Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: MANDOBLE on January 25, 2002, 06:57:19 PM
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Some of you will ask for a video, but this is something too easy to test and verify.
1 - Go to hangar, select D9 and set convergence to 600 yards
2 - Take off and select a course parallel to the wind (activate wind info from the clipboard top buttons).
3 - Level and switch on autopilot.
4 - Activate zoom.
5 - Regulate zoom to maximum.
6 - Start firing guns (20mm) ONLY.
You will notice 99% of the bullets deviating a lot to the left of the gunsight center, almost none going to the right.
Is that correct? If so, why?
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Hum, that is interesting. I didn't notice that when I tested the guns. Does it only happen at 600 yd convergence?
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Try it with any conv, more noticeable with 600 or more yards conv.
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You may very well be right here, but I honestly can't tell. The first test I did seemed to show that the bullets went down and to the left when I set the convergence to 600 and the target to 600. I would have thought the 'beaten zone' would have been centered on the targeting dot, it did not seem to be. However, the leftward drift I am not so sure about, because as I went to do my second and third tests I noticed the target 'drifting'. Turns out I was a fraction of a degree off true north, which caused the target to drift very slowly to the right, which may very well have caused the center of the 'beaten zone' to appear to be off to the left of my target dot (btw, beaten zone is a 'land based' term, not sure if it applies to airborne MGs and cannon, but I can't see why not).
I did think that if you set convergence at a certain point it meant that the bullets were supposed to 'hit' the crosshair at that point X number of yards in space, that didn't seem to be happening at 600 yards. Seemed to be maybe 10 feet below the aiming point.
Perhaps the Mg151/20 round doesn't have enough velocity for a convergence setting of 600 yards? I don't know. It is rather interesting though, I hope HTC can look into it.
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Tu sabes que si se desviara a la derecha seria un maricon ;)
Sera que le jalas mucho hehehe.
A ver que dice HT o los demas sobre tus resultados :)
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Urchin, what target are you talking about. If it is the center dot of the GS, you simply align the wind and switch A/P ON.
The test is extremely simple, just level, set up a normal speed (250 MPH, for example), maximize zoom and start shooting, nothing more, nothing less. You will find almost all the bullets dropping at the left of GS center. 13mm MGs has the same problem in D9. The effect is really noticeable.
Now try 190F8, you will find that the bullets drop much more centered.
I was testing that with StSanta first time in Dueling Arena, I suppose DA has same setting as MA and offline, but not 100% sure.
Jeje, Tac, apuesto a que NA DA.
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mandoble offline you can type .target 600
it will put a bid bullzi in front of your plane as long as you head do north.
by keeping the plane exactly n and the gunsite centered in the target you can judge bullet drop and converge cone.
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I know Wotan, thanks, but that was not involved in the procedure of the test. If you follow the steps described, you will see 99% of the tracers falling well at the left of the GS center (zoom on, and maximized). So, you'll notice the effect, in fact, a bit farther than convergence range. The effect is so noticeable that you dont need to see back dots painted at any target.
Perhaps that target could be used, but setting it at 700 yards for 600 yards convergence, and dont aimming to the center of the target, aming at the top of the target and centered horizontaly. The problem is that you will need to make corrections to keep the target at the desired possition.
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MANDOBLE,
The target can be set at whatever range you wish.
My question to you is, why not just zero the wind out? That would take one factor out of the equation.
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Same results with 0 wind. We tested that in DA, no way to change winds there.
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Mandoble, that wasnt what I was saying. The .Target (the bigass bullseye) seemed to be drifting to the right very very slowly. This would make it appear that your bullets were flying to the left of where you aimed them, although they in fact were hitting where you aimed (since your gunsight has moved relative to the target). I think it was happening because I wasn't flying EXACTLY north, even though my compass said I was and my gunsight pipper was in the middle of the 'bullseye' when I started. Perhaps if I wasn't pointed directly at the bullseye (perhaps only a half degree off) that would be enough deviation to make it appear that the guns were significantly off?
Perhaps I'm not doing a very good job of explaining it. TAc or someone, can you make sense of what I am saying and post it in Spanish? I'd try but my Spanish just isnt good enough to get my point across.
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Originally posted by MANDOBLE
Some of you will ask for a video, but this is something too easy to test and verify.
1 - Go to hangar, select D9 and set convergence to 600 yards
2 - Take off and select a course parallel to the wind (activate wind info from the clipboard top buttons).
3 - Level and switch on autopilot.
4 - Activate zoom.
5 - Regulate zoom to maximum.
6 - Start firing guns (20mm) ONLY.
You will notice 99% of the bullets deviating a lot to the left of the gunsight center, almost none going to the right.
Is that correct? If so, why?
