Compound Radius Vs. Straight neck

[thearmofbarlow]

compound radii are probably 99% of their neck business

I'd actually be interested in finding out, because an awful lot of us seem to be ordering 12" straights - I think compound might be more like 70%. And among the OEM market, an awful lot of the "re-assembler" companies would like you to think that their guitars really are scratched out of ancient wood by little forest gnomes and hand-everything - and advertising "compound radius" and "side-adjuster" is kind of a dead giveaway that them little forest gnomes are sitting at a desk making up advertising whooey in between screwing together other people's parts. I don't suppose Warmoth is going to tell li'l ol' me, not about the OEM biz at least  :-\

It would also be nice to know, in an idle- curiosity kind of way, what percentage of their business is off the showcase and what percent is their normal, special, orders? I date back to the days when there was no showcase so special was normal, but it seems to be blooping up into this huge thing. And based on the seemingly-huge percentage of ordinary Strat/ordinary whammy/standard thin w/Kluson-orifice stuff they Showcase, there are a lot of people out there not on the forum - like 80, 90%? (And ALL furtively buying imitation "Fender" decals offa Ebay, so they can pretend they got their guitar at Musician's Friend!?!)

Mostly correct, except for the MF part. They'll whack a CS neckplate or sticker or some crap on it and brag about this awesome deal they got on eBay...

It really sickens me how attached people are to meaningless names.

Then again my main guitar, the one that's stuck by me while eighty or ninety others have fallen, is a Charvette neck on a Washburn body that cost me $90 total to build. So I may be biased in favor of offbeat stuff. :laughing11:

 

[Super Turbo Deluxe Custom]

compound radii are probably 99% of their neck business

I'd actually be interested in finding out, because an awful lot of us seem to be ordering 12" straights - I think compound might be more like 70%.

I just ordered a straight 12 for no other reason so that I can actually work on it.  How would one go about using/finding/making a compound block?  Much of the hoopla about the advantages of a compound radius are touted by those moving from a rounder, vintage radius. 

 

[SustainerPlayer]

How would one go about using/finding/making a compound block? 

For fret leveling? You don't use that. I use a levelling file.

Combine that with the Ron Kirn way of levelling frets and you are good to go. Compound radius or not.

 

[Cagey]

I don't know. I've never heard of a compound block. I doubt such a thing exists. I typically use a flat hard rubber block if there are any contours to deal with, or ultra-flat diamond-impregnated steel, depending on what I'm doing. If something is past the point where either of those would work, it's time to replace it. For what high-quality necks go for these days, it's rarely even worth re-fretting them unless it's a highly unusual neck. Buy a new one, dress it, throw a sticker on it and call it a love story.

 

[croquet hoop]

Since we're talking about leveling : it is worth it to try to find something flat and long enough to cover the entire fretboard (like Ron Kirn's piece of Corian), or will using something shorter like this or that (or any other straight 6" file) be equally convenient/productive?

 

[thearmofbarlow]

Since we're talking about leveling : it is worth it to try to find something flat and long enough to cover the entire fretboard (like Ron Kirn's piece of Corian), or will using something shorter like this or that (or any other straight 6" file) be equally convenient/productive?

I keep one of the smaller fret level files in my toolbox, if that's any indication. Probably not.  :laughing3:

The shorter files are just fine. The idea is that you're making long, straight strokes from one end to the other (no jokes), without hitting the nut (no jokes), or head (stock (no jokes)).

Wait, what are we talking about?

Oh yeah. The smaller type has worked for a very long time and will continue doing so. It's really just what you're used to. It would take me some time to get the Kirn method working for me, but with the smaller files I could do the job without thinking about it.

 

[stubhead]

It's important -critical! - to have a straight edge that's as long as the neck (I actually like my 32" and 36" ones too, hello bridge!). But for leveling, no - as long you check what you're doing with the long one. You're leveling the INK off. I use a 10" Sharpening stone (that's never sharpened anything) and I don't use the stone to cut the frets, I wrap it with sandpaper. There's a sea-change here, as the quality of abrasive papers get better there are less and less things being done with toothy files and more and more being done with sandpaper, diamond and tungsten carbide. Chatter marks are so-oo old-fashioned... the improvements in the abrasives are, more than anything, improvement in the glues.

 

[thearmofbarlow]

Something else I thought I'd add... I've seen people being warned off of using ToM's with compound radius boards. This doesn't make sense to me.

It doesn't make that much of a difference as far as playability unless you're one of the people that's UBER sensitive to string height. It will vary from place to place up and down the neck but it shouldn't be noticeable for most people.

When it comes to matching radius... well, that's not going to happen with anything you use. Either way you're screwed. With individual height adjustment you'll be doing one of two things. Matching one or the other radius, or finding a compromise. More often than not it's a compromise and, really, that's exactly what a ToM radius is.

 

[Cagey]

Since we're talking about leveling : it is worth it to try to find something flat and long enough to cover the entire fretboard (like Ron Kirn's piece of Corian), or will using something shorter like this or that (or any other straight 6" file) be equally convenient/productive?

