Official FlightLine RC 1600mm Spitfire Mk. IX Thread

[franky]

Thanks Gross, i will use the recommended CG and move the lipo backwards and see if the Spit balance well.

[radfordc]

Hi guys, i need some clarification about the CG. I always thought that the CG was unchangable. Now i have read at RCGroups that (also the Spit thread) others are moving the CG for- or backwards according the weight of the lipo. I am intending to try some heavier lipos ( around 870-900 grams) . Must i change the CG? I thought to use the CG which is recommend in the manual.

The CG depends on where the mass of the plane is located...if you add mass to the tail the CG moves back; if you add mass to the nose the CG moves forward.

To fly correctly, the CG must be in the proper location with reference to the wing...normally about 25-30% aft of the leading edge (or mean aerodynamic chord for an elliptical wing like the Spit). For this plane you want the CG to be located 90mm aft of the LE at the fuselage. If you add a heavier battery check to be sure that the CG isn't way out of the proper location. I'm using a heavy 5800 pack pushed all the way forward and the CG is located 95mm aft of the LE. The plane flys very good.

[MesRcPilot]

Hi guys, i need some clarification about the CG. I always thought that the CG was unchangable. Now i have read at RCGroups that (also the Spit thread) others are moving the CG for- or backwards according the weight of the lipo. I am intending to try some heavier lipos ( around 870-900 grams) . Must i change the CG? I thought to use the CG which is recommend in the manual.

Hi Franky, the RC models we are flying today, ARTF or similar, have already set up CoG by the manufacturer, and allow fewer forward and backward changes, depending on the type of model and its use, for example: 3D or Warbird. If you need a stronger battery, so that it creates a ''nose down'', the ballast (lead) is added to the tail for compensates, so that in principle the CoG is always in the factory settings.
Note: Some of the lesser quality manufacturers, of the models, have the 'wrong' CoG. Three years ago, my Mustang P-51 had a CoG on 100 millimeters from the root of leading edge, and the actual was 80 milimeter. I was lucky on the maiden flight.
Thank you and all the best in next model setting .

[CDN_Iceman]

WOW Jiggz and lindeman, fantastic job on your planes. Man you guys have raised the bar to a new level. Thank you for posting the pictures of the final results. I am going to start practicing on some older planes before I do my Spitfire.

Who says foamies can't look amazing

Jeff

[Hiflyer45]

Yeah I used it in my 1700mm FMS P-51 but an earlier version. Works great and plenty loud plus if you lose the plane it has a beeper that automatically sounds off to help find the plane. One problem I have is the sound of the merlin keeps you from hearing the electric motor for landings. I used the battery timer trick to let me know what the real throttle setting is on approach. I have it set at 25%. One other problem is that if you have a low battery and it shuts down during flight, you won't know it because the sound system keeps going merrily on it's way as you watch the plane stall into the weeds. Yes, it did happen to me...... that's how I know about the beeper! Brad

Thanks I'll take your advice!

[benjack71]

So I finally got my spit in the air. I failed to do a proper ground check and put it up with ailerons reversed. Only damage is all the props got broke. In my 6 years of being in this hobby I have never ever done that. I did today. It happened. Its over. Lesson learned. Now since motion is obviously out of props, RC Castle them but that will be ten days before they arrive. The Rend Lake Warbird fly in is this coming weekend. I am assuming I will not get the RC Castle props by Friday. So, does anyone have a clue if there is some props that will match up from another model? Does anyone have a spare set they would be willing to sell at double the cost and i pay shipping?

[franky]

Thank you guys about the CG clarification, do you think that a 900 gr. lipo would be too heavy for this bird?
Radfordc: what is the weight of your 5800 lipo? I'm intend to order a 6200

[lindeman]

Hi All,
Test flew on Sunday, using a 4500 pack fully forward the cg came out as per specs, a larger battery may have to go back a bit but there is room enough, so I will look at a 5800 pack for the next outing, oh, it flew very well by the way, landing without flap was perfect, on the mains and the tail dropped as speed bled off, looked great in the air as well, full flap does need some up mixed in so I will do just that, all in all lovely model to fly, low pass, climb out into a roll, looked great. I wonder what will come next, ME 109 or FW190D would be nice, only thing that spoiled the day was a fellow club member backed into my car as he was leaving, insurance job but not how I wanted the day to end.

[MesRcPilot]

Thank you guys about the CG clarification, do you think that a 900 gr. lipo would be too heavy for this bird?
Radfordc: what is the weight of your 5800 lipo? I'm intend to order a 6200

It is possible but, I SAY AGAIN, that the CoG has to STILL stay at the existing default position !!, that will require the addition a ballast lead to the tail section , and it will generally increase the weight .... and we know that the weight of the RC model is a very important factor for scale and pleasant RC flying.
Rgds
Mes

[franky]

you are right Mes, i sure don't want to put extra weight at the tailsection.

[radfordc]

It is possible but, I SAY AGAIN, that the CoG has to STILL stay at the existing default position !!, that will require the addition a ballast lead to the tail section , and it will generally increase the weight .... and we know that the weight of the RC model is a very important factor for scale and pleasant RC flying.
Rgds
Mes

If you move the 6200 pack back a little you should not need any additional weight in the tail. I'm flying a 5800 pack shoved all the way forward and the CG is at 95mm....perfect flights.

