Main Discussion Area > Flight Bows
Virtual Mass revisited
DC:
I've looked at those until I'm cross eyed. To me it looks like a low spined arrow has a slower "wave" and if it is low enough the fletching hits the bow. I really can't see what goes wrong with a too stiff arrow. Anyone help me?
Badger:
Too stiff will often hit the bow and kick left
avcase:
--- Quote from: willie on September 30, 2020, 02:19:11 pm ---Alan, would you be willing to speculate or comment about any limb designs features that may affect these harmonics? or how one could "tune" their design to a particular weight arrow? This goes a bit beyond making tips lighter or stiffer I presume.
--- End quote ---
I like to try to find ways to minimize the interaction of various harmonics on the shot. The best ways to do this is to push secondary vibration modes to as high a frequency as possible. This is done by following the familiar advice of focusing the bending area over as small an area as possible and using a string with maximum tensile stiffness. Otherwise, it is a matter of being aware that these interactions exist. A long thin flexible limb design should be more troublesome. A full working recurve with very flexible tips is probably going to be the most susceptible to bad behavior over a very wide range of arrows.
Alan
willie:
Thanks Alan. I was playing around with some take down limbs in the riser fixture recently and was reminded of just how much limb vibration occurs when the tips do not come home at the same time.
avcase:
The out of sync vibration does feel bad at the handle. There can be very high lost energy even if the limbs are perfectly in sync. It is dominated by a little different mode shape, which is the mid limb popping forward and back.
Alan
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version