Arrow specs and charts… NEED HELP

[Vintage Archer]

#5393

Arrow specs and charts.

I have people continually asking questions about what carbon arrows they should use to attain high FOC. Basically the arrow companies arrow charts only go to 200grains up front.

There must be a way mathematically to compute a chart that could go to 400 or 500 grain up front. I don’t believe the arrow companies test each arrow but they are computed figures using log rhythms or some other method.

Does any one have a idea how this is done. I know charts are not the complete answer but a starting point

Could use some help. THANKS

[Stephen Graf]

#40668

vintage archer wrote: Arrow specs and charts.

…using log rhythms or some other method…

I don’t think dancing firewood will help you… 😆 Developing a “formula” may or may not include logarithmic equations… Not everything that can be put in tabular form can be set to an equation.

Good topic, can’t wait to see what people say!

I’ve been shooting some gold tips 55-75 with 300 grains up front. I quit adding weight because the bare shaft was showing slightly weak. But I just couldn’t get happy with the way it shot from my 55lb recurve, and so I went ahead and added another 50 grains. And guess what, the bare shaft shoots straight now.

Another example are the gold tip entrada arrows which have a 600 spine. I started bare shaft tuning them with 100 grains thinking they would still be way to weak for my 50lb long bow. I ended up with over 250 grains on the end. I could probably add a smidge more.

I think something changes as the FOC moves toward the tip. You can’t just extrapolate from the old charts to find out what should or shouldn’t work.

Bottom line when picking shafts for high FOC arrows – get light arrows. Anything over 8 grains per inch makes it hard to get really high EFOC. There are only a few brands that meet this weight requirement. My own preference is to get the most FOC I can without exceeding 12 grains per pound.

[Greg Ragan]

#40794

Try out Stu miller’s calculator. I think you can go up very high in point weight:

http://heilakka.com/stumiller/

[Vintage Archer]

#41876

two4hooking wrote: Try out Stu miller’s calculator. I think you can go up very high in point weight:

http://heilakka.com/stumiller/

I have tried Stu’s calculator and find it overwhelming, I am looking for a fast reference that can be posted on the web site so people can look at something visual instead of interactive, I find that switching to FOC arrows is sometimes monumental to the costumer and they walk away rather than experiment. My goal is to simplify the process getting more converts to heavy arrows and FOC. Thanks for the suggestion in the end Stu’s calculator may be that only alternative.

[Ed Ashby]

#42065

Coming up with a chart is going to be difficult, Joe, because there are so many variables and one cannot go just on draw length, draw weight and point weight. For example, take two identical traditional bows but put a thin arrow plate on one and a thicker arrow plate on the other – or even the same thin plate on the other except with a piece of toothpick, a match stem or a piece of leather boot lacing beneath the thin plate – and you end up with two bows that vary greatly in the degree of centershot and that can significantly change the shaft that will tune. It becomes even harder when we look at the huge variance in the degree of centershot on trad bows.

Shaft diameter also affects the selection. A small diameter shaft, like the Victory, sits closer to the riser and needs to be stiffer than a similar shaft having a larger diameter, such as a GT Ultra Light.

What we really need is for every producer of shafts we’re commonly using for EFOC/UEFOC arrows to offer single shafts for tuning purposes. Then we could buy the two or three shafts likely to tune and work with them to find the correct shaft. Lots of luck getting that done.

An interesting sidelight is that a true centershot situation, with the center-line of the arrow shaft precisely in line with the string, requires a VERY stiff spined shaft and is very difficult to tune. At ‘dead center’ the shaft does not know which direction to try to flex first, to the left or right. On one shot its initial flex might be away from the riser and the next time it may try to flex towards the riser, causing it to bounce away from the riser. With any true centershot bow I’m trying to tune, whether a traditional bow or a compound, the first thing I do is move the arrow at least a little bit away from true centershot. It makes the tuning far easier.

Ed

[gigglemonk]

#44641

I found an app in iTunes (not all that trad!) called Spine Calculator that has the same limitations you mentioned regarding tip weight. I emailed the app creator and he got back to me rather quickly. Maybe its worth contacting him?

http://www.arnegockeln.com

The site is in German but its easy to find the KONTAKT link.

