Jon and Tim and Paul and Frank... you guys have done an outstanding job with your work on these tests. I am very pleased to see how close these two planes handle and perform. This is a very exciting event for me and I can never thank you all enough for doing such a wonderful job and making it a reality. Can't wait for the next set of tests. - Dick
Cool tests, looking forward to seeing more results from comparing the two wing designs. Just as a bystander that was there, it appeared as Tim said the KFm Airfoil was a touch more stable in climbs and gliding near stall speeds. The Conventional Airfoil seemd just a tiny bit faster. Keep up the good work guys! Paul
Well, I'm impressed! The KFm-3 looks hokey at first glance and much like a bumblebee, it shouldn't work aerodynamically, but somehow, it does anyway! Plus, the ease of construction and added strength at the expense of only a slightly decreased foil efficiency would seem to be a good trade-off. Overall, a perfectly viable way to build an aircraft.
@JC0926 yea that has been suggested, I was waiting on the programming card to come in stock for the ESC. Normally I have no luck with stick programming :) I went ahead and gave it a shot and have the brake set now. we were planning on running this test periodically throughout the testing to maintain a good baseline on how the planes are preforming. to make sure that noting changes or happens to the planes in storage/transport. I will let you know if it makes any major changes. Jon
Interesting test guys. The KFM will have higher drag - separation is drag. The chief advantage I can see of the KFM is ease of construction on some models. Our models are relatively draggy and over powered, so it's a hard thing to measure. Thus the difference may not have been obvious in this test. A boat operates differently. Steps on a boat hull cause an aeration of the flow between the water and the surface, reducing the contact area, but not increasing lift on the hull.
@BMFoamy we had planned to swap wings back and forth. This however proved much more difficult to do than I expected. we will do it later for some of the testing that doesn't require us to be flying side by side. Its easy to swap 2 wings on one plane, its very hard it turns out to swap 2 wings on 2 planes. Thanks for watching Jon
@daveyedgar THANKS!! keep watching, we have more tests planned and will be posting more video soon. going to try to get at least one test per week done. Jon
We did do several videos testing the 2 planes side by side. It has been a while. It was a good wing design both for its ease of build but also for its stability. All of my favorite plans were my KF builds. There is a whole playlist of Project Big Step. It was a lot of fun to do.
Where did you put the CG on the green plane? I heard one of you say that you needed a little up elevator. I think this may be because it was a little nose heavy, as the KF airfoils tend to like a CG around 40% of the chord.
Tim/Jon, I have a question, I watched the video twice before I ask. Do you think that you should be using the braking feature on the esc? That would allow a better glide rate and more consistent testing , with the prop still spinning with no power this creates resistance. Just an idea, I know it makes a difference with my glider. You may be able to achieve different results it the speed of the planes is faster. Make sense? Just my thoughts, love the planes!
this test is pretty unscientific, you need to figure out your airplane's minimum drag airspeed which occurs when both induced drag and parasite drag are lowest. if you can find that speed and trim the planes for their Vglide speed, you could more accurately test. There is a most efficient climb and glide speed for a given airfoil and if you don't peg those speeds, the test is arbitrary in it's findings due to added variables.
ahaha tell me oh wise arse how could it be more scientific..youre a nutter.. two pilots alternating the same flight paths at the same altitudes at the same speeds at the same time..youre insane.try anuttther jr college..doc johnny
Jon and Tim and Paul and Frank... you guys have done an outstanding job with your work on these tests. I am very pleased to see how close these two planes handle and perform. This is a very exciting event for me and I can never thank you all enough for doing such a wonderful job and making it a reality. Can't wait for the next set of tests.
- Dick
Same principle is applied to high speed boats. It's called a 'stepped hull' and it's all about reducing friction.
I've had so much fun watching these engineers.
Cool tests, looking forward to seeing more results from comparing the two wing designs. Just as a bystander that was there, it appeared as Tim said the KFm Airfoil was a touch more stable in climbs and gliding near stall speeds. The Conventional Airfoil seemd just a tiny bit faster. Keep up the good work guys!
