CMP BF109F BUILDING THREAD
10-20-2008 | 02:41 PM
#426
RE: CMP BF109F BUILDING THREAD
There might be a reason then to use the top air brake portion. Dunno of course until someone does, but the top side air brake piece should induce a good deal more drag. However, one person's flying style or feel for the plane might not translate to everyone. Case in point, a friend of mine likes to fly his planes with little expo on any of the surfaces, however, I prefer to have about 50% expo.
Someone might think the landing speed it too fast on one plane while another person is comfortable with the same speed.
So, unless Ramstein were to make the airbrakes functional, there's no way for him to know if it would help or hinder HIS comfort level as it relates to how he is used to doing things.
I am waiting on another light kit and as such, I havent worked on my wing for that reason. The light kit I have has landing lights and the real plane did not, so, Im not expecting to get the wing finished for another 2 weeks or so(unless the light kit showed up today). Who knows. It should have been here already, but, coming from Honk Kong, sometimes packages take forever and sometimes they arrive within a week. Its already been 2 weeks almost.
Someone might think the landing speed it too fast on one plane while another person is comfortable with the same speed.
So, unless Ramstein were to make the airbrakes functional, there's no way for him to know if it would help or hinder HIS comfort level as it relates to how he is used to doing things.
I am waiting on another light kit and as such, I havent worked on my wing for that reason. The light kit I have has landing lights and the real plane did not, so, Im not expecting to get the wing finished for another 2 weeks or so(unless the light kit showed up today). Who knows. It should have been here already, but, coming from Honk Kong, sometimes packages take forever and sometimes they arrive within a week. Its already been 2 weeks almost.
10-20-2008 | 03:20 PM
#427
My Feedback: (157)
RE: CMP BF109F BUILDING THREAD
Once again, thank you kahloq
I had to go through my post and see where I stated the landing speed was fast... I didn't find that but I did say that the planes speed on the ground after landing was to fast to maneuver with the gear being so close to the scale position and had to be bled off beforehand as you added. I don’t want people getting it confused.
Landing speed was very reasonable for this size bird with my setup. In the air the plane is fast. I'll go out again thursday and we'll do it again.
I had to go through my post and see where I stated the landing speed was fast... I didn't find that but I did say that the planes speed on the ground after landing was to fast to maneuver with the gear being so close to the scale position and had to be bled off beforehand as you added. I don’t want people getting it confused.
Landing speed was very reasonable for this size bird with my setup. In the air the plane is fast. I'll go out again thursday and we'll do it again.
10-20-2008 | 04:50 PM
#428
RE: CMP BF109F BUILDING THREAD
I was not refering to landing speed on this plane being fast. I was making a general statement about how two(or more) ppl would see the same thing differently according to their viewpoint and how they are used to flying. The expo example was supposed to illustrate this point.
The statement saying one person might think the landing speed too fast while another might think its not were just comparing two people's perceptual differences but using the same plane(not this ME-109....but a generic fill in the blank plane).
I was saying that....in relation to the airbrakes on this plane...... one person might think the airbrakes helpful, while another person might not. Since you've flown yours without functional airbrakes, only you would know if they helped YOU and how YOU fly. Each person sees things different. Although the airbrakes might help in one sense to slow the plane down, it might also cause a different reaction that YOU might not be comfortable with, but someone else wouldnt care or would be willing to deal with. It's all subjective and thats all i was trying to say. I will have the airbrakes functional, but not at the same deflection percentage as the lower oil cooler flap portion. Will this help me? I dunno. Id like to hope so, but it may end up being just a cosmetic "isnt that neat" feature.
The statement saying one person might think the landing speed too fast while another might think its not were just comparing two people's perceptual differences but using the same plane(not this ME-109....but a generic fill in the blank plane).
