Craig and Matt's Sopwith Camel Released 12th

[Bomber_12th]

I have had the chance to take her up (did so as soon as was practical! : ) ), and what an excellent production all around, from all of those that were involved - superb visuals, flight dynamics, and sounds. When taking this aircraft up, I couldn't help but be thankful that I have rudder pedals to really fully enjoy this aircraft, as it is an aircraft that is meant to be flown with the rudder, and that certainly comes through with the flight dynamics. You can feel that it is unstable, allowing it to be a nimble fighter. Its a joy to fly an aircraft in FS that requires attention on all flight controls - very much like the Neoqb Fokker Dr.1, which until today, was my favorite WWI aircraft to fly in FSX.

One item I thought should be touched on, is the common belief/myth about the rotary engine. There were several different companies that produced rotary engines during WWI, and different versions of the Camel had different manufacturer's engines fitted. The biggest myth concerning rotary engines is that they didn't have conventional throttles, where as in reality most rotary engines did have conventional throttles. Because of the popularity of the Gnome rotary engine in the years since WWI (used on several WWI replica aircraft that fly today, and discussed quite a bit, with its unique operation), it tends to create the idea that all rotary engines operated as it does (it having that selector mag to control the speed, instead of a throttle, with four settings - eighth-speed, quarter-speed, half-speed, and full-speed). I believe the majority of Sopwith Camels were produced with Clerget engines, while others had le Rhone's, Bentley's, or Gnome's (it sounds like the RNAS Camels always had Bentley engines, standard), and all of these, except for the Gnome's, used a conventional throttle. This model, as well as all other FS Camels that have come before, has a coventional throttle in the cockpit, and this is accurate for all of those Camels that had engines other than the Gnome. 'Conventional' isn't quite right to describe the throttle on these, though, as you couldn't just jockey the throttle to control the engine - whenever you made changes with the throttle, you would also have to make changes to the fuel/air mixture at the same time, and if not done right, the engine would quit and you would be looking at dead-sticking it in. As a result, once full power was attained, many pilots, from what I seem to recall, liked to just use the blip switch and not mess around with the throttle - this was especially the case on landing, when the pilot couldn't be focused on having to adjust multiple controls to both lower the speed and still keep the engine running. This therefore answers the question as to why they would keep the blip switch, inspite of having a throttle.

So, when using your joystick throttle with the aircraft in the sim, it actually is more accurate than you might otherwise be led to believe.

I noticed that the horsepower in the engine section is 160, which is indicating the very late Gnome 9N, which I believe is the type found on the Camels operated today in New Zealand and at Old Rhinebeck. During WWI, these are all of the different engines that were fitted to the Camel, and their individual horsepower:

Clerget 9B - 130 Hp (conventional throttle)
Clerget 9Bf - 140 Hp (conventional throttle)
Le Rhone 9J - 110 Hp (conventional throttle)
Bentley Br1 - 150 Hp (conventional throttle - probably the best engine ever fitted to this aircraft - for the first time in decades, one is now operating, on Kermit Weeks' Sopwith Snipe)
Gnome 9B-2 - 100 Hp (no throttle)
Gnome 9N - 150 Hp or 160 Hp (no throttle)

[warchild]

I can explain the orque force when the engines are off.. you see, FSX has only a single entry for toque and nowhere else is it calculated. That entry is Torque_on_roll in the aircraft.cfg file and its job is to apply an amount of torque when you roll the plane left or right.. That wasnt going to get it with this plane. I searched online for a couple days for information about torque in fsx including places like fsdeveloper, and came up empty handed, so i realized that if we were going to have torque, we had to invent it. Annnnnd about that moment Craig shipped over an almost finished version of the plane and everything went EEK!!!.. We didnt have a lot of time.. There was an old trick they used with some rotary engines on real aircraft to counter the torque effects. They would offset the engines position a very small amount. I chose to expand on this idea and used a bipolar ofset. the cg is offset to one side, and the engine offset to the other side. this allowed me to ( quickly ) create a torque like effect that could be adjusted for force by simply balancing out the locations of the engine and cg. Now, for all intents and purposes in this aircraft, the cg, is not the cg. Rather, its the rotational center, or, the place on the aircraft around which the rotational force is experienced during pitch or banking. As i mentioned earlier, we could not have built this aircraft using standard techniques and gotten it close to flying like a real camel, so, everything in the flight model was developed around forces insted of empirical data and locations. however, moving the cg off to one side creates an issue wherein you will always experience some rotational force, except for the moment you begin to decelerate. at that moment, torque is reversed as the plane wants to rotate with the engine as it winds down. I do wish we were able to do better with the torque effects, but as i said, its a new invention in fsx and we havent perfected it yet..
Pam

