PDA

View Full Version : Recoil



Stafroty
02-11-2006, 12:46 PM
why does 4 x hispanos in wing mounts with some 200 000 KJ recoil force alltogether have almost same recoil effect than nose mounted MK108 with its 84 000 recoil force? how can it be explained? plane weight differencies between hurricane and 109 isnt so big, that it could explain this http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Why is 30mm mk108 cannon so inaccurate when compared to other cannons? as the same cannon, in different consept; AGL17 Plamya, tripod mounted autogrenade launcher, has accurate range at 800 meters, some 2400 ft. in game cannon is hard to hit even at 200m range http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif its like ***** moving all around inside engine and spitting rounds at all directions in wide cone http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif Spreadfire cannon!! did germans trust so much on their minengeshoss rounds that they were spraying all around, cos one hit per engine number was needed to bring down plane of anysize.

Can someone explain this to me in Common physics, reports and without believing in something which is only an opinion????

(‚¬īapinoiden planeetta‚¬ī is nice movie)

p1ngu666
02-11-2006, 01:49 PM
did quick test
hurri IIC 25 fuel rad closed (same for following)

i could get upto 50kph from firing guns (unlimited ammo) i got upto 60 but that may have been from tailwheel kicked in the air.

k4 c3 can hardly move
g6late mk108, can hardly move
109z http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif with mk103, got upto 70kph then crashed
190a8, mk108 hardly moves plane, need to fire all guns to get it to really move, 20mm+mg doesnt move it that quick
similer with mk103 gunpods

firing on 109 makes it shimmer from left to right

Stafroty
02-11-2006, 02:51 PM
pingu, does drag and other charasterics affect on ground speed when reversing with guns? does recoil do something else than reduce speed? does the position of the guns matter at all? how close centerline of the mass they are? does recoil really affect as much it does in sim? how much airstream holds plane in `position` while flyin? can it be compared with stickin 3500kg of metal on rope, hangin it on air and attachin cannon on it and fire, does it mean the same as on moving aircraft? wont the airstream really ‚¬ītie‚¬ī the plane in ‚¬īlocked position??
(you can bet im way better in explaining things in english language than that with my own)

i bet that inaccuracy of certain guns are overmodelled as is recoil even without taking in count the "physical" position of guns!

Game is realistic but in which point?

Stafroty
02-11-2006, 02:57 PM
like: mg151 has recoil KJ force of ~41250KJ (ammo 110g, 750m/s), plane weights ~3200kg

u is wrong http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Gibbage1
02-11-2006, 03:04 PM
Tempest. 6,142KG

109G 3,200KG

Recoil effects lighter aircraft more. Since the 109 is half the weight, and has half the recoil, it should be similar.

Stafroty
02-11-2006, 03:09 PM
only that: tempest has 4 cannons which has recoil force over 200 000KJ while 109 has 41250KJ with 20mm and 83000 with 30mm http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif and position still, affects http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif or are the guns in sync?

p1ngu666
02-11-2006, 05:21 PM
the guns are slightly out of sync as the hurri didnt move back in a straight line, kept trying to turn.

unless the ground physics/rolling resistance is for no aprent reason is much higher on german planes, the hispanos pack alot of recoil.

the mk108 is mounted between the pilots legs, and it did aprently shake the cockpit

the rifle call's on the spit and il2 used to shake your head like they where stuck to it, i havent tried them yet.. but cannons didnt shake u that much

ill try out a early p39 wid hispano..

p1ngu666
02-11-2006, 05:43 PM
p39 hardly moves, even boosting it with mg doesnt help too much.

i tried dispersion with a test runway and just looking at the tracers, and yes there is now a fair bit of dispersion on the guns i tested.

mk108 the most probably
hispano, 1/2 to 3/4ths of mk108
109 mg guns are more acurate, but theres the convergance.... theres a fair bit of depth tho, deffo some dispersion
tried the mg131's and whatever the email model has

ill leave it to others todo more testing as im going tobe out most of tomoz, and i suspect this will be 3 pages by then

Stafroty
02-11-2006, 06:10 PM
Originally posted by p1ngu666:
the guns are slightly out of sync as the hurri didnt move back in a straight line, kept trying to turn.

unless the ground physics/rolling resistance is for no aprent reason is much higher on german planes, the hispanos pack alot of recoil.

the mk108 is mounted between the pilots legs, and it did aprently shake the cockpit

the rifle call's on the spit and il2 used to shake your head like they where stuck to it, i havent tried them yet.. but cannons didnt shake u that much

ill try out a early p39 wid hispano..

hehe, mk108 cant shake pilots head before you fire it http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif still, you cant hit at what you aim at http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
Our guns are too inaccurate, while our gunsights are too accurate, or how should we think this? how accurate were the aimpoint gunsights? guns were accurate, thats for sure, that you can see at photos where guns are adjusted on ground.

