Arrow Wind drift explained; heavy vs light, thin vs fat

Archery Education Video 7. This time we get into the math of how wind affects arrows in flight including comparison between heavy arrows and light arrows. A comparison between standard diameter, small diameter, and micro diameter shafts. Best arrow in the wind.
Future videos:
Penetration in depth:
Ballistic Calculator
Arrow build suggestions
Bow tuning
Broadhead design
Arrow geometry and fletching effects on drag and energy,
Bow tuning effects on energy loss
Bow tuning effect on penetration
Arrow impact angle effects
Arrow momentum
Target/animal forces opposing penetration
and more as the questions come in.
Archery equipment Testing
Camera gear:
Sony A7c
deity d4 duo mic
tamron 28-200mm
tamron 20-40mm
Sirui tripod
Iphone 13 pro max
Gear review and testing videos coming as well
#archery #education #outdoors #physics #bow #arrow #arrows #penetration #foc #fast #light #heavy #hunting #deer #elk

[@Lucas_Palmer_bownerd_engineer]

Hey everyone, it has come to my attention I have made a mistake in my calculations. I considered the cross wind to always be 10 MPH acting on the arrow. When in reality as the arrow begins to drift sideways the relative wind to the arrow will decrease. I will release an updated video soon discussing my mistake and updating the table and formula. As always I appreciate your support. We have a lot more to discuss and testing to due! I hope you all enjoy the information! Thanks, Lucas

[@statgenie6575]

I think FOC will affect the drift too

[@statgenie6575]

I believe higher FOC will have less wind drift, but at a price of faster (very slightly) reduction of speed

[@TheBladeSled]

Great info I can trust

[@sheyanderson4371]

Appreciate the video and really enjoying the entire series. Wind affect is always a consideration in my hunting setup, as I hunt in Southern Idaho. Personally, I want a setup that, within my range, I don't have to adjust or compensate for wind. Anything that would make me think twice about compensating or adjusting for, lets me know not to take the shot. I didn't do the math, but have field tested and heavier arrows, with higher FOC, and less fletching in the back buck the wind better (who knew). With hunting, it's just a matter of finding the preferred weight and trajectory, but also just the right amount of fletching to steer my broadhead. Looking forward to more videos, keep them coming.

[@Lucas_Palmer_bownerd_engineer]

Sounds like a good combination. Higher FOC is great for reducing fletching size, which in turn reduces cross sectional area. I plan on doing a separate video purely talking about fletching size effects on wind drift. Thanks for watching!

[@charlierobertsendurance3489]

I’m currently on the range and it’s blowing about 40mh gusts. Thanks for the info! 👍🏻

[@Lucas_Palmer_bownerd_engineer]

You are welcome be sure to check out part two of wind drift I did make a bad assumption in this video! Take care, Lucas

[@TheArrowBuilder]

Great info again! One thing that should be considered as well is the surface area of the broadhead. Having a large unvented head in windy conditions is going to be a large determinate of wind drift. Especially in 2 blade configuration as it has inconsistent pressures as it rotates. I've been thinking about it for awhile - but as you mention a 3 fletch is better for wind in theory. I've been interested in a smaller vane in 5 fletch for wind as the average cross section is smaller than a 5 fletch. It would be interesting to see some numbers on that.

[@Lucas_Palmer_bownerd_engineer]

Absolutely in reality the vanes and the broadhead should be a projected areas that changes at a rate relative to the spin rate of the arrow in a cyclic manor relative to a cross wind. Then you have to consider the disruption of flow created by the vents in the broadhead and the spinning of both vanes and broadhead. That's something I want to see if I can test in the wind tunnel but we will see. You might be able to test in a CFD model but in a wind tunnel or shooting with a slow mo camera would be best.

[@craigarnold323]

Really wish you would redo this test and use a FOB fletching. Thank you for all the effort you put into your testing!

[@Lucas_Palmer_bownerd_engineer]

Great suggestion! I'll try to remember to add a fob into physical testing. Thanks for watching!

[@Lucas_Palmer_bownerd_engineer]

I also am planing a separate video for isolating the affects of different fletchings on wind drift. I will include the FOB in that video. Thanks again.

[@denniswehling2147]

Great information and keep up the good work! Thanks

[@Lucas_Palmer_bownerd_engineer]

Thanks Dennis! still working on that wind tunnel.

