3pc takedown recurve tillering

[talkingcabbage]

K, so I'm at it again.  I've gotten all the way to tillering this thing without any major hiccups or mistakes, and now I'm stuck.  

I'm working on a Binghams 3 pc takedown recurve and I have one limb that's way out of tiller.  The book says "if the limb tip points, say, to the right, then mark that side.  Unstring the bow and deepen the string grove on the marked side by 1/8".  Then remove material from the edge of the limb from the string groove to about midlimb."  

I've done this just as I understand - take material off the side that the limb tip points.  I have the bow strung and the funny limb pointing toward my belly.  The tip points to the left.  I marked the left side, and took material off the left side.  I restring the bow and the tip points more to the left!  Am I reading this wrong?  Should I be taking more material off the right side instead?

[jess stuart]

I think you need to take material off the right side.  Remember the limb will turn towards the weakest side of the limb.  When you view the limb from the string side (belly) you would deepen the nock on the narrow side.  Which should move the string in the same direction that you are deepening the nock.  Should you remove material on the same side of the limb it will move even more in that direction.  

I believe what the instructions are talking about is after you deepen the nock you remove material to keep the depth of the nocks equal.  Be sure that your nocks are cut in directly across from each other as well.

[bjansen]

[Joey V.]

In addition, make sure to drilled the limb alignment pin right down the center as well as the riser right down the center.  If your limb tip is pointing real bad to one side even when unstrung it could be a pin alignment problem.  I did this once being in a hurry.  If you find that your alignment pin is off even a touch it can be off over an inch by the time you get to the tip.  The way I fixed my limb if by epoxying in a dowel rod into the alignment pin hole that I screwed up and simply re-drilling it correctly.  The limb is still perfect and has been a shooter for many yrs now.  I love this bow because it reminds me to take my time.

[strungstick]

Make sure your string grooves are not causing some of the problem and then go to the limb.  Don't get carried away with both edge removal and string groove removel at the same time.  Go slow with both so you can get a better idea of what is causing the issue.  From what I can see of the limb it appears the problem is in the recurve (outer 1/3) of the limb and not your limb attachment.

[Jered Shofner]

Brad, I'm glad the pictures of my twisted limb can be used as an example!

[talkingcabbage]

I called Binghams today, and he told me that I needed to deepen the string nock on the same side that the tip is pointing (like the picture above) and to take material off the same side (not like the picture above).  Now I'm really confused!  I figured I'd get it straight from the horses mouth, but what the picture shows is what I thought made sense too.  Does anyone else have experience with this?

[greyhawk39]

I hope this picture will help.When you look at the picture you will notice that the left knock  or groove is shallow and the string is shorter, when you look down the limb,You have to deepen that side.Then take a sanding block and take alttle bit of material at a time on the tip area and down to where it narrows,just take a few swipes at a time.This might take a few times until it pulls straight to center. Thats my two bits worth hope the pic helps..
 

[Joey V.]

Grey hawk great pic! He is spot on in what he is telling you.  If you did that same thing Joe T and it got worse then you have an alignment issue 99% of the time.  Doing what GreyH is telling fixes twist and sting center. If your tip is "pointing" to the one side that is alignment. You could also have a bad sloped limb mold too and that can cause the same prob.  Post a couple pics if you can of your limbs just like GreyH did. Post it strung and unstrung so that we can see the riser a lil too. I bet it is alignment...

[jess stuart]

The picture that Brad posted is worth  a thousand words.  It explain excatly what I was trying to say.

[talkingcabbage]

i'm trying to realign the limb now, but it really seems like it's actually pulling at the tip (not saying its not alignment, it's probably a combination of things).  So I definately take material off the same side as the side I want to deepen the nock.  Not deepen the nock on one side and take material off the other, right?  I'll try to get some pics up, but my wife has the camera and she's not coming back till tomorrow.  
As far as the mold, this is a brand new one I just built.  I took the extra time to make sure everything is right, even down to using the waterjet at work to cut it out, so I'm sure it's not sloped.  I couldn't get that thing more square and true if I tried.  It could also be the lams I suppose, but I'm with you all betting its a combination of alignment and some minor twist.
After this one, I think I'm done with the 3 piece.  They're nothing but hassles, everything has to be just perfect.  I think I'll try my hand at a reflex/deflex longbow or something!

[Joey V.]

