Wind Drift - Just the facts

[Merlin Archery]

Thanks for all the info. I'll check out some of these programs. One thing did stand out in particular. Old bloke can FLY? how cool is that!

[Dante]

All to techi for me by the time I had calculated anything the wind is bound to have changed direction. I use a fairly simple solution, ignore the wind it's not going to make much difference to the way I shoot.

[MaxAutobrake]

Not really practical to utilise aircraft drift computers as has been suggested.

There are 3 velocities (= 6 pieces of info as a velocity implies a speed & direction) : wind velocity (direction & speed); arrow track (actual path taken by arrow) and its groundspeed (its true airspeed plus or minus and head or tailwind component); and arrow heading (ie its direction laying off drift) & its true airspeed.

Knowing any 4 - you can calculate the other 2 - in this case the heading you need to give the arrow (windage) & its groundspeed - which of course becomes irrelevant. Therefore you need to know wind velocity (spd & direction) and arrow true airspeed and track ( ie direction of the gold).

However, wind at ground level is affected by friction and it swirls around buildings, trees etc changing its direction & speed making almost impossible to accurate calculate from one minute to the next.

Hence windage is always going to be a bit of trial and error, making adjustments as you think fit.

[Rik]

Originally Posted by Random_guy

Hmmm intrigueing. I'm about to buy new arrows and was playing with Joe Tapley's drift program (am trying to decide between nav's and ACE's...). Even after altering the ACE diameter to fit the updated measurements on the website, the program showed negligible difference between the ACE's and Nav's for the spines i'd want (compared ACE 670's to Nav 710's, as there are no Nav 660's on there...).

Very strange indeed. Perhaps at the smaller diameter end of the scale, the benefit of the barrelling on the ACE's and the lighter shaft is lost? (both came up similiar in weight). Just a thought....

hmmm. Did you try Triple 700s in comparison to ACE 670s - that might be a more interesting exercise. NAV 710s are on the light side and comparable diameter to ACEs (I would guess, data being hard to come by for ACE diameters). Given that the 670 is at the start of a "step" in the ACE sizes, there might be too much in the way of barrelling.

[Merlin Archery]

I downloaded Joe's drift program. The one thats listed on http://homepage.ntlworld.com/joetapley/

Doesn't seem to work. Is this the program you are talking about?

[Merlin Archery]

Originally Posted by Marcus26

Accurate Sights has it built in, plus a very very neat Matchplay simulator.

Could you point me in the right direction for this program? Thanks.

[Marcus26]

That thread is for the updates
You will need the full application as well
http://www.imparchery.com/download_as6.php

[Random_guy]

Didn't try the triples as wasn't planning on buying them! They've come up in price since i got my last set and are now not much cheaper than the nav's, and I had a few inconsistencies in shaft diameter with my 900's, so decided to go the easton route.

The nav's tune at about half an inch shorter than i'd cut them were i to buy them new myself (someone at the club has a set that ian bought the wrong spine, so are now homeless. I was playing with them, along with my spare button....) but were a touch on the weak side and only had 100 grain points in. So i figure half an inch longer and a spine stiffer should give me a decent tune, and will probably whack 120gr points in to try and kick the wind drift that is enivatble with short, light arrows.

Just not sure whether to buy the nav's second hand and use them or buy ACE's new, hence the comparison...

[JohnR]

How accurate is this program at spining arrows - particularly at the junior/adult crossover where the Easton charts become almost guesswork?

Originally Posted by stu369

Ben
Check out Software for Archers (SFA) at - www.pinwheelsoftware.com
I have this program - its a little bit of a handful to get used to but it will give you all of the data that you are looking for

John

[joetapley]

Originally Posted by Merlin Archery

I downloaded Joe's drift program. The one thats listed on http://homepage.ntlworld.com/joetapley/

Doesn't seem to work. Is this the program you are talking about?

No idea what the problem was - but as I needed to update the help files anyway has prompted me to to a rebuild which is now up.