[warchild]

I noticed that the horsepower in the engine section is 160, which is indicating the very late Gnome 9N, which I believe is the type found on the Camels operated today in New Zealand and at Old Rhinebeck. During WWI, these are all of the different engines that were fitted to the Camel, and their individual horsepower:

Clerget 9B - 130 Hp (conventional throttle)
Clerget 9Bf - 140 Hp (conventional throttle)
Le Rhone 9J - 110 Hp (conventional throttle)
Bentley Br1 - 150 Hp (conventional throttle - probably the best engine ever fitted to this aircraft - for the first time in decades, one is now operating, on Kermit Weeks' Sopwith Snipe)
Gnome 9B-2 - 100 Hp (no throttle)
Gnome 9N - 150 Hp or 160 Hp (no throttle)

your absolutely dead on the money John. I put a 9n in there. the reason for that is very simple. i can open you tube and watch how that engine performs. i can hear it; almost smell it and feel it ( i can be very imaginative ). over all, it has in my opinion the very best documentation of all the engines because i can do more than read about it. the bentley was my second choice, although those were fewer in number due to their high cost, and the fact that the admiralty didnt really like letting go of them. So, i stuck with the 160 hp 9N. also i kind of liked the fact that it had no throttle.. hopefully, somewhere down the road someone will create three position magneto's and blip switches that can be used in these old birds and i can finish it properly ..

[warchild]

Thanks for you kind comments everyone

I'd like to echo what Craig said above. Thank you all.. .. I hope our humble little offering continues to bring you pleasure for many years to come.
Pam

[JohnC]

I can explain the orque force when the engines are off.. you see, FSX has only a single entry for toque and nowhere else is it calculated. That entry is Torque_on_roll in the aircraft.cfg file and its job is to apply an amount of torque when you roll the plane left or right.. That wasnt going to get it with this plane. I searched online for a couple days for information about torque in fsx including places like fsdeveloper, and came up empty handed, so i realized that if we were going to have torque, we had to invent it. Annnnnd about that moment Craig shipped over an almost finished version of the plane and everything went EEK!!!.. We didnt have a lot of time.. There was an old trick they used with some rotary engines on real aircraft to counter the torque effects. They would offset the engines position a very small amount. I chose to expand on this idea and used a bipolar ofset. the cg is offset to one side, and the engine offset to the other side. this allowed me to ( quickly ) create a torque like effect that could be adjusted for force by simply balancing out the locations of the engine and cg. Now, for all intents and purposes in this aircraft, the cg, is not the cg. Rather, its the rotational center, or, the place on the aircraft around which the rotational force is experienced during pitch or banking. As i mentioned earlier, we could not have built this aircraft using standard techniques and gotten it close to flying like a real camel, so, everything in the flight model was developed around forces insted of empirical data and locations. however, moving the cg off to one side creates an issue wherein you will always experience some rotational force, except for the moment you begin to decelerate. at that moment, torque is reversed as the plane wants to rotate with the engine as it winds down. I do wish we were able to do better with the torque effects, but as i said, its a new invention in fsx and we havent perfected it yet..
Pam

That's actually not entirely true. Most of the issues associated with the rotary engine were not torque, but angular momentum. When angular momentum is forced to change it's direction it becomes gyroscopic procession. Skip ahead to 2:00 and you'll see the classical example of pitch turning into yaw.

http://www.youtube.com/watch?v=sy5NY-Dqdys

This effect is actually modeled into FSX, and is nestled away in the propeller MOI, [propeller geometry]. Since the entire engine is rotating with the propeller, the MOI is increased by an order of magnitude. A crude calculation of the 9B simplified as uniformly dense thin disc comes arrives at an MOI of 33.1 slugs*ft^2, which is more than ten times the current entry of 2.3 (a very reasonable number for just a propeller).

