Come Fly with Us

[Colin]

Just wondering whether anybody is going to the Flight Shoot on 28/4/2002 at Yarra Valley?

[Marcus]

What target round are you planning on shooting in the afternoon? I will look into it today and see if I can get some shooters along.
I'm 95% sure I'm coming to it.

[James Park]

Colin,
I know of at least:
Jim Park
Bryce Lee (plus girlfriend)
Leigh Cornish
Kate Hamond
Matt Hamond
Possibly Alan White (who is talking about a 90 pound compound).
Regards,
Jim

[Marcus]

What are the rules etc for it?

[Colin]

Dont Quote me But I think the Plan is:
8am meet at YVA
Drive to Rifle Range abou 15 mins
Be Shooting b4 9am
You can shoot in any or all divisions /6 arrows each person / division.
Return to YVA for Bacon & Eggs (included in Price)
Then Shooting a Launceston - You also guess what score you will get the closest gets a Prize.

[Marcus]

Just realised that the due date is the 10th of April. We havn't sent our entries in yet so if you could let them know that I want to raise some interest on the weekend and send em in on Monday if that's cool. I want at least 2 of the juniors to come along and shoot the Launceston.

[Colin]

next week is fine

[James Park]

I have a quite specific objective in the flight competition next weekend. Aside from trying to shoot a long way (I am putting together a bow to try to get 550M), I want to use the opportunity to refine the drag calculations in Accurate Sights.
In Accurate Sights I need to calculate the aerodynamic drag for the arrows used by the archer, as this affects the shape of the sight curve, and the ultimate accuracy of the calculated sight settings. This calculation is quite complex (but fortunately I studied it in some detail during the second year of my engineering degree), and you need to make a number of assumptions. What I want to do is to check those assumptions.
To do this, I need to have archers shoot arrows at a known velocity and see how far they go in a flight shoot.
Consequently, it would help me a lot if you have calculated your sight settings using Accurate Sights and hence have the arrow velocity (I trust Accurate Sights more than I trust chronometers). If you can then record that velocity, together with your arrow details (as listed in Accurate Sights), and tell me how far they went when you shoot the flight competition, I can then use the information to refine the program. I you do not have Accurate Sights but want to participate in the calculation, you could do so by sending me the Accurate Sights input data for your setup and I can calculate the velocity for you (let me know if you would like to do this and I will tell you what data I need).
To help in this I will also shoot my standard target bow (PSE Quantum) with my normal target arrows (X10), for which I have a very well defined velocity (268 ft/s). My current drag calculations tell me that the maximum distance I should get (in still air) is about 400 M. It will be interesting to see what the real distance is.
The calculation of maximum distance in Accurate Sights is extremely onerous: I calculate the arrow position evrey millisecond until it hits the ground (that is wht it takes quite a long time). However, when I get a very good and well refined drag calculation, it should give a quite good calculation of the maximum distance rather than the estimate that it currently gives.

[James Park]

An addition thing that Accurate Sights can tell you about flight shooting is the angle you need to use to get the maximum distance.
Without air resistance it is of course 45 degrees.
When air resistance is added, you need to use a lower angle, and it depends on the drag of the arrow. For example, I need to use 40 degrees for my Quantum and X10's.
Fortunately you do not need to be very accurate with this angle, as the distance does not change much for a few degrees error - near enough is good enough.

For those who under estimate recurve bows: I have a Drake flight bow from the late 1960's. It is 50 pounds at full draw, and I have shot over 500 M with it (further than just about all of our target compound bows will get). I will take it along next weekend, but do not plan to shoot it as it is a bit old and much too valuable to risk breaking.

[Marcus]

So do you think an arrow with little of no fletching is better than one with?

[Marcus]

BTW DVA has about 5 people coming along. I'll send the entry forms tomorrow.

[James Park]

My experience is that fletching is necessary. However as the arrow veleocity increases you need less fletching. With the sort of arrow velocities we get with our compound bows I have found that a typical crossbow size fletch is sufficient. That is: about 1 inch long should be ok.
When you calculate the aerodynamic drag for an arrow the dominating factor is the shaft surface area, followed by the fletch area. Hence the key to long distances is small diameter and small fletches.
The arrows used to set the extreme distances with flight bows are solid carbon, 2 mm diameter, 18 inches long, and fletches 1 inch long. They are extremely difficult to find when you are shooting around 600-800 Metres!!

[James Park]

I had a look at Leigh's flight bow this evening: 60 pounds, hatchet cams, 6 inch brace height, pretty aggressive force-draw curve, 4 inch overdraw, about 24 inch arrows, about 28 inch draw, 200 grain arrows. I think he will do well.

I should get mine going tomorrow night: 80 pounds (using 70 pound limbs bent a bit more than normal), single cam, 6 inch brace height, 2 inch overdraw, about 210 grain arrows, about 29 inch arrows, 30 inch draw. Not sure whether I will be able to get it tuned or not, but I will try.

[Marcus]

We should make a rule, if you shoot it at the flight you have to shoot it at the state indoor. ;) :) (just kidding)

Looking forward to seeing some of these beasts in action. I'll try and bring my Dad's chrono that screws into the stabilizer hole so we can check the speeds too.

[mike]

Sounds quite interesting.

Accurate sights tells me I can shoot around the 360m mark with my arrows -- not very impressive!