The-Pizza-Man
02-11-2006, 07:58 PM
Originally posted by Stafroty:
why does 4 x hispanos in wing mounts with some 200 000 KJ recoil force alltogether have almost same recoil effect than nose mounted MK108 with its 84 000 recoil force? how can it be explained? plane weight differencies between hurricane and 109 isnt so big, that it could explain this http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Why is 30mm mk108 cannon so inaccurate when compared to other cannons? as the same cannon, in different consept; AGL17 Plamya, tripod mounted autogrenade launcher, has accurate range at 800 meters, some 2400 ft. in game cannon is hard to hit even at 200m range http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif its like ***** moving all around inside engine and spitting rounds at all directions in wide cone http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif Spreadfire cannon!! did germans trust so much on their minengeshoss rounds that they were spraying all around, cos one hit per engine number was needed to bring down plane of anysize.

Can someone explain this to me in Common physics, reports and without believing in something which is only an opinion????

(‚¬īapinoiden planeetta‚¬ī is nice movie)

First off your using the wrong units to measure force. kJ is energy not force they are two very different things.

So on with the explanation. F=MA right. A being acceleration is rate of change of velocity. So F=MA=d(MV)/dt. Mass x Velocity is equal to momentum(P). Thus you can say that Force is equal to the rate of change of momentum. Because the momentum has to be conserved. That is to say P before the guns are fired = P after the guns are fired.

So if the plane is sitting on the tarmac P=MV, V=0 so P1=0. Because P1=P2, P2=0 as well. P2 is the momentum of the whole system after the guns have been fired, it is the momentum of the plane plus the momentum of the bullets. So P2=Pplane+Pbullets. Because P2=0 you can say Pplane=Pbullets. Now remember that Force is equal to the rate of change of momentum. So the force on the plane is equal to the change of momentum over time. Fplane=dPbullets/dt.

Therefore the recoil force is equal to mass of the shell times the muzzle velocity times the number of shells per second.

Thus the Mk108 with a 330 gram shell and a muzzle velocity of 505m/s and a rate of fire of 650 RPM causes a rearward force of 1.8kN. A Hispano II with a shell of 130 grams, muzzle velocity 880 m/s and a rate of fire of 600 RPM exerts a recoil force of 1.15kN, with 4 of them it totals 4.6 kN.

This, however, is the time averaged force. The peak recoil forces would be somewhat higher. On the ground that might make some difference due to the force required to overcome the static friction of the tarmac but in the air the difference would be negligible

Stafroty
02-11-2006, 09:57 PM
why it would be in air negliable? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif because you cant use your math to calculate the airstream effect on recoil? can you define it to the very end?

why we have such recoil, like that some guns are accurate, (UBS) and some arent (mk108, engine *****)

is the engine shaking mk108 so much, but not mk151/20 that much? or are the grenades flying thru nose of the 109 when cannon is fired? what would happen, if Oleg orders his team that make MK108 rounds come out from the cannon barrel, not from the nose of the aircraft, very different thing, how many hits we would score on own engine as the MK108 has been fired in nose mount? i think quite many. or is the tube after cannon barrel still takin contact to MK108 shells and direct shots and this way, makin em bounce from that tube walls, makin rounds unstable and to fly all over directions, sideways, rearwards, rolling..
C‚¬īmon. it wasnt so bad, they for sure didnt want to go so close to bombers to shoot em down, as if .50cal turret gunners were so accurate while cannons on fighters werent.

isnt there something wrong when compared to reality? or is it just right as we "deserve" balancing for bomber pilots..
yea, i know, its not fun to fly bomber in middle of enemy fighters, alone, if you cannot shoot 5 of them down before selling your own skin.

sure lone bombers where bigger threat to fighter plane than enemy fighter. thats how it is, and in my eyes, just for balancing game for bomber crews, otherwise no one would fly bombers whihc now has been modelled in sim. Dev team could make it differently. makin rules in DF servers, that some 10% of pilots is needed per side, or other side, to take bombers, and others are to defend them, if bombers got shot down, its time to load next map. something like that. dunno what. but balancing sucks. it just makes problems.

