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I'm ready to install my bridge. It has the pin holes but no slot yet. This is a Martin style guitar. The dimensions for the saddle are there but confusing.

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Hutch

Get the heck off the couch and go build a guitar!!!!

the variable is where the fretboard ends up you place the bridge after the neck is sent you can't place a bridge until you know where the nut is.

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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

Like John said. Work off of what’s actually there not theoreticals. Don’t forget to add compensation.

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Jim Watts
http://jameswattsguitars.com

I find the stew Mac fret calculator quite accurate, and will give you the actual speaking length of each string with compensation. You should be able to get a location from that…

And if you have an inclination to be hyper precise what really matters is the saddle location for intonation. The bridge location matters for proper placement over the X brace since the bridge is one of the most massive and important braces on a guitar top.

But the saddle location is all about playing in tune. We glue our bridges on without a saddle slot and then we mill the saddle slot.

Be sure to be precise on the left to right, right to left placement of the bridge too so strings are not too close to the edge or hanging off the neck. There are fancy centerline finders for necks offered at StewMac and my favorite Luthier Tools where I bought mine nearly 20 years ago now. But at work we just use a straight edge and masking tape in four locations on the neck making a pencil dot for the center and extending the straight edge over the bridge patch on the top to transfer the center.

there are a few variable on this process. The higher the action you want the closer to the front of the slot you want to be.

How much the top will rise is another. So follow this video and you will be fine. There should be enough room that after a few weeks you can compensate the saddle for final intonation
https://www.youtube.com/watch?v=EJG5Frbu78c

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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

If not set up to mill the slot on the body after bridge install (agree with Mr. Breakstone - it really is the best method for shops doing a lot of reset or bridge location correction work), determine the saddle compensation desired and mill the bridge slot. An option is to measure off an existing bridge to get minimum slot-to-pin centerline distance, or pull the measurements from the drawings on the SM site.

- Locate the bridge on the centerline of the neck and square it up

- Use a Saddlematic set for your compensation and fine-tune the bridge location so that the front of the saddle slot coincides with the treble and bass side pointers ( I built mine from some hobby shop music wire, some set screws, and a bit of scrap phenolic - no more or less accurate than the StewMac version, but with time being money, you might just spend the $80 or so and hire it done)

- Recheck the bridge for square to the centerline (it should be if on centerline and compensation pins set correctly)

- Use some low-tack signmaker's tape (StewMac also sells this, or source from industry suppliers) to mark the front edge and end-of-wing placement of bridge on guitar top, then either pocket or scribe and strip the finish off for net-shape install the bridge on the top.

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For the times they are a changin'

- Bob Dylan

What are you guys using to mill the saddle slot after bridge is installed? A mill or CNC?

I use the StewMac saddle slot jig and a Rigid laminate trimmer. Boy, that jig sure has gotten expensive!

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Steve Smith
"Music is what feelings sound like"

I just made my own saddle slotting jig.
I've seen several on this forum made just from scrap ply which work fine.
Mine is 4 strips of 50mm x 6mm aluminium, a 150mm square of perspex, and some screws. There are felt lined supports in each corner.
I use a Makita 700/ series laminate trimmer which is shared between several other jigs with their own bases.
Relatively simple and inexpensive.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

My opinion:

I think if ya gotta ask, then you don't already have the experience and maybe not the tooling. Yes, it's ideal to cut the saddle slot 'in situ', but I suggest that the end result drives the process and slotting in place is a heap harder than cutting the slot with a benchtop process. And a Saddlematic locates the slot where it needs to be and the bridge follows after the slot is cut on the bridge prior to installation. Besides which, slotting mistakes are lots easier to address if the bridge isn't glued on.

As an experiment, I used a Saddlematic to locate a bridge and then asked a luthier to locate the bridge to his standard. Same answer, within a whisker. I trust my Saddlematic.

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Peter Havriluk

Richard, I match the center line of the bridge (between the 3 and four pin hole) with the centerline from the LUTHIER SUPPLIERS jig (marked on white tape on the bridge position). I locate the position of the bridge/ saddle with the Saddlematic. I use masking tape block locators (thanks Beau Hannom) to locate the bridge position solidly, clamp the bridge in place and drill 2 pilots in the top and continue with surface prep and glueing of the bridge.

