New Offset Bridge Design - the Toughset

[ThePearDream]

Totally awesome! Fantastic work! I look forward to seeing and hearing more.

[Embenny]

This looks great and I'll absolutely be interested in trying it out on one of my guitars whenever it's ready!

[antisymmetric]

A product could be made of angel dust, adamantium and rhino horn, but if there are underlying issues with the geometry and engineering of the design, it doesn't matter. We've taken a physics-first approach, tackling the core principles properly before incorporating those into a packaging puzzle.

Of course, all the fundamental issues with the offset bridges concern the insufficient vectorisation of forces which arise from the shallow break angle. Many components are forced to do too much, because they were copied and pasted from existing Fender saddle designs which had a much greater break angle.

From the beginning, our philosophy has been that every part of the design should be tightly affixed to the bridge chassis once all setup adjustments have been made so they cannot come loose or drift over time, and (most importantly) that the string tension is not parasitised to maintain the set geometry, as it is to a greater or lesser extent in every adjustable offset bridge currently on the market.

Once set, the Tuffset bridge from post to post behaves as a single piece of machined steel, with no moving parts and nothing that can come loose. I intend to knock it in testing tomorrow, and I expect it to ring like a bell.

Totally agree with all this, and I'm very keen to see the results of your efforts!

[Deed_Poll]

Today was a big day!

My first impressions on seeing and feeling the bridge were how precisely, intricately and densely made it is! The engineering firm have really done a spectacular job. The tolerances are in the tens of microns and you can really see and feel it, even just fiddling with it!

The next prototype will have brass saddles, so we can compare the tone and machining practicalities of both. Using extremely tiny tools to cut very tough billet steel at obscenely high tool velocity is creating a challenge with the feed speeds, which are currently glacial. Several of the operations can yet be optimised, and a couple of custom-made tools will be useful for scaling production sufficiently to suit the price point.

If we made all of them the same as this prototype, they would cost $600 each! But we're confident we can bring that down very substantially. The key is going to be in making clever investments in custom tooling and jigging so higher batch volume can be our friend - unfortunately, it's not as simple as saying "I'll take 100 just like that" and the price per unit magically diminishing! So we have to get smart.

Everything feels slick and adjusts eagerly. I preemptively set the E and e strings at zero height and the D and G strings at maximum height, with the A and B strings a little over half way. This is a vintage guitar with a 7-1/4" radius, and as such poses the ultimate test of height adjustment range.

With the height eyeballed, I went about my usual "best guess" intonation pattern - a slim spread with A and G roughly equal, and D and B roughly equal, their average centred on the midpoint of the intonation range.

Now it was time to get it on the guitar - I wish I'd had time to throw a fresh set of strings on the old girl, as these are feeling a bit claggy and delicate! I loosen them down a few dozen turns each until they'll allow the vintage bridge to lift out. I eyeball the post height relative to the string slots, and set the Tuffset to be in the same neighbourhood.

In goes the Tuffset! At first, it feels a little unsure of itself and wobbly in the thimbles, as I knew it would. First I bring the E and e strings up to tension, and use these to set the post heights. Once they're correct, I chase in the followers - tiny locking set screws that snug up to the posts themselves and lock them in place.

Now I set the heights of the remaining strings, from the outside in. The A and B need to come up a little; the D and G can actually go down a fraction (phew!). I tune the guitar open as usual, being careful to lift each string above the saddle / nut periodically so the tension is even behind the bridge and above the nut. Each string sounds loudly, and the system feels robust. I can't resist a divebomb! It returns to pitch well.

With those set, all that remains is to set the intonation. A quarter-turn anticlockwise on the locking screw atop the saddle is enough to unstick it. I can slide the saddle into place, tune, test intonation, adjust. The string tension holds the saddle's position, but it can be moved deliberately. When I find the correct intonation point, a quarter-turn clockwise and it's locked in. Repeat for all strings, and she's ready!

