Bridge grain direction?

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ChuckBarnett

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Newbie... again...

From the LMI plan that I have for this tenor ukulele it looks like the grain direction for the bridge blank is not completely vertical but more like on a 45-degree direction. Leads me to think that grain direction on a bridge is not all that big a deal? I'm working with bird's-eye maple for a bridge.

As always, very grateful for this forum! :)
 
I think that is a good thing to prevent splitting as with the bridge plate, especially with a pin bridge. Correct me if i'm wrong.
This is assuming Chuck is talking about grain direction when looking end on.
 
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Hey Chuck....I think you are referring to quartersawn or not and you seem to be saying you have a bridge blank that is a little out of quarter or maybe rift sawn and wondering what to do? Not that uncommon these days when ordering from suppliers.

If I am correct with this assumption I would advise that you consider the forces of the strings pulling against those grain lines ....so orientate it so that the string forces pull the grain lines down toward the soundboard rather than against them where it can pull grain lines from each other.

Does this make sense or help at all?
 
Here is the portion of the plan that I am wanting to understand. Does it make sense to have the grain vertical in relationship to the soundboard, that is perpendicular? Or would you want strength in line with string tension? Or should the grain be somewhere in between at an angle as in the drawing?
 

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I did some research on this a while ago, asking a similar question regards the bridge plate. I concluded that the grain direction was better angled rather than quartered as shown in the diagram. As I said earlier, this is to prevent splitting. So, looking at the diagram I would say that the bridge is ok but the bridge plate not so much.
Once again, I state that my conclusion was based on pin bridge construction. The above bridge may be fine as it is.
 
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ChuckBarnett said:
Here is the portion of the plan that I am wanting to understand. Does it make sense to have the grain vertical in relationship to the soundboard, that is perpendicular? Or would you want strength in line with string tension? Or should the grain be somewhere in between at an angle as in the drawing?
Click to expand...

As I can’t see the whole of the drawing I might be incorrect in believing that your question arises from confusing intended drawing lines with woodgrain. On manufacturing drawings a crossection view is normally shown crosshatched, it’s a means of visual differention. On the crossection of the saddle (a view that could be for any of the string holes and slots) lines are also shown through the soundboard and the reinforcing plate too, they aren’t grain lines. The saddle hasn’t been hatched (to show it’s a crosssection view) but, strictly speaking, it should have been.
 
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Thanks, Graham, for your attention to detail. I looked at the plan and saw that the convention is to show grain direction. So it looks like they want that bridge to be of an angled grain pattern.
 
You are correct Chuck....
If you think about the forces at work they can pull at the grain if orientated improperly (opposite of your plan) and therefore be more prone to split along the grain line. Therefore, it is best to work with those forces and have the grain lines in the direction indicated on your plan. This way the string tension is more or less pulling the grain lines together rather than apart.

Sometimes it takes a year or two before the subtle nuances of grain direction becomes apparent in various parts of building instruments. Once it does sink in it will become second nature and you will never look at wood the same again.
 
Thanks, Mike. That seems to be the consensus. I will go with it. Think I want to have the 4th string low rather than tuned high. Don't expect that that will make much tension difference though. I am considering trying a pin bridge rather than what is on the plan.
 
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