One could make either of these jigs but it would take time, precision and materials. I am 100% satisfied with the tools, process and results, and the sting of the price of the centerline and saddle location jigs is long forgotten.

THe Saddlematic jig has (free) downloadable PDF instruction from StewMac. You might have a look at these. The location of the slot/saddle is a bit confusing as StewMac uses two different methods to describe it throughout their site (compensation values in fractions of an inch + location of the pins). BOTH descriptions yield the same placement. This is because one description uses the center of the saddle with one distance of the pins, while the other description uses the front of the saddle with a different distance of the pins. BOTH yield the same location, so pick ONE and stick with the measurements and the method of saddle location (front edge or center).

If the slot/ saddle location being quoted is the front of the slot/ saddle the compensation distance quoted is shorter by [1/2 the slot width]. Drawing both out on paper (front of saddle/ slot and middle of saddle slot) with their respective compensation measurements helps to remove the confusion (sort of).

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Measure Twice,

Karl Borum

In case you didn't see my other thread, I made my own saddlematic and it was dead simple. Of course the proof is in the pudding. I will be stringing this up over the coming weekend. After almost 6 years.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Kewl!!!! Nicely done Colin that looks fantastic!

Peter my mention of slotting on the guitar is for people who can't get enough Lutherie information and want to know and learn as much as they can. I didn't post it as an "easy" solution even though it is much easier than not slotting on the guitar when you have the proper jig.

Additionally someone who has an interest in say a saddle slotting jig also along the way HAS to learn how to locate the saddle properly from scratch like I did yesterday on a bass with a sliding bridge so they know where to put the jig. There was a method here to my suggestion.

I don't doubt that your saddlematic is accurate but it's also very limited in what it can do. Martin used a jig like the saddlematic too and it was corrupted in the early 70's and no one noticed that it had been moved a tad. Thousands of 18's, 28's and 35's were built with the saddle, in Martin's case the bridge in the wrong location as a result. This is well known and for decades now Martin has been covering the fix under warranty if it bothers the original owner. It's not noticeable most of the time in the cowboy chord region but people who use the neck notice it. We've fixed dozens perhaps more and it was an easy fix for us with the saddle jig.

1) Mill a uniform slot
2). Plug with matching wood
3) Cut new slot in the proper location
4) next

It's also a solution to other saddle related issues and makes some pretty sexy functionality available to us such as an imbedded slot in a slot for a UST (under saddle transducer). No need to make a new saddle or reduce the height of the existing one unless it's wrong from the get go.

Want to lean your saddle back which I don't personally agree with.... no problem it does that too.

One thing I've learned in my nearly 20 years on the OLF is that some of us want to learn all we can and if there is that last 5% of accuracy available somehow someone here will be keen to want to get there. We were and we are not alone there are lots of folks here who took jig making to the extreme and ended up with some pretty cool functionality.

So I mention the 400 level stuff for those who are interested and as we can see Colin certainly was enough to build his own saddle slotting jig. Very cool.

By the way slotting on the guitar is taught as the way to go even for beginning builders at one school that I know of. They have a saddle jig which is pretty much a must for a professional Luthier.

So lots of ways to proceed and had I not brought that up we may not have had the opportunity to see what our friend Colin came up with that looks excellent to me.

Colin I love the knob with lines and numbers. We don't have those but your idea makes things repeatable, very cool.

I did see that post, after the fact- very well executed.
Looking forward to your long-awaited string up.
The first couple of minutes is always amazing, how the sound improves, and it never stops getting better.
Someone said, "it's the wood learning to be a guitar".

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Measure Twice,

Karl Borum

I guess I did a poor job of communicating this. I was really looking for how far to set the slot from the front edge of the bridge. How close to the pins. I scaled it off the print but I would have liked more numbers for everything about a standard bridge. I have no problem locating the saddle slot. It's already done and installed but there's always next time.

The dimensions on the plan that I showed are weird. One goes to the back of the saddle and the other is in space. I didn't use either one.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Hutch there is no such thing as a standard bridge. Everyone does their own thing.

There are however many best practices and physics too that should inform your choices.