WWMaxGunz
02-11-2006, 10:16 PM
Arcade on, park the plane, shoot the smokestack one shot, wait, shoot again, wait, repeat.
Screenshot the spread and track the whole procedure. Measure the dispersion, what is it?
Now go find actual dispersion for the Mk108. Is the measure perhaps 3x wider?

OTOH, just keep posting that something is true using such terms as ***** and nothing will
happen unless someone else makes it so. Maybe someone will refill the bottle and change
the diaper after enough crying.

Stafroty
02-11-2006, 10:29 PM
maybe max maybe http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif would it make you jealous? http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif) hehe, who said im crying here? maybe im just having fun with your illusion of truth here http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

The-Pizza-Man
02-11-2006, 10:34 PM
why it would be in air negliable? Wink because you cant use your math to calculate the airstream effect on recoil? can you define it to the very end?

Read the last paragraph again. It isn't about drag. It is about the difference you would get if you modeled the cannon recoil as a time averaged force or a series of impulses from each bullet firing. On the ground the aircraft has to overcome static friction to begin rolling. It may or may not be the case that the time averaged force would not be enough to overcome this yet the peak recoil force would be. It is impossible to calculate without knowing information at least a dozen other variables. In the air it doesn't matter because it is already in a state of dynamic friction so the time average force will show, if any, a negligible difference when compared with a more complex model.

Gibbage1
02-11-2006, 10:44 PM
For some reason, I dont think Stafroty wants a logical reply or an answer too his delima of why he gets shot down so much by "inferior" aircraft. He just wants someone to say "Ya, your correct! We should get this fixed!". Unfortunatly, STafroty does not live in his world, but the real world.

Stafroty
02-11-2006, 10:44 PM
and using ***** term from the gun makes you not understand the point? no it seems.

just compare mk108 on this, just for bringing thoughs in your mind:

AGS-17 Plamya auto grenade launcher.

http://faq.guns.ru/images/ags17.jpg

http://faq.guns.ru/images/ags-17.gif

http://www.mil.fi/maavoimat/kalustoesittely/00044.dsp

AGS-17 Plamya (Flame)

it says that AGS17 has muzzle velocity of 185m/sec, weight of the grenade 280g, max useful direct fire range 700m which also is its main way of use, indirect bout 1700m, ROF is 6-7rnds/sec, single fire 1-2/rnds /sec..
>>"weapon is REALLY accurate which allows that it can be used to shoot near own troops in close quarter fights."<<
"Ase on eritt√¬§in tarkka, mink√¬§ ansiosta sill√¬§ voidaan l√¬§hitaistelutilanteessa tulittaa hyvinkin l√¬§helle omia joukkoja."

how can be tripod mounted gun, which weights 30kg plus 15kg of ammo = 45 kg, deal such high recoil.. just look the configuration of gun. it should fly on its back when fired, in Oleg created world http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Gibbage1
02-11-2006, 10:48 PM
Thats not a Mk-108. Why dont you compair a Mk-108 to a Mk-108? Why dont you pay attention to pilot quotes that say the gun shook the aircraft "like a jackhammer".

Why not? Because you dont care about the truth. You just want to whine.

WWMaxGunz
02-11-2006, 11:27 PM
Originally posted by Stafroty:
and using ***** term from the gun makes you not understand the point? no it seems.

I understand enough to think you are talking about dispersion of fire and blame the recoil.
So I tell you that step one is show how much dispersion and then next step. You show the
dispersion and others will try and others will find the documents. There was a very good
French site with German document scans and I think Mk 108 was in there, btw.

Show is worth 1000 tell.
Do the same as was done with the .50's. Blip the trigger very quick on and off to cut down
recoil effect. Notice if gunsight moves, that is recoil and did you have brakes on yes?
Set up smokestack as target

AEP Mk 108 could hit straight flying fighters at 800 to 1200 meters range.


how can be tripod mounted gun, which weights 30kg plus 15kg of ammo = 45 kg, deal such high recoil.. just look the configuration of gun. it should fly on its back when fired, in Oleg created world http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

You don't have to tell me. Been there and done things like it.

BTW, there is a US model similar. It was shown on the cable show "Mail Call" where an
ex-marine sergeant goes out, shows and has fun with guns that I am SURE you would like.
Really, the watermelon gets shot sometimes and car wrecks others and so it goes. When
the grenade launcher was used I only got to see 5 minutes but those were good. I would
like to see the same from other places only I would need subtitles to follow along. I
have avi's of discovery shows in English with Swedish subtitles (many WWII history shows)
so why not in Finnish, Swedish, German, Russian, French and subtitles in English? Maybe
next year or the next? Somebody gets old hardware and a place then videos a shuetzen
party with some teaching... can't that be sold direct on VCD's or DVD's?

