Originally posted by Tree man:
Monterey, I don't want to fight-I don't even want Dr. Ashby to be wrong. I do want everyone to THINK. Time at a cuttingboard can be enlightening but I wish to remind you that if time or distance are varied in the application of force then you are no longer comparing equal force.
And all you STOS shooters -it IS a lovely head but do the math, it isn't 3/1. It isn't even close to 3/1.-It just seems "close" because it is a little more than 2/1.
Tree Man, Hey I hope you didn't think I was pickin a fight with you! :eek: My own skin is dang near as thick as those buffs ashby shoots and maybe I tend to think others are or should be the same. If you took it as overly adversarial, I apologize.
I realize the cutting board experiment was not the best example but it's warmer in the kitchen that outside and a heck of a lot less windy!
The distance is dictated by the simulation of the length of the broadhead cutting edge, the time can only be guestimated and the force applied downward as you move forward needs to be guestimated too. Like I said, not the best analogy but if done carefully, it does illustrate the virtues of high mechanical advantage.
I felt that Ashby presented the physics of KE, momentum, force and force over time very well.
Most trad hunters are aware of the failings of the mechanical broadheads and while the energy wasted in opening the blades is the most commonly identified issue, I think an even larger issue in their poor penetration is the angle of the blades once they do open. Most seem to present a rather large angle with extremely low mechanical advantage.
The STOS is not the only vendor touting a 3/1 broadhead that isn't. Several years ago I was scanning Kustom King and 3 Rivers catalogs and came across many broadheads touted as 3/1 with their actual measurements listed below them. Not a single one was 3/1
But, it shows the influence of Ashby's research that so many broadhead manufacturers would want to make the claim. Too bad they don't want to expend some resources to actually produce a tough 3/1 broadhead :(
I've been shooting 190 ribteks for a while and they, like the grizz can be modified to suit. I'll probably drop them though given the roughness of the ferrule which, according to Ashby, will inhibit penetration. Makes sense to me. I never hit an animal with a Ribtek so I can't comment on it from first hand experience.
I think it's significant that Ribtek is bringing out a 3/1 head with a nonvented ferrule that weighs in at 258 grains.
One of the most surprising findings to me was the relative toughness of wood shafts. They apparently sustained far less damage than aluminum or carbon. My local trad dealer tells me that four or five years ago he was making and selling 25 or 30 dozen wood arrows per month. Now it's down to only a few dozen.
Sorry for the rambling, but wanted to interject a few and various thoughts on this subject, all of which may not be closely related. Just some observations, etc.