Home › Forums › Bows and Equipment › Help With Some Comparisons on EFOC?
-
AuthorPosts
-
-
Guys and Gals,
In the midst of all the EFOC and Ultra EFOC arrow building we’ve all done while seaching for the arrow combo that gives us each, individually, what we want in end results, a lot of information is available between us.
I’d like to build a speadsheet of arrows and EFOC for comparison sake that may give us some insight on “where to start” when we build another and/or give those not yet having done so a starting point.
“Trial and Error” always works in time, but I thought if we could all share this info, compare the arrows already assembled and note relationships of length, total head weight and shaft weight we may have an improved foresight with more accurate expectations of the end result BEFORE building one.
IF SO, it would save some of us money on the “wrong” shafts, head weights, etc. and more quickly give us desired end results.This SHOULD also give us a good look at HOW MUCH each factor affects the total EFOC end calculation. That would help us hit the total arrow weight range we seek by selecting the right components when starting to get a particular EFOC.
While a lot of us realize that “the most weight up front and the least to the rear” will give us the max, some have shafts in possession that they would like to see what improvements can be made or simply don’t know which spine and/or weight shafts to buy.
I think the end results will clear up some questions some of us have (me, LOL).
Any arrow specs that have 20 percent EFOC and higher is the target but all are appreciated. You cannot give me too much information here and no one’s set up is up for comparison to others. This is a FACT FINDING through comparison expedition only.
Weights of arrows I prefer to be WEIGHED for total arrow weight reports, not calculated, or indicate the weight is calculated, please. Head combination weights are acceptable in total of mfg specs but if you have a grain scale and CAN weight a head combo? Super!
Grains and inches please. ALL arrows you have put together with an EFOC is data I can use. Accuracy in calculations is important. PM me if help is needed. No offense intended to anyone.
Info needed is at the very least:
1. TOTAL head weight = broadhead + adapter + insert and how much OF that total is INSERT or internal/external footing.
2. TOTAL completed arrow weight
3. Length of arrow from the bottom of the nock to BOP.
4. EFOC or distance from BOP to balance point.ADDITIONAL and OPTIONAL information only if you so wish is below but not mandatory.
5. Your shaft’s GPI (grain per inch)
6. The shaft size or deflection.
7. Length and number of fletching.
8. Weight of wrap, if one is used.
9. What bow weight (at draw length) and bow type the arrow is shot out of.Anyone willing to share can post here or send a PM if preferred. All accepted with my grateful “THANK YOU” in advance.
No, Dr. Ashby, I don’t expect YOU to send me all yours. I cannot imagine the time that would take!! Any of the later ones you have in the Ultra range would be appreciated in time. No rush to anyone here. I dont think I’m going anywhere just yet. 😀
God Bless
Steve Sr. -
Steve,
Another aspect to consider is draw length. Another guy shooting basically the setup as mine got very different results with two inches less draw, but anyway….I have thought that there has to be some type of physics formula that will allow one to jump a few steps to get to the desired setup. Below is some of my data. I hope it may help.
Black Widow PSA X 71@31
GT Big Game 100, .280 deflection, 10.6 gr./in.
32.5 in. long (nock groove to end of insert)
846 total grains
190 gr. Grizzly Grande
125 gr. steel adapter
100 gr. brass insert
31 gr. 2216 external footing
51 gr. lead worm weight
3 gr. 3- 2.5 inch turkey feathers
5 gr. 3 inch wrap
9 gr. nock
29.3% EFOCLet me know what else you may need.
Richie
-
Thank, Doc.
I agree and it will take awhile to accumulate enough but this wasn’t started as a one season endeavor so anyone having or knowing of any assembled that would acquire the information needed will be a huge part in our success with it.Richie,
There exists “calculators” around online for FOC but..no offense to the person or persons creating them, they don’t always work for me. One is for a specific Mfg of shaft and one is off as much as 4-5 percent on one of my set ups.
Calculators are great but, in my case, a list of numerous examples gives me what I feel to be a wider range of options when I know the arrow mfg and gpi used to make a certain arrow at a certain length.
There is also a certain relationship within the factors we will be listing that I want to see what pattern develops in these two factors alone. I’ll probably find I was imagining things but nothing lost watching and much to gain for us all with whatever the results will be.
Again, this is going to take quite some time. I am fully counting on those here willing to do so, to forward what they can as they can and I will be adding several myself.
Please keep in mind even arrows assembled that FAILED to get your desired EFOC, have merit here. Each still offer data useful in this gathering of information.
Just head weight, arrow length and total weight, with the FOC calculated is a good comparison for us since we are starting from scratch.
God Bless
Steve Sr. -
Just a clarification after getting some feed back. ALL info above is not needed but FOUR are the main target group. The remainder is additional info perhaps useful down the line.
The MAIN FOUR that most all of you have available are the
1. Total arrow weight
2. Total head weight
3. Arrow length
4. EFOCDr. Ashby’s FOC chart is here in this site as well. No computations needed.
Again, if you would provide these four statistics, that’s SUPER!!
Sometimes asking for too much is a pain so, please, these four are great, easily gotten and appreciated.
God Bless
Steve Sr. -
Remember, I’m just beginning this journey…
Total arrow weight: 482 grains
Total head weight: 145 grains
Arrow Length: 29.125 inches
E(???)FOC: 10.94%2413 Easton X-7 shaft, 10.2 gpi, 60 lb. hard cam Bear Truth compound (27 inch draw), 235 fps
3, 2 inch Blazer vanes (total weight 19.5 grains), 11.3 grain Bohnig Signature nockThe doctor is correct in that tuning the alloy shaft to the bow is more critical than when using carbon composites. I have attempted adding weight to the point ends of these shafts. Groups open rapidly and trajectories degrade dramatically as well.
I hope this helps.I sense new ammo on the horizon.
-
-
AuthorPosts
- You must be logged in to reply to this topic.