By the way, just ordered my first Tuffheads today!

g

[Vintage Archer]

#44764

Ed thanks for your input. You are right but trying to get arrow companies to make sample kits for testing .That maybe in the same category as developing a chart.Not about to happen.:D

[Brennan Herr]

#44863

If you look hard there are a couple places on-line to by single shafts…lancaster archery and I think eagle archery.

[Ed Ashby]

#45494

That’s potentially a very good ‘nitch’ business. Someone should start buying up arrows, of all the commonly used types for EFOC/UEFOC, and breaking them up and selling them as single shafts, just for tuning purposes … then make that known on the verious chat sites.

Ed

[Fletcher]

#46084

I absolutely concur with Dr. Ashby’s observation on centershot bows. A finger release will start the arrow flexing in one direction, but with no bow to have to bend around, it takes a very stiff arrow to come out straight. I don’t want a bow cut past center.

Just to clarify, center cut and center shot are not the same.

I have no desire to mess with carbon arrows, Joe, but carbon test kits might be a good add on to the Tuffhead line. Test arrows, whether carbon, alum or wood, are absolutely the best way to get the right spine.

[Vintage Archer]

#46606

Fletcher wrote:

I haveno desire to mess with carbon arrows, Joe, but carbon test kits might be a good add on to the Tuffhead line. Test arrows, whether carbon, alum or wood, are absolutely the best way to get the right spine.

.

Ed and Fletcher that is a good suggestion.I am going to give it strong consederation. Thanks!

[Stephen Graf]

#47756

3Rivers sells test kits; of 3 arrows. For example, you can get a Carbon Express Test kit with a 150, 250, and 350 arrow. They do it by brand.

I guess you are talking a test kit of 1 arrow?

Being an arrow distributor can be a tough business. The minimum order numbers are pretty high… But you could become the first business to sell the compete Ashby Arrow with all the bells and whistles: High FOC, 650 grain total wt, Turbulator, A&H Fletching, Brass Inserts, and Aluminum Collar around the front end.

[Vintage Archer]

#47787

Steve Graf wrote: 3Rivers sells test kits; of 3 arrows. For example, you can get a Carbon Express Test kit with a 150, 250, and 350 arrow. They do it by brand.

I guess you are talking a test kit of 1 arrow?

Being an arrow distributor can be a tough business. The minimum order numbers are pretty high… But you could become the first business to sell the compete Ashby Arrow with all the bells and whistles: High FOC, 650 grain total wt, Turbulator, A&H Fletching, Brass Inserts, and Aluminum Collar around the front end.

Steve I was thinking of a test kit of three arrows.

I am in the exploratory stage right now. like every thing else there are always complications.

I am sure the arrow bussiness is competive and complicated about like the broadhead bussiness:D .I am thinking I would just sell test kits once the person decides on a arrow they can go to a arrow dealer and purchase from them . .It would be more of a service to our customers than a high profit item.

Still in thinking stage it might not work out.I have looked at a lot of things that never materialized .

[Ed Ashby]

#48057

If one goes slowly and carefully when shortening their shafts during bare shaft tuning just one single shaft in each ‘likely to work’ spine range should be sufficient to find the correct dynamic spine. I think the ideal situation would be to have a source to buy the shafts desired for testing as singles. If one thinks they need 2 or 3 of the same spine to find the correct choice then they can order 2 or 3 singles of each desired test shafts.

I find that the spine ranges (or deflection) stated by different manufacturers don’t always end up tuning the same. For example, not every 300, 400 or 500 deflection spine tunes the same. Being able to purchase single shafts would offer the option of economically testing differing brands of shafts having the same ‘stated’ deflection or spine range.

It’s just like developing a handload for my rifles. When I’m doing that I carry my components and portable hand press to the range and load just the number of test rounds I need for testing, one cartridge at a time. That makes it easy to start with just a few test loads and then work around the most promising ones by making small changes. It simply conserves materials and reduces overall cost of finding that ‘right’ load.

Ed

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