WWMaxGunz
02-11-2006, 11:45 PM
Originally posted by Gibbage1:
Thats not a Mk-108. Why dont you compair a Mk-108 to a Mk-108? Why dont you pay attention to pilot quotes that say the gun shook the aircraft "like a jackhammer".

Why not? Because you dont care about the truth. You just want to whine.

Gib, I think maybe I could find such quotes about .50's in US planes.
What does it mean in terms of numbers?

What I've never seen is any quote about gunfire changing the path of the plane.
Never anything about needing to hold or correct sustained fire except on moving,
dodging targets. That's for any plane except maybe Mossie with 57mm and B-25G
that did have to be re-aimed between shots.

Stafroty
02-11-2006, 11:48 PM
Originally posted by Gibbage1:
Thats not a Mk-108. Why dont you compair a Mk-108 to a Mk-108? Why dont you pay attention to pilot quotes that say the gun shook the aircraft "like a jackhammer".

Why not? Because you dont care about the truth. You just want to whine.

what kind of shook it that? why to compare to same thing? do you compare urself to urself? do you look at mirrow cos of that? or fix and check appearence of urself?

like i said: just compare mk108 on this, just for bringing thoughs in your mind.
calculate how much recoil does that make and compare it to recoil what is get from cannons of different types?

Stafroty
02-12-2006, 12:06 AM
Originally posted by WWMaxGunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Stafroty:
and using ***** term from the gun makes you not understand the point? no it seems.

I understand enough to think you are talking about dispersion of fire and blame the recoil.

you succeed to understand it completelly wrong, is that your hobby, or do you do it on purpose? or is it just that u urself just dont get it?
you need to be clarified on this it seems. Should i make other thread talking about dispersion? you dont see the recoil to be in connection with disperse, is that what you understand, or is the game to truth to you nowadays as it would like to seem to us?

should you start new thread about *****s and weapons at general discussions, as you stick on non important WORDS, you completelly fail to see message in the middle of the words. dont be angry to us as you cant understand everything so well. do you need smiley here so you would not feel so insulted by your own thoughts.

So I tell you that step one is show how much dispersion and then next step. You show the
dispersion and others will try and others will find the documents. There was a very good
French site with German document scans and I think Mk 108 was in there, btw.

Show is worth 1000 tell.
Do the same as was done with the .50's. Blip the trigger very quick on and off to cut down
recoil effect. Notice if gunsight moves, that is recoil and did you have brakes on yes?
Set up smokestack as target

can we trust on gunsight when lookin at recoil?? try tempest, gunsight stays almost perfectly in position, no matter what you do, bank or turn, pilot is tied tightly in cockpit, wonder how he had turn his head in it..
but this is your way and method testing recoil. be fine with that.

AEP Mk 108 could hit straight flying fighters at 800 to 1200 meters range.

we are here playing pasific fighters, see, you are bit behind OUR time here. 1200m range?? with 30mm? are you sure? didnt the rounds disappear at 800-900m range? is that all you can shoot at, straight flying fighters? be proud.


how can be tripod mounted gun, which weights 30kg plus 15kg of ammo = 45 kg, deal such high recoil.. just look the configuration of gun. it should fly on its back when fired, in Oleg created world http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

You don't have to tell me. Been there and done things like it.

no in he**? i though you were mamas sissy boy lurkin at home, doing nothing else than believing own documents which gives you much of joy to read, like its all of the life, all whats its about. again, be proud, and be sure.

BTW, there is a US model similar. It was shown on the cable show "Mail Call" where an
ex-marine sergeant goes out, shows and has fun with guns that I am SURE you would like.

why you like i would like guns? im no kid anymore who gets it hard when shooting things, not anymore. but again nice that you are so sure, like always, never making mistakes. you are the perfect human, again, be proud, oh, forget to say, be proud about yourself. try to be bit more of that, can it be possible?

Really, the watermelon gets shot sometimes and car wrecks others and so it goes.

would have never believe that http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif im jeallous for you that u seen something im not http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif be proud of yourself !!

When
the grenade launcher was used I only got to see 5 minutes but those were good.

sure they were, good that you got so good time as well. again reason to be proud of yourself.

