Short bow tiller check

[Mo_coon-catcher]

I want to get some opinions on the tiller before I pull it back much further. It seems like it is still too stiff in the top limb above my hand. I want to get it to 20" draw at about 50-60lbs draw, right now it is 35lbs at about 12". It has been heavily heat treated and it feels like it hits a wall when I go to pull it back any further. I took it out shooting at 12" draw and it right now it shoots a 450 gr arrow 90 yards at the short draw. So what do you all think of the tiller before I go to draw it any further? Sorry about the fuzzy pic, I had my friend take it for me.

[DarkSoul]

What wood is it? Self or backed? Is it from a stave or a board? What does the unbraced profile look like? Is it straight or with natural bends? What does the front profile (width profile) look like? The tiller should match the width profile. How long is it? A lot of questions, haha! It's all in the details, you know. Please provide us with all the information you can, so we can give you the best specific advice rather than general statements that apply to any shortbow.

Tiller doesn't look bad. The upper limb looks a lot longer than the bottom limb? I agree that the upper inner limb seems somewhat stiff, but that could be a natural reflex area in a natural stave...
If you're at 35#@12" now, it seems unlikely you'll reach 60#@20". Maybe 50 pounds, but that's pushing it. I presume it has a short string (full brace height) at this point?

[Mo_coon-catcher]

Sorry about that lack of info, I didn't even think about that. But it's black locust that has been heat treated and is from a stave. The middle of the bow is actually where my thumb is at and is where I am applying all the pressure. I figured I would end up being low in weight from what I wanted.The bow is almost perfectly flat with about 3/8" of deflex when the back is resting on a flat surface. Once I get out of class I'll get some pictures of it up just braced and unbraced. I am at what I would call the final brace, at least for this short of a bow. When the bow is laying on a table the brace is 4 3/4" from the back to the string. It has a 6" handle that I want to get bending a little that is 1" wide that goes to 1 1/2" wide limbs that keep that width for half the limb length that tapers to 1/2" at the tips. I plan to thin the tips down once I get it shooting at full draw. It started as a longer bow till I broke it trying to make a recurve. Now it is  44" NTN.

[JackCrafty]

Tiller looks very good, actually.

One thing that is a good indicator of what's going on with a bow is the amount of set it is taking during tillering.  This may be a generalization, but the specifics won't tell you as much as this simple observation.

Making a bow that is 44" with a 20" draw can be done, of course.  Amerindians did it all the time.  Making the draw weight 60lb is putting a lot of stress on the wood, however.  This is especially true if you want a stiff handle with your 44" bow.  Most ancient bows with your desired stats bent through the handle.

If you feel like you are hitting a wall with the draw weight, it may be the string angle.  I don't recommend removing any more wood from the tips unless the tips remain unbending for at least 4".

[JackCrafty]

Here is a bow that I made a while ago (2009) that has a similar length and draw to your bow.  It is 46" NtoN with a 20" draw.  http://www.primitivearcher.com/smf/index.php/topic,11486.0.html





After being shot a bunch of times, it still has less than 1/2" of set.  (pictures taken this morning).




The draw weight is much less than 60#, however.  It's draw weight is 28#.

Now, if I wanted to increase the poundage to 60#, what would be the best way to do it?  There are two things that you can do to accomplish this:  use a more dense wood and increase the thickness and/or width.  Using a more dense wood is a no-brainer but there is some confusion among new bowmakers as to how develop the best cross section.  Is it better to increase thickness?  Width? Both? Let the wood decide?  Pick a design and then try to find a wood to fit the design and your requirements?

In my opinion, increasing the thickness is the most efficient way to increase the poundage PROVIDING that the bow does not develop excessive set.  If there seems to be too much set creeping in, then you must increase the width.  That's why you see the "paddle bow" style among a lot of Amerindian cultures.  It's not so much that they liked the shape, the shape was dictated by the demands of the wood.

[Mo_coon-catcher]

I actually am aiming for it to be a bendy handle but it's taking a lot of scraping to get it bending at all. I'm hoping to get the handle bending toward the end of the draw.  I might drop my weight expectation down a bit to about 45-50 lbs. It's weird, the string angle is no where near 90 degrees but it feels like the weight is adding on quickly. That's an awesome bend you have in that bow jack, I hope I can get this one to look that good.

[mikebarg]

newbie question, in the original post I noticed Mo_coon-catcher said " it feels like it hits a wall when I go to pull it back any further" that's called stack right?
and you don't want to draw the bow to the point were it is stacking ?

[JackCrafty]

Just keep scraping, Catcher!  It's worth the results if you're patient.  And sometimes other things feel like stack.  For example, you might be feeling "stack" in the string.  Flexible strings stop stretching at some point and that's what you might be feeling.  It could also be that you are feeling the finger pinch of the string and that makes it harder to hold onto.  Just guessing, though.

Mike, you can draw the bow past the "stacking" point and most bows will be OK.  We try to eliminate stack because it makes the bow uncomfortable to shoot and there may also be a danger of the string coming off the tip if you have pin nocks, for example.

[longbow steve]

Hi Mo, it may feel like you are hitting the wall because of the draw weight at a short draw length. It probably feels foriegn to your muscles and when you think about it it is probably 75-80 # at 28" and 20" is all I can draw bow of that weight  . Cheers Steve