Making this change doesn't produce a huge effect, however, but it does when increased to 50 slugs*ft^2 (simply to illustrate that it does work). This probably means one or both of the static yaw stability coefficients (Cy_dBeta, and Cy_dBeta-dot) are a touch high.

I'm not at all trying to be critical on a splendid release. I know that Pam is always looking to improve her flight modeling knowledge and thought I'd offer some insight.

Great job!

:ernae:

[delta558]

The reason for the prop MOI being set so low is entirely mine - Pam was quite adamant that it should be higher. However, in an attempt to replicate the fairly sharp power changes caused by 'blipping' the un-throttled 160hp Gnome rotary engine, it was necessary to reduce the MOI in order to create a more responsive engine. Pam's original MOI setting was 9.3, but the result of that was that when you put power back on it took an absolute age to get anywhere near full power. The same was noticeable in throttle reduction - you could slam the throttle shut but still be waiting for the thrust to decrease a good few seconds later. It did not create anywhere near the effect seen in the many videos which are available on YouTube, the rocking as power is momentarily interrupted then re-applied for example. In fact, increasing the prop MOI had completely the opposite effect of that which can be seen in the videos: increasing the throttle and decreasing the throttle would have so much lag that the engine response was slow enough to completely ruin any of the effects created by the rotary engine.

What we have tried to create is something that takes the constant rotation of the engine as being the most stable point (hence the rotational effect at idle throttle), and then create a faster reaction to the throttle to give the effect of the sudden application of full power with no middle ground.

Hope that helps to explain our thinking behind this a little bit.

[fleurdelys]

This plane is gorgeous. It is a handfull but truly fun plane to fly...

I still have to work on the takeoffs but the landing are OK as long as you have a LARGE landing strip, like a field with no obstacles around...

I have tried the guns and noticed that the sound kept shooting after the gun flashes had stopped for up to half a second to a full second. There is an easy fix to this. Open the "fx_spandau_s" effect and correct the second entry (sound) with the following...

[Sound]
FileName=wwi_guns.wav
MinAttenuationDistance=500.00
Looping=False

It should bring the sound and flashes in sync.

[JohnC]

The reason for the prop MOI being set so low is entirely mine - Pam was quite adamant that it should be higher. However, in an attempt to replicate the fairly sharp power changes caused by 'blipping' the un-throttled 160hp Gnome rotary engine, it was necessary to reduce the MOI in order to create a more responsive engine. Pam's original MOI setting was 9.3, but the result of that was that when you put power back on it took an absolute age to get anywhere near full power. The same was noticeable in throttle reduction - you could slam the throttle shut but still be waiting for the thrust to decrease a good few seconds later. It did not create anywhere near the effect seen in the many videos which are available on YouTube, the rocking as power is momentarily interrupted then re-applied for example. In fact, increasing the prop MOI had completely the opposite effect of that which can be seen in the videos: increasing the throttle and decreasing the throttle would have so much lag that the engine response was slow enough to completely ruin any of the effects created by the rotary engine.

What we have tried to create is something that takes the constant rotation of the engine as being the most stable point (hence the rotational effect at idle throttle), and then create a faster reaction to the throttle to give the effect of the sudden application of full power with no middle ground.

Hope that helps to explain our thinking behind this a little bit.

Gotcha! In that case, it's another level or two deeper. If you know the MOI is plausibly accurate, but the power off response is not acceptable (how was the power on respose, slow or okay?)....then there are a couple of possibilities. Using the modified version of Newton's second Law; sum of external moments = MOI*angular acceleration; it has to be one of the external moments.

One of the most prominent possibilities is the prop power coefficient. It's a big ugly table to edit, and is the more obscure of two primary power off propeller torque inputs (where the other is cylinder friction). All the values in the Camel's table are positive and that's unusual, as they should dive to zero and then into the negative with increasing advance ratio (image below). It's not at all intuitive, but the negative CP region defines the power off response. Probably goes beyond the scope of the project, but is little more information none the less.