First of all, congratulations on running some tests! See, this way you have some actual data we can discuss. Much better. :)
But, I see a problem with your testing methodology. Auto-trim for level. The auto-trim modes constantly change your trim condition to attempt to maintain straight and level flight, but they are not perfect. As you fire your guns, the auto-trim will be adjusting your trim condition and slightly changing your plane's direction and such. If you use the .target and watch you pipper's movement against the target, you can see that it doesn't stay in exactly the same spot.
Now, I went to check this out myself, and here is what I found:
Tests done offline in the Duelling Arena terrain with all wind set to 0. I went to 5k feet and about 350 MPH. I set auto-trim to level and fired several long bursts from the cannons.
While there does seem to be a dispersion patter to the left generally, I'm not sure why. The combination of the gun recoil and the auto-trim may be the problem. I think we need to try and do this by manually flying the plane and holding the pipper dead center and shooting. We could film that and with the target it would be quite plain if there was a problem. I don't have time now, but I'll try that later tonight or tomorrow.
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Done manually with 190F8 and D9, D9 massive dispersion to the left, F8 more balanced dispersion.
Done also with autotrim, D9 and F8, same results.
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Maybe instead of a problem with the 190D-9's guns, there's a problem with its gunsight? If the D-9's gunsight is centered incorrectly in the plane's model, this would explain why the D-9 loses accuracy despite using the same guns as on other 190's.
Just something to check out :)
J_A_B
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JAB, look at the image and the dispersion zone, now compare right with left side of that zone , very different right?
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Very interesting. If the dispersion isnt the same for the two planes, there is definately something that isnt right about the Doras guns after all. Good work Mandoble.
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Mandoble, what I see in the image up there is the bullets are mostly striking slightly to the left of the gunsight's center dot.
This could indeed mean there is something wrong with the D-9's guns/dispersion.
However, it might also mean that the gunsight is in the wrong place. With the new gunsights, the sight is now fixed in relation to your viewpoint; if the Dora's sight is fixed in the wrong place (slightly to the right of where it should be), it would have the same effect of making the bullets fall left of the gunsight.
In my own trials the machine gun rounds fall to the left of the gunsight, just as the cannons do. Therefore, if there IS a problem with the D-9's guns, it's not just limited to the cannons.
J_A_B
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J_A_B there are two different problems:
1 - bullets go to the left of the GS center. That could be due a GS problem.
2 - If you take a look to the hits, left hits have markably different dispersion than right ones. That could be due bad aligment of each gun relative to the other one.
And you are right, MGs have same problem as guns.
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Originally posted by Urchin
Very interesting. If the dispersion isnt the same for the two planes, there is definately something that isnt right about the Doras guns after all. Good work Mandoble.
Urchin, if the had same disperion for the two planes, then we had a common problem for both.
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Draw an imaginary line down the center of the black hit dot circle in lephturns picture.
Notice how much tighter the dots are in the left half of the cicle both verically and horizontally.
There is much tighter dispersion on left than on right. Gunsite issues or not.
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GRUNHERZ, that is just what I mean. IMO, guns have some kind of problem, perhaps, also the GS.
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Positioned a D9 in the hanger, hit the " H " button then F3 and zero to get a head on look at it, tapped the " B " button to fire, seemed like the right wing gun fired far left a whole lot more than the left wing gun fired far right, this was done backed of as far a way as the braket keys would send me, not bench test data but take a look and see if a few more of ya see the same thing ! The " B " button was tapped slowly to get a good look at each tracer shot.
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maybe a lame solution, but adjusting your gunsights a bit to the left would neutralize this effect?
I remember when the dispersion for the guns used to give a "+" pattern, was hilarious.
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190D9
(http://www.terra.es/personal2/matias.s/190D9DSP.jpg)
190F8
(http://www.terra.es/personal2/matias.s/190F8DSP.jpg)
As you can see, F8 suffers a bit of left deviation, but not as noticeable as with 190D9.
Conv 600, target 600 yards.
Test done shot by shot, not spraying, only 20mm.
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I'll be sure to aim a little more to the right of the bogey, next time I fly a D-9 :)
I do hope there is a proper explanation for this.
Or if there ain't, we may declare the thing 'broken' :rolleyes: and plead to the HTC to fix it :)
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Originally posted by Kweassa
I'll be sure to aim a little more to the right of the bogey, next time I fly a D-9 :)
I do hope there is a proper explanation for this.
Or if there ain't, we may declare the thing 'broken' :rolleyes: and plead to the HTC to fix it :)
This might explain some of the weakness many experience in dora guns.
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could this be a trim/engine torque issue?
could someone do similar tests but with the typhoon to see if its bullets drift to the right?
