Was out blasting through a bunch more lipos this morning doing another bit of a fly off between my stock RCP Mig29 V4 and my NAMC modded Mig29 V4M3e3.
I now have 147 flights on my stock Mig29 V4 and 75 flights on my V4M3e3. Although I have yet to have ideal conditions to really dial in the high alpha setup on my V4M3e3 since it has been too windy, for all other flying I have it dialed in pretty much exactly the way I want it and through 75 flights have put it through it's paces in just about every imaginable attitude and aerobatics that my skill levels allow me to attempt.
It had been almost two weeks since I last flew my stock V4 and once again it reminded me of why it is without a doubt my favorite stock built park jet of all time. If I could never modify a plane ever again and could only fly a stock built Mig29 V4, I would still be the happiest guy at the field. I know that sometimes it seems like in my excitement of how great a modified plane flies that it seems like I might make the stock plane sound like it is not even worth building. That has never been the case and as I have posted here on this blog and many times on the RC Powers forum when I was still actively posting there, the Mig29 V4 is the best stock built park jet I have ever built and flown.
So, having said that and I know I may be a bit biased as I shared in the ideas and modifications for the V4M3e3, it is simply a more stable, more precise and better flying plane in all aspects with really just a few simple, very achievable modifications. I know I have already said this when I did the first comparison when I maidened the V4M3e3 and wrote my post flight report comparing the stock and NAMC modified Mig29 V4, but now that I have significantly more flights under my belt, I would like to report some more in depth findings I noticed today.
I know I don't have side by side video comparison or wind tunnel tests or anything else to compare and unless you actually are standing at the field, you wouldn't see the difference, but there are a few simple aerodynamic differences that help back up some of my opinions.
The smaller control surfaces, especially the modified elevons and vert stab/rudders make a big difference in how precise this plane is, how much quieter it is not only it how it flies, but physically quieter which I will describe in a bit.
So here are a few numbers to put things in perspective hopefully. As I said throughout the build process and early flights, I estimate the total reduction in elevon surface area between stock and the V4M3e3 is about 15% and total reduction in aileron surface is about 40%. The rudders may be about the same size in surface area, but the orientation of the hinge and trailing edge is what makes the big difference in rudder performance.
For my flying style and since I fly at the same field all the time, I have developed a certain amount of muscle memory in my thumbs when I turn especially and I tend to adjust the expo and throw on each new plane to account for that. Meaning I put the same amount of input in the sticks to get the plane to turn 180 degrees at each end of the field without hitting the trees and then just adjust how much throw I need with each new plane to allow me to do that without adjusting my flying style too much. Hopefully that makes sense... :/
So here are my expo and throws for the stock V4 to allow me to fly the way I like to fly
- Rudder - 60% expo, 100% throws;
- Elevator - 55% expo, 75% throws; and
- Aileron - 60% expo, 50% throws.
Here are my expo and throws for the V4M3e3
- Rudder - 60% expo, 100% throws;
- Elevator - 55% expo, 80% throws; and
- Aileron - 60% expo, 65% throws.
So not a huge difference in settings to allow me the same turn rate and roll rate between both planes. This is logical considering the difference in size of the elevons and ailerons that a bit more travel sometimes would be required to get the same pitch and roll rates.
However, in how the planes fly, a noticeable difference.
In turns, the stock V4 still will occasionally bobble a bit or have negative behavior from elevon polar pitch effect (EPPE which Stephan and I have discussed on the blog in depth). It is still very smooth, but not as "quiet" as the V4M3e3. As I have mentioned several times, the V4M3e3 just carves through the air with minimum wasted movement or effort, it tracks more solid than any other plane I have ever flown.
In loops, with the V4M3e3 having less moving surface, I can put on 60% power, pull about 50% down on the elevator and it just flies a smooth, constant loop all the way through with no real requirement to modify the control inputs.