I would
like to see the same from other places only I would need subtitles to follow along. I
have avi's of discovery shows in English with Swedish subtitles (many WWII history shows)
so why not in Finnish, Swedish, German, Russian, French and subtitles in English?

Thats damn lots of reason to be bold and proud, now you are my god! MUCHO ***** PROUDNESS for you http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif no one could have seen anything like you have seen. be proud.

Maybe
next year or the next? Somebody gets old hardware and a place then videos a shuetzen
party with some teaching... can't that be sold direct on VCD's or DVD's? </div></BLOCKQUOTE>

you sniff business idea?? again, you know and dont want to admit, but say it to yourself, that you are proud http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif we all praise you http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

The-Pizza-Man
02-12-2006, 12:18 AM
Originally posted by Stafroty:
and using ***** term from the gun makes you not understand the point? no it seems.

just compare mk108 on this, just for bringing thoughs in your mind:

AGS-17 Plamya auto grenade launcher.

http://faq.guns.ru/images/ags17.jpg

http://faq.guns.ru/images/ags-17.gif

http://www.mil.fi/maavoimat/kalustoesittely/00044.dsp

AGS-17 Plamya (Flame)

it says that AGS17 has muzzle velocity of 185m/sec, weight of the grenade 280g, max useful direct fire range 700m which also is its main way of use, indirect bout 1700m, ROF is 6-7rnds/sec, single fire 1-2/rnds /sec..
>>"weapon is REALLY accurate which allows that it can be used to shoot near own troops in close quarter fights."<<
"Ase on eritt√¬§in tarkka, mink√¬§ ansiosta sill√¬§ voidaan l√¬§hitaistelutilanteessa tulittaa hyvinkin l√¬§helle omia joukkoja."

how can be tripod mounted gun, which weights 30kg plus 15kg of ammo = 45 kg, deal such high recoil.. just look the configuration of gun. it should fly on its back when fired, in Oleg created world http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Just do the maths, that thing has an average recoil of 310 N compared with 1,800 N of the Mk 108 and 184 N of a Browning .303 and 504 N for .50.

EDIT: One thing that I didn't mention was the recoil effect of the escaping gas. It didn't occur to me earlier but it would be significant, particularly in a short barreled weapon like the Mk 108. Calculating the effect of the gas is impossible without information like it's escape velocity, pressure and density. That sort of thing is very difficult to come by. But rest assured the Mk 108 would have quite a bit of recoil.

pourshot
02-12-2006, 01:18 AM
Another thing that may affect recoil on the Hispano is the fact that the guns were mounted on springs and the recoil would I suppose be delivered over a greater time period and this in turn could dampen the oscillations.

But really if you think the mk108 has a problem with dispersion you should run some test and if you can show it is wrong you will get support to have it fixed, otherwise it just looks like whining.

Stafroty
02-12-2006, 01:43 AM
mk108 fires at open bolt, spring takes the hit of the bolt and sends it back towards barrel with new ammo with it.

so, bolt takes some amount of the recoil, as it is not closed bolt like GAS operated guns have. it makes difference. so it would for sure dampem more of those oscillations than hispanos in wings http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif wing itself can and will shake when fired , fuselage structure is for sure much more solid place for weapon, when fuselage and engine are holding the cannon on its place, than in wing, which would vibrate much easier.



6 x .50cal brownings cause 3000N, bit over 3,5 x .50cal makes same recoil as does MK108.

pourshot
02-12-2006, 02:12 AM
Originally posted by Stafroty:
mk108 fires at open bolt, spring takes the hit of the bolt and sends it back towards barrel with new ammo with it.

so, bolt takes some amount of the recoil, as it is not closed bolt like GAS operated guns have. it makes difference. so it would for sure dampem more of those oscillations than hispanos in wings http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif wing itself can and will shake when fired , fuselage structure is for sure much more solid place for weapon, when fuselage and engine are holding the cannon on its place, than in wing, which would vibrate much easier.



6 x .50cal brownings cause 3000N, bit over 3,5 x .50cal makes same recoil as does MK108.

So it sounds like you need to run some Hispano test and mk108 test.

Also 6x.50 with a high ROF (or any other size guns for that matter) firing a long burst will tend to push back with a more or less constant force, it would feel differant to the womp womp of the mk108, think like six small hammers as opposed to a sledge hammer.

pourshot
02-12-2006, 02:23 AM
One more thing be careful what you wish for with regards to dispersion for a lot of people making the .50 shoot more tightly also made hitting harder for some, the complete opposite to what was wanted.