for what it's worth) while being fine enough to tune accurately. I know Ola has some YT videos on how to setup the bridge and tuners so you can get a good look at how it functions/goes together.

 

[ardgedee]

I know Steinberger is the OG in the headless bass tuner world, but anyone ever played/looked at Strandberg? My Boden Prog 5 has a pretty good bridge/tuner setup. It doesn't ever slip and the biggest complaint I have is that you need a good amount of finger grip strength to turn it once you have tension on it.

[Invalid or Expired Link Removed]

[Invalid or Expired Link Removed]

I think the thread issue is pretty well solved in that there's plenty of travel for pulling on the string and the threads are coarse enough to be strong so they don't pull out (anodized Al, not brass, for what it's worth) while being fine enough to tune accurately. I know Ola has some YT videos on how to setup the bridge and tuners so you can get a good look at how it functions/goes together.

Strandberg's seem pretty similar in structure to Nova tuners. ABM has something that looks more like Strandberg's, but it allows you to adjust intonation by moving the string saddle independently of the entire bridge unit.

Nova:


ABM:


Edited to add: Ibanez uses monorail tuner bridges of their own design on their headless basses. They look kind of over-complicated but also look like they'd be easier to make fine adjustments on.

 

[ctmullins]

The ABMs are four times heavier than the Nova. I love them both, but would also welcome additional choices.

 

[ardgedee]

The ABMs are four times heavier than the Nova. I love them both, but would also welcome additional choices.

...also two times more expensive... (Although to their credit they're offering free international shipping in August, which can amount to a pretty nice discount. You have to accept that the order won't go out until they're back from vacation though.)

The mass is an interesting factor. Setting aside the "heavy bridge is just better" aspect, I can see how it can be more practical for some builds than others. So it's good to have a variety of options.

Since the Ibanez monorails are on current production instruments it looks like they can be sourced through any authorized Ibanez dealer that sells parts, as well as the Indonesian grey market. Prices are going to range a bit, somewhere between the Nova and the ABM, I couldn't find a US dealer listing them. Drums Etc. is the usual go-to for price checks but they list a *lot* of things that Ibanez discontinued years ago, and are failing to list a lot of in-production items, so I think they just haven't updated their catalog in years; I'd be wary about placing an order for a discontinued item.

And since I'm ranting I'd like to take a moment to make an unrelated complaint that ABM has handsome photos of their tuner anchor blocks in their online catalog, but they haven't put any up for sale for quite a while now. I doubt I could budget for one anyway, but it'd at least be nice to have the opportunity to confirm that I can't.