Question about curved arms

[AuxArcher]

I agree, ash is the best wood for these machines (and historically correct), but cost are always an issue, eh? I'm fond of birch for arrows, but not for other purposes. However, if you have done the machine in that wood, well....good luck

But, for safety's sake, consider a bit more expense for the arms. I'd hate to see those arms disintegrate on you. For traditional bows, birch is just terrible, and they explode quite regularly, with just 30 or 40 pounds of draw.