String setup on compound radius neck

[Tom]

Im aware that the bridge saddles should be adjusted to mimic the neck radius in order to ensure the string action is consistent across the width of the neck (correct me if I'm wrong). So wondering how you might tackle the setup on Warmoth's 10/16 compound radius neck?

Would the bridge saddles be set up with a 16 degree radius?

If so - what happens at the nut ... I'm installing the LSR nut, so I don't think there is an option for nut slots to be filed to a 10 degree radius???

 

[Cagey]

Because a 10"-16" compound radius neck essentially forms a cone, the bridge radius ends up needing to be ~18" for proper string height along the way.

I think an LSR nut is designed for ~9.5" radius, so it's very close to what you want. In any event, I've never had any problem with them. They come with shims to set the height.

 

[Ddbltrbl]

So, just to make sure, the measurements are in inches of radius, not degrees; the longer the radius, the flatter the surface of the circle, or in this case the surface of the fret board. It sounds like you get that, so yes, with a compound radius neck you set the bridge to match the larger of the 2 numbers, in this case 16 inches. (Edit: I bow to Cagey's expertise here, but I set mine bridges at about 16" and am totally happy with them. But, setting them to 18" might allow for a little lower action, something I am not overly concerned with.)

An LSR nut is typically designed to work on anything from a 9 inch to a 12 inch radius, so that makes it just right to fit on 10 inch side of a compound radius neck. I have factory installed LSR on a Fender American Deluxe, and have played a Warmoth installed one and really can't tell a difference.

Hope that helps.

 

[Cagey]

...with a compound radius neck you set the bridge to match the larger of the 2 numbers, in this case 16 inches.

No, it forms a cone, so the curve continues to flatten as the radius grows as you get to the bridge. That's why it ends up needing to be about 18" to be perfect.

 

[Ddbltrbl]

Cagey is of course correct!  :icon_thumright:

 

[Cagey]

To be fair, there's "perfect" and there's "practical". As long as you have adjustable saddle height (or can file/shim them to get there), you just make it work; forget about the math. String type/gauge and player comfort/style will dictate what what really works.

 

[Tom]

Awesome info - exactly what I needed ... you guys rock! arty07:

 

[Jumble Jumble]

It's very true: I've never seen an 18" (or 18.35" I think it would be) radius gauge, so I'm not sure how I'd go about setting the bridge to that. Instead, you can just set the string height in the usual way, by measuring it above the frets to start with, and then according to personal preference. On the two 10-16 necks I have, I have no idea what the bridge radius is set at.

 

[Tony Ounsworth]

Yeah, I just raise and lower the saddles until I've got the strings how I like them, assuming you've done all the usual neck adjustments of course.

 

[Super Turbo Deluxe Custom]

If you do have a 16" radius gauge, use it on the strings at the end of the fretboard instead of at the saddles.

 

[MikeW]

Are you using a Wilkinson bridge? If so, here's a simple trick to get the radius on the bridge right.

Start with the outer saddles (1 and 6) flat on the baseplate and raise or lower the two post screws until the 1 and 6 strings are just resting on the last fret. Raise/lower the center saddles until the center strings are just resting on the last fret as well. (You'll know when you're there if when you raise either of the adjustment screws, the string lifts from the fret.) Once you've got the strings set there, then raise the entire bridge by the post screws to the height you want. Voila!

I suppose this will work for any bridge with adjustment screws that will raise the height, now that I think about it. And yeah, this also assumes that the nut is the correct radius at the other end too. I have an LSR roller nut on the Strat I did this with and it worked like a charm, but YMMV.

 

[Cagey]

Clever! Let reality be your gauge!

 

[Jumble Jumble]

Great idea!

 

[Surf n Music]

Mike W, very awesome! I am gonna be doing a set up in the next few weeks. Great advice!!  :hello2:

 

[MikeW]

Thanks all. I aim to please!
:icon_biggrin:

I hit on the idea when I was wondering this exact thing. I didn't want to have to build or buy an 18" radius gauge, and as I sat there thinking about the cone the fretboard makes, it just hit me. Easy as pie because the strings will traversing exactly on the surface of the cone.

[geek out]
Think of the cone not being the fretboard, but being the strings. All you need to do is match the radius of the string's cone with the radius of the fretboard's cone and the surfaces of the cones will have to be 'parallel'. Bingo! Of course, the geometry will be off by a smidge because the strings aren't sitting exactly on the fretboard at the nut. The height of the string slots will cause the radii of the cones to be slightly off, but the difference in radius at the bottom end (bridge) of the cone would be negligible. If you have a low action, the angle that's created between the base of the nut, the strings where they contact the last fret, and the bottom of the string slots will be very low so the radii of the cones should be very close.
[/geek out]

It works out great for setting your action low and still being able to pull up on the bridge. Very versatile setup this way and no measurements needed.

 

[SustainerPlayer]

That MikeW idea deserves a sticky  :sign13:

 

[Tom]

Ha - I agree, such an obvious solution - brilliant!

 

[Strat Avenger]

If you have a bridge with individually adjustable saddles, it's a non-issue. Just set the action where you like it.

It becomes an issue only with saddles that are not individually adjustable, for example, a Floyd Rose bridge would need shims under the saddles (I discovered this when I built my Soloist); usually 2 under the high and low E strings, and 1 under the A and B string.

The TOM/STP setup can also be a challenge for the compound radius.

The 9.5" radius LSR roller nut is also an non-issue for the 10" radius at the first fret.

 

[Ddbltrbl]

That MikeW idea deserves a sticky  :sign13:

+1  ccasion14:

 

[Tom]

It becomes an issue only with saddles that are not individually adjustable, for example, a Floyd Rose bridge would need shims under the saddles (I discovered this when I built my Soloist); usually 2 under the high and low E strings, and 1 under the A and B string.

I was wondering about that ... got an itch to build an old-school 80's Soloist with the Floyd Rose, but with the compound neck, and wasn't sure about setting that thing up for a 16 inch radius (or as previously pointed out 18 inch radius by the time you extend the cone to the bridge). I think the Floyd's are built at 10.5 inch radius. So thanks for bringing that up ...