Joe T. You are correct if the nocks are equal and perfect and the limb is pulling left it is because the left side of the limb is stronger than the right.  If you deepen the left nock and sand the left side it will weaken it and cause it to track back to the right because now the right side will be stronger than the left. Think of it like a seesaw / teeter totter.  If you take weight off out end the other will move up.
Before you do any realignment work simply take out the pin for the limb and lightly screw down the limb bolt so the limb can still move. DON'T string it like that but shift the limb to see if the unstrung alignment is off in relation to the riser. If it is dead on then it is a limb twist issue for sure.
Build more take downs the first and even second rarely work out great. The 3rd, 4th, 5th, etc will all be great shooters.
P.S. I am jealous you get to cut forms on the water jet. It certainly is not going to be a form slop issue with that type of precision. Wanna cut all my future forms?   -

[talkingcabbage]

Thanks for all the help guys.  I'm gonna try to do something on it this weekend, maybe even tonight.  I need to get this thing done so I can start on my osage bow that I've been waiting to do for about a year now.  Those are easy compared to this stuff.  I guess I just understand them better.  Oh well, live and learn.  

Anyway, thanks again.  I'll let ya'll know how it turns out.

[Jason Scott]

This is a confusing issue to understand. The main reason it is confusing is because there are several reasons that cause a tip to wander off to one side. What is confusing is that you are getting advise to correct the wayward tip that is caused by two different reasons. You should try to determine the cause of the tip lean before you choose which approach to go with. Re-evaluate the centerline and limb width profile closely and the cause should be evident, then you choose which method. If you assume incorrectly and do the wrong one first, or worse, try both at the same time you could go too far and ruin the limbs.

The binghams directions remedy is for if you simply didn't layout the centerline correctly, deepen the nock groove on the side it points to and then remove a little material on that same side to make the depth of groove the same as the opposing side. The key here is to only remove material near the tip area, not the whole side of the working section of the limb, just enough material removal for a smooth transition at the tip. I think bingham should do a better job with the dirrections he gives. I see too many people that remove material too far down into the working limb from the side the tip is leaning and that just makes things unfixable. Never remove material from the working limb section on the side that the tip is pointing, just from the few inches at the tip only after deepening the groove, and that material removal is just to make both string grooves symetrical. Binghams method is for if the centerline is off and you need to shift the string over some.

If that didn't do enough to correct the lean then you should remove material opposite the lean and that should be taken from the working section of the limb, as illustrated in bjansen's pic. This is for if you have issues in the mid limb area and should remove material from the limb side opposite the lean in order to weeken it and bring the limb tip back arround. You can often see a side bulge on that side when the bow is strung causing it to push the tip around.

Another thing, make small adjustments, don't start off with deepening the groove by a whole 1/8" because that could be too much. Don't get too happy removing material by deepening grooves or removal from the side of the limb because when it gets close it will come around fast. And try one thing at a time. Pull the bow to halfdraw and back down several times so the string sits where it will to see if it is still leans after each adjustment.

[rogers]

Jason Scott is spot on. Remove material from the opposite side your limb tip is pointing.  Removing material from mid limb of the side that your limb is pointing to will only make it worse and could cause you to ruin the limbs.  When the bow is strung and you sight down the string on the belly you should be able to clearly see which side has more material on it in relation to the string, the side with more material on it is the strong side which should be sanded and the side with less material on it will be the weak side which will be the side that the limb tip will be pointing and should not be sanded.  Go slow, be patient and check with your tiller stick often.  
Most of the time I dont come out with alot of twist because of the extreme care I take sanding the limbs down the shape.  I usually put 20" tiller stick in place and then sand carefully, taking the tiller stick out often and drawing the bow several times so the string will adjust and naturally fall in where it wants to go, I can pretty much see the limb twist straighting out as I go.

[greyhawk39]

Elmont bingham is right on all the way...he has been building bows when most of us were in diapers.My picture illistrates if your knock is not deep enough.When I say sand down to where it narrows we are talking very little material is being taken down to pull straight to center.There is so many variables that come into play.It usually is the knock groove on the opposite limb which will twist your limb and effect the tiller on the other limb.Your brace height is a factor aswell if one limb is stronger than the other and pulling more on that side,it goes on and on. I hate tillering with a passion, but if you take all these thing into account it will work out  again this is my 2 bits worth.Here is another pic that I do if your knocks are even across that will make things easier...I glue my tips on, then tiller and make sure the string is even side to side.  
 

[talkingcabbage]

Thanks again guys.  After looking everything over, I think the problem lies on one end of the riser.  It looks like one of the inserts is about 1/32" off center from the other.  I've removed the insert and filled the hole.  Now I'm gonna redrill the hole and see if it helps.  

Jason - Your explanation makes sense to me.  That is the way I thought it should work before I ever read the "directions".  After I read them, that's when I got confused.  

I'll see how this lays out with the new hole and let ya'll know.  When this thing is finally finished, I'll post pics.  It should be one cool looking bow!

Thanks again all.

Joe