Paul
@TheDickeroo Thanks for bringing the idea to us. It has been a fun, exciting adventure and I have learned A LOT.
Jon
Well, I'm impressed! The KFm-3 looks hokey at first glance and much like a bumblebee, it shouldn't work aerodynamically, but somehow, it does anyway! Plus, the ease of construction and added strength at the expense of only a slightly decreased foil efficiency would seem to be a good trade-off. Overall, a perfectly viable way to build an aircraft.
@JC0926 yea that has been suggested, I was waiting on the programming card to come in stock for the ESC. Normally I have no luck with stick programming :) I went ahead and gave it a shot and have the brake set now. we were planning on running this test periodically throughout the testing to maintain a good baseline on how the planes are preforming. to make sure that noting changes or happens to the planes in storage/transport. I will let you know if it makes any major changes.
Jon
Interesting test guys. The KFM will have higher drag - separation is drag. The chief advantage I can see of the KFM is ease of construction on some models. Our models are relatively draggy and over powered, so it's a hard thing to measure. Thus the difference may not have been obvious in this test. A boat operates differently. Steps on a boat hull cause an aeration of the flow between the water and the surface, reducing the contact area, but not increasing lift on the hull.
Bravo... gentils hommes
@rcFoamFighters Thanks for all the help. we had a great day all around!
Jon
@BMFoamy we had planned to swap wings back and forth. This however proved much more difficult to do than I expected. we will do it later for some of the testing that doesn't require us to be flying side by side. Its easy to swap 2 wings on one plane, its very hard it turns out to swap 2 wings on 2 planes.
Thanks for watching
Jon
@gripchion Thanks
More to come.
Jon
awesome! tests for rc flyer enthusiasts well overdue
@daveyedgar THANKS!!
keep watching, we have more tests planned and will be posting more video soon. going to try to get at least one test per week done.
Jon
@TheMoritzHoffmann there will be plans. I couldn't live with myself if I didn't let other enjoy this awesome to fly plane :)
Jon
I was wondering if you did any other video on this subject. I am working on project for missionary group and would like to use a KFM-3 airfoil
We did do several videos testing the 2 planes side by side. It has been a while. It was a good wing design both for its ease of build but also for its stability. All of my favorite plans were my KF builds. There is a whole playlist of Project Big Step. It was a lot of fun to do.
@@nightphall6810 --is possible to get a link to those videos? Thank for your time -- Steve
@@nightphall6810 How thick where your steps?
Where did you put the CG on the green plane? I heard one of you say that you needed a little up elevator. I think this may be because it was a little nose heavy, as the KF airfoils tend to like a CG around 40% of the chord.
Great Job !!!!
Tim/Jon, I have a question, I watched the video twice before I ask. Do you think that you should be using the braking feature on the esc? That would allow a better glide rate and more consistent testing , with the prop still spinning with no power this creates resistance. Just an idea, I know it makes a difference with my glider. You may be able to achieve different results it the speed of the planes is faster. Make sense? Just my thoughts, love the planes!
i hope there going to be plans for this planes
so which one is which airfoil.. that would have been more helpful in your discussions
The first 30 sec of the video tell you which is which. The Orange plane is conventional airfoil and the green was the KFm3 stepped airfoil.
What is that plane?
Not saying your not credible, but a conventional airfoil usually performs much worse due to small imperfections than a Kfm airfoil.
ok now prove that statement
this test is pretty unscientific, you need to figure out your airplane's minimum drag airspeed which occurs when both induced drag and parasite drag are lowest. if you can find that speed and trim the planes for their Vglide speed, you could more accurately test. There is a most efficient climb and glide speed for a given airfoil and if you don't peg those speeds, the test is arbitrary in it's findings due to added variables.
ahaha tell me oh wise arse how could it be more scientific..youre a nutter.. two pilots alternating the same flight paths at the same altitudes at the same speeds at the same time..youre insane.try anuttther jr college..doc johnny