Banjo Hangout Logo
Banjo Hangout Logo

Premier Sponsors

667
Banjo Lovers Online


May 16, 2021 - 4:49:01 PM
94 posts since 2/18/2021

I just finished assembling a Saga OK-2 kit and can't get the neck centered properly, side-to-side. I've tried shifting the neck to the right (facing the front) as much as I can, but it runs into the j-hook near the 1st string -- can only do so much. 

Advice on the proper way to address this would be much appreciated. 

This was my first attempt at finishing a banjo neck and doing an overlay. It's not perfect, but I'm pretty proud of how the peg head turned out (wanted to try an inlay, but figured I'd start simple). Not sure that I'm going to love the aluminum pot or the arch top, but time will tell. 


Edited by - Clutch Cargo on 05/16/2021 16:50:10

May 16, 2021 - 5:04:43 PM
like this

mbanza

USA

2340 posts since 9/16/2007

First, you need to ensure that the tailpiece is centered. If it is, you can proceed to move the neck to the left which should improve your banjo's geometry. After that, if you still can't get the strings centered, the heel cut is a bit off and can be addressed with a shim on the side where needed or by slight re-carving of the heel.

May 16, 2021 - 5:52:41 PM
like this

3758 posts since 5/29/2011

Follow Verne's suggestions. If you do need to shim the neck to center it then try using a flat toothpick(if you can still find one). The neck is not off center enough to need more than that.
Saga does make a resonator kit if you find you don't care for the open backed arch top. These banjos sound pretty decent when they are set up properly. BTW, you did a fine job on your finish work.

May 16, 2021 - 8:02:56 PM

94 posts since 2/18/2021

quote:
Originally posted by mbanza

First, you need to ensure that the tailpiece is centered. If it is, you can proceed to move the neck to the left which should improve your banjo's geometry. After that, if you still can't get the strings centered, the heel cut is a bit off and can be addressed with a shim on the side where needed or by slight re-carving of the heel.


I'll check again, but already tried moving the tailpiece and neck to the extents that they could move, so I suspect a shim and/or re-carving the heel is next. 

When you say move the neck to the left, is that with the orientation in the first picture? (facing the top of the banjo with neck pointing up)? If so, wouldn't that move the 1st string even closer to the edge?

May 16, 2021 - 8:15:24 PM

94 posts since 2/18/2021

quote:
Originally posted by Culloden

Follow Verne's suggestions. If you do need to shim the neck to center it then try using a flat toothpick(if you can still find one). The neck is not off center enough to need more than that.
Saga does make a resonator kit if you find you don't care for the open backed arch top. These banjos sound pretty decent when they are set up properly. BTW, you did a fine job on your finish work.


I'll try the flat toothpick trick. Not long ago I had to adjust the neck angle on an old Kay banjo and the only thing I could think of was to use a few layers of cloth gaffers tape. It seems to work fine, but hard to say if it will hold up over time.

I can see how the aluminum rim would make sense with a resonator.

Thanks for the kind words on the finish.

Edited by - Clutch Cargo on 05/16/2021 20:18:24

May 16, 2021 - 8:46:21 PM
like this

mbanza

USA

2340 posts since 9/16/2007

Clutch Cargo: "When you say move the neck to the left, is that with the orientation in the first picture? (facing the top of the banjo with neck pointing up)? If so, wouldn't that move the 1st string even closer to the edge?"

To answer this question, yes, it is with that orientation, and since you are rotating the neck about a center, the strings will move the same direction you have moved the neck. Seems counter intuitive, but tie a string to the end of a pencil and move it around a cup, you'll see how it works.

May 17, 2021 - 8:31:58 AM

94 posts since 2/18/2021

quote:
Originally posted by mbanza

Clutch Cargo: "When you say move the neck to the left, is that with the orientation in the first picture? (facing the top of the banjo with neck pointing up)? If so, wouldn't that move the 1st string even closer to the edge?"

To answer this question, yes, it is with that orientation, and since you are rotating the neck about a center, the strings will move the same direction you have moved the neck. Seems counter intuitive, but tie a string to the end of a pencil and move it around a cup, you'll see how it works.


hmmm.... yes, that is counter-intuitive, but I see what you mean. Moving the neck to the left is really rotating it CCW about the center of the rim. I are an engineer, so I like to quantify things if it's easy (it is in this case). A formula to estimate the nut movement is: 

nut movement = angle * radius/57.3 

Guessing a radius of 30 inches from the center of the pot to the nut and a neck rotation of 1 degree, the nut will move about 0.52". Half an inch per degree of neck rotation is a pretty big movement.

