static recurve design

[WhistlingBadger]

Howdy, boys and girls.  I've got a juniper heartwood bow almost roughed out (did I mention this wood is really, really pretty?!)  Want to put static curves on the end.  I have my head around the process pretty well, but I'm wondering about design.

The ends taper 10" from 2" wide (might end up more like 1.5") down to 1/2" at the tips.  Planning to bend the tips to about 45 degrees over about 6", if that makes sense.

I assume I want to leave the curve a little thicker to keep it from moving at full draw, correct?  How thick should I keep it?  Any other tips on design?  I've never worked with juniper and I've never put in recurves, so this is all new to me, but WOW, this wood is pretty and I'd feel terrible ruining it.  So, any help appreciated! 
Thomas

[WhistlingBadger]

Bumpity-bump.

What kind of dimensions should I go for when roughing out a static recurve?  I want it thick enough that it won't pull out, but thin enough to shoot fast.  Rocky mountain juniper heartwood.  Thanks!

[RyanY]

Recurves should be as thick or a hair thicker than the last part of the working limb to not bend. They don’t have to be substantially thicker as that portion of the limb is usually rigid as it is. I put in the recurves once the bend is good and symmetrical on the tillering tree. With such a wide thickness taper I doubt you’ll have problems with them pulling out if they’re as thick as the working limb.

[WhistlingBadger]

Recurves should be as thick or a hair thicker than the last part of the working limb to not bend. They don’t have to be substantially thicker as that portion of the limb is usually rigid as it is. I put in the recurves once the bend is good and symmetrical on the tillering tree. With such a wide thickness taper I doubt you’ll have problems with them pulling out if they’re as thick as the working limb.

OK, thanks.  That's what I figured, but wanted to be sure.  Once you rasp that wood off, it's awfully hard to get it back on!

Another recurve question:  What angle for the nocks?  I usually do 45 degrees on straight bows; is it the same for curves?

[RyanY]

I’ve done 45 and haven’t had any issues.

[bownarra]

Put a temperary overlay on. See what angle the string sits at then cut the nock grooves to suit.

[mmattockx]

Once you rasp that wood off, it's awfully hard to get it back on!

Nah, that's what underlays are for. 

They also allow you to thin the tips enough for easy bending and then add extra material back just where you need it for stiffness.

Another recurve question:  What angle for the nocks?  I usually do 45 degrees on straight bows; is it the same for curves?

This is why I like smooth sided nocks and pin nocks, the string self adjusts to whatever angle it wants to be at without a problem.


Mark

[bownarra]

Fine on a straight bow but you do want string grooves on a contact recurve.
Also strings wear out slightly faster when you just have 'sides'. String grooves allow you to finesse things and reduce the strain on the string  

[Pat B]

I use temporary nocks until I first brace the recurve then trace the track of the string around the nock with a pencil and cut it in with a chainsaw file. Make sure all edges are rounded and the string loop rides smoothly along the string grooves. I usually make the initial groove at about 45 degrees.

[chasonhayes]

Does anyone have a picture of what a temporary nock looks like or can describe it in detail? i can see myself accidentally making the nocks permanent not understanding how to do it

[Pat B]

My temporary nocks are chainsaw slots cut perpendicular to the limb tip just deep enough to hold the string. I always leave the tips wide, 3/4" to 1" so when time to shape the final tips the temporary nocks are removed.

[bownarra]

Many ways to do things but there are a lot of advantages to simply getting a slither of wood making a small wedge out of it and gluing it to the back with a dot of superglue. I then take some serving thread or similar and wrap the tip on. Soak in thin superglue to avoid it coming off during tillering. Once you have finished with it it will be obvious where you need to cut your final grooves. Just pop it off with a knife. I've been doing it this way for years and can't find a better way. I do it on all my bows.

[mmattockx]

Fine on a straight bow but you do want string grooves on a contact recurve.

I agree on the smooth sided nocks, straight bows only. How are string grooves any different than pin nocks once you have cleared the side area needed to accommodate the sweep of the loop as the bow is drawn? The pin nock is really just a string groove nock with the tip portion of wood beyond the string shoulder removed.


Mark

[WhistlingBadger]

So, by "smooth nocks" do you mean perpendicular like Pat B described?  I could see cutting in perpendicular nocks, then once I'm to brace cut them into the correct angle and turn them into pin nocks.    Might just do it that way.

I'm also interested in Bownarra's method of slapping on a temporary overlay and cutting the nock into that, then replacing it once I've got the angle figured.

But...wouldn't it be easier just to put on the permanent overlay, cut the nock into the back enough to hold the string, then put in the side nocks once the angle is figured?

So many options.  And whichever one I choose, I bet I'll find a way to do it wrong.  It's how I roll.   

[mmattockx]

So, by "smooth nocks" do you mean perpendicular like Pat B described?

This style of nock:




Mark