Primitive Archer

Main Discussion Area => Bows => Topic started by: radius on July 12, 2009, 09:44:47 pm

Title: holmegaard vis a vis recurve
Post by: radius on July 12, 2009, 09:44:47 pm
Hey guys,

Would you say that the holmegaard style (non bending tips) are a poor man's version of a recurve?  Is there any value in recurving the tips of a holmegaard?  Right now i have a yew stave under the knife and i'm thinking about steaming the tips and bending em...but other than for cool appearance, let's get some opinions and see what people think of this idea.  Anybody try this yet?

radius
Title: Re: holmegaard vis a vis recurve
Post by: ravenbeak on July 12, 2009, 09:53:56 pm
without putting too much thought into it,  i'd say that recurving the tips of a holmie is gonna put even more stress on the bending portions of the limb,  which are already satrained to the max,..   i'd say not a good idea for a holm

unless you sinew back just the working portions of the limb to help with the stress.
Title: Re: holmegaard vis a vis recurve
Post by: Justin Snyder on July 12, 2009, 09:58:52 pm
I wouldn't call it a poor mans recurve at all. A holmie is a bow with a couple of leavers attached to the end of each limb. The leavers work much like an atl atl. The problem you may have with recurving a true holmie is lateral stability because of the narrow limbs. Remember that the leavers will exaggerate any flaw and make your stability even worse. Justin
Title: Re: holmegaard vis a vis recurve
Post by: radius on July 12, 2009, 10:09:37 pm
do you mean narrow limbs, or thin limbs? 

I thought i would make the transition to the lever quite suddenly, like adb's.  But then i would taper it back down again so that the last few inches would be thin enough to steam-bend easily, but the whole thing would act like static.

I'm gonna do it.  I'll let ya know how it goes!

Title: Re: holmegaard vis a vis recurve
Post by: Michael C. on July 13, 2009, 01:04:57 am
You should try one of the Holmegaard-Andaman bows that they talk about in TBB V.4, the specs on it look like it performs really well. I don't know as I haven't made one yet but it seems to have a better performance than the straight Holmegaard design. I think it bends a bit more throughout the body than the Holmegaards do, not as much of a whip design, but it was a bit longer.
Title: Re: holmegaard vis a vis recurve
Post by: Kegan on July 13, 2009, 01:41:03 pm
Thimo did one like that a while back, a big heavy one out of elm. It worked pretty well from the looks of it (I think he said he was going to use it for a hunting arrow flight bow?), I say give it a shot. Best of luck.
Title: Re: holmegaard vis a vis recurve
Post by: radius on July 13, 2009, 09:25:14 pm
ravenbeak was over here last night, and we were talking staves and strings, and i showed him the stave i plan to make this bow from.  Right now it's a giant club with a triple-sized outline carved in.  The stave is a good 1.25 " thick at the tips...it's actually enough room to simply carve the recurves in rather than bending them...any thoughts?

radius
Title: Re: holmegaard vis a vis recurve
Post by: Michael C. on July 13, 2009, 09:59:16 pm
Thimo did one like that a while back, a big heavy one out of elm. It worked pretty well from the looks of it (I think he said he was going to use it for a hunting arrow flight bow?), I say give it a shot. Best of luck.

Yeah I looked at that one after you mentioned it and that has a wicked looking paint job on it.
Title: Re: holmegaard vis a vis recurve
Post by: radius on July 13, 2009, 10:25:09 pm
yeah, michael i just read it too...pretty damn wide, but he got a cool canvas and a 100#'er

I've started drawknifing my yew stave into shape.  Drawknife works great!  Perfect for the apartment dwelling bowmaker.
Title: Re: holmegaard vis a vis recurve
Post by: Pat B on July 13, 2009, 11:20:42 pm
If you bend in the recurve you are maintaining the integrity of the wood by not damaging the grain. If you cut the recurve into a thick end you are cutting through the grain and weakening the strength considerably.
 When I bend in recurves(dry heat with oil) I get both the back and belly to one growth ring(but not the same one  ;D ). By leaving the tips thicker and wide you can reduce the thickness to a reasonable bending thickness, with one ring along its surface like on the back. this will allow a better chance of bending without splintering. I also use a metal support band on the outside of the curve.  Once everything is bent and lined up, and the working portion of the limbs are tillered then you can shape the tips to the desired shape(width and thickness). You may have to do some fine tuning later but that can usually be done with a little heat and a bit of pressure. 
   FYI...I have never recurved yew!
Holmegaard is one of the oldest wood bow designs that we have physical samples of. It can hold its own under survival conditions. It doesn't need recurving.  ???  ;)  Many wood recurves, if you stretched them out flat, would have a flat bow design with Holmegaard tendencies  ;D . Narrow, thick tips! These are physically lighter but maintain strength so they are a good candidate for static recurves.
Title: Re: holmegaard vis a vis recurve
Post by: radius on July 13, 2009, 11:24:29 pm
i know what you mean, Pat, that's why i called it the poor man's recurve...i'm gonna try it though!