I use both, depending on the needs of the job at hand. With necks that are in fairly sad shape I'll just knock the nut off and start with a long tool, then finish up with something shorter before moving on to crowning.

 

[croquet hoop]

Thanks for all the answers!

 

[stubhead]

When it comes to matching radius... well, that's not going to happen with anything you use. Either way you're screwed. With individual height adjustment you'll be doing one of two things. Matching one or the other radius, or finding a compromise. More often than not it's a compromise and, really, that's exactly what a ToM radius is.

I have to say, you misunderstand the math here. A compound radius fingerboard is a section of a cone, and the cone keeps increasing in flatness as it continues past the end of the neck, over the pickups, and to the bridge. In fact, for a guitar to be correctly setup for Warmoth's 10"-16" radius neck, the bridge pieces need to be set for about a 19" radius. So a Floyd Rose or a tune-o-matic bridge needs to actually be flatter for a Warmoth compound neck, than it would need to be for a straight 16" radius.

I have my own reasons for preferring a straight 12" but good action is still good action. Of course, action height and how well a guitar plays is a subjective thing, and it matters more for some styles far more than for others. But people like Paul Gilbert, John McLaughlin, and Brent Mason don't spend $300 on a fret level for no reason, and Ron Kirn's "about ten minutes" was a little joke, as anybody who's read the rest of his posts will realize.

Here's the math for shimming a Floyd:

This is an easy guide to shimming your Original Floyd Rose saddles to get a close match to your fretboard radius. This way you can dial it in very fast to get very close to a perfect match for best action.

Note: Unless your guitar has a 10" non-compound fretboard radius, you will need to shim your floyd saddles if you want good action. This is because the ORIGINAL Floyd bridge radius = 10".

You can buy .2mm shims that fit Floyd saddles on the internet in packs of 6 or 12. Just do a google search. To find out how many .2 mm shims to add to each string saddle, see below (note that the D and G strings get no shim):

Fingerboard Radius (at bridge) / E strings # shims / A and B strings # shims
10" / 0 / 0
12" / 1 / 0
14" / 2 / 1
16" / 2 / 1
18" / 3 / 1

You can also make your own shims out of coke soda cans (cut out of the coke can skin, which is about .1mm thick) or you can use copper shielding tape (that you shield your guitar with.) If you do either of these, you should measure the thickness with a micrometer. You can also cut up feeler gages to get your appropriate thickness. Here is a table of thickness to add to each string:

Fingerboard Radius (at bridge) / E strings / A and B strings
10" / none / none
12" / .2 mm / .1 mm
14" / .4 mm / .2 mm
16" / .5 mm / .2 mm
18" / .6 mm / .2 mm

For Warmoth compound necks, use the 18" row for radius at bridge to find out what to add. For some other compound neck, you'll need to estimate or calculate your fretboard radius at the bridge ( the radius flattens as you get closer to the bridge for a compound neck.

 

[Dan025]

you can also measure individual string height. and get them all the same.

i guess some don't get the point of a compound radius. in an ideal compound radius setup the taper of the nut width to bridge if projected past the nut converges over the tip of the cone that the compund radius creates. it's not to have a big radius for bends and small for comfort, that's a side effect. using this geometry gets rid of a situation where the outer strings are not parallel to the axis of the cylinder that the fretboard is a part of. when the strings can't shar a plane with the axis of the playing surface there is a hump the strings pass over. this hump is reduced by neck relief and added bridge height helps but with a compound radius those things can be more a part of preference or feel and less necessity. there will still need to be either releif or added bridge height for the arc a vibrating string creates but a compound eliminates the additional factor.

the fact that a smaller radius makes playing more comfortable and bigger makes bends go farther only makes compounds more logical. infact a compound should rival the bendability of a strait radius that's near the bridge radius so you may get all around better performance and comfort than a strait 16"

i kind wish there was 2 or 3 compound options though. maybe one that starts at 8" to 9" to get the fender diehards to try it. a little flatter than 7-1/4 but still a noticeable radius and not as flat as 9-1/2 but easily as playable as 9-1/2. then maybe a compound that starts at 12 or 14 for the jackson fans.

 

[thearmofbarlow]

When it comes to matching radius... well, that's not going to happen with anything you use. Either way you're screwed. With individual height adjustment you'll be doing one of two things. Matching one or the other radius, or finding a compromise. More often than not it's a compromise and, really, that's exactly what a ToM radius is.

I have to say, you misunderstand the math here. A compound radius fingerboard is a section of a cone, and the cone keeps increasing in flatness as it continues past the end of the neck, over the pickups, and to the bridge. In fact, for a guitar to be correctly setup for Warmoth's 10"-16" radius neck, the bridge pieces need to be set for about a 19" radius. So a Floyd Rose or a tune-o-matic bridge needs to actually be flatter for a Warmoth compound neck, than it would need to be for a straight 16" radius.

Have I said how much I love this place? I really freaking do.

