Anyone, Formula for Stored Energy.


Thanks Bob

Not one response? Had 4 on another site....

I would say Morrison X Cheyenne = Awesome

Is there a reliable formula?  I'm no bowyer, don't even pretend to be one on television, but I'm pretty sure there are lots of variables...bow design, bow length, draw length, draw weight, bow material, etc.  Then you have efficiency of transfer which will add arrow weight, string material, string weight, where that weight is placed (i.e. in the loops or in the center serving), etc. etc. etc.  Can't see there being a formula that works across the board...but again, I'm not even a pretend expert in the field.  Hoping to see more on this.

Chad

Chad, I really don't think there is, but was hoping there might be. Any bow will do what it will do, Numbers really don't tell the story, if it don't feel good and shoot good its not for me. and knowing the SE makes no difference. But today some feel they need to know things like that in order to take game.. I have figured out at my age I don't have near the SE I used to have.

Bob,  If you still have your Rhino software, you can plot your graph in it and have it find the area under for you.  Very accurate.

Mike

Quote from: wingnut on November 03, 2018, 10:37:00 AM
Bob,  If you still have your Rhino software, you can plot your graph in it and have it find the area under for you.  Very accurate.

Mike

I wonder about that.  If we define stored energy as being the area under the force draw curve, knowing that area would indeed give you a very accurate measurement of stored energy.  However, because of the variables noted by Chad, and probably other variables as well, it may not be an accurate measurement of the actual energy pushing the arrow.  I.e., two bows with the same stored energy may not have the same cast.

Thanks Mike. I do and still use it a lot. Rhino cam also. I'll look into that and see what I can come up with.

QuoteI have figured out at my age I don't have near the SE I used to have.

According to my gut I have plenty stored...I just don't have an effective way to transfer it!

I'm like you...it either works or it doesn't.  I've never been one to worry about trying to calculate FOC, or FPS, or SE, or momentum, or KE...but I have eaten several MRE's and did a lot of PT as a PVT......

As long as I get good arrow flight, hit where I aim, and my arrow either passes through or gets stopped by the off-side shoulder...I'm good.  Dead deer don't care about physics (I asked)....

Same here Chad, never had a dead deer ask if I was getting a full 26" draw or if I had enough speed or wide enough broadhead.

Its about time to head to the woods, hope I have enough SE to get treestand in and back to the Jeep.

Yep, to know STORED energy, you need a F/D curve. There are methods of summation that get very good answers, or you can find a program that will plot the F/D curve and do the math for you. Basically it's a calculus problem.)

Once you have that need you need a chrono, and you need to know arrow weight. That way you can find the Energy delivered to the arrow.

Then you can find Efficiency, which is Stored Energy/Delivered Energy, (Potential Energy/Kinetic energy=PE/KE)

And it sounds like what you're after is actually Efficiency.

^^^this

"Then you can find Efficiency, which is STORED ENGERY/Delivered Energy, (Potential Energy/Kinetic energy=PE/KE)
And it sounds like what you're after is actually Efficiency."
Maybe Efficiency is what we are really after. Still SE not known, now DEL/Energy. I'm using a excel spreadsheet and getting everything I want. except  SE I'm sure the formula is wrong (=total of 22 poundage reading for DFC, divided by 12) this may be right? I don't know what if there are only 15 to total /12 can't be right. If SE is something we can not verify fairly easy It should not be used to claim performance by anyone. If the formula in excel is correct great (Kinda hard to take Super Short limbs to 32" draw) and get a poundage that means anything. This stuff is still fun.