48" Korean EDIT Hungarian bow

[Mad Max]

Is there any measurement's for the core pieces and angle/length of the Siyah ? 
James Parker gave me a tracing of the glueup form for his Glass replica, fun project.

I can't seam to find anything

[Pat B]

Mark, see if you can find a copy of Karpowitz(sp) book on building Asiatic horn bows.

[Mad Max]

I can't find it 

[superdav95]

Adams book has the measurements.  i got mine off of amazon as a kindle or digital book. 

a more basic book with good info is also found on amazon. introduction to composite bow making by Tu Viet Thanh.  best of luck

[Mad Max]

Thanks

[superdav95]

Is there any measurement's for the core pieces and angle/length of the Siyah ? 
James Parker gave me a tracing of the glueup form for his Glass replica, fun project.

I can't seam to find anything

fyi... im doing a build along for a couple turkish style horn bows that will have some pics and measures as i go along.  the angle i set my siyahs jig to is about 130-150 degrees.  if you can find a natural bend in a tree limb of about 4-6" diameter you could get both siyahs from split. for steam bending i leave them long for leverage about 18" then cut them down to 10-12" or more depending on desired length of tip.   my limbs are steam bent on a jig also to 150 degrees.  Again, I leave them plenty long for the jig when steam bending about 20" but then cut them down to about 12-18" depending on the bow type or length.   

[Mad Max]

Ok thanks

[Mad Max]

Adams book has the measurements.  i got mine off of amazon as a kindle or digital book. 

a more basic book with good info is also found on amazon. introduction to composite bow making by Tu Viet Thanh.  best of luck

Ok I got the "Introduction to composite bow making" by Tu Viet Thanh
So not a Korean bow but it doesn't matter.
This is the bow from the book I want to build



The tip of the Animals horn goes to the handle, I would have though the other way.


The picture of the horn strip looks like 70mm on the back and 50mm on the belly? I'm guessing this is normal ?

[superdav95]

Ive done it both ways just fine for the horn.  Just as long as you orient both the same way on each limb I dont think it matters terribly.   This type of bow would be a good one to start with as the reflex is not as extreme.  you have shorter working areas also.  its more like a magyar style bow or similar. 

[Mad Max]

How many grams of sinew to make a horn bow?
Looking at some for sale and it comes  75 grams 150, 300 and so on.

[superdav95]

It depends on the length and style of horn bow you make but usually around 60-80grams.  The ones I’m building now will have about 60-70.  I’ve had some builds lime a tartar bow that had closer to 80. 

[Mad Max]

Ok thanks

[Mad Max]

Help me understand?
FYI I have been build bows for 20 years, BBO's, BBI's, selfbows and Fiberglass bows.
The core wood is tapered in thickness after the horn is glued on, in this book.
It's showing a radius of 70mm on the back of the horn and 50mm on the belly (reading the first line, 50-70 in the picture) of the horn for a 30-40mm wide bow
also the horn is 5mm thick for a 74-79 lb. bow--let's stay with 5mm for this conversation.



34mm at the widest point


I like to draw up the parts so I can see what's going on.
White is 5mm thick, the horn would have to be 7.1mm thick for this picture to be true.
This picture is showing the horn finished on the belly, but it would not be for the glue up.
For a 50 lb. bow what thickness should I start with?

[superdav95]

Without having every detail of the bow build a general basic starting thickness for your horn for 50lbs draw will vary quite a bit.  But if you are sticking to the Korean 48” they are narrow limbed bow compared to Turkish or ottoman style bows.  So with that being said you may want to be around 3-4mm thick and it is also rounded and dished out on its glueing surface.  This is the 70mm radius he is taking about for the scraper used for your dished out horn surface.  I actually do mine a little less dished out then this.  Just slightly rounded.  On your Korean you could likley get away with very little curving on the scraper for your horn.  I’ve done them with mostly flat horn that was grooved that were just fine.  On wider limbed horn bows I would recommend a radius for the horn.  This helps with counteracting the Poisson effect.  On narrower limbed bows it is t as much a problem.  Or least to the same degree.  Lime I said before you will be surprised how little horn thickness you will need for a 50lb bow.  A general rule is 1/3:1/3:1/3 for horn wood and sinew.  Variables come into play here depending on your type of bow build obviously but as a basic rule following this you will at least end up with a bow that functions and shoots.  Ratio changes impacts the performance and mass of the bow.  Hope this helps a little anyway. 

[Mad Max]

Flat, grooved horn would be easer for me, 50 lb. is what I was thinking to shoot for.
3.5 mm would be .137" thick