Hello!
While slowly (etremely slowly) buildind a shamisen, I decided to give a try at making a koma. I could not resist buying a faux tortoise hair clip and “ruin” it to see if it could work out for the koma. As a first try, I wasn´t extra worried about keeping everything strait but the outcome was not as terrible as at the beginning 
Materials used: bamboo, acrylic tortoise, Pattex glue.
Looks really good! I would suggest to use a bone guitar saddle blank for the tip instead of the acrylic.
Hi Alexey! Thanks for the suggestion and it goes onto my to-do list right away The acrylic was just pretty, sound wise, it will probably be awful… I still have a nagauta shamisen waiting to be repaired, then I will be able to try it out.
Hello Stefanie
Sound of bamboo coma with acrylic tip would be softer with less high frequency but better than just the bamboo. Bone tip would add highs and crispiness to the sound. Also one of the main parameters is a height of the koma. Nagauta koma is higher compared to the tsugaru shamisen. Typical range from 9 to 12mm. Mine is 9.5mm. So if you used profile from the Kyle’s book it might be a bit small.
Just one thing: is it a photo or the top edge is slightly curved? I would suggest to sand it down to flat and add the notches for the strings to assure proper strings placing distance.
The photo enhances it but yeah, the top is slightly curved, not on purpose though. The whole koma project actually started from a misfit but I decided to give it a go so to test the materials and their workability. Ah, but good to know the height, it will fit the nagauta - 12mm exactly. So it won´t be a total waste after all… 