You are of course correct. I was never good at conic sections. :laughing11:

 

[stubhead]

Have I said how much I love this place? I really freaking do.

Well, you sir, at least, didn't try and Stand Tall and Argue about the damn things - this place is littered with the corpses of dwarves we've had to crush with the Mighty Weight of Pure Logic.

You are of course correct. I was never good at conic sections.

Neither was I, till I found out how much I enjoyed crushing dwarves. :hello2:

 

[thearmofbarlow]

Well, you sir, at least, didn't try and Stand Tall and Argue about the damn things - this place is littered with the corpses of dwarves we've had to crush with the Mighty Weight of Pure Logic.

The dumbass part is that prior to posting that I was thinking about how compound radius boards are just conic sections.  :laughing7:

I'll stand up and argue with anyone as long as they're wrong and stupid (I think I've been banned from TGP like three times now for doing just that) but when someone points out that I am, in fact, wrong... I'm usually happy about that. I can't stand the spread of misinformation and will append my knowledge accordingly.

Which is why I prefer to argue about stuff you can't prove one way or the other. Much more interesting.  :laughing3:

 

[Strat Avenger]

I keep seeing people state that the Floyd is a 10" radius. It's not. It is a 12" radius, and the locking nut is a 10" radius.

I also have a really hard time buying the "math" described here for radius.
Anything past the last fret is irrelevant as far as I'm concerned. I adjust my action @ the 12th fret, so if the radius (compound) at the 12th is 12" or 14", that's what my bridge radius needs to be to make the string height even for all 6 strings over the 12th fret. Not 18" or 19".  If I wanted to set my action at the 22nd fret, then my bridge would need to be set (or shimmed as the case may be) to 16".  If the fretboard continued to the bridge, and you wanted to set your action at the last fret, you would need to set it at 18" or 19", but that is never the case.

The fretboard radius graduates, not the string radius.

 

[thearmofbarlow]

Anything past the last fret is irrelevant as far as I'm concerned.

As far as physics and reality are concerned they're completely relevant.

I adjust my action @ the 12th fret, so if the radius (compound) at the 12th is 12" or 14", that's what my bridge radius needs to be to make the string height even for all 6 strings over the 12th fret. Not 18" or 19".  If I wanted to set my action at the 22nd fret, then my bridge would need to be set (or shimmed as the case may be) to 16".  If the fretboard continued to the bridge, and you wanted to set your action at the last fret, you would need to set it at 18" or 19", but that is never the case.

The fretboard radius graduates, not the string radius.

There is no difference between fretboard and string radius. You want the strings to maintain a consistent height above the fret throughout its entire length on a compound radius.

Let's say that yellow 9" radius line is the nut and the red 16" line is the end of the fretboard. See how the height differs? It does the same on your guitars. Further, the radius is constantly changing. It's different from one fret to another. By setting the bridge radius to match the middle of the fretboard you're doing two detrimental things to your setup. One, you're raising the outer strings up higher near the nut. This can mask issues that may be present at that end. Second, you're raising the middle strings up higher at the end of the fretboard. This will create an unbalanced feel. If you're not sensitive to string height or radius then screw it. It doesn't matter anyway.

Take some time and set your bridge up with a larger radius someday. You'll probably note a marked improvement in playability.

 

[Cagey]

The fretboard radius graduates, not the string radius. 

The string radius also has to graduate in order to follow the fretboard radius.

Let's look at it a different way - by losing one dimension.

Assume you have a perfectly flat neck and bridge; no radius at all. Now it's a two dimensional plane having length and width. If your neck runs from 1 11/16" wide at the nut to 2 3/16" wide at the heel (pretty common dimensions), then playable string spacing at the nut will be about 1 9/16" wide and 2 1/16" wide at the heel in order for the strings to evenly follow the edges of the neck. The strings are fanning out.

Since the end points of the strings are well past the heel, the strings will continue to fan out until they reach their endpoint (the bridge), so the spacing will have to be a little wider there as well. Figure about 2 3/16".

Now, add a third dimension - height. But, it's not a uniform dimension; it's a curve that varies at a constant rate perpendicular to length. Picture a cone. The same thing happens - the farther along the length you go, the flatter the curve gets. So, if you start at a point on the cone where it has a 10" radius and at ~18 linear inches down the cone you have a radius of 16", then at ~25" (our endpoint) you have a radius of ~19". This allows us to have a fairly constant string height.

Of course, the strings are different diameters and vibrate different distances, and the neck is not flat along its linear length due to the need for relief to accommodate clearance for string vibration, so dimensional reality will be a bit off theoretical. But, the end result is a compound radius neck will require a flatter bridge (larger radius) than the finishing radius on the neck.

 

[Super Turbo Deluxe Custom]

 

The fretboard radius graduates, not the string radius.

You want the strings to match the fretboard radius, so they must graduate the entire scale length on a compound radius, not just the length of the fretboard.

 

[Super Turbo Deluxe Custom]

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It's so simple.  It's all ball bearings these days.​