Primitive Archer

At 60" I don't think you can shorten it at least not much. Maybe you can take an inch off of each tip then narrow the tips to reduce tip weight. With 4 layers of sinew any more would be counter productive but it the sinew hasn't been on for long maybe it will pick up a little weight as it dries more., that is if you used hide glue for the sinew. With it at 45# now you might just make a 50# bow, or close if all the above mentioned changes are successful.

Thanks, Pat.  I think I'll just leave it be.  I'm hoping the juniper-sinew combo will shoot hard enough to hunt with even though it's a little light.  If not, it was a good learning experience.

Is that one of those new trans or somethink bows ie  Identifies as straight but is really crooked?

I think it's a bonsai tree that identifies as a bow.      

I made a Yew stick bow that looks very much like that for one of my field archer chums. He enjoys the quizzical looks and comments he gets from fellow archers.
Del

Yeah, I'm looking forward to that at the next shoot.  I'll try to post a back picture tonight.  The only places the string aligns with the limbs are at tips and the handle.  It'll be interesting to see how it shoots.

Last night I wrapped the biggest knot with sinew and hide glue, since that's the most likely place for it to come apart.  I plan to put a few arrows through it tonight if the weather is decent.  Stay tuned...

Is that one of those new trans or somethink bows ie  Identifies as straight but is really crooked?

Quote from: willie on December 16, 2025, 09:28:18 pm

Quote from: Tuomo on December 16, 2025, 04:18:20 pm

Also, the more whip-tillered the bow is, the more efficient it becomes (the reason here being lower tip mass)

Although the tip area with the steep taper is somewhat lighter, I dont think those FPS are attainable because the max strains in bow 9 are 73% higher than bow 4

Of course not! Those are only theoretical values within given boundaries; there is no set, for example. When modelling bows made from natural materials, it is important to interpret the results correctly – what is realistic and what is not. This is where practical experience in making natural-material bows becomes essential. You can learn a lot from theory, but you should not believe everything.

Virtualbow is a nice tool for modeling theoretical bows.  The properties of natural materiels is of course, much more complex.

(From the other thread)

viscoelastic material properties are time-dependent. A well-known example of this is that with a fast release we obtain a higher arrow speed than with a long anchor at full draw. Thus, the main reason lies in the intrinsic material properties, which we do not know well enough and which are difficult to model accurately. In practice, we must rely on measured data. For example, the measured difference between hickory and bamboo backing is both interesting and important.

I find operating virtualbow to be much easier than determining a working stress to design to.
Has having access to a thickness sander made your materiel testing any easier?

What's the length, t/t? What is the draw length and draw weight now? How much sinew have you added to this bow?

It's 60" ntn, another inch or so tip to tip.  It has four layers of sinew.  Currently pulling about 43# @ 25".

Kinkier than a garden hose wrapped around a lawnmower.

That tiller looks good considering the limbs each leave the handle at a different angle.

Good one.  Mrs. Badger said it's kinkier than a presidential mistress.  I'm actually fairly tickled with how good the tiller looks, given where it started.  The right limb looks stiffer at full draw, but it's got more reflex unbraced, so I think it's working about as hard as the left.  And some of the spots on the left limb that look like they aren't bending are either knots that I left stiff on purpose, or little reflex kinks that straighten out rather than bending into deflex. 

Just wish I hadn't had to remove so much weight to get there.  I might try to get it to full draw  27" tonight and see what the weight is looking like.  I'd like it to be at least 50# to hunt elk; 55 would be better.  I'm guessing it'll be fairly close but a little under.