Setup/ bridge

[Tsc3]

Greetings,
My name is Tim. I’m out here in Santa Barbara, CA. I just finished my first tenor ukulele. I just strung it up and I was checking my string heights both at the first fret and 12th. Pressing down the 3rd fret my string clearance at the 1st fret is perfect ( almost touching). But at the 12th, I’m a bit over 3 mm on the 4th string and just under 3 mm at the 1st string. So, I also have very little saddle height above the bridge slot.

I was just about to remove about 1 mm f wood both sides of the slot and suddenly decided to ask for a little help. I have about .5-1 mm left at the base of the slot to the level of the wings of the bridge. So, I could take a bit more away there carefully. The strings are touching the wood on the beveled ramp at the back of the saddle slot. I want to remove a little there for sure.

My question is: is it a good idea to lower the slot more or remove a little more from the top of the bridge. If I go too deep in the slot, won’t it make the bridge much weaker for the lateral forces. But, then reducing the bridge height would do the same? I’m a little confused on this choice. Right now, my gut tells me I’d be okay to lower the slot to the height of the bridge wings. Then, also reducing the wood at the top of the bridge saddle slot area would be okay here as well. Kind of splitting the difference of the forces here.

I have Koa back and sides, with a redwood top. Rosette is Sitka spruce and everything else is Indian Rosewood. Very simple. I had some difficulty in the build as I cut all my binding channels by hand. Oh, they were okay but I had some gaps here and there that needed to be filled.

Thanks for any help here!

 

[Island Jim]

That is a nice looking uke, very good for a first build. Cutting the slot in the bridge deeper won't help you, the saddle is already too close to the top of the bridge. You could plane 1mm off the top of the bridge saddle slot and .5 mm off the saddle, that will help, but the break angle is pretty shallow already. I think the best option is carefully removing the bridge and thinning it down by sanding the bottom, or making a new bridge that isn't as tall.

 

[Tsc3]

Oooo,
I was just thinking of taking a bit off the bottom of the slot and noticed the ” break angle”. Again, I saw the shallow angle and wondered if I would be making a fatal mistake I couldn’t back out of!

I like your idea here. I’m going to do exactly as you say, but I may try to take a smaller bite off. Maybe .5-.75 mm. I’m thinking no matter which side I take off, the break angle will change?

I looked at the base of the bridge and noted that I could have thinned that before I glued it up. Next time for sure! It looks like I’m at 2 mm. I could take off .5 mm I think and still have enough for the domed shape I need.

Maybe a thicker fingerboard next time? I got my fingerboard from Luthiers Mercantile finished at about .25 “.( I’m really bummed out they are closing their doors!)

Thank you so much for the reply.I think I will take some off the top of the bridge to begin. Also, after measuring again I believe I will need to take off another .5 mm from the bottom of the saddle. Boy, this is a tightrope act!?
T

 

[Island Jim]

It is a tightrope act for sure. The trick is to get it right before gluing everything together. Allen talked about this in another post. Before I fasten the neck on I place the fretted fingerboard on the neck and the bridge in place then use a straight edge to check , the straight edge should fall right on top of of the bridge or a little bit lower. I go one step farther and put a saddle on the bridge then I can check the action before gluing up! Stew Mac sells fretted fingerboards and fret wire that is perfect for the slots. If you are going to build more I would recommend getting a Stew Mac membership that gives you free shipping.

 

[Tsc3]

Thank you for this explanation!!!!! I will definitely use this method. I like the explanation of where the straight edge should fall! I did not know this before. To be honest, I was going with the hunch that supply houses have an idea of what thicknesses can work for a project. So, I trusted that. It’s close but now, I can get waaaay closer.
T

 

[Tsc3]

Oh yes. Stewmac for sure.

 

[Kelali Kev]

It looks to me like the bridge is too thick, probably a premade bridge. You need your bridge to be the same thickness as your fingerboard to start with. I make my own bridges from fingerboards cut to bridge dimensions so the thickness is the same. If I read your description correctly, for your measurements you need to look for string height above the fret from where you are holding down the string toward the saddle and not worry about string height between the fretted string and the nut. The setup starts with the nut, making it the height you want, generally about the height of a zero fret plus a little to leave room to cut the string slots. Then when making the saddle, I have a piece of wood already made that is the thickness of the string height I want at the 12th fret, for me that is 2.6mm. I lay a straight edge on the nut and 12 fret string height gauge laying on the 12th fret, and mark the height where it hits the saddle in the bridge slot. Then you can shorten the rough saddle to that height and crown it to match your compensated saddle length. So the jist of this diatribe is that you can probably lower your bridge height in place and check your saddle height. The amount of exposure of your saddle above the bridge does not matter so much as long as it it not too tall. Hope that makes sense. Anyway you made a beautiful instrument with more detail than I would have attempted on my first instrument.

 

[Alain Lambert]

If the neck is removable, you can change the angle very slightly and the action at 12 will go down.
You can do that with the "floss" method like in a neck reset.

 

[Tsc3]

Thank you all! I shaved the bridge down and had to remake the saddle. I knew that though. I used an old saddle I had to get a ballpark on height. Then, I copied it after taking down the bridge about .75-1 mm.
Kelali, the block of wood rings a bell with me. I made a couple of classical guitars. During the setup ( I’m doing this without checking notes) I have a block of wood that simulates the bridge height. Then I place a 1 mm shim at the first fret(?) and a 2 mm shim at the 12th. This represents the string heights and gets me close.

But, making a ukulele is a different animal. I’m noting that I made things that were more like the guitar. In dimension. That was a mistake. But, these are sure a kick to make!!!! I’m already thinking of making a walnut one with probably sinker redwood or some kind of nice spruce or even lutz. But, it’s a kick!

Alain, alas my neck is not removable. But, I have been thinking of trying that. In fact, I wouldn’t mind making a steel string guitar with a removable neck. I just don’t know how. I think I need a different mold that the Spanish heel type builds I do. Trevor Gore has a newer style of bracing that would be great but, I think difficult for a first try. He uses carbon fiber and epoxy to fix the braces. Yikes! Supposed to be great though. All this will take a different mole system.

I think building another uke will really help. who knows, maybe the ukulele will be the ones I build from now on. They sure are popular here in Santa Barbara. I see big groups of people get together and play songs as a group!

 

[Tsc3]

I want to add something here that I found. Using the bridge caul was really hard. I can’t get my hand into the soundhole.

I made the caul then added a small plastic pipe clamp ( u type) to the back edge of the caul. Still not good enough. So, I drilled a hole in the plastic clamp and screwed a load wood screw to it.

I put the caul into the soundhole and got it in place without using the screw. But, getting the block out is tough. So, I screwed in the screw and used it as a lever to get the caul out. ( double sided masking tape a fixed it- a very very small amount for sure).

I’m going to re- visit that for sure. That’s a tough situation I didn’t anticipate.

 

[Tsc3]

Kelali, I make my own bridges now using a technique from Robert O’Brien. It works great but the table saw blade is just a tad too thick to use stock normal saddles. I had to sand a thicker one down to fit the slot.

I think you are exactly right about the base being too thick. Next time ……