Kara Kurszan hornbow from Tc log - twist.. sinew damage?

KenH · Post by **KenH** » Fri Apr 22, 2016 11:45 am

Stick around!

I think most of the ATARN activity takes place on Facebook, and this site has become the Archive more or less. Activity slowed here several years back when Stephen Selby retired and ceased managing ATARN.net. Over time this place has become somewhat "broken". For example on the left here it says I live in Venice, FL. Haven't been there in 6 years but the site won't let me change that! ANdthe Search here is not all that good...

But I saw several posts recently, where Peter Dekker is renovating this site and plans on re-energizing it in the next couple months. Type www.atarn.org and you'll see what I mean.

The Facebook page is OK, but too many people try to post things that are just too in-depth for a "small post" site like Facebook. Plus not everyone likes or wants to take part in Facebook, for a variety of reasons.

I used to be involved with Primative Archer and Paleoplanet, but the majority of the folks there are not interested in historical accuracy. or for that matter Asian Traditional Archery. This is still the best place on the Internet for the subject in all its broad coverage.

pcoutin · Post by **pcoutin** » Sat Apr 23, 2016 10:29 am

Thanks

Here are more pictures. I now string the bow after putting the tepeliks by having it face with the back down, one ear on the ground and holding it on the other ear and stepping in the handle. Seems stable enough.

The string I made stretched a bit... brace height went a bit down.

Thinking I'll make an endless one w/ double loops. Hopefully the loops won't slip with this 'dyneema'... either way the string shouldn't fall apart since I'll keep the double loops long outside the knot with stopper knots.

Bubbles and dumb camera that doesn't want to focus on what is centered. Pretty sure thse bubbles are just the shellac. Maybe the crack on the belly was just a crack on the shellac...

This limb seems pretty good.

Less twist? Well, I think it got worse recently :\ We'll see again hopefully this Sunday. Maybe, if it was worse, it was from the sun heating it up this Tuesday... sigh.

Thinking I may tie blocks and a bamboo slat to the twisted side to try to correct the twist. Tc gave me advice to clamp it to do the same..

The twisted limb, I think? Ear looks misaligned but it's sort-of-overall-aligned... looks aligned when Iooked through the belly and it seems to bisect the bow sort of evenly.

Self-made arrows with ugly plastic points that are a bit too light and apparently not stiff enough, and a very beautiful bow

Twisted limb touching my leg

Bisected

pcoutin · Post by **pcoutin** » Tue Apr 26, 2016 4:34 am

Ugh, part of the.. splice lifted off while printing. Should use helper disks next time. Also, the hole for rope is too small..

pcoutin · Post by **pcoutin** » Mon May 09, 2016 2:02 am

The 3d printed teplik exploded. May try printing the half that broke again, rasping, re-gluing, and using it for a mold.

wonder if i should make aluminum tepeliks

A.Haydar · Post by **A.Haydar** » Tue May 10, 2016 5:35 pm

cmiiw, but too light arrow might effect similar to dry fire your bow..

pcoutin · Post by **pcoutin** » Tue May 10, 2016 7:13 pm

A.Haydar wrote:cmiiw, but too light arrow might effect similar to dry fire your bow..

yes
just in case, a tepelik exploded, not the bow. the bow is fine it's just the limb is a bit twisted w/ the limb tracking to the side
but i've heard of adam karpowicz testing hornbows at 3gpp or so? ridiculously light imo.
The lightest arrow I shot was an easton jazz 1916 30" with the smaller point (75 or 100gr... probably 100) a few times though, that was around 6-7gpp. Had handshock. The bamboo arrows like in the video had no handshock.
however this bow is pretty slow due to the horn on the ears and thick ears.. may be similar to historical magyar bows with antler plates though
but the string was stiffer than dacron... maybe that contributed
i'm waiting for istvan to tell me about how to apply heat and pressure to correct the limb which is tracking to the side, I assume while it's unstrung

pcoutin · Post by **pcoutin** » Thu May 19, 2016 7:13 am

yup. clamps.

and stuff.

for now, the bow stacks at 28.5" from the back more or less with a 6.5" brace height

pcoutin · Post by **pcoutin** » Sun Jul 10, 2016 2:45 am

It's been difficult to re-straighten it. Maybe once we move in around a month and I have a workbench. And am getting more money I'll be willing to spend on tools and such.

there was some other method with a pipe clamp..

Anyway it's maybe a bit less twisted now, I judged it shootable yet it was quite handshocky. I still have a small scar on my bow hand from it... ... (after maybe 2 dozen shots). I think at the "root of the hand", above the the hypothenar eminence, right under the base of the little finger. I don't think it was wrong nock point, the arrow was going pretty straight up/down.

I need to experiment more before making any conclusions.