I was saying that....in relation to the airbrakes on this plane...... one person might think the airbrakes helpful, while another person might not. Since you've flown yours without functional airbrakes, only you would know if they helped YOU and how YOU fly. Each person sees things different. Although the airbrakes might help in one sense to slow the plane down, it might also cause a different reaction that YOU might not be comfortable with, but someone else wouldnt care or would be willing to deal with. It's all subjective and thats all i was trying to say. I will have the airbrakes functional, but not at the same deflection percentage as the lower oil cooler flap portion. Will this help me? I dunno. Id like to hope so, but it may end up being just a cosmetic "isnt that neat" feature.
10-20-2008 | 04:56 PM
#429
My Feedback: (13)
RE: CMP BF109F BUILDING THREAD
Hi Guys
On my 48" span 109 with landing gear in a scale position, the landings are impacted quite a bit by the wind. In the event there is a slight cross wind the model wants to lift a wing, so I have learned to use aileron, rudder and a bit of body english when landing. And keeping it straight as until it settles in. As well as keeping an eye on the wind sock.
It all comes down to practice and learning the models characteristics . From take offs to dead stick slope soaring the model in safely.
Steve
On my 48" span 109 with landing gear in a scale position, the landings are impacted quite a bit by the wind. In the event there is a slight cross wind the model wants to lift a wing, so I have learned to use aileron, rudder and a bit of body english when landing. And keeping it straight as until it settles in. As well as keeping an eye on the wind sock.
It all comes down to practice and learning the models characteristics . From take offs to dead stick slope soaring the model in safely.
Steve
10-20-2008 | 05:02 PM
#430
My Feedback: (157)
RE: CMP BF109F BUILDING THREAD
ORIGINAL: kahloq
I was not refering to landing speed on this plane being fast. I was making a general statement about how two(or more) ppl would see the same thing differently according to their viewpoint and how they are used to flying. The expo example was supposed to illustrate this point.
The statement saying one person might think the landing speed too fast while another might think its not were just comparing two people's perceptual differences but using the same plane(not this ME-109....but a generic fill in the blank plane).
I was saying that....in relation to the airbrakes on this plane...... one person might think the airbrakes helpful, while another person might not. Since you've flown yours without functional airbrakes, only you would know if they helped YOU and how YOU fly. Each person sees things different. Although the airbrakes might help in one sense to slow the plane down, it might also cause a different reaction that YOU might not be comfortable with, but someone else wouldnt care or would be willing to deal with. It's all subjective and thats all i was trying to say. I will have the airbrakes functional, but not at the same deflection percentage as the lower oil cooler flap portion. Will this help me? I dunno. Id like to hope so, but it may end up being just a cosmetic "isnt that neat" feature.
I was not refering to landing speed on this plane being fast. I was making a general statement about how two(or more) ppl would see the same thing differently according to their viewpoint and how they are used to flying. The expo example was supposed to illustrate this point.
The statement saying one person might think the landing speed too fast while another might think its not were just comparing two people's perceptual differences but using the same plane(not this ME-109....but a generic fill in the blank plane).
I was saying that....in relation to the airbrakes on this plane...... one person might think the airbrakes helpful, while another person might not. Since you've flown yours without functional airbrakes, only you would know if they helped YOU and how YOU fly. Each person sees things different. Although the airbrakes might help in one sense to slow the plane down, it might also cause a different reaction that YOU might not be comfortable with, but someone else wouldnt care or would be willing to deal with. It's all subjective and thats all i was trying to say. I will have the airbrakes functional, but not at the same deflection percentage as the lower oil cooler flap portion. Will this help me? I dunno. Id like to hope so, but it may end up being just a cosmetic "isnt that neat" feature.
10-20-2008 | 05:31 PM
#431
RE: CMP BF109F BUILDING THREAD
Please dont just watch. Your input is well needed since yours is one of only a select few that have flown.
Id like to get your impression on different flying traits, etc since we are both at the same elevation, its direct useable info for me.
I have the 220 in my H9 1.50 p-51 and I think its ok, but not overpowered and the plane only weighs like 17 pounds or so.
