Hotspur wrote:This is what I get from the youtube sound track.
The shot at the 57 second point. Microphone at the target so we need to add speed of sound from trigger to mic.
Recorded sound .086 milliseconds
Speed of sound 1107.28346456693 feet per second
Range 60 feet 60/ 1107.28346456693 = 0.0541866666666666
Time to add
Recorded flight .086 + .054 = 0.13919
time plus speed
Flight time 0.13919 / 60 = 431 fps
divided by 60 ft
Yes, you are definitely right. I also get 0,086 seconsds on that arrow and since I usually place the microphone exacly halway to target, I have forgotten to involve the speed of sound in my calculation. Sorry! -I stand corrected!
One more observation is thath arrow no 3 and 4 seems to penetrate the target less deep. Does the crossbow loose power or is the target used a lot so it has softer areas?
To mee it´s still an interesting design but it would be faster with this new lighter pivot-arms? Now it seems having the same speed as the website says it had with the old arms.
I earlier calculated the efficiensy to be around 60% and I guess the design would win on being an insving design allowing shorter (=lighter) arms but having the same powerstroke.
As said before only a real speed test can bring total thruth in this but it seems to be 431 fps right now.
Another thing -Please handle all users of this fine forum with respect.