With the stock V4, I have to be more gentle with the initial input or the plane will go straight vertical rather than "arching" it's back and entering the loop smoothly. Then throughout the loop, much more finesse is required with the throttle and elevator to get the plane to maintain a uniform circle and pull out in the same spot/altitude where it entered. For how I like to fly, it has just a bit too much moving surface in the elevator and there is too much drag and turbulence caused by this bigger surface while it is deflected. Now I know that in theory a good smooth loop is an aerobatic move that does require the pilot to adjust power and control surface inputs to maintain a uniform circle, but with the V4M3e3, it is just so much easier and smoother.
For rudder performance, there is really no comparison if you want to execute maneuvers that require good solid, responsive rudder input that will move the plane properly in the yaw axis without having to compensate for too much roll. For me, I have found that a good way to evaluate how "clean" and direct rudder movement is in a plane is to execute a stall turn http://en.wikipedia.org/wiki/Stall_turn. I know the diagram below is a bit simplified, but it essentially is going vertical at about half throttle, letting the speed bleed off till almost in the stall and then kicking the rudder full left or right. The plane should do what the plane is doing in the diagram. With the V4M3e3, I can do this with little to no opposite aileron input and the plane goes through 180 degrees of yaw and starts it's decent within about one to two wingspans of space. I almost never see any tendency to want to roll while it is going through the stall turn.
With the stock V4, I have to coordinate the rudder kick and feed in opposite aileron to keep the airplane from rolling rather than just kicking the nose through 180 degrees in the yaw axis, meaning the rudder is causing roll input as well as yaw, not something I really want my rudder to do, but again, just what I want/expect from my planes. Also, by having to put quite a bit of opposite aileron to prevent the roll, the move ends up looking more like a wingover http://en.wikipedia.org/wiki/Wingover than a stall turn as it can take almost 4 wingspans to get the plane through 180 degrees.
Having said that, the wingover is another good maneuver to use lots of rudder and see what the plane does, although with both planes I found opposite aileron was required, just lots more with the stock V4.
So earlier in this post I mentioned not only does the V4M3e3 fly "quieter" in that it is much smoother with less bobble, bouncing around, etc., it is physically quieter. Now before you think I am losing it... :/, try the following the next time you are flying and see what sort of sounds (other than the prop) you can hear your airplane making.
I flew several close passes in front of myself with both planes, about 10 ft in front of me at about eye level, so about 6 ft off the ground and at about 75% throttle. I flew these passes in both directions with the wind and into the wind. As the stock V4 flew by, I could easily hear a "whoosh" as the air flowed over the plane. As the V4M3e3 flew by, it was about 50% quieter. I can only put this down to reduced turbulence brought on by smaller elevon span and vertical trailing edge on the rudder/vert stab.
As you probably know, turbulent air causes sound. As I drove home from the field, I had my car window rolled down and it drove this point home. By having the window rolled down, I was reducing the aerodynamics of my car, causing turbulent airflow over my car and increased noise. In the case of the two planes, I can only assume the difference in the "tail feathers" (elevons/vert stabs/rudder) was responsible for the much quieter sound of the V4M3e3. It is without doubt more sleek and "quieter" through the air which also leads me to believe it is more efficient through the whole speed range. I have already clocked it as being 6 mph faster than stock, even when it is about an oz heavier! So reduced drag and turbulence due to size of the elevons and orientation of the vert stab/rudder seem to be the only answer as the finish of bevelled/symmetrical leading and trailing edges is identical on both planes.
This fact was also driven home to me again in approach and landing. The V4M3e3 glides about 25% further than the stock V4, again leading me to believe there is a noticeable decrease in drag and turbulence and increase in efficiency as the plane passes through the air.
So as I have said before, I know not every plane can have the vertical hinged rudders or have vertical trailing edges on the rudder/vert stab, that would like kinda weird on an F18, but the smaller elevons and ailerons are definitely big winners. I also think that the 40% KF has an important role to play in increased stability and lift. I know it isn't a big increase over stock, but working in conjunction with all the other modifications, it all makes a big difference.
