Official Luthiers Forum!

Hi Folks

My current build has rather perplexed me... heres the situation -

As you can see from the photo the saddle is rather low, 2mm-ish (.080").... i'm very confused about this... i've done nothing out of the ordinary... normal neck angle using the Robbie O'Brien jig and method. So i'm quite confused... normally my saddles come in a bit higher than this... and i'm worried that when the eventual slight bellying occurs or humidity rises, i've no more saddle to remove to compensate and its reset time.

So, here are some facts / numbers to help diagnose the situation.... i am grateful for any help.

When i place a straight edge on the frets it comes in just over the bridge, (see photo).

The neck has a small amount of relief when strung up... more or less flat when not. The frets however are level when unstrung.

The action when strung is about 2.5mm (.099" or 3/32nds - ish .... Sorry... i'm a metric guy).

The top has the correct radius (25ft).

No humidity issues, we are right around 45%.

So i'm very confused... everything works, it plays, sounds great, good action... its just a rather low saddle...

Hope y'all can help me out...

Kind Regards.

Gary.

_________________
www.leddingtonguitars.com

How thick is your bridge?

_________________
"I've been had again"
Tim Benware
Creedmoor, NC

8mm or about 5/16ths.

And the fingerboard is about 6mm or 1/4"...

G.

_________________
www.leddingtonguitars.com

I usually have anywhere from a 1/64 to 1/16 gap between the top of the bridge and bottom of the straightedge. I put my hand in the sound hole and push up on the top at the bridge plate. If I feel it have a little more give than usual, I set the gap closer to the 1/16.

So you think my neck is slightly underset?

_________________
www.leddingtonguitars.com

The top might be deflecting too much. I made a simple tool to measure that. Just measure the deflection on a "known" top with strings off then on and compare to your top with the low saddle. You can just use a stick with coins under each end, keep track of the change.

https://imgur.com/3vrRyaw

I wouldn't call the saddle low until the guitar is strung up and actual string height is measured.

_________________
"Act your age, not your shoe size" - Prince

8mm bridge + 2mm saddle = 10mm strings above top.

I would consider that within the normal range.

If the fret plane is within normal limits unstrung (fret tops line up just over the bridge) then bridge thickness shouln't factor in. If the saddle then needs to be lower to have appropriate action, it seems that the string tension is introducing the issue. That would mean it is either A) the neck block or neck rotating slightly under tension (probably not likely) or B) the top rising more that you are used to under tension. Is this built lighter that previous guitars?

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Not sure how you got there - most of the ideas have been canvassed. Did you cut the neck mortice (might have cut the angle slightly under target) or did you start with an already morticed neck block (in which case the angle has shifted a bit while you glued it in).

How to fix? You could certainly take the bridge down a bit to give yourself more exposed saddle.

I think 25 is too much you should be about 28 to 30 if you used a 25 foot and radiused the entire top you made the center too high thusly you need more neck angle I like to see about 3/8 inch off the top of the fret plane at the point of the saddle

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

"The neck has a small amount of relief when strung up... more or less flat when not. The frets however are level when unstrung.
The action when strung is about 2.5mm (.099" or 3/32nds - ish .... Sorry... i'm a metric guy). "

Assuming you have an adjustable truss rod, if you dial out the relief it has when strung up, how much more saddle height does it give you?

Gary,

One thing that I noticed from your detailed description is that your straight-edge is on top of the frets and then just barely over the bridge. When I learned that method (from Robbie), I was taught to do that same 'measurement' without frets installed. Frets are around 1mm tall. Which might explain how you got here, but not much help in the 'what do I do now' department.

Steve

Probably But:
If it sounds good, plays good... enjoy it. Let it settle in for a few months and worse case scenario, you’ll need to set the neck back a tad. I’m asssume this is a git for yourself and not a customer.

If you have done exactly the same method before and come up with a taller saddle, then I would say your top is just flexing more than before.

It will be fine the way it is, but if you want more saddle height, you need more neck angle.

_________________
Pat

Thanks for the tips folks... i will take you advices and delve deeper into this mystery... but indeed, for now i will just play it as is and see how tings progress.

Best.

G.

_________________
www.leddingtonguitars.com