Tiller Help

[brianvanh]

First off, I'm a newbie.  Working on my first full sized bow....my only other build was a bow for my daughter.  Turned out pretty well...but a lot different than a man-sized bow.

The bow I'm building is a board bow...cherry backed with quartersawn white oak.  

Below is where I'm at with the tillering process.  I'm interested in any and all feedback.  I've added 3 black lines to the image to better balance the photo.  

I appreciate any input.  Oh, and it has a long tiller string on it and that's 30 pounds of draw weight right there.  I think that'd be about full brace.

Don't hold back...I'm new to this so if I'm screwing up, I want to know.  It looks pretty good to me, but I'm no expert.

   

[Art B]

Looks good enough to string up if you ask me. I would go to a regular string at full brace height at this stage myself. Tiller is going to change for sure, but you need to move ahead.......Art

[psychmonky]

Looks great! Im with art! Brace it and see what you get.

The left limb looks about a "hole" stiffer than the right which isn't much lol.

Oh, and you need to blend those fades into the limbs better so that there isn't such an abrupt transition between riser and limb.

[brianvanh]

Thanks guys.  Appreciate the feedback.

I haven't yet shaped the riser/fades because I didn't want to do a ton of shaping only to have it break on me.  I'm SUPER paranoid because I broke 4 (or was it 5?) bows making my daughter's bow.  I know that stuff happens and that's how you learn, but I've been super careful with this bow...trying hard to be patient and not to break it.  

Time to quit being a sissy, buck up and brace the sucker.  I'll try that tomorrow and let you know how it goes.  Thanks!...Brian

[Pat B]

Shaping the fades on the belly side so they blend into the bow belly won't effect the handle but will help the limbs bend off the handle. The abrupt transition that you have there will concentrate the stresses of the inner limb at that point instead of allowing it to flow into the fades.

[brianvanh]

There you go....learned something today. I'll get the handle roughed out and clean up the fades before doing anything else.  Thanks Pat.

[Pat B]

Brian, I'm a firm believer in leaving the handle area big and bulky until later in the bow building process. That bulky handle area is a great place to clamp the bow to work on it without effecting the ulitmate bow or handle.
 Tillering gets the limbs bending evenly and together and that can be done with a blocky handle area and wide, stiff tips.
  Blending the fades into the limb is more critical to the process.

[brianvanh]

Ok, here's an update.  I shaped the handle and did some basic work with the nocks.

Anyway, I braced the bow for the first time and worked it a bit.  Here is the bow on the tree.  30 pounds at 20".  I think it's looking pretty darn good...what do you guys think?

Here is my next question...Should I just keep pulling on the bow?  If the tiller looks good, do I just keep drawing it until I get to my draw weight?  Again, I really don't want to break it.  What next?

First image is with horizontal lines.
   
 
Second image has an ellipse in it so you can see the bend.

   

[gringol]

Looks good.  Draw a little farther and check tiller.  If you see a problem, fix it.  Keep doing that until you get it to full draw.

[Steve B.]

I like the tiller of the limbs but I'd like to see a close up of the fades area movement, especially the right limb.  
What I do at this point is start drawing by hand and using camera shots or mirror to begin fine tuning the tiller.  That's just me I know.
I would draw to that 20" two dozen times then scrape a little, draw another inch, draw two dozen times, etc.
But right where your handle tapers down to the limb on the belly seems too abrupt to me, or something.  Maybe an illusion, but you want minimal movement there right now.

What's the length of the bow and your intended draw length?

[brianvanh]

Very interesting.  Here is a closer look.  Are you suggesting that I need to knock some of the wood off of the fades to blend them better?  I can do that.

The bow is 68" and my draw length is 27".  I'd love to end up with something between 45-50 lbs.

   

[psychmonky]

Brian, that tiller is BEAUTIFUL so far!

Yes, I would make them more gradual. Instead of the basically straight ramp that you have now, make it more like a wheel chalk that they put under truck tires. Like a quarter of a circle....obviously if it has to be taller than it is wide or vice versa, that's ok.

Also, that's just how I do mine, some guys prolly do it differently and have great luck.

[brianvanh]

Bad news....I went a little farther with my tillering, and I lifted a rather large splinter on the backing.  The good news is that it's all still in one piece and you can't see the lifted splinter with the string off.  The bad news is that I think the bow is toast as it sits.

However, I think I can recover.  My first thought was to try and glue the splinter down, but I don't think that'll work and even if it did, it'd look weird, I think.  My next thought was to put some black fiberglass on the back.  Not what I wanted to do, but when God gives you lemons, make lemonade, right?

See any issues with any of that?  What else can I do?  

I sincerely believe that God got me interested in bow making because I need to learn patience....today was a good lesson.

[ALW]

Glue that splinter down with superblue then clamp it and let it dry.  Sand the excess glue away and do a sting wrap around the splinter or put a back on it of some sort.  Rawhide, silk, linen, etc..  Then see if you can get it a little farther.  Just might hold up.

Aaron

[Eric Krewson]

A super glue soaked thread wrap will keep the bow togehter. This one is nylon serving thread.

 

[Steve B.]

Don't do anything based on just my advice.  But I would work on those fades so that they are more gradual, even at the expense of the handle design.  You can always rebuild a handle.
You're at 30 lbs. at 20" and you want to be 50 lbs. at 27".  You might be there now so that means you'll be pulling another 7" with that current design.  I think that is too much pressure on the area above and below the fades.

You want no movement in the handle, little movement in the fades, more movement above that, lots of movement mid limb, then gradual decrease in movement to non moving tips. Your fades appear to be moving now so they will move more at 27".  I think they should move no more at 27" than they are moving now.  So you have to make your limbs longer now by making your handle smaller and new fades thicker and more gradual.

And I would back it also but I'm not sure that's necessary.

[brianvanh]

Thanks for the info everyone.  Right or wrong, here is what I did/am doing.

1.  Shaped the handle as suggested.  Gave it a much more gradual blend.
2.  Added a black fiberglass backer.  Not at all what I wanted, but I felt it was the best thing for me to do right now.  And I think the black will look good.

This thing may blow up yet, but I've learned so much.  I'm actually feeling somewhat positive about it.

Thanks again.