Will try playing with it again tonight, still think I'm going to need some type of shim to tweak the angle but will start with centering the tailpiece and work from there. Thanks for your help.

May 17, 2021 - 8:53:56 AM

3061 posts since 2/18/2009

From the pictures, to my eye it looks like either the hooks are angled to one side or the hole in the neck heel or the hole in the rim is off center. It seems like the neck should be centered between the adjacent hooks, but I can't see enough to tell why it's not. If this is off it can make the neck be skewed to one side, but you may not need to shim it if the neck is indeed off center on the pot.

May 17, 2021 - 11:01:57 AM

94 posts since 2/18/2021

quote:
Originally posted by Zachary Hoyt

From the pictures, to my eye it looks like either the hooks are angled to one side or the hole in the neck heel or the hole in the rim is off center. It seems like the neck should be centered between the adjacent hooks, but I can't see enough to tell why it's not. If this is off it can make the neck be skewed to one side, but you may not need to shim it if the neck is indeed off center on the pot.


The first picture shows my (failed) attempt to center the strings by moving the neck as far right/CW as it will go, that's why it looks so cockeyed. The hooks are actually pretty straight (at a right angle to top/bottom of the rim), so I think the tension hoop is in the right vicinity.

Based on Mbanza's advice, I made sure the tailpiece was centered and then moved the neck as far left as it would go. Unfortunately, the strings are still pretty skewed toward the 1st string side. Good news is, the neck is centered between the hooks pretty well now.

See the pictures here... sorry, it's hard to get rid of the parallax entirely.. I can take more pictures on request.

Would it make sense to slightly enlarge the holes in the rim to allow the neck more travel to the left/CCW? I'm an old hand at metal work, filing aluminum with a round file or dremel with a 3/8" sanding drum, etc. But then the neck might end up against the other hook?

I'd rather deal with the root cause of the problem (like the holes in the rim being off, or the heel being carved incorrectly) if at all possible.


May 17, 2021 - 11:41:45 AM
likes this

1711 posts since 2/4/2013

quote:
Originally posted by Clutch Cargo

Would it make sense to slightly enlarge the holes in the rim to allow the neck more travel to the left/CCW? I'm an old hand at metal work, filing aluminum with a round file or dremel with a 3/8" sanding drum, etc. But then the neck might end up against the other hook?

I'd rather deal with the root cause of the problem (like the holes in the rim being off, or the heel being carved incorrectly) if at all possible.


Could the problem be that the bolts in the neck have been installed in slightly the wrong place?

May 17, 2021 - 12:33:16 PM
like this

3061 posts since 2/18/2009

Once the neck is centered on the rim and the tailpiece is centered on the other side then I think the only remaining possibility is that the heel cut is slightly out of alignment. As others have suggested a shim is a good way to test this, and then if you prefer you can trim a bit off the long side of the heel, or just leave it with a shim on the short side.

May 17, 2021 - 2:26:53 PM

94 posts since 2/18/2021

quote:
Originally posted by GrahamHawker
quote:
Originally posted by Clutch Cargo

Would it make sense to slightly enlarge the holes in the rim to allow the neck more travel to the left/CCW? I'm an old hand at metal work, filing aluminum with a round file or dremel with a 3/8" sanding drum, etc. But then the neck might end up against the other hook?

I'd rather deal with the root cause of the problem (like the holes in the rim being off, or the heel being carved incorrectly) if at all possible.


Could the problem be that the bolts in the neck have been installed in slightly the wrong place?


Yes, that seems like a possibility, but I kind of hope not -- not sure  where the right spot is supposed to be. Dead center on the heel? Slightly off to one side?

It probably makes the most sense to start with options/tests that don't require any permanent modifications. So after moving the neck and tailpiece have failed, a shim is probably the next thing to try.

May 17, 2021 - 2:35:13 PM

94 posts since 2/18/2021

quote:
Originally posted by Zachary Hoyt

Once the neck is centered on the rim and the tailpiece is centered on the other side then I think the only remaining possibility is that the heel cut is slightly out of alignment. As others have suggested a shim is a good way to test this, and then if you prefer you can trim a bit off the long side of the heel, or just leave it with a shim on the short side.


Wondering how trimming the heel is done without losing the rim radius? Round file or rasp and cover the surface to be trimmed with pencil lead so you can track that material is being removed evenly? Seems like there's a lot of ways to make things worse!

Maybe a sanding block with the diameter of the rim?