[@jamesmurphy6403]

I love that you use actual data to back up your thesis, your a smart cookie keep it coming

[@Lucas_Palmer_bownerd_engineer]

Thanks!

[@josephtreadlightly5686]

I'm In central MN & my 3 2 mm bare shaft is all I can do right now due to the weather. I'm shooting a recurve & I have these shafts cut to 3 different lengths just to determine overall shaft length. I'm sill waiting on some 2" feathers i ordered just cuz of overkill with the shafts that I put on a 3" feather. It is very windy here right now in cevtral MN.😮

[@bill-winke]

I agree that fletching size has a lot to do with wind drift. My best success has come with small diameter heavy arrows with small surface area vanes.

[@bill-winke]

Another reason why I liked mechanical broadheads for so many years - less cross-sectional area and also less chance to steer the arrow off-line of the fletchings get pushed to the side and cause the arrow to fly slightly sideways.

[@Lucas_Palmer_bownerd_engineer]

That is definitely an advantage, what is your favorite broadhead?

[@statgenie6575]

My thoughts exactly. I use SEVR broadheads, I think it is close to fieldpoint. Additional, moving the vanes back as much as you can

[@paulkysar6207]

Love the videos. I have never followed the trend or hype. For 20 plus years I have shot standard arrow standard insert. I couldn't care less about FOC or how many grains my arrow is. I wanted to shoot a round 300 FPS

[@Lucas_Palmer_bownerd_engineer]

Thanks! Glad they have been helpful.

[@wrobo6122]

Great video! Thanks!

[@Lucas_Palmer_bownerd_engineer]

Glad you liked it!

[@rchapman8865]

Super info dude. Love these vids

[@Lucas_Palmer_bownerd_engineer]

Glad to hear it! Thanks for watching!

[@seanohagan1996]

Great Videos and Info! Thanks

[@Lucas_Palmer_bownerd_engineer]

Thanks for watching!

[@TrueLineOutdoors]

Excellent video nice work man!

[@Lucas_Palmer_bownerd_engineer]

Appreciate it!!

[@randyg4713]

Another great video. Keep it up

[@Lucas_Palmer_bownerd_engineer]

Thanks again!

[@jackbuendgen389]

Great video 😊

[@Lucas_Palmer_bownerd_engineer]

Thanks! 😊

[@YoureSoVane]

@0:35 This is incorrect. Wind does hit the side of a stationary arrow, but not a moving arrow. The arrow is ALWAYS flying straight, the air itself is moving. It's like driving an RC car on a rug while you're pulling the rug sideways. From your stationary reference, the car is moving at an angle. From the car's perspective, it's driving straight along the rug. The angle into the wind is the sum of the vectors. The arrow always aligns to the apparent direction of travel. The nock is always pointing in the direction of air resistance. This should be super obvious for anyone who's shot in high winds and had an inch of drift to 40 yards and maybe a foot at 100.

[@Lucas_Palmer_bownerd_engineer]

Can you elaborate more I'm not sure I understand your comment. First part your saying that a cross wind does not hit the side of the arrow? Where does it hit or affect the arrow? Second the arrow aligns to the direction of travel. So that is to say that as wind pushes the arrow left, for example, the tip of the arrow points left since the direction of travel is now changing? I agree the nock always points in the direction of the sum of the air resistance, the resistance from the cross wind and the resistance due to the forward movement of the shaft. So from the previous example a wind from the left would create a vector directed left while the forward motion creates a drag vector opposite the direction of arrow flight, rearward. So the sum of the two would cause the nock to drift left. This drift then increases the amount of drag from forward motion increasing the value of the vector pointed rearward. This video provides a good illustration of how the wind pushes the back of the arrow more than the tip, look at his shaft impact at 100 yards. This is in a wind with a peak of around 15mph measured on sight. kzbin.info/www/bejne/aafcgKF9nsqri8k I appreciate your feedback.

[@YoureSoVane]

@@Lucas_Palmer_bownerd_engineer the wind pushes the whole arrow equally, but the back moves more freely, hence the illusion. If the arrow has a perfect drag coefficient and does not slow down at all, there will be no wind drift. A better description of wind drift is the measure of how much the air slows the projectile down combined with the direction of the force interaction. If the arrow is stationary or held in place, the air hits the side of the arrow. If the arrow is able to pivot and rotate, it aligns to the wind. During launch this aligns the arrow to the point of aim. Therefore the only predictor of wind drift is a combination of drag coefficient at a reference condition and how often the projectile stays in that reference condition.

