Re: First Holmegaard - Now finished

[gstoneberg]

Adb's build-along peaked my interest about Holmegaard bows.  I had a thin osage propeller stave I wanted to do something with,



so I brought it in the house with my ruler and sat with my laptop tuned up to adb's data and laid the outline of the design out.  His was a board stave, but I'm hoping it works the same way for a regular stave. Boy, cutting out a bow like this on the band saw is quite a bit faster than the normal way I do it.  Here's how it looks after a couple hours of drawing, cutting and sanding.





My question is about the natural deflex in this stave.  Should I heat bend the limbs back straight, or even into some reflex?  Or, should I bend recurves into the levers?  I'm shocked at how thin and dainty they are.

Thanks,
George

[bubby]

I would give it just a tad bit of reflex, the couple of this type that I've built shoot the heck out of an arrow, good luck, Bub

[ollive]

+1
I have just finished one in Black Locust. No deflex but 1" of reflex in the "siyah" giving 1" total of reflex for the bow. Impressive speed, and no string follow at all so far. With the deflex you have I would definitely try to induce a minimum of 1 to 2" of reflex. You'll get a natural D/R holmegaard, which design is I think a killer, combining lightweight outer limbs and increased initial draw weight. On my next bows I'll experiment further pushing the limits on outer limbs width and amount of reflex here.
Good luck.
Oll

[Cameroo]

Looking good! That build along has inspired me as well.  I have a holmie roughed out of what was a 3 inch diameter chokecherry stave, I'm just waiting for it to season a bit.  I'm looking forward to seeing how yours turns out!!

[gstoneberg]

Thanks guys, I hope this one turns out well.

I finished the heat bending.  I was trying to put a little reflex in each limb but it came out straight as a string.  Couldn't do that again if my life depended on it.



I really like the look of lightly toasted osage. 



I may mottle the whole bow that way, I've seen others do it and it sure looks cool.  It took 5 heat bends to get what I wanted.  Now the tillering can begin in earnest.  Gotta move fast to finish this in time for Christmas.

George

[Pat B]

George, don't "mottle" the bows back. It will weaken it!

[gstoneberg]

OK thanks.  I really babied the back when I did these bends, but I confess I wondered how  a darkened back would look.  Maybe some stain would be a lot safer.  I've never painted a bow back before, but I've sure seen some beauties since joining here.  So many possibilities, so little time.  And I've only scratched the surface of the different styles of bows to make.

Anyway, thanks for reminding me.  I'll be careful of the back.

George

[Del the cat]

It might be interesting to just reflex the levers relative to the working limb...
Oh no, another thing to add to the to do list
Del

[gstoneberg]

Del, I almost did that when I was doing the other bending.  I'm for sure game to try it.   Any suggestions on the amount of reflex and distance from the end of the lever it should be?  I will say the further inbound, the harder it will be as the depth of the lever really makes bending that direction.  It was tough bending it sideways and that's just an inch of depth.  I'm thinking midpoint on the lever as the cross section is almost square there.  But, this is a new one for me so I'm open to suggestion.

George

[Klandaght]

George- Look at your tips again. I fear you will develop a hinge and possibly breaking your bow.  The transition from the wide limb at the shoulders should be a gradual thickening of the outer limb while narrowing toward the tip.  The thickest part of the narrow outer limb should not be at the shoulders. Think of it as somewhat like the profile of a canoe.

[gstoneberg]

Dang, I hope not.   Here's are pictures of the limb to lever junction.





The lever is 1" deep where the limb has thinned to 1".  I misspoke when I talked of the platform being square in the center of the lever.  It's basically square all the way to the end, thinning gradually in both width and depth.  The limb is not as wide as a typical bow of this design because the stave was this narrow and since it is osage I hoped it would be stout enough.

What should I be doing differently?
 
George

[Klandaght]

George, the thinning of the tips is correct, however the tips should thicken as they get closer to the nock.  In doing so in the right proportion, low mass can be achieved with very narrow tips for non bending outer limb. I have gone as thin as 1/4"

[Klandaght]

Here is an example. Not my bow, but gives you an idea of what I was saying. The tips can be thinner in depth than this one as long as the tips remain unbending.

[Klandaght]

One more example with more subtle tips.

[gstoneberg]

I love that thick tip look, very nice pictures.  I might have to do one like that in the future for sure.

I honestly don't think there'll be a problem because I'm floor tillering right on the thin tips now and so far they are not bending.  I was quite curious when I first did it to see if they would be OK.  I'll watch it closely and we'll see what happens.  As always, I can't put any wood back on the bow.  If it fails, I'll post pictures for sure.  There's more wood out on the pile where that came from.

Thanks for the help.
George