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Last night I tried this and noticed that even in auto-level the plane (p47) slowy yawed right. Firing over several seconds, I got a pattern similar to mandoble's.
I'm not sure whether the plane was yawing right or the target was moving left, but either way something is screwy, and not neccessarily the guns.
If youre seeing a left-biased pattern put up a target and zoom in and just watch it. It also may depend on plane type as the p38 does it very very slowly, taking several minutes to notice any change at all.
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Regurge, each shot implies a "vibration" that cause a little yaw to the left or to the right depending on the firing gun. I've noticed that if you fire a single shot and wait, the plane will yaw a bit to one side and, inmediately, it will compensate to the other side, keeping your nose pointing to the original course. If you keep spraying, you may have a real (minimal) course change.
Cause that, my test was done shot by shot. That is, shot, wait til vibration is compensated (your GS center aims again at the original point), shot again, and so on. Doing these tests at a constant 250 mph speed you ensures that torque effect does not affect the aiming. Supposing it was due a minimal yaw caused by torque, it should displace your GS center to the left, and you'll see the hits displaced to the right in the target (190D9).
If in your P47 test you noticed a yaw to the left, then you'll have just opposite results to mine. Your GS will move to the left and you'll see the hits displaced to the right in the target.
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You can sit on the ground and do a .target 100 and get the target close enough to see, eng off, brakes on, fire away, there you can see what your guns are doin in relation to you sight without the worry of side to side movement, you can also set your convergence to 150 yards to get a real good idea, the p47 sits pretty high so you may have to fiddle a bit with the settings but you can pretty well extrapolate whats going on as to whether the sight needs to go up and left or whatever !
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Ok it looks like there is a bug in auto-level. It keeps your pitch and roll contant but NOT yaw. I just checked the d9 and like the p47 it yaws to the RIGHT very slowly. Its like a very slow rudder turn to the right.
The best way to see this is to put the center gunsight dot right on the edge of the target and hit auto-level. Looking at the center dot, you'll notice that the target moves left 1 pixel every couple of seconds. It takes roughly 10 minutes for the sight to move from the center of the target to the edge, which corresponds to about 3/4 tick on the compass. This occurs when the guns are NOT firing, and presumably when they are firing as well.
Obviously, this is going to accont for some of the left-bias shooting.
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That .target command is pretty sweet :)
But it isn't published in the Help or short doc.
Are there anyother dot commands that people know of that aren't published in the HC docs?
AKEagle+
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Mandoble and I both posted on the D9 guns about 6 months ago after talking in the MA. I flew the D9 just about exclusively since its' introduction into the game.
I noticed that the Pilot had to almost "stick" the guns in the enemies canopy to get a good kill. 300 or closer was the norm.
I flew it enough to get over 200 killz in it in one campaign...and believe me it was a chore.
Now I fly the P47D30, I have more guns (8X.50s') and have the convergence set further out then I did in the D9. One would think that with 8 guns firing as opposed to four, and from firing farther out in the P47 my hit percentage would be lower ( faster rate of fire, more ammo and more guns, and firing from greater range) but that's not the case?? It's improved.
Now I do know that from firing at closer range your hit percentage would be better (patience in getting a firing solution etc.) And if one flew the D9 enough they would understand what MANDOBLE is talking about. It is a very tough plane to get clean kills in. You'll lead the league in assists.
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Well, Hajo, after hundreds of kills with D9 I've find out how to kill a 250 yards static target aproaching by its dead six. And this is not a joke, believe it or not, that situation ends a lot of times with only two or three pings.
In the past tours I've flown several missions with 50" armed planes (P47, F6F, P51 and P38), all of them have extremely accurate weapons, specially the P38. All of them able to disintegrate a 500 yards static target aproaching by its dead six with a single short burst.
Actually I continue flying D9, and using the GS center to aim at anything is the best way to fail every shot.
It may sound like a whine, but, IMO, there is too many recoil effect/vibration/dispersion for wingROOT mounted guns. I thought wing root was a very stable placement for these very lo-rof, lo-muzzle-vel guns. Based on this asumption, IMO, wing (not root) mounted hi-rof, hi muzzle-vel (supposedly very hi recoil effect) hispanos should have much more dispersion/vibration effects, specialy when spraying.
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Does Ju-88 still shake when you fire that one 7,92mm ?
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At the CON, HiTech was showing a few of us the gun target feature.
He said that you had to perform any tests with autopilot off, because it will constantly adjust the attitude of the aircraft and give you bogus results.
Just FYI
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Originally posted by Staga
Does Ju-88 still shake when you fire that one 7,92mm ?
Yes, and I always thought that was hilarious. Shakes the Ju88 more than it does the plane you're hitting.