In your 109, you said its too much motor? Is that simply because of the vibration or that it simply pulls the plane around with little effort?
Mine is electric, with 2000 watts available. Of course thats well over the 80 watts per pound required for SCALE flying(on a warbird) assuming a 15 pound plane...in fact its pretty close to 3D capable at 133 watts per pound. Even at 16 pounds, it would still be 125 watts per pound. So, do you think the stress of the power from the 220 is a little more then the plane is designed for requiring additional mods from the builder?
Id like to get your impression on different flying traits, etc since we are both at the same elevation, its direct useable info for me.
I have the 220 in my H9 1.50 p-51 and I think its ok, but not overpowered and the plane only weighs like 17 pounds or so.
In your 109, you said its too much motor? Is that simply because of the vibration or that it simply pulls the plane around with little effort?
Mine is electric, with 2000 watts available. Of course thats well over the 80 watts per pound required for SCALE flying(on a warbird) assuming a 15 pound plane...in fact its pretty close to 3D capable at 133 watts per pound. Even at 16 pounds, it would still be 125 watts per pound. So, do you think the stress of the power from the 220 is a little more then the plane is designed for requiring additional mods from the builder?
10-20-2008 | 06:20 PM
#432
My Feedback: (157)
RE: CMP BF109F BUILDING THREAD
ORIGINAL: kahloq
Please dont just watch. Your input is well needed since yours is one of only a select few that have flown.
Id like to get your impression on different flying traits, etc since we are both at the same elevation, its direct useable info for me.
I have the 220 in my H9 1.50 p-51 and I think its ok, but not overpowered and the plane only weighs like 17 pounds or so.
In your 109, you said its too much motor? Is that simply because of the vibration or that it simply pulls the plane around with little effort?
Mine is electric, with 2000 watts available. Of course thats well over the 80 watts per pound required for SCALE flying(on a warbird) assuming a 15 pound plane...in fact its pretty close to 3D capable at 133 watts per pound. Even at 16 pounds, it would still be 125 watts per pound. So, do you think the stress of the power from the 220 is a little more then the plane is designed for requiring additional mods from the builder?
Please dont just watch. Your input is well needed since yours is one of only a select few that have flown.
Id like to get your impression on different flying traits, etc since we are both at the same elevation, its direct useable info for me.
I have the 220 in my H9 1.50 p-51 and I think its ok, but not overpowered and the plane only weighs like 17 pounds or so.
In your 109, you said its too much motor? Is that simply because of the vibration or that it simply pulls the plane around with little effort?
Mine is electric, with 2000 watts available. Of course thats well over the 80 watts per pound required for SCALE flying(on a warbird) assuming a 15 pound plane...in fact its pretty close to 3D capable at 133 watts per pound. Even at 16 pounds, it would still be 125 watts per pound. So, do you think the stress of the power from the 220 is a little more then the plane is designed for requiring additional mods from the builder?
10-21-2008 | 07:26 AM
#436
My Feedback: (1)
RE: CMP BF109F BUILDING THREAD
He said in an earlier post he balanced at 112mm Bob. I was wondering if during the maiden he had a chance to fly inverted to test the amount of down elevator needed to fly level. It seems to be a decent way to check the CG setting on a Warbird.
10-21-2008 | 10:13 AM
#437
RE: CMP BF109F BUILDING THREAD
ORIGINAL: Hot Rod Todd
He said in an earlier post he balanced at 112mm Bob. I was wondering if during the maiden he had a chance to fly inverted to test the amount of down elevator needed to fly level. It seems to be a decent way to check the CG setting on a Warbird.
He said in an earlier post he balanced at 112mm Bob. I was wondering if during the maiden he had a chance to fly inverted to test the amount of down elevator needed to fly level. It seems to be a decent way to check the CG setting on a Warbird.
