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View Full Version : Oleg: Whay does P38 shake more with 20mm than 109G2?



GR142_Astro
10-11-2004, 09:02 AM
Try it for yourself.

Shoot at aerial targets with a 109G2 with 1x20mm cannon in the nose and then try it with the P38 with 1 x 20mm in the nose (don't use .50s).

The P38 is much heavier, has 2 counter-rotating engines and was designed from the outset to be a stable gun platform.

Why does the P38 nose shake more than the 109G2? Please answer.

GR142_Astro
10-11-2004, 09:02 AM
Try it for yourself.

Shoot at aerial targets with a 109G2 with 1x20mm cannon in the nose and then try it with the P38 with 1 x 20mm in the nose (don't use .50s).

The P38 is much heavier, has 2 counter-rotating engines and was designed from the outset to be a stable gun platform.

Why does the P38 nose shake more than the 109G2? Please answer.

MEGILE
10-11-2004, 09:07 AM
Beause this is a game, and not everything can correspond to real life. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Zen--
10-11-2004, 09:22 AM
I'd like to know this also, it seems very disproportionate considering the reputation of the plane and pilot accounts.

Oh wait...pilot accounts are irrelevant, sorry nm

http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif


Seriously, based on the history of the plane it seems that there are several areas that need investigation. Considering how important shooting is in the game, I'd think the noseshake definately needs an explanation.

WWMaxGunz
10-11-2004, 09:25 AM
Hispano shoots heavier shells at higher muzzle velocity.
109 nose 20mm is mounted directly to the mass of engine.

It is the model.


Neal

p1ngu666
10-11-2004, 10:20 AM
p38s nose is pretty packed too
what about mk108? that has more energy going on, fancy damping thing or not

p1ngu666
10-11-2004, 10:25 AM
tried a yak3p
shake seems close, but less, others should try that
fire teh single cannon, then the 2 on top, then all together

faustnik
10-11-2004, 11:31 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by p1ngu666:
tried a yak3p
shake seems close, but less, others should try that
fire teh single cannon, then the 2 on top, then all together <HR></BLOCKQUOTE>

Yeah, but a P-38 is a much heavier plane than a Yak. Its center nacelle is attached to the two wing pylons by thick wing sections, all strong rigid construction.

Ugly_Kid
10-11-2004, 12:08 PM
Mmmm...of course you have to compare with Bf-109G-2. Somehow that gives the impression that people fly online and if the fight can't be won there and then playing the game, the next stop is ORR. By all means compare the recoil with Spitfire too - two of them Hispanos and on the wings! Yet comparison has to be done with aircraft which has nothing to do with P-38 (except it is often flown against one and often very succesfully). G-2 has one big advantage in respect to recoil. The heaviest concentrated mass of the whole aircraft is tied together with the gun installation another minor factor is the fact that it shoots through large rotating mass which also provides gyroscopic stability...

P-38 cockpit alone is not a heavy concentrated mass - it is very much possible that with this battery of guns the shaking occurs locally and not as you think that the whole aircraft shakes. If you put 20 mm on B-17 gun turret it might be off for some serious shaking too, in spite of B-17 being quite big and heavy...

VW-IceFire
10-11-2004, 12:15 PM
I always figured it had to do with the fact that you've got a 20mm cannon (a big heavy one too) and 4 .50cal machine guns in there. Thats one large cannon and 4 of the heaviest of machine guns around.

Thats alot of firepower concentrated in the nose.

Since the other changes were made to the P-38 its quite a capable shooter. The trick in aiming is to get a feel for how the aircraft handles...because the twin booms give it a different feel than the Bf 109G-2 for instance.

Korolov
10-11-2004, 12:18 PM
I really don't see where this "nose shake" is coming from, because I don't see it...

Astro, maybe you could provide us with a track to demonstrate?

Agamemnon22
10-11-2004, 02:00 PM
Yeah I just took out a P-38... what shake?
In level flight there's barely any vibration. It seems to wobble up and down when applying elevator and firing, but I don't know if that's my stick. I've been having problems with it lately.

VW-IceFire
10-11-2004, 03:53 PM
Only the view shakes a bit...the actual aircraft does not. Try flying the Bf-110 or the IL-2 and fire all of your guns at once while applying a bit of rudder or elevator...THAT...is shake.

