2 tillering questions

[ajbruggink]

Hey Guys,

I have 2 tillering questions. I am working on my second bow, this one I have been working on for too long and it is being made for a friend. I'm finally to the tillering stage and I worked on it for awhile on Saturday, I tillered with the long string to about 25", 2 more inches to go to match his draw length. (I've included a picture of what it looks like, its not perfect) But my real question is why I'm developing string follow already with the long string. (I've included pictures of that too). Am I exercising the limbs too much when I'm tillering with the long string? I thought possibly I designed the bow incorrectly. My friend wants a yew bow, I told him he didn't a yew for want he wanted, but he insisted on it and was willing to pay for it. Well I thought it would be a great learning experience if all else failed, anyway to cut to the meat, he wanted a unbacked bow, so I did not attempt to thin the sapwood because all my research has indicated that this is a tricky thing to do with yew and so I decided not to push my luck and just leave it how it was. But now I'm thinking I didn't leave enough heartwood and the lack of it is causing the set but I'm not sure. So my first question is what could I be doing wrong to have set already with the long string? My second question is about tillering strings. With my first bow, I attempted to use a continous loop tillering string to tiller the bow. The upper loop kept coming loose. I kept waxing the string and filing the nock grooves deeper but the problem continued. Finally, I threw the wretched string thing away and used a piece of paracord instead. That solved the problem of the upper knot coming loose but the paracord becomes slack with every pull on it. So with this bow, I tried a different tillering string, still the same problem so I'm using the paracord again. What am I missing here? Bowbuilding books tell me to use a real string but I can't get it to work. I've been using a timberhitch on the top but it doesn't stay very well. Any replies are greatly appreciated.

Thanks,
Aaron

[Pat B]

 I wouldn't use the long string past 10" or so of tip movement. At that point I low brace a bow to about 3". Now I can see how the limb tracks and a truer view of actual tiller. The long string give you false reading after a few inches and should be used only long enough to get to low brace.
  With yew you don't have to worry too much about sapwood violation. Get the sapwood backing about 1/4" or so and do the best you can on the back.
 Do you make your own strings? Flemish twist strings are quite simple to make and you don't need to have any special tools, only bow string material. For my tillering string I use a Flemish twist string with a twisted loop for the top limb and a bowyers knot(timber hitch) for the bottom so I can adjust the string length for different stages of the tillering process and for different bows. I make all the strings for the bows I make Flemish twist. You have to be sure the timber hitch(bowyers knot) lays properly as you tighten it in the nock.

[ajbruggink]

Thanks, Pat B, I won't use the long string anymore past 10" like you said, it'll probably save a lot of time as well. The problem for me will be string building.

[Pat B]

Like I said it is very simple. I think there are a lot of videos on YouTube. You can buy a spool od B-50 bow string for about $10 or less or trade for some with someone.

[CustomArcher15]

You can also buy a Flemish string for $10 in the meantime but it would get pricey fast if you didn't make your own. I make mine and with serving is <.50 a string

[CustomArcher15]

You can also buy a Flemish string for $10 in the meantime but it would get pricey fast if you didn't make your own. I make mine and with serving is <$.50 a string

[4giveme]

Aj,
I sent you a pm.

[GB]

Do you have a meter to check the moisture content of the wood?  If the MC is too high, that would contribute to the bow taking set.  I'm in Wisconsin (Neenah) and checked the MC on an elm board bow I just floor tillered; it was 14%.  Two days in my drying box brought it down to 9%.
Don't sweat the string making.  Once you find a tutorial to follow, make a jig, and make a few strings, it gets to be surprisingly easy.  Hang in there and best of luck on the bow. 

[George Tsoukalas]

10" of tip movement is way too much. 10" of string movement is about right.
Leaving it drawn on t stick may result in set. The wood may also not be dry enough.

Looks like it needs a bit more bending mid limb on.

I don't understand how  an endless string could unravel at the loops.

I never heard the  term continuous loop. There's endless and flemish.

Here check my site.

http://georgeandjoni.home.comcast.net/~georgeandjoni/index.html

Jawge

[ajbruggink]

10" of tip movement is way too much. 10" of string movement is about right.
Leaving it drawn on t stick may result in set. The wood may also not be dry enough.

Looks like it needs a bit more bending mid limb on.

I don't understand how  an endless string could unravel at the loops.

I never heard the  term continuous loop. There's endless and flemish.

Here check my site.

http://georgeandjoni.home.comcast.net/~georgeandjoni/index.html

Jawge

You're right, I don't know where I got the term continous loop either , a loop can't really be continous

[bradsmith2010]

good advice from above,, just wanted to second not leaving the bow pulled with the long string,,,,it  probably caused the set you have,, and possibly the moisture as stated,, that being said,, a little set should not keep you from getting a fine bow,,

[dwardo]

Seems to be bending a lot around the middle and into the first third on each limb. Where the bow is taking set is where its bending too much. If it were me I would get those mid to outers working straight away. You dont want more than the last 6 inch or so to be stiff. Hard to see the profile from the pics though. One the tiller is evened out you could shift a bit of the set with heat.