All my warbirds require quite a bit of down elevator to fly inverted. Of course I program very little elevator throw and even then use quite a bit of expo.
10-21-2008 | 01:11 PM
#438
My Feedback: (157)
RE: CMP BF109F BUILDING THREAD
ORIGINAL: Hot Rod Todd
He said in an earlier post he balanced at 112mm Bob. I was wondering if during the maiden he had a chance to fly inverted to test the amount of down elevator needed to fly level. It seems to be a decent way to check the CG setting on a Warbird.
He said in an earlier post he balanced at 112mm Bob. I was wondering if during the maiden he had a chance to fly inverted to test the amount of down elevator needed to fly level. It seems to be a decent way to check the CG setting on a Warbird.
10-21-2008 | 03:19 PM
#439
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From: Almelo, NETHERLANDS
RE: CMP BF109F BUILDING THREAD
Hello guys,
The engine I use pulls a 16x8 prop. I use a 120 AX. Due to the big spinner, 6 inch of the prop is covered by the spinner. Does this mean I can use a bigger prop than usual, say 18 or 19x8?
Regards,
Eric Schumacher, Netherlands.
The engine I use pulls a 16x8 prop. I use a 120 AX. Due to the big spinner, 6 inch of the prop is covered by the spinner. Does this mean I can use a bigger prop than usual, say 18 or 19x8?
Regards,
Eric Schumacher, Netherlands.
10-21-2008 | 03:25 PM
#440
My Feedback: (13)
RE: CMP BF109F BUILDING THREAD
With all due respect. Our opinion around here is that too many factors come into play when using inverted flight as a CG check. We feel its inaccurate .
Things like the airfoil of the wing, incidence of surfaces, angle of engine.
After you have given it your best guess on the bench...
One of the things we use to give a fairly good indication of good Cg location is the elevator position after the first flight once relatively level flight is found with trim. Near zero is good. Another good indicator is upon landing. If the model doesn't do anything you didn't want it to do, your pretty close.
Aside from a stall due to one hanging on the up elevator trying to float a warbird like this in
upon landing.
CMP is not known for accurate CG locations normally, but it worked for Ram44, plus the ability for Ram44 to keep the anxiety level down. Something I still issues with when flying.
Just a thought
Steve
Things like the airfoil of the wing, incidence of surfaces, angle of engine.
After you have given it your best guess on the bench...
One of the things we use to give a fairly good indication of good Cg location is the elevator position after the first flight once relatively level flight is found with trim. Near zero is good. Another good indicator is upon landing. If the model doesn't do anything you didn't want it to do, your pretty close.
Aside from a stall due to one hanging on the up elevator trying to float a warbird like this in
upon landing.
CMP is not known for accurate CG locations normally, but it worked for Ram44, plus the ability for Ram44 to keep the anxiety level down. Something I still issues with when flying.
Just a thought
Steve
10-22-2008 | 02:51 PM
#442
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From: Emerald Isle,
NC
RE: CMP BF109F BUILDING THREAD
Hot Rod Todd,
I was looking at your 109 tailwheel rig few pages back. Where does the contol rod off of the tailwheel arm terminate, like stock ? Did you connect it to the rudder /hinge or did you run a seperate conrol rod to the servo?
Thanks,
Freddie
I was looking at your 109 tailwheel rig few pages back. Where does the contol rod off of the tailwheel arm terminate, like stock ? Did you connect it to the rudder /hinge or did you run a seperate conrol rod to the servo?
Thanks,
Freddie
10-23-2008 | 10:36 AM
#443
My Feedback: (1)
RE: CMP BF109F BUILDING THREAD
Fearless: The tailwheel will connect the the hinge like stock, but I will use a better ball link and a 4-40 rod.
Scalecraft: I have found that the final elevator position does not always relate to balance. If all of your surfaces have the exact proper alignment, it could mean something, but many of these ARFs have too much positive angle on the elevator in relation to the wing and thrust line making down elevator after trim a common occurance.
