Tillering Problems - Fixed, now a build-along

[OzarkMatt]

I just started tillering my new bow and after working with it for a while and getting a few inches of movement on the longstring I noticed that one of the limbs had taken about 1/2" of set while the other had taken none. I looked very carefully for hinges but can't find any. I have it tillered right now so that the limb without the set bends even with the limb with set.

What should I be doing here? Should I tiller the limbs separately so that the one with the set ends up about 1/2" lower then the other at full draw? Should I make the limbs come to even at full draw?

Bow info: Red oak, drywall tape backed, Flipped tips set in with heat, 70" OAL, 1 1/4" wide at the handle continuing out to 12" from the tips where it starts narrowing to 1/2" wide tips.

Pic with few in. of limb movement. The limb on the right has the set.    

[SportHunter]

Looks like your limbs are very stiff & the only bending is at the fades. You need to taper the limb thickness slowly from thicker at the fades to thinner at the nocks & get more of the limb bending. Just to give you an idea the limb at the fades may be 9/16' to 3/4' thick then thin to 1/2'' thick then to 3/8'' by the time it gets to the nock area.

 You want the thicknes to be gradual and smooth.
Also look up how to make a "gizmo" (its in the "How to" forum) that will help you tremendously with tillering.

Of course if you are working with a pyramid style design the thickness taper will be very slight.

[OzarkMatt]

SportHunter, I forgot to mention it in the original post but I did taper it almost exactly like you said, starting at 3//4" thick then narrowing to 3/8" thick at the tips.

[SportHunter]

Just making sure you get the concept. Just keep thinning the limbs that way. The limbs will start bending more. I like using a scaper at this point so wood removal is controlled. Scrape with the grain. I would start scraping your mid limbs say 4''-6'' past your fades to get the mid limb bending, leave the outer 6-8'' stiff for now.

Take it slow, take it slow, take it slow... scrape, test scrape test etc. I stick the bow in a vice on its side this early and test each limb so I can see movement & try to get both limbs bending by hand a bit.

[OzarkMatt]

Ok, I thinned the midlimbs some more and basically ignored the fact that one limb has slightly more set then the other and here is how it looks:
   

Better, maybe thin the right limb some more... Time for short string soon. I don't like how this bow wants to pick up set, I'll stick with the wide and flat design next time.

[SportHunter]

I think the set came from having too stiff of limbs which overpowered the wood near the fades which is also where you can pick up set rapidly. The design layout is sound, although with red oak the limbs probably should have been a bit wider to start to minimize set. The left limb is just starting to bend, the right still very stiff. Keep going...

[OzarkMatt]

Yep, that right limb was just starting because it is the one with a bit of deflex to it. As I work the bow though it seems that the set is evening out.  
That's at 6" of string travel.

[George Tsoukalas]

Get some bending mid limb to to tips. Set happens.    Jawge

[k-hat]

Red oak will take an inch or so of set with even the best tillering.  Unevenness is probly due to differences in the limbs, small as those differences may be.  Sporthunter's diagnosis is right, your set is probly all in the near handle area due to stressing that area so much early on.  And the design is quite narrow, so you're gonna end up with probly 1.5 to 2" of set in the end, even with good tillering.  Red oak ideally needs to be about 1-3/4 to 2" wide to minimize set.  

Hope i don't sound put-offish there!  That said, she'll still make a great shooter and even Howard Hill swore by a little stringfollow/set to make shooting more pleasant    

Keep moving forward and posting progress!

[OzarkMatt]

I think it's coming along pretty nicely now, still a little work and I need to lose some weight still but here it is strung and unstrung.  
   
Btw, the last red oak bow I made had 3/4" of set  :D  This is an experiment though, I am making a bow more suited for hunting then my other bows. This is my first time with the flipped tips and I also don't usually make them this narrow or with as high of a draw weight(I'm going for 55lbs.) Hopefully it'll be a sweet bow    

[fujimo]

remember she will tell a different story with the short string on her.
 i always make my "long string" as short as i can possibly make it!!- right from the beginning.and in fact my progression to the short string in an incremental one- as i keep shortening my long string until it eventually becomes the short string. i dont have a long string, that i remove and then put on a short string.
i have come very close to missing weight when i started like that.
as thge short string gives you a very different bend profile, and then suddenly there are not very many #'s to rectify the profile..
yup, on the fades being stressed, and yup on the very narrow design.
but hats off for being adventurous, having a goal and working towards it. it is really starting to look nice !
enjoy the journey!!  

[PEARL DRUMS]

The bow needs a short 2-3" brace now. It will pull the tips down and in which will change your "flat" mids considerably.

[OzarkMatt]

It's strung at full brace in the last pic, I just left the stringer on to help show the tiller. Here's more pics taken after a lot more work. I still have plenty of weight to take off so if you see something, let me know please    It is a little funky because of one limb having a little more set then the other, but I'm tillering it so that the limbs are even at full draw. The limb on the right is the one with the extra set.

     
   
   
   
   

[PEARL DRUMS]

Perfect so far. Go SLOW and stay about 5# above your target. When you get there shoot it several hundred times. It will lose some more weight then and when you sand it.

[k-hat]

Lookin real good there!  Keep it up  

[SportHunter]

Looking good Matt.

[OzarkMatt]

Well, I've been reducing the draw weight, I shaped the tips and narrowed them as well. I'm going to go ahead and shape the handle and cut the arrow notch and start shooting it. The bow is pulling about >55lbs right now. Here's some shots of the tiller. I think it could use a little more off of the bottom(right) limb's tip... What do ya'll think?

   
   

I didn't realize my belt was that loose when I took the picture...  

[Roy from Pa]

Dems some purty undies. LMAO:)

OH, the tiller looks nice...

[OzarkMatt]

Got my handle roughed out, I took photos but they turned out blurry so I'll try again later.

[OzarkMatt]

Wow, this thing shoots hard! The 3rd and 4th shots went within a 1/4" of eachother, same with my 6th and 7th.    
And finishing, which I really do enjoy.