[MesRcPilot]

If you move the 6200 pack back a little you should not need any additional weight in the tail. I'm flying a 5800 pack shoved all the way forward and the CG is at 95mm....perfect flights.

Hi Radfordc , I don't doubt that your Spit is flying perfect, but I wish that Franky not to enter in an experiments at the beginning of his Spitfire ''career''...yet..:Whew:thanks for exchanging technical knowledge!

[franky]

[QUOTE=radfordc;n96558]

If you move the 6200 pack back a little you should not need any additional weight in the tail. I'm flying a 5800 pack shoved all the way forward and the CG is at 95mm....perfect flights.[/Q

Sorry Rad but now i am confused again about the CG. Why have you change the CG to 95. The default is 90. Please explain i want to understand this CG subject good.

[franky]

Hi Radfordc , I don't doubt that your Spit is flying perfect, but I wish that Franky not to enter in an experiments at the beginning of his Spitfire ''career''...yet..:Whew:thanks for exchanging technical knowledge!

I'm very happy with my Spit and hope to fly it as long as possible, thats why my questions about the CG, i'm open to learn from others about several subject in the RC world, especially planes.

[MesRcPilot]

[QUOTE=franky;n96585]

If you move the 6200 pack back a little you should not need any additional weight in the tail. I'm flying a 5800 pack shoved all the way forward and the CG is at 95mm....perfect flights.[/Q

Sorry Rad but now i am confused again about the CG. Why have you change the CG to 95. The default is 90. Please explain i want to understand this CG subject good.

G/DayFranky, not my turn but I feel some responsibility...so...Do not be confused, it's possible to "manipulate" the position of CoG ... at some limits, ahead-back of 3, 4, 5 mm, but than you have to use a different way of flying. For example, if CoG set back (tail heavy) is more likely to be stalled. On the other hand, if CoG is pushed forward, the speed must be added for correction of suddenly fast diving , etc. The best way is exercise (which can be expensive) to get useful information on setting generally for CoG. My attitude and view is that the Spitfire is not a beginner model and she does not tolerate an experimentation.
All the best
Mes

[Dewey H Lee]

Hey Franky. Everyone flies a plane a different way. Some pilots like there planes a little nose heavy and some almost a tade tail heavy. Dont be mistaken by the term for a tade tail heavy being for a beginner or novice pilot. This mostly is done by very good pilots that fly 3d. The cg for the plane is recommended at 90mm and that is what you should strive to accomplish by moving your battery forwards or backwards to accomplish this for your first flights and then determine if it flies good there for your way of flying. Just remember that a tail heavy plane seldom makes it back to the ground in one piece. This plane is also not a beginner plane. It flies very docile and elegant but it is a warbird. What goes up must sooner or later land and the spit lands well if you have low wing warbird experience. I hope this helps a little. Just start with the suggested cg and you will be fine. What someone else is flying might not be right for you.:Cool:

[franky]

Thank you Mes and Dewey for advice, I will use the recommended CG of 90 and move the lipo for a good balance.

[radfordc]

Hi Radfordc , I don't doubt that your Spit is flying perfect, but I wish that Franky not to enter in an experiments at the beginning of his Spitfire ''career''...yet..:Whew:thanks for exchanging technical knowledge!

No experimenting required. He should fly with the CG at 90mm back just as the manual states. If he uses a larger battery that causes the CG to be too far forward then it is better to move the battery back to achieve the correct CG rather than adding weight to the tail of the plane.

[radfordc]

[QUOTE=franky;n96585]

If you move the 6200 pack back a little you should not need any additional weight in the tail. I'm flying a 5800 pack shoved all the way forward and the CG is at 95mm....perfect flights.[/Q

Sorry Rad but now i am confused again about the CG. Why have you change the CG to 95. The default is 90. Please explain i want to understand this CG subject good.

All planes have a range of CG locations that are safe. The CG specified in the manual is a good place to start....most manuals show a very safe CG location that is on the forward end of the CG range. This makes the plane slightly nose heavy and therefore just a little more stable. If you move the CG too far forward you will reach a point where the plane will want to fall on it's nose and you don't have enough elevator control to hold the nose up when landing. Moving the CG back causes the plane to be more maneuverable...but if you go too far back the plane becomes unstable and impossible to fly.

My CG is at 95mm because that's where it came out with the battery I'm using. I didn't want to add lead to the nose of the plane to move the CG forward to 90mm.

[MesRcPilot]

No experimenting required. He should fly with the CG at 90mm back just as the manual states. If he uses a larger battery that causes the CG to be too far forward then it is better to move the battery back to achieve the correct CG rather than adding weight to the tail of the plane.

Hello Rad , this is a misunderstanding (my English is probably ''guilty'' for it )... So ... CoG must always be close to the factory setting, and minimum shifts are allowed.
If it happens that some actions are disrupted a CoG, we can correct it with a heavier or lighter battery, fewer or more lead additions where needed.
If you do not agree.. I'm sorry, but the books say this..also ..I'm old dog ...for new tricks.
Regards,and thanks for your time.
Mes