Onto the playing, and the first thing that hits me is something fairly subconscious; that there is, on almost all 25-1/2" scale Fender guitars below 13 gauge strings, a strange "fizzy" feeling which transmits to the fretting fingers. I feel its absence - this is more Gibson-like in feel, clear and direct.

Gradually, I start to play as if I'm holding a Stratocaster, Telecaster, SG - I realise I'm leaning hard on the bridge with my picking hand, and it feels robust and assured as a tune-o-matic. This was a surprise, since I fully expected that some degree of the loose-ness / delicate feel of an Offset bridge was down to the rocking post design, and so I expected more of that to remain in the Tuffset. But it really is extremely solid, and I am finding my dynamics from playing *hard* moreso than from playing *softly*. In this regard, it starts to feel more Fender than Gibson again.

The sound is weighty. Bigger, somehow - as if it has added a few winds to the pickups. Midrange is forward on attack, especially on the bridge pickup, and the low-end lingers long and clear. Cleans are punchy, chords meld together pleasingly with gain.

I test the vibrato in earnest - it returns to pitch brilliantly, but then the rusted vintage saddles always did a great job of this, too. It retains the elastic "wallop" that marks an Offset vibrato system to me, debiting the power on dive and releasing it with interest on return to pitch. I am surprised that the vibrato action feels stiffer than I remember, in a way I don't entirely like and cannot explain, but I feel I could probably dial this out as there is plenty of range left in the arm's action.

I am due to visit Rexter down the road - I dearly want to keep the Tuffset in place and bring it with me, to hear the guitar in another's hands and get his feedback! But it is prudent to leave the prototype with Rob for reference and development. I put the old bridge back on the guitar, and tune it up. It feels like putting on a comfortable, but slightly worn and damp old pair of trainers.

[Larry Mal]

Well, I think it looks fantastic.

[CROSS_guitars]

Seeing it installed like that, looks way cool.

[PorkyPrimeCut]

Wow!! I love it!!

I think it looks spot on. Somewhere in between a TOM and a StayTrem but still retaining that vintage look.
It also doesn't look overly complicated or ugly (hello Mastery!) Just very compact & functional.

Well done, sir!!

[Deed_Poll]

Cheers for the kind words on the appearance, guys!

On reflection, I'm probably going to change / experiment with a few aspects of the design.

First, I think I'm going to make the bridge broader (along the intonation axis). It doesn't need the extra intonation range as the saddles can actually overlap the edges slightly if needs be. I just think it would look better closer to a vintage footprint, and that might be less distracting in the context of a vintage guitar.

Secondly, I might make the chassis just a millimetre or so thicker underneath. I don't *like* to add more distance between the string break height and the underside, due to so many offset bridges running low / scraping the pickguard! But it's still a lower profile than a Vintage bridge, so I'm considering it for rigidity.

Although it was no problem at all when installed on the guitar (under string tension), when off the guitar I was able to prise the posts apart a little, enough that the saddles were rubbing slightly against each other. I don't think it will be an issue even with the largest string gauges and highest break angle, but it might allow us to try a brass chassis to see, feel and hear how that performs.

I'm also going to try some different string slot depths, though I personally didn't feel there was any detriment to having all slots at the full depth. Perhaps we will manufacture seven or eight different depths so we can have a "standard" model for string gauges up to 0.011 gauge, and offer a different "heavy" or "superheavy" model which has all these saddles moved down one or two spaces for heavier or Baritone/ Bass VI application, but that would certainly be a later development.

Thanks all for your thoughts and feedback over such a long period! It feels great to be entering the final furlong with your help.

Dan

[tammyw]

That's some impressive work, good job! I'm jealous.

[GuitarsnGravel]

Nice design!

[Deed_Poll]

Hello all! The Tuffset Bridge story continues here:

viewtopic.php?f=8&t=126191&p=1790375#p1790375

Cheers and see you on the other side!