latest GUAVA, ........a short Cotton backed flatbow (Pics & full draw )

[DanaM]

As everyone else outstanding, I'm wondering if anyone else is having trouble with the full draw pics their only loading about
half the picture I'm sure your tiller is spot on Manny I just can't see it

[DCM]

I started to post about that Dana, but the mood of the thread was not right.  IMHO what you see is the natural asym of such a design in a short bow, ie. the nock point does not bisect the string so the upper limb looks overly bent and the lower like it has a free ride.  The string segments are also more obviously asym, which contributes to the effect.  It works like this, the bow shoots great I imagine, but to me it looks "funny."

[NOMADIC PIRATE]

Mimms, that's why I really dislike full draw shots from the tree.
No matter how you try you can't reproduce the 3 fingers drawing hand, or even the rigth position, and the hand pressure on the handle.

I tiller my bows to 18" on the tree, ......and the rest is in front of the mirror.

As you can see by the shape of my handles, they are made for heeling the bow, and the hook on the drawing string is still about almost 2" under the nocking point.

I always wander about those bows that loook perfectly tillered being drawn strait down in the middle on the tree,...how they really look when drawn by the archer?

The bow is actually symmetrical, you can see the difference on the limbs on the unbraced profile, the bottom has a more steady reflex, the top is more flat but than kick up towards the tip, you can see how at full draw the tips almost match in reflaxed shape, but still when drawn by hand the lower limb comes around more because of the heeling and higher placement of the drawing hand.

..BTW, you can't expect to much, I'm still a rookie bowyer  ...I'll get better, I just need some time and practice 


Ho yeah, the bow does shoot really nice

[DCM]

Manny,

You make a good point about the two limbs not starting out equal.  And also a very good point about the tree not recreating the actual forces at play when hand drawn.  Please don't regard my comments a criticism.  You got the chops son, for sure.  Just that I'm predisposed to this particular observation, for whatever reason is seems to interest me.  Perhaps because I was so perplexed by the issue in my own crafting. 

Got a few projects in the works myself, after a pretty good little dry spell.  I better lookout, I'm libel to have to walk the talk!

[NOMADIC PIRATE]

Nah, nah Mimms, I like criticism, I have a lot to learn about this craft, when you and Lennie (what happen to Lennie by the way) and even Steve discuss bow design, I have no clue what you guys are talking about ...migth as well speak chinese

I just have a real dislike for full draw pictures taken from the tree, .....and real big reservations on perfect looking tillers, taken from trees.

I like where I am at the moment with my progress in bowmaking, but make no mistake I know perfectly well I have a long, long way to go and I listen a lot so I prefer criticism than suger coating too

So fire away 

[Gordon]

I'm not sure what others are seeing in your tiller. The string angle coming off the nocks is slightly larger on the top limb - which is what I would expect with a little positive tiller. And this should help distribute the work evenly between limbs when the bow is heeled at full draw. The tiller looks good to me.

[DCM]

Just to be clear, there is nothing "wrong" with the tiller on Manny's bow.

What I observe in the full draw pick is that the upper limb bends more than the lower, and that the draw hook (nock point) does not bisect the string.  This is inherent in every bow where the arrow pass is 1 1/2" or 2" above dimensional center.  It is in my view slightly imbalanced because the upper limb is both shorter (the distance from the arrow pass to the string groove) and more strained (positive tiller) than the lower. I propose that having the nock point closer to dimensional center, particularly on short bows, helps to balance the load to the lower limb (made equal with the upper by virtue of arrow pass at center).  Essentially folks give the lower limb the benefit, and thus deprive the upper limb, of the entire lenght of the "handle" in the initial layout, one they may have read or seen posted, and then don't ever take the time to work thru what the implications of this choice are in the finished bow.

Again, it's a fine bow and demonstrates admirably the so called "symetrical" design.  I'm simply saying there is another, better in my view, way.

[NOMADIC PIRATE]

Interesting Mimms, so basically you are a proponent of the assymetrical design rigth ?

What are the mesuraments you prefer ?

when I lay out my bows assymetricaly I put the center of the bow 1  1/2" above the center of the handle.

Mimms thanks for bringing the subject up I've being wandering about the assym  VS symm  for I wile now, and I was wandering if on symmetrical bows there should be no positive tiller at all.

Thanks

[Gordon]

I build my bows with asymetrical limbs. The arrow rest is 1" above the center of the bow. That makes the upper limb 2" longer than the lower. I also give the upper limb 1/4" positive tiller. I learned this from John Strunk. I think he does it because it more evenly distributes the work over both limbs. But I like it because it gives the bow better balance when carrying it in your hand - which I do a lot of when I am hunting.

[Pappy]

Very well done Manny,very nice bow ,love the tip and grip.
   Pappy

[DCM]

To be honest Manny my bows are all over the road, from arrow pass dead center to 1 1/2" above, to I don't even know for sure.  Usually the longer the bow the higher above center.  I'm not a slave to my initial layout, and often fudge a 1/2" or so in placing the arrow pass by shooting the bow after it's finished and then deciding.  I may also pike a limb a little, recut a string groove or whatever if I get in pickle and that has an effect.  To say I advocate the so called asym design might be a little strong, although I admit I speak to the topic more frequently than most.  Perhaps more accurate to say I think I understand the difference, and see at least theoretically the benefit of bisecting the string on a shorter bow.  And I can see the difference in my minds eye on full draw pics.  Can you?

As I understand it MORE tiller would be required for the so called sym design (ie. arrow pass 2", or half the handle lenght, above center).  Tiller's purpose is to offset the shortened upper limb, so you would conclude a more geometrically balanced design would result in a less shortened, and thus less weakened limb.  So, the "shorter" lower limb or so called asym bow would require less tilller.

http://www.goarchers.org.uk/mechanics/

I've ciited this thing a thousand times but it's the only explanation I've found on the net.  See the page [Bow Mechanics], [Tiller].

[NOMADIC PIRATE]

O.K., let me see if I understand what you're saying (because I don't think I do)

are you saying the for symmetrical limbs would be better to have no positive tiller ?

[NOMADIC PIRATE]

Thanks Pappy,

........and how rude of me,  thanks Dana, Bob, Justin, cowboy, Ediie and Keenan.

I just got sidetracked

[david w.]

wow you make really really nice bows. i really like those tips too

[DanaM]

Nah not rude Manny just busy like the rest of us eh