Again, I know I am a bit biased, but I am amazed at how a few changes here and there make such big differences in the performance of a plane. It is fun to experiment and educational, as I learn so much with each new plane as to how little modifications here and there are affecting airflow, drag, turbulence and overall aircraft performance.
Cheers,
Scott
For rudder performance, there is really no comparison if you want to execute maneuvers that require good solid, responsive rudder input that will move the plane properly in the yaw axis without having to compensate for too much roll. For me, I have found that a good way to evaluate how "clean" and direct rudder movement is in a plane is to execute a stall turn http://en.wikipedia.org/wiki/Stall_turn. I know the diagram below is a bit simplified, but it essentially is going vertical at about half throttle, letting the speed bleed off till almost in the stall and then kicking the rudder full left or right. The plane should do what the plane is doing in the diagram. With the V4M3e3, I can do this with little to no opposite aileron input and the plane goes through 180 degrees of yaw and starts it's decent within about one to two wingspans of space. I almost never see any tendency to want to roll while it is going through the stall turn.
With the stock V4, I have to coordinate the rudder kick and feed in opposite aileron to keep the airplane from rolling rather than just kicking the nose through 180 degrees in the yaw axis, meaning the rudder is causing roll input as well as yaw, not something I really want my rudder to do, but again, just what I want/expect from my planes. Also, by having to put quite a bit of opposite aileron to prevent the roll, the move ends up looking more like a wingover http://en.wikipedia.org/wiki/Wingover than a stall turn as it can take almost 4 wingspans to get the plane through 180 degrees.
Having said that, the wingover is another good maneuver to use lots of rudder and see what the plane does, although with both planes I found opposite aileron was required, just lots more with the stock V4.
So earlier in this post I mentioned not only does the V4M3e3 fly "quieter" in that it is much smoother with less bobble, bouncing around, etc., it is physically quieter. Now before you think I am losing it... :/, try the following the next time you are flying and see what sort of sounds (other than the prop) you can hear your airplane making.
I flew several close passes in front of myself with both planes, about 10 ft in front of me at about eye level, so about 6 ft off the ground and at about 75% throttle. I flew these passes in both directions with the wind and into the wind. As the stock V4 flew by, I could easily hear a "whoosh" as the air flowed over the plane. As the V4M3e3 flew by, it was about 50% quieter. I can only put this down to reduced turbulence brought on by smaller elevon span and vertical trailing edge on the rudder/vert stab.
As you probably know, turbulent air causes sound. As I drove home from the field, I had my car window rolled down and it drove this point home. By having the window rolled down, I was reducing the aerodynamics of my car, causing turbulent airflow over my car and increased noise. In the case of the two planes, I can only assume the difference in the "tail feathers" (elevons/vert stabs/rudder) was responsible for the much quieter sound of the V4M3e3. It is without doubt more sleek and "quieter" through the air which also leads me to believe it is more efficient through the whole speed range. I have already clocked it as being 6 mph faster than stock, even when it is about an oz heavier! So reduced drag and turbulence due to size of the elevons and orientation of the vert stab/rudder seem to be the only answer as the finish of bevelled/symmetrical leading and trailing edges is identical on both planes.
This fact was also driven home to me again in approach and landing. The V4M3e3 glides about 25% further than the stock V4, again leading me to believe there is a noticeable decrease in drag and turbulence and increase in efficiency as the plane passes through the air.
So as I have said before, I know not every plane can have the vertical hinged rudders or have vertical trailing edges on the rudder/vert stab, that would like kinda weird on an F18, but the smaller elevons and ailerons are definitely big winners. I also think that the 40% KF has an important role to play in increased stability and lift. I know it isn't a big increase over stock, but working in conjunction with all the other modifications, it all makes a big difference.
Again, I know I am a bit biased, but I am amazed at how a few changes here and there make such big differences in the performance of a plane. It is fun to experiment and educational, as I learn so much with each new plane as to how little modifications here and there are affecting airflow, drag, turbulence and overall aircraft performance.
Cheers,
Scott
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