Atzebrueck
10-11-2004, 04:07 PM
In the German planes, with their offset ReVi, you have to fly with the "Gunsight-View (shift-F1)". That causes the view to "lock on" the gunsight. This view isn't affected by the recoil and G-forces as strong as the "normal view".
In my opinion, that's why you have got the impression, that the P38 is more shaking than the G2.

Fly it with the shift-F1 view.

GR142_Astro
10-11-2004, 08:35 PM
IceFire - I specified in my original post to only fire the 20mm and not the .50's.

Koro - I don't know if a track will do much, but I will certainly give it a try. I might only suggest that you are a known accomplished P38 flier and you might simply find this quirk to be quite normal.

To the poster being paranoid about the G2, then substitute a Yak3. Makes no difference to me.

The fact is that my gunnery ranges from competent to downright deadly. Depends on whether or not my "game" is on. From the standpoint of my rig (Athlon 1.3ghz, GeoTi4200, X45), the P38's nose bounces around like it has a mk108 strapped to it. No matter if I'm "on" or not.

Last item. In all due respect to those who have posted about engine mass of the single engine setup with hub firing 20mm vs the P38 in regards to stability, I remain unconvinced. Are you telling me that a 20mm gun is going to twist the cockpit module around as it sits between the twin Allisons? http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

&lt;S&gt; all, and great discussion thus far.

Korolov
10-11-2004, 10:01 PM
Astro, just take a track and point out at what point when firing the guns (and what time on the track) the shaking occurs. You're possibly right that I don't see it, or I'm not looking in the right place.

VMF513_Sandman
10-12-2004, 07:11 AM
ur probably looking at the target and not the gunsite dot and circle since ur used to how it shoots; but if u look at the circle, u might see it on a up and under shot. the p-63's 50 cal's do this also, not counting the 37mm nose cannon which should generate a very heavy kick. but i do see where astro's coming from and u. in ur tracks, ur diving right on the target from above where u get ur best accuracy. if u try in a quick snapshot in the deflection, u might notice it a bit more, or do a direct 6 shot. but again, when u let em rip, the bogey is bye bye.

btw astro, if u can somehow sneak up on a bogey till the wings touch both sides of the gunsite, the bandit is fish ready to be fried. looking at the ship in the outside view, the nose doesnt bob and weave...maybe its the recoil coming thru the yoke and shakin the chit outta the pilot itself

GR142_Astro
10-12-2004, 08:24 AM
Entirely possible.

I'm trying to work out a method to do the tracks right now. I did one firing at the ball turret only on a friendly B17 and I have a few others. Will try to post something up soon.

Thanks guys.

crazyivan1970
10-12-2004, 10:49 AM
I don`t think G2 is a right thing to compare to Astro... in G2 nose is much heavier then in P-38 due to engine weight. I tried P-38 as well, it does shake a bit...but not as noticable IMO.

Resident_Jock
10-12-2004, 02:24 PM
I don't notice any shake in the 38, like someone else said the primary reason any shaking occured was firing during lateral maneuvers. I did several QMB missions just now and it seemed entirely stable.

VMF513_Sandman
10-13-2004, 05:26 AM
if u look at the cockpit frame, u will see the shake, but the ship itself wont shake when u look at it from the outside. might be possible that the gun recoil is being transmitted to the yoke and then to the pilot.

Vipez-
10-16-2004, 09:28 AM
I dont see why are you comparing it to 109 G-2.. howabout you compare it to actually light planes or planes which actually might had some stability problems with guns, like Yaks (like Yak-9T, no recoil what so ever with her big cannon, quite well considering the Yak beeing so lightweighted plane..)

WWMaxGunz
10-16-2004, 01:11 PM
What Ugly Kid wrote about cannon barrel being through engine and propeller
axis, the weight of engine and gyroscope of propeller and engine being
forces to hold the gun steady... Yak does not have those? In P-38 the
engines are not with the guns. Compare more like nose guns of Bf-110.


Neal

VW-IceFire
10-16-2004, 02:52 PM
Different guns did have different amounts of recoil. Some were more effective than others at trying to lessen the hit. So that may explain it ...or not. But its not strictly 20mm = X amount of recoil.

BTW: In my subjective testing...the P-38, Bf109G-2, and Yak-3 against Stuka Dive bombers...each plane was virtually the same in terms of recoil. The P-38 perhaps shakes a tad bit more...but that seems to be consistent with all other aircraft firing the Hispano cannon. The ShVAK shakes a fair amount and the MG151/20 seems to produce the least amount of shake on the 109.