Kindest Regards,
John

[warchild]

Gotcha! In that case, it's another level or two deeper. If you know the MOI is plausibly accurate, but the power off response is not acceptable (how was the power on respose, slow or okay?)....then there are a couple of possibilities. Using the modified version of Newton's second Law; sum of external moments = MOI*angular acceleration; it has to be one of the external moments.

One of the most prominent possibilities is the prop power coefficient. It's a big ugly table to edit, and is the more obscure of two primary power off propeller torque inputs (where the other is cylinder friction). All the values in the Camel's table are positive and that's unusual, as they should dive to zero and then into the negative with increasing advance ratio (image below). It's not at all intuitive, but the negative CP region defines the power off response. Probably goes beyond the scope of the project, but is little more information none the less.

Kindest Regards,
John

Yeahhh.. the imposing agent here was time. i didnt feel we had the time to do the prop table propperly. also, if you look at prop efficiency, you'll see that its a very weird table.. i'd never seen anything like that before and frankly, it unnerved me, so i left it alone as much as possible..
But yeahh, technically the moi on that prop with a 345 pound engine attached should be around 129 or so.. So when Paul told me what he needed the moi to be, i blew a fuse :;lol:;..

[JohnC]

Yeahhh.. the imposing agent here was time. i didnt feel we had the time to do the prop table propperly. also, if you look at prop efficiency, you'll see that its a very weird table.. i'd never seen anything like that before and frankly, it unnerved me, so i left it alone as much as possible..
But yeahh, technically the moi on that prop with a 345 pound engine attached should be around 129 or so.. So when Paul told me what he needed the moi to be, i blew a fuse :;lol:;..

FSX Stock Prop Tables = Camel Dung (saying from an old prof I had)

You did a great job Pam.

[warchild]

Its all craigs fault. his work just kept getting better and better.. I had to keep up ya know .. thanks John

[Daube]

Thanks for these explanations about the engine torque and prop MOI.
The edition of the flight model really looks like a nightmare for a developper

[Bruce Thompson]

I have tried the guns and noticed that the sound kept shooting after the gun flashes had stopped for up to half a second to a full second. There is an easy fix to this. Open the "fx_spandau_s" effect and correct the second entry (sound) with the following...

[Sound]
FileName=wwi_guns.wav
MinAttenuationDistance=500.00
Looping=False

It should bring the sound and flashes in sync.

Thank you for the HU on the gun sound fleurdelys, I have had the same problem.

I also have another looping sound after landing, like the undercarriage touchdown repeating over and over even after shutting down the engine.
Hitting the Q key does not stop it either, any idea's?

Bruce.

[FentiFlier1]

Well I took it for a spin this morning and it's challenging. Flying in clouds without an attitude indicator is one thing, flying this Camel in clouds without an attitude indicator is another :isadizzy:

[MudMarine]

I can't get it to download? Probably because I'm only a blue member.

[Pips]

I haven't had so much fun flapping around in an aeroplane in ages! Flying the Camel is pure joy. My most sncere thanks for the effort folks. You really have outdone yourselves!

[MDIvey]

MudMarine... I dont think you have to be in the Red to download(Do You?) but if so have you tried downloading directly from Craig's site...there are some links a few pages back (page 6)

Matt

[Roger]

Should be avaiable to both charter and non-charter members.

[fleurdelys]

Thank you for the HU on the gun sound fleurdelys, I have had the same problem.

I also have another looping sound after landing, like the undercarriage touchdown repeating over and over even after shutting down the engine.
Hitting the Q key does not stop it either, any idea's?

Bruce.

Bonjour Bruce,

I also have the same problem with the touchdown sound repeating over and over...

I have tried different approaches which have not worked :
- changing the touchdown sounds with other touchdown sounds; it still repeats itself, albeit differently.
- changing the sound file altogether; still repeating when the engine is shut down.

Since you and I seem to be the only ones affected with this problem, and we are both of the same age, I think that we may have been singled out...

