Osage HLD Flatbow- “Irma”

[leonwood]

Looks good! I think the essential part in HLD bows is that the hollow shape follows the crown and that the sides are thinner than the middle so the stresses from drawing the bow can redirect to the sidewalls. According to Simon the limbs even flatten out a bit at full draw. I think this flattening should occur from the sides coming up a bit, essentially directing the compression forces away from the middle. (I hope this makes any sense, kinda hard to put this in words) I am almost finished with a 60 lbs elder hollow limb where I really payed attention to the sidewalls compared to the middle section, will probably put on some pics in a week or so.

[Parnell]

Something just occurred to me with this talk of the HLD talk and the relationship between the hollow portion and thickness of walls.

When I went through this I hollowed out the limbs before I tillered them.  The walls of were significantly thicker before I tillered because I really didn't tiller the bow by scraping thickness from the bows belly...as I normally would.  I tillered the bow by essentially scraping the backs edges and sides as if I were "trapping" the bow. 

Hmmm, it'll be interesting.  It's fun to have a "new" mission to work through.

[simson]

You caught my interest, Stephan.
I have never done a HLD like you decribed - scraping back edges.
Leon gave a good explanation above.
I think, to get the full benefit of a HLD you have get the limbs flattening out. Otherwise you get"only" the mass minimized - which is a lot for itself.
But the flattening out has an effect on the behavier of drawing (flatter curve in the outer draw) and also in stress minimizing.
If you have interest in my article it is here: http://primitive-bows.com/hld-a-new-progressive-design-for-selfbows/

Please keep us updated, I personally just curious what you get. HLD is most efficient design I know.

[Parnell]

You bet, Simon.  This bow will be wrapping up soon.  Thanks.

[Parnell]

Finished.  I’ve decide against wrapping the handle.  Shipping this bow out as the gift I missed giving because of Hurricane Irma.  So, the bow has been named Irma.  My scale is screwed so not exactly sure but she is definitely closer to 60# at 28”.  Lots of strength for a fairly slender lady.

[Parnell]

I finished it using Clint’s automotive wheel finish idea.  Super good.

[leonwood]

That turned out great! Beatiful bend on that one! I gueass it is pretty smooth and fast!

[Parnell]

The bow shoots fast and hard.  To the point that I went back and made a slower b-50 string.  I like it better on this bow.  I’m amazed at how strong the bow stayed in design.  On to another hld, but am at least flipping tips on the next and will push it harder.

[simson]

Yeahhh!
That's a good piece of HLD, tiller is simple perfect
How long is the bow?
Make a 6 strand string out of BCY 452x and you will be happy!
Any chance for a chrony?

[Parnell]

Thanks guys.  I like the tiller.

Simon, I don’t have a chronograph but we might be able to make that happen in Nashville...the bows  future home.  I’ll see what we can do.  Also, the bow is 64” total.

[upstatenybowyer]

That tiller looks absolutely dead on. I love everything about this bow. 

[Badger]

  Beautiful bow!! How thick is the limb if you ignore the hollow area while measuring. Very impressive!

[osage outlaw]

Really impressive work Parnell.  The tiller looks great.  I hope to see that one in the BOM contest.

[Parnell]

  Beautiful bow!! How thick is the limb if you ignore the hollow area while measuring. Very impressive!

I'm humbled by the compliments, a sincere thank you guys.

Steve, the bows back is slightly convex and as I wrote earlier, after I hollowed the limb I tillered in part by trapping out the sides...so the sides of the back are softened.  That said, out of the fade 9/16, 7/16 at mid-limb, 5/16.  The last 6" I scraped  flat to thin tips.

[sleek]

Do the limbs flatten out at draw any?