Puujousi

Jousi valmistui kesä-heinäkuun taitteessa taas kerran muutaman mutkan kautta. Tarina kokonaisuudessaan naapurisivustoilla:

http://perinnejousi.yuku.com/topic/102/BambuIpeOsage-2?page=1#.V3yuXPl96Hs

http://www.primitivearcher.com/smf/index.php/topic,57462.0.html

Joulua odotellessa aloittelin uuden jousiprojektin. Tuomon ajatusten pohjalta päädyin kokeilemaan yhdistelmää, jossa 5-6 mm bambuselkä (Kone-Glans) ja 8 mm ipevatsa (Tuomolta). Keskellä kiilaksi hiottua cumarua (Rautia), lapojen päissä n. 3 mm ja keskellä n. 8 mm. Kahvan kohdalle liimasin vielä massarandubasiivun paksuutta antamaan. Liimana Unibond-800. Kärjet nostin n. 7,5 cm pöydän pinnasta ja 25 cm kärjistä painoin lapojen alapinnan n. 3,5 cm pöydän pinnasta.

Jatkoa hissuksiin, kun keretään...

Kopioin tämän Primitive Archerin sivuilta tännekin ihmeteltäväksi sellaisenaan, kun en laiskana uusiksi viitsinyt suomeksi kirjailla:

This BPCM1 bow caused plenty of "headache" while making it. This one started as Bamboo-Purpleheart-Osage Orange stave aimed to be some 70-74 pounder, glued with Unibond800. Unfortunately I used ca. 11 mm thick purpleheart core meaning most of the osage disappeared from the limbs while tillering. The exposed purpleheart didn´t stand compression under bamboo and started to generate chrysals during tillering.

Fixing plan #1 was to sand some of the purpleheart away and glue osage slices on the limbs to block the compression stress. Unfortunately I used Titebond III to glue the slices and that didn´t stand at the fades near the handle.

Fixing plan #2 was to sand all of the osage away and replace it with hickory; glued it with Unibond. Should have known that this is a bad choice; severe chrysals immediately on it.

Fixing plan #3 was to sand hickory away and purple heart down to 8 mm at handle and 3 mm at tips. Then I glued a 5 mm slice of cumaru as second core wood and massaranduba as new belly; cumaru alone on belly would explode due to very curly grains. This combination seemed to work and no more problems arised.

I had to quit sanding and leave the bow stronger than originally planned before all of the massaranduba would have gone. Then I made water buffalo horn nocks and arrow pass and the bow was ready for test shooting. After three sessions on three days the bow was still alive and time to finish it with 6-7 layers of Danish Oil. The handle is made of leather from old boots and the string is Dacron B-50, 16 strands, yellow and red.

Here are the details of this bow:
Strengh: 83 lbs @ 28"
Length n-t-n: 181 cm (71,2")
Width @ Handle: 27 mm (1 1/16")
Depth @ Handle: 24 mm (15/16")
Round @ Horn Nocks: 13 mm (1/2")