[@anthonyforfare7223]

Great information ! 👍😁 well done 😎😊👌🏹🎯 Keep it coming 😄 God Bless 🙏😇❤️🇺🇸

[@Lucas_Palmer_bownerd_engineer]

Thank you! Will do!

[@TraditionalArcheryJourney]

Nutter gud un. Keeps em comin.

[@Lucas_Palmer_bownerd_engineer]

Thank you, will do.

[@dmouse522]

Thanks for looking at FOC. Considering high FOC; does the arrow try to correct while in flight or after hitting the target....or both due to the lever arm?

[@Lucas_Palmer_bownerd_engineer]

Great question. The arrow will try to correct in flight. Once the arrow hits the target the tip/broadhead takes over the direction of travel. I touch on this a little more with my video on penetration and FOC more towards the end of each of those videos. Thanks for watching.

[@TheArrowBuilder]

I will say - My crude testing hasn't shown this high of wind drift. Setting myself deliberately perpendicular to high winds that exceed 10 mph, I've never experienced this much wind drift. It's more in the 3 inches at 50 with 450 grain .233 OD micro and maybe 4 inches with a V-Force with lower FOC. The groups overlap a lot actually - more than I expected. I did similar but rougher math years ago and that's the reason I decided to go with the smallest micros I can. The biggest takeaway I get from this and from my tests have been that I shouldn't shoot far in high winds. Sounds simple - but it's darn tough to be able to shoot in that wind and I'm the limiting factor not the arrow. My ability to shoot in high winds even with quiver off is greatly diminished. In your equation - How are you taking into account in "A" the side area of the arrow as a cylinder? This is where I went sideways with my calcs. The increased diameter doesn't have nearly the affect with a cylinder as the same area is perpendicular to the force. The rest is at an angle and reduced the affect significantly.

[@Lucas_Palmer_bownerd_engineer]

Hey good question, because we are using the drag equation to determine our force the area is the projected area of the cylinder which would appear as a rectangle. The coefficient of drag is used to account for how easily or difficult it is for the wind to pass over the objects. This is where the curve of the shaft is considered. For a cylinder the Cd is about 1 depending on Reynolds number. A plate or rectangle would be in the neighborhood of 2 or more. I felt that the numbers seemed high as well. But reached a similar conclusion wind is a very bad idea to shoot far in (at animals) especially considering how an archers accuracy is reduced. Another consideration is that as you get closer to the ground the wind is dramatically reduced due to friction with the ground any vegetation or object also reduce and sometimes change direction of the wind or create eddies. I did not consider that as the arrow pitches, back of shaft, due to the wind the cross sectional area will be reduced. I essentially made the assumption that the fletching and drag from forward movement would keep the arrow perpendicular to the wind. All of these will increase the force value and therefore the drift.

[@TheArrowBuilder]

@@Lucas_Palmer_bownerd_engineer interesting. I think that might need some more diving into. Good work though!

[@remieoh7338]

I love the way you explain things by using calculated values based on proven or at least accepted theory and/or equations. I know way back when some dude did the same thing. I believe his last name is Einstein...😀

[@Lucas_Palmer_bownerd_engineer]

Thanks!

[@statgenie6575]

Great topic, would like to see heavy vs light arrow difference in the wind for a given bow

[@Lucas_Palmer_bownerd_engineer]

Great suggestion! Thanks for watching!

[@statgenie6575]

You are a genius. Hope you can have a calculator out soon. If I use an arrow with high spine index (150) and high FOC (20-25%), total weight 450gr. Should I get as small as possible vanes to reduce wind drift while providing enough lift for arrow correction?

[@Lucas_Palmer_bownerd_engineer]

That would be my suggestion you use a vane that corrects your arrow in all situations a proper amount any more and you’re just wasting energy. Group size and accuracy is very important to this as well.

[@Lucas_Palmer_bownerd_engineer]

FYI the calculator is now available on iOS working on android version now. Archery ballistics and pro archery ballistics.

[@XXXston3wallXXX]

Thank you.

[@Lucas_Palmer_bownerd_engineer]

Thanks for watching!