I have a theory that it could be a programming disfunction, meaning that the sound xml or whatever it is called is missing one part to tell the sound to shut up completely when the plane is no longer moving or the engine is shutdown and the pilot out to lunch...:salute:
But that is only a theory and above my paygrade. You might try to:

1. Ignore it altogether;

2. Hit the "Q" key which obliterates the sound completely after you finish rolling and shutdown the engine ...

Hope somebody else out there has a workable idea to help us out.

Cheers,

Fleurdelys

P.S.: in reference to my earlier tweak on the "Spandau" sound tweak, I wasn't completely satisfied and borrowed from another gun effect with a much better result as far a getting the effect to sync. Try this on for size...

[Library Effect]
Lifetime=5
Version=1.00
Radius=-1
Priority=0
[Sound]
FileName=wwi_guns.wav
MinAttenuationDistance=500.00
Looping=False

I don't have the foggiest idea as to what or why, but it seems to be working for me.

[Bruce Thompson]

Bonjour Bruce,

I also have the same problem with the touchdown sound repeating over and over...

I have tried different approaches which have not worked :
- changing the touchdown sounds with other touchdown sounds; it still repeats itself, albeit differently.
- changing the sound file altogether; still repeating when the engine is shut down.

Since you and I seem to be the only ones affected with this problem, and we are both of the same age, I think that we may have been singled out...

I have a theory that it could be a programming disfunction, meaning that the sound xml or whatever it is called is missing one part to tell the sound to shut up completely when the plane is no longer moving or the engine is shutdown and the pilot out to lunch...:salute:
But that is only a theory and above my paygrade. You might try to:

1. Ignore it altogether;

2. Hit the "Q" key which obliterates the sound completely after you finish rolling and shutdown the engine ...

Hope somebody else out there has a workable idea to help us out.

Cheers,

Fleurdelys

P.S.: in reference to my earlier tweak on the "Spandau" sound tweak, I wasn't completely satisfied and borrowed from another gun effect with a much better result as far a getting the effect to sync. Try this on for size...

[Library Effect]
Lifetime=5
Version=1.00
Radius=-1
Priority=0
[Sound]
FileName=wwi_guns.wav
MinAttenuationDistance=500.00
Looping=False

I don't have the foggiest idea as to what or why, but it seems to be working for me.

Hi Fluerdelys

Thanks again for your help, I will give this new gun tweak a try this evening, will let you know how I get on.

With regard to the touchdown sound repeating over and over, I think we had this problem with another aircraft a short while ago,
but being nearly 67:isadizzy::isadizzy:: I can't remember where or when.

If I do find it I will let you know straight away, I think it was to do with contact points.

Regards

Bruce.

[dvj]

I am totally smitten by this model.

[Sieggie]

1. The Sopwith had a twin magneto ignition system. One magneto was used by pressing a button on the stick and would engage all nine cylinders or cut the power to that magneto. it was called the "blip" switch. The other magneto had a three position selector switch which allowed you to use either three, six, or all nine cylinders. there was no throttle as we know them today. The closest we can mimic this in FSX is to suggest that you fly withyour throttle at either 33%, 66% or 100% settings. You can also set up FSUIPC to create a type of "blip" switch too.

Love you all..
Pam

Pam, I understand the throttle setting simulating the 3, 6 or 9 cylinders, but what do you program into the blip switch?

I am guessing min throttle should be 33% not 0%?

Thanks,

Dave

[warchild]

I believe the blip switch was additive ( i could be wrong ). If the second magneto was set to 3 cylinders then the blip switch would kick in all nine cylinders and revert to the 3 cylinders when released. likewise if you were using 6 cylinders on the second magneto. of course, this is just my supposition. i truly do not know how else it may have worked.
In FSX Paul set up a sort of blip switch using fsuipc, but i simply set my throttle at the percentage that would provide approximates for the three magneto settings.

[jetstreamsky]

In FSX Paul set up a sort of blip switch using fsuipc.

and there's a good reason to get the full deal

[full]

Ok guys I've been looking into the sound issue after landing a can confirm that is the tail skid causing the problem.

You can get the new sound.cfg here ----> http://www.classicwings.net/freeplan...amel/sound.cfg

Please let me know if this fix's the issue. BTW nice screen shots everyone ! keep them coming