Edited by - Clutch Cargo on 05/17/2021 14:37:45

May 17, 2021 - 2:56:12 PM

8 posts since 10/11/2018

Why dont you plug the tailpiece and slightly move to the left ? cheers Rick

May 17, 2021 - 3:15:26 PM

3061 posts since 2/18/2009

When I have to trim a heel I use a short chip carving knife and a 1/2" chisel, both made as sharp as I can get them, and proceed carefully. In your case there are other options, since you have a coordinator rod instead of a dowel stick, so you can remove it and have unobstructed access to the full heel. All that matters is that the two sides fit well against the rim, and it looks better if the bottom and top fit nicely too. The interior of the heel surface can be cut slightly deeper without doing any harm. If you figure out what size of shim is needed and you don't want a permanent shim you can cut away the thickness of the shim from the 5th string side of the neck and then taper the cut to nothing near the 1st string side. Or there's nothing wrong with keeping the shim, it will work fine and since it's your banjo you don't have to worry what anyone else thinks about the shim.

May 17, 2021 - 7:25:31 PM
likes this

94 posts since 2/18/2021

quote:
Originally posted by Zachary Hoyt

When I have to trim a heel I use a short chip carving knife and a 1/2" chisel, both made as sharp as I can get them, and proceed carefully. In your case there are other options, since you have a coordinator rod instead of a dowel stick, so you can remove it and have unobstructed access to the full heel. All that matters is that the two sides fit well against the rim, and it looks better if the bottom and top fit nicely too. The interior of the heel surface can be cut slightly deeper without doing any harm. If you figure out what size of shim is needed and you don't want a permanent shim you can cut away the thickness of the shim from the 5th string side of the neck and then taper the cut to nothing near the 1st string side. Or there's nothing wrong with keeping the shim, it will work fine and since it's your banjo you don't have to worry what anyone else thinks about the shim.


I made a shim from 3 layers of cloth gaffer's tape which measures out to about 0.030" uncompressed. This seems to get things pretty close to centered, the banjo is playable now.

Will let that be for awhile, and just play it for now. Maybe later will try trimming the 5th string side by that thickness as you say above.

Thanks to you and everyone else for the advice!


May 18, 2021 - 11:29:02 AM

94 posts since 2/18/2021

One more question: does the heel need to be trimmed to get the right neck angle also? and what is the right angle?

When I first attached the neck, I snugged the coordinator rod so the heel was perfectly in contact with the rim, but the action seemed very low. Not knowing any better, I used the coordinator rod to change the neck angle to get the string action I wanted. You can see the gap at the bottom of the heel in the picture above, which bothers me.

Then Zach's comments about trimming the heel for centering and how it should contact the rim got me thinking. Then I searched through old threads about coordinator rod adjustment and realize I'm totally out of my depth here and don't know what I'm doing.

May 18, 2021 - 11:51:37 AM

1711 posts since 2/4/2013

quote:
Originally posted by Clutch Cargo

 

When I first attached the neck, I snugged the coordinator rod so the heel was perfectly in contact with the rim, but the action seemed very low. Not knowing any better, I used the coordinator rod to change the neck angle to get the string action I wanted. You can see the gap at the bottom of the heel in the picture above, which bothers me.

 


I must admit I didn't like that gap either. Of course I know very little about this stuff. What I have learned is it's best not to do much with co-ordinator rods, although I've seen very minor adjustments have positive effects, and people tend to recommend shims instead. As you seem happy with doing shims you probably need to shim some more.

May 18, 2021 - 12:14:59 PM

68 posts since 4/14/2021

I'm new to banjos and the BHO. I like to follow these build and repair threads to gain insight as to how problems are dealt with. Most of the materials are wood. But this particular piece has an aluminum pot.

Metal fab is my game. I will put this out there, and maybe it's totally off base and not even worthy of consideration, since I know very little about instrument building.

Instead of massaging the neck, what about using a metal filled epoxy, something such as JB Weld, to build up the pot where the neck joins? The advantage is, is if it doesn't turn out right, just do it over. Much less risk than removing material from the neck, at least the way I see it. Also, much easier to file and shape a convex surface.

Just a thought from a metal fab perspective. But I think if I were building one of these kits and ran into this problem, that's how I would handle it.

