amount of reflex/deflex AND bamboo node spacing

[arachnid]

I`ve been wondering..... How do you determine the "right" amount of a glued-in reflex/deflex design?
It seems to me that most people just do it randomly...

and while were talking about bamboo- what is the minimum "safe" spacing between nodes?
I have a large diameter pole but the space between nodes is only 6-7 inches. Safe of trash?

Dor

[bushboy]

I go with a hint of deflex and loads of reflex to a point.as tillered reflex will be lost and deflex will increase due to set.

[bubby]

Dor i think most guys do some experimenting to try and get whay they feel is that sweet spot, some may also pm an experianced hmm owyer that builds alot of d/r bows

[Mark Smeltzer]

I have tried many different combinations and some worked and some didnt.  Also depends on if you're talkin glass bows, selfbows or laminated wood.

[arachnid]

laminated- bamboo/white oak backed ipe.

[Del the cat]

I think it's down to feel.
If you assume your dead straight bow was stressed to 90% then you can't add much reflex without going over 100%, unless you add a bit of deflex to compensate or go longer or wider/thinner on the design.
Too much reflex is a pain on the tiller.. hard to get to brace and then you come in underweight (or so I've heard )
Bottom line there is no "free lunch" with bows. Ok some designs are geometrically more efficient, but you are still limited by the materials.
It depends whether you want smooth and forgiving or pure speed... hunting or flight?
That's why we all keep messin' with the wood
Del

[arachnid]

And on the same topic (kind of....). I have this piece of bamboofor backing. it has this "knot" () sticking out
of one of the nodes (the one closest to the tip). Will it pose a problem?
I also have to narrow this part of the bamboo since it`s right in the middle of the width taper towards the tips, so
I`ll probably have to cut through this thing... SOOOOOO, what do you say?

[Dances with squirrels]

That knot is a serious concern. Equally as concerning is the lateral gauge a few inches above it. I'd look for another piece.

[mikekeswick]

Chances are that's just in the rind. Until you scrape it off you won't know for sure. All nodes on bamboo have those 'knots'. It's just a leaf that hasn't had it's 'root' cut off flush with the surface.

[arachnid]

Chances are that's just in the rind. Until you scrape it off you won't know for sure. All nodes on bamboo have those 'knots'. It's just a leaf that hasn't had it's 'root' cut off flush with the surface.

How do I scrape it? from the sides or from the top?
and while were talking about bamboo- what is the minimum "safe" spacing between nodes?
I have a large diameter pole but the space between nodes is only 6-7 inches. Safe of trash?

[Badger]

  When I am doing a glue up I have pretty much settled on about 3/4" deflex mid limb and then reflexing about 3" past the back of the bow. That seems to be the sweet spot where I can maintain my profile pretty well through tillering. If I end up with 1 1/2" reflex when finished I am happy.

[KS51]

Node spacing is not really a concern.  Each node does affect how you tiller since the limb is thicker at a node and depending on how you finish the back, each node is a chance to accidently violate the back.  For that reason the fewer the number of nodes the easier it is.  Undercutting just after a node is the thing to watch out for.

One side note.  Based upon some research into bamboo properties, the base of a bamboo stalk is typically stronger than the top.  The node spacing is also smaller at the base than at the top.  However, plant age has a greater effect, with 5 years being about the peak time for bamboo strength.  Both of these effects are due to fiber bundle density at the outer surface.

Ken

[Dances with squirrels]

Mike, zoom in on that gauge. It certainly appears deeper than the rind.

[PatM]

 That is just a leaf scar but not all bamboo types have leaf scars on every node.