I agree that the inverted flight test is not the best way to check balance. The only real factor to check that takes everything into account is flight performance. I would try to feel the elevator sensitivity at various speeds to get a feel for the CG for the particular airframe. Most of my warbirds end up needing a bit of down elevator when inverted, so I was just curious how the 109 felt in the same condition.
Scalecraft: I have found that the final elevator position does not always relate to balance. If all of your surfaces have the exact proper alignment, it could mean something, but many of these ARFs have too much positive angle on the elevator in relation to the wing and thrust line making down elevator after trim a common occurance.
I agree that the inverted flight test is not the best way to check balance. The only real factor to check that takes everything into account is flight performance. I would try to feel the elevator sensitivity at various speeds to get a feel for the CG for the particular airframe. Most of my warbirds end up needing a bit of down elevator when inverted, so I was just curious how the 109 felt in the same condition.
10-23-2008 | 10:59 AM
#444
My Feedback: (13)
RE: CMP BF109F BUILDING THREAD
HR Todd
I agree with you.
The elevator is just one of the indicators one can use. The more you know about the airframes construction, the more you know what your models info/behavior upon your first flight means.
Arfs being pre fab models opens up many variables. If one doesn't check/know things like all incidence, engine angle, and stuff like that, the elevator info could be misleading or useless or even create more confusion to the modeler.
In this 109 at 71-72" span @around 13-14lbs, I believe it should be pretty forgiving to the seasoned semi scale warbird modeler.
I have managed to pick up 2 full sets of spare parts minus only the fuses. I will probably throw a CMP factory wing together real quick, just for the sake of seeing if its a model I want to keep indefinitely.
Steve
I agree with you.
The elevator is just one of the indicators one can use. The more you know about the airframes construction, the more you know what your models info/behavior upon your first flight means.
Arfs being pre fab models opens up many variables. If one doesn't check/know things like all incidence, engine angle, and stuff like that, the elevator info could be misleading or useless or even create more confusion to the modeler.
In this 109 at 71-72" span @around 13-14lbs, I believe it should be pretty forgiving to the seasoned semi scale warbird modeler.
I have managed to pick up 2 full sets of spare parts minus only the fuses. I will probably throw a CMP factory wing together real quick, just for the sake of seeing if its a model I want to keep indefinitely.
Steve
10-23-2008 | 11:41 AM
#445
My Feedback: (1)
RE: CMP BF109F BUILDING THREAD
I agree, I too think this plane will be a good flier at 13-14 lbs. The CMP website lists the span as 72.8" and the wing area at 868 sq. in. The only people who may have problems are those used to light warbirds like the ones from Hanger 9. Anyone who has some CMP planes should find this one as forgiving as any. The wing loading will be high enough that it could bite those who go too slow or pull up too soon though. My CMP Mosquito wing is listed as 821 sq. in., and it flies well at 12.5 lbs.
10-23-2008 | 11:45 AM
#446
My Feedback: (13)
RE: CMP BF109F BUILDING THREAD
A pic of my OS 108 muffler. Since I am using a smaller than most engines I have seen here, I need the extra weight to CG this model. So....
After measuring the volume in a OS 108 type muffler, I configured an exhaust system to provide for a similar volume to avoid limiting the engines performance. Maybe even better flow. The engine is rated at 3 hp. It has flown the Platt 79" span 109 @20lbs very well.
It also allow me more access to the fuel tank connections, and I had the aluminum laying around any how. And around $8.00 worth of aluminum and some alone time.
Steve
After measuring the volume in a OS 108 type muffler, I configured an exhaust system to provide for a similar volume to avoid limiting the engines performance. Maybe even better flow. The engine is rated at 3 hp. It has flown the Platt 79" span 109 @20lbs very well.
It also allow me more access to the fuel tank connections, and I had the aluminum laying around any how. And around $8.00 worth of aluminum and some alone time.
Steve