I wont be shooting it, but I might come down just to see these hotted up machines of Jims and Leighs!!

interesting -- 80lbs is a lot of draw weight Jim, you might do you shoulder -- makes the next tournament just that little bit easier, he he he :D

[Colin]

I had my first look at the range , the grass is long at short distance, and the range is on a slight up hill. I hope that this will not muck up your calculations Jim.

[James Park]

Colin, slight up hill won't worry me. Hope we can find our arrows if the grass is long! How far do we need to get to get to the shorter grass?

[James Park]

I now have my bow ready. It is a PSE Nitro, 77 pounds at 30 inches, 6 inch brace height, short overdraw, with 250 grain arrows. The arrows seem to go remarkably fast, they tuned excellently (first shot with a good guess), and it just about chops my wrist off each shot.
I will also try my 70 pound longbow, with 29 inch Safari's.
I will also try my PSE Quantum, set up as I normally use it for target (58 pounds, 29 inch draw, with 340 grain X10's), so that I can check the arrow drag as outlined in a previous posting.
I am tempted to shoot a couple with my PSE Thunderbolt (same bow I used to win the State Target in 2000), as it is a very fast bow indeed (as well as very accurate).
I will take my 1960's Drake flight bow, but do not expect to shoot it. I have several arrows of the correct length for it but they are way too heavy and of too great a diameter.
I hope the grass is not too long!!

[Kuru]

Goodluck today everyone, looks like it's going to be a nice day for it. James hope the nitro goes well, I don't think i could even pull 77 pounds back !!!

[Marcus]

Well that was a bit of fun. Quite enjoyed it. Only shot 3 arrows as I didn't want to lose any (down to last 7 ACE's). I put 2 turns on the UltraTec before hand and the scales they used said it was 53#. I doubt that very much, in fact according to their scales all their members shoot around 48# and one turn on the UltraTec only moved 0.5# in weight. Beofre I added the turns my club scales, which we get certified, said it was on 53#.
Another set of scales there suggested it was on 59# which is more likely.
My best distance was 389m. I checked my bow speed after it which showed up as being about 280fps.
This allowed me to finish 4th behind Leigh Cornish and Annete Couts (who used the same bow and arrows. What is the point in that??? :confused :confused ) and Andy Alston.

Next time this is held I will look into a faster bow for the job and really try and break the 400m mark.
What were the final best distances shot?

[James Park]

Colin,
A great flight shoot - I was very impressed with the number of people who turned out.
While I did manage to pull back my 77 pounds, it didn't go as far as I wanted!! Already thinking about what to do next year.
Very impressed with Leigh's 547 Metres - that is a really long way, and difficult to do.
very impressed with Jason's excellent group of arrows at 260 Metres!! Might have scored well on a clout target.
Regarding my test of the drag coefficient used in Accurate Sights: My calculation was that my Quantum with X10's would get about 410 Metres - in fact I got about 430 Metres. Hence, I will make a (quite small) correction to the drag coefficient. This small a change will not be noticable in the sight setting tape, but will make the maximum distance calculation more exact. I have wanted to do this check for a long time (and was annoyed I missed the previous flight event through being overseas at the time). The excellent weather, and lack of wind, made it an ideal time to do the test. I would be very grateful if any of the other shooters who know their arrow velocity could send me their distance shot and the details of their arrows - this will further assist me in refining the drag calculation.

[Colin]

Yet another Shoot where the scoring took longer than the shooting.. Sorry about that :rolleyes . We will inprove this next year. But on our behalf, if we do it again we will have to make sure that entry forms are filled in and returned before the shoot. Also that all the arrows are marked properly. Sorry people had to leave before the target. we shot a Standard FITA Jarrad Alston won with 699, I came 2nd with 695 even after only shooting 5 arrows on one end. :mad
I have sent you the results,maybe you can post them on here.

[James Park]

I have used Accurate Sights to study Leigh Cornish's long flight shot at the weekend. (Actually I had to modify some of the limits in Accurate Sights to accomodate the arrow velocity involved, so it is not something you will be able to do with your copy).

The arrow Leigh shot 547 Metres was a 1413 turned backwards, with the nock taper used as the point (this is a trick we used to use back in the 1970's, and Leigh and I discussed it on the night prior to the event - he then made some up on the Saturday night). The arrow weight was 175 grains, and the length about 24 inches.

Such an arrow has a very high drag, because it has quite a large diameter for the weight. Hence, to get a long distance it has to have a very high velocity.

From my calculations, the arrow velocity must have been well over 500 ft/sec (in fact my calculation gave about 550 ft/sec or about half the speed of sound). No wonder it went with a real crack each time he shot!! Leigh did try to measure the velocity with his chronograph (at my request), but found that shooting the arrows into his target at home resulted in them shattering as they hit the target.

While the velocity has been calculated rather than measured directly, I am quite confident in the maths, and have my flight distances with well known arrow velocities to back it up.

Hence: impressive!!!

[James Park]

A few more bit of info:
- My John Clark built longbow gave a velocity of 240 ft/sec with 307 grain arrows, 70 pounds and a 29 inch draw. That gave 274 Metres.
- My Drake flight bow gave a velocity of 250 ft/sec with 180 grain arrows, 50 pounds, and a 21 inch draw. That gave 323 Metres. Proper arrows for this bow would be about 100 grains and smaller diameter than the X10's I used.