I need a better scale, these measurements are ballpark. Arrows shot:

Big aluminum with 200gr point: 600-700gr - 10-12gpp..
Bamboo flu flu: 550gr or so - 9.3gpp
Cheap chinese bamboo: 480grains - 8.13gpp
Korean carbon arrow: 463grains - 7.8gpp

pcoutin · Post by **pcoutin** » Sun Jul 31, 2016 8:59 pm

Coming next at some point:

Fixing the twist, perhaps this way (from vine maple build along, Primitive Archer howto's and build alongs, by Gordon). I think the twist is near the end of the 'sal'... Need pipe clamp, C clamps, wood.

Improving the tepeliks. Cabinet scraper and bubble/spirit level to make sure it's level. A router or a curved scraper for the concavity? Rawhide from pet store dog chews to cover the tepeliks. Sanding & shellac for the finish.

Making a Korean style jig for putting on tepeliks. Need wood, Japanese saw.

Making a bow stringer from paracord for stringing once the tepeliks are on.

Finding grip & nock point for balance?

force/draw curve

Making weight matched arrows, need a grain or gram scale.

-grain scale
-spirit level
-wood 2x4
-thinner, larger wood plank
-rawhide dog chews or leather
-tanning solution, container?
-more paracord?
-pipe clamp
-4 C clamps
-cabinet scraper, curved & straight
-infrared thermometer
-shellac chips & solvent? the pre-dissolved shellac expires..
-forrester wood shafts?

Hopefully this thread could help people know what it's like to care for hornbows, know what to do..

Bow hasn't been strung for about 2 weeks, it's not all that reflexed now though. I want it to rest because it got unbalanced last time, idk. also don't wanna string it much with that twist..

May have to end up making new tepeliks from pine rather than fir, since pine is easier to carve and all that.. I guess, if I mess them up.

pcoutin · Post by **pcoutin** » Sun Aug 14, 2016 8:59 pm

Got some 4" vise and some other stuff. Forgot the spirit level... at least I got an infrared temperature sensor so I won't overheat the bow. Also, apparently heat corrections should be done from the horn side, according to The Art of Shooting a Short Reflexed Bow with a Thumb Ring. I imagine horn is less susceptible to heat damage than sinew and collagen glue...

The shellac on this bow has been peeling off, thinking button lac could work better.

Wrapped a mushamma with some black leather from a chair (not the temporary black bow sock on the pictures). the handle got all nasty from my sweat dissolving with the shellac and sinew, which I may try cleaning up with clear rum or something.. and it was a bit small anyway, though wide-ish and flat

Took these pictures, the twist is visible. I really, really need to work on my strength, flexibility and technique..

pcoutin · Post by **pcoutin** » Thu Aug 18, 2016 4:41 am

I wonder if that crack was just on the shellac and not the horn...

want to get: pine board, spirit level

next up: Korean style dojigae (tepelik) jig from pine
Doing better concavity on tepeliks with cabinet scraper, making sure they're level using spirit level. Will need to make sure table & vise are level..
Finishing tepeliks and putting on leather
Bow rack!!
Jig pegboard thing for twist correction... no clamps, just pegs and rope twisting for tension?

pcoutin · Post by **pcoutin** » Mon Nov 07, 2016 12:11 am

So many things. I need to stop getting overwhelmed. One thing at a time.

Next up: Make sinew glue by 'cooking' at 70 C in water for 24 hours. Apply to the sinew blemish in the inner limb. I think I might've created that blemish with the edge of a clamp or something when trying to correct the twist last time. That blemish just seems to have been getting slowly worse and worse.

https://goo.gl/photos/dyzq69sgSmyEgor37

Also make blueprints for tepelik (again) and for twist fixing tools.. hope I can get them done for me O_o

pcoutin · Post by **pcoutin** » Fri Mar 17, 2017 1:44 am

For the glue... should I use tap water, filtered water or distilled water?... Maybe I should just pour filtered water on it/dissolve glue on that

pcoutin · Post by **pcoutin** » Fri Jun 09, 2017 2:52 am

Finally made new tepeliks with poplar - level and the correct width! used a jigsaw and a bench disk sander. need to concave it with a chisel and sandpaper (and a half moon rasp?), then find some leather to glue on top of it somehow. it's kind of hard to make straight cuts with a jigsaw...

Haha this is total baby stuff

Next up is untwisting and more hide glue and sinew wrapping... after I graduate and move out of here, most likely. i'll have to scavenge for a big piece of plywood somewhere. don't wanna buy one.

Guess it's about time I get started sizing the bow with wood and pressing it with plastic while hot, I should have enough time in finals week...

Also sort of started making a 76"ntn maple D bow, hopefully with hemp fiber backing, aiming for 60#@32". I have no idea if I'll be able to make that with that board.

I haven't strung Kurszan in... a long time. Several months.

Hopefully I'll be able to just untwist it and balance it, and it'll be fine.