Much has been shared and written on the OLF including my famous thread that brought the house down long ago with people fighting openly called "Why Are Bridges Shaped As They Are." I think that Lance had to delete the entire thread we got so ugly over this.... Like you I wanted to know the design details and goals and that thread got very ugly back in maybe in 2006ish.

Anyway serviceability should guide what you do. You want a saddle that can be removed and serviced and in some parts/climates people swap out saddles seasonally. Some builders ship with winter and summer saddles. I did and got the idea from Mario P on the OLF back when he could stand it here.

Break angle is important too you want enough but not too much so look into that.

Enough wood in front of the saddle so that the saddle over time does not split the bridge which we see in the repair business from time to time.

Even how the bridge blank is cut, riff sawn is less prone to splitting along the pin holes should be considered.

I was of the camp that I wanted about 2/3rds of my saddle in the slot and 1/3 of the saddle proud of the slot when all was said and done. Others do it differently.

The compensation angle is key too and not everyone uses the same angle.

This is important some things will happen to any guitar years out such as the need for a neck reset or a bridge lifting. So the shape of a bridge is key to how serviceable it is. Will a skilled luthier be able to remove the bridge and reinstall with zero hint or finish damage that it was ever repaired is and should be a consideration. Bridges shaped with elaborate designs perhaps like turkey feathers are a PITA and relegate the instrument to a messy repair some day what will likely show and devalue the instrument perhaps greatly....

Do you shape the bridge bottom to match the dome of the top, I did and we, our business does or do you make it flat and smash it on with the biggest clamps you can find (not recommended although major makers and even some repair people do this).

The design of the wings needs to again consider serviceability. If the wings are very thin when the bridge has to be reglued someday cleaning up the bottom may and does reduce the thickness of the bridge. Make sure there is enough thickness in your design of the wings that the bridge can be lowered with losing its profile and shape.

Or.....

You can for now look at a Martin bridge, even purchase one and go with that they work just fine and meet all the above criteria.

Bridge weight is a science unto itself as are what materials make great bridges.

Bridges with inlay or laminated construction perhaps with CF layers will they be able to stand me and my heat lamp when the dang thing lifts and your client brings it to me to fix? Again serviceability should be a North Star in your thinking and you may also find that serviceability rules out a lot of the stuff that makes a guitar more complex to make and much more difficult to maintain.

Funny thing I spent a lot of time on my Heshtone bridge design and looking back I still got some thing wrong. Nothing huge mind you but my wings are a bit too thin and my pin hole pattern compromised some break angles.

Oh and before I go what about a pick-up? If there is any chance of a pick-up make the instrument pick-up friendly and don't use a split saddle or a configuration that commercial, off the shelf pup offerings will not fit.

Or, again just use a Martin style bridge and decide what you want to do about a personal bridge design perhaps on subsequent builds. A lot to be said for finishing these early instruments and moving on.

Hesh, that was a wonderful read and the take from it was, just use Martin style bridges. Well I guess I'll have to buy one to get the dimensions off of it. Nah, I'll take some measurements at my next jam. Everyone plays martins there so I should be able to get good measurements from several guitars.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Here is a blueprint of a Martin style bridge, provided by our friends at StewMac:

https://www.stewmac.com/parts-and-hardw ... ar-bridge/

Click on the third photo.

Thanks Hutch and Don: Yeah there is a tendency here to get all creative on early builds but folks who do this without understanding why stuff looks like it does today are taking a big risk and we often see the down side of that risk. Reinventing the wheel really should include fully understanding the wheel as it is first in my experience.

There is a very good reason why a conventionally built and styled instrument like a Martin has endured. They work.

It's sort of like realizing how smart our parents got after we turned thirtry...

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Peter Havriluk

Copying a Martin bridge was what I did when I started and quite honestly the only major change I made later was aligning the pin holes parallel to the saddle slot and going with unslotted bridge pins.

One thing I like about the Martin design is the asymmetric radius that helps even out the amount of exposed saddle on the bass and treble side.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Thank you so much. That's exactly what I needed.

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Hutch

Get the heck off the couch and go build a guitar!!!!

It is! Very well said Peter! I got that one wrong with my parents too...