If it is totally off base, just ignore it and be about your business

May 18, 2021 - 12:21:16 PM
likes this

3061 posts since 2/18/2009

The tape shim looks good. With a single rod like this banjo has I think you will want it to be tight, for tuning stability. I would use a taller bridge if the action is too low. If you aren't sure how much taller you want the bridge to be you can use anything flat, like popsicle sticks or coins, to go under the feet of the current bridge. They won't sound good but once you get the action height you want you can measure the height of bridge that you need. You can make your own out of maple or anything hard-ish, or you can get them pre-made in a lot of different sizes. I always make mine, it depends what you have for tools whether it's an easy or a hard job.

May 18, 2021 - 1:17:49 PM

94 posts since 2/18/2021

quote:
Originally posted by GrahamHawker
quote:
Originally posted by Clutch Cargo

 

When I first attached the neck, I snugged the coordinator rod so the heel was perfectly in contact with the rim, but the action seemed very low. Not knowing any better, I used the coordinator rod to change the neck angle to get the string action I wanted. You can see the gap at the bottom of the heel in the picture above, which bothers me.

 


I must admit I didn't like that gap either. Of course I know very little about this stuff. What I have learned is it's best not to do much with co-ordinator rods, although I've seen very minor adjustments have positive effects, and people tend to recommend shims instead. As you seem happy with doing shims you probably need to shim some more.


Another thought: when I first assembled and started playing the instrument, the truss rod was loose and rattling, so I tightened it up just enough to stop the noise . The instrument plays fine, with no buzzing frets, but it's unlikely the truss rod is adjusted properly.

I'm thinking the best thing is to adjust the co-rod so the neck is back in full contact with the rim, and then learn how to adjust the truss rod correctly. And as Zach says, adjust the bridge to get the string height I want.

Are there any standards though for the range of acceptable neck angles? Just so I can check that Saga didn't do something crazy.

Edited by - Clutch Cargo on 05/18/2021 13:22:44

May 18, 2021 - 1:48:40 PM
likes this

94 posts since 2/18/2021

quote:
Originally posted by Mikey Lawless

I'm new to banjos and the BHO. I like to follow these build and repair threads to gain insight as to how problems are dealt with. Most of the materials are wood. But this particular piece has an aluminum pot.

Metal fab is my game. I will put this out there, and maybe it's totally off base and not even worthy of consideration, since I know very little about instrument building.

Instead of massaging the neck, what about using a metal filled epoxy, something such as JB Weld, to build up the pot where the neck joins? The advantage is, is if it doesn't turn out right, just do it over. Much less risk than removing material from the neck, at least the way I see it. Also, much easier to file and shape a convex surface.

Just a thought from a metal fab perspective. But I think if I were building one of these kits and ran into this problem, that's how I would handle it.

If it is totally off base, just ignore it and be about your business


I agree with you about not wanting to modify the neck more than necessary.

You could use epoxy on the rim, but I just made a shim out of a few layers of a high quality cloth gaffers tape (~0.010" thick per layer).  The gaffers tape is easy to cut/shape and it's easy to add or remove layers to get the thickness you want. Also, the tape has  enough adhesive to stay put when you're assembling things, but it's made to not leave sticky residue behind, so maybe not such a bad solution.

For me, the point of getting a kit was to run into problems like this and learn things, so in that regard it's proving to be a big success. Luckily, I'm pretty happy with the instrument coming out of it too, although it weighs a ton with the aluminum pot!

May 18, 2021 - 3:06:37 PM

68 posts since 4/14/2021

Rich, I really enjoyed reading over your progress on this, and I had looked at those kits a few weeks ago.

I might give it a go my own self!

I appreciate the guided tour, so to speak!

May 20, 2021 - 7:53:05 AM

94 posts since 2/18/2021

So I read post posts and watched videos on truss rod adjustment, then gave it a try. While everything suggests that a small turn of the truss rod can make a big difference in the neck curvature, I'm not finding that for this neck.

In fact, no matter how far I turn the truss rod in either direction, I can't get any clearance at the 7th fret, period. To test clearance, I'm putting a capo on the first fret, fretting at the 22nd fret, then checking clearance between the 3rd string and the 7th fret. The string is always touching or almost touching the fret.

Is this a problem? There's no buzzing, but it bothers me that the truss rod seems to be only for show.

Would you expect the neck to be curved and the truss rod flattens the neck as it's tightened? Or the opposite?

-------
Note: I started out by turning clockwise, and it definitely tightened. I'm nervous about turning CCW too far in case the threaded stop would come off the rod... no idea if this is a one way or two way truss rod.

Edited by - Clutch Cargo on 05/20/2021 08:01:20

Hangout Network Help

View All Topics  |  View Categories

0.3125