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Aug 31, 2019, 07:08 PM
Registered User
subarujunky's Avatar
Hey guys.

Has anyone had the problem of this model going into ground effect upon landing?

I'm using flaperons and tailerons. The model comes in with a slight nose up attitude, then right before touchdown I pull up slightly to flair...

The model will touchdown for a moment then get airborne again, then come down hard.

I've already bend the strut back straight on the nose gear...

Should I not being giving up elevator just before touch down to flair??

Am I coming in too fast??

Thanks.

Sent from my SM-N960U using Tapatalk
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Aug 31, 2019, 08:00 PM
Registered User
I can say I’ve messed up my fair share of landings but none like you’re describing. Sounds like you might be nose heavy, which can cause porpoising. If the CG is too far in front of the mains, the nose comes down hard and bounces back up, getting you airborne again and causing the dreaded porpoising bounce.

Regarding the flare, I don’t really flare my F-16 on landing. I try to establish the right attitude and sink rate between 5-10 feet and then hold it until contact.
Aug 31, 2019, 11:01 PM
Nose down, you're gonna stall
rowdyjoe's Avatar
Quote:
Originally Posted by subarujunky
Hey guys.

Has anyone had the problem of this model going into ground effect upon landing?

I'm using flaperons and tailerons. The model comes in with a slight nose up attitude, then right before touchdown I pull up slightly to flair...

The model will touchdown for a moment then get airborne again, then come down hard.

I've already bend the strut back straight on the nose gear...

Should I not being giving up elevator just before touch down to flair??

Am I coming in too fast??

Thanks.

Sent from my SM-N960U using Tapatalk

As RYGUY said ....establish the correct landing attitude while on final approach and control decent with your throttle. Flatten out your approach. This airplane must be "flown" all the way to landing. I usually hold a bit of throttle ON while on final and cut the power when the wheels touch. If you try to force it to land before it's ready, you'll cause the problem you're experiencing. It's all about airspeed and nose attitude. You can land fast but, roll out will be long. You can land slower and get a shorter roll-out but, you'll need a high nose attitude (aka "high alpha). I have Up Elevator mixed with my flaperons to minimize the landing workload. It helps a lot. I don't use tailerons.

Also, check for excess elevator travel which can exacerbate the problem.
Last edited by rowdyjoe; Sep 06, 2019 at 08:49 PM.
Sep 01, 2019, 12:57 PM
Registered User
subarujunky's Avatar
Quote:
Originally Posted by rowdyjoe
As RYGUY said ....establish the correct landing attitude while on final approach and control decent with your throttle. Flatten our your approach. This airplane must be "flown" all the way to landing. I usually hold a bit of throttle ON while on final and cut the power when the wheels touch. If you try to force it to land before it's ready, you'll cause the problem you're experiencing. It's all about airspeed and nose attitude. You can land fast but, roll out will be long. You can land slower and get a shorter roll-out but, you'll need a high nose attitude (aka "high alpha). I have Up Elevator mixed with my flaperons to minimize the landing workload. It helps a lot. I don't use tailerons.



Also, check for excess elevator travel which can exacerbate the problem.
Ok.
I'm definitely forcing it to land.
I flew 4 packs this morning and only had one decent landing.
Its porpoising like crazy..
I have flaperons set at 40% but have not mixed in any up elevator...
Will this help if I do mix in Up elevator?

I haven't flown a jet in almost 3 years. Been flying 3D planes...
They've ruined my ability for precise landings needed for jets...

Sent from my SM-N960U using Tapatalk
Sep 01, 2019, 02:56 PM
Nose down, you're gonna stall
rowdyjoe's Avatar
Quote:
Originally Posted by subarujunky
Ok.
I'm definitely forcing it to land.
I flew 4 packs this morning and only had one decent landing.
Its porpoising like crazy..
I have flaperons set at 40% but have not mixed in any up elevator...
Will this help if I do mix in Up elevator?

I haven't flown a jet in almost 3 years. Been flying 3D planes...
They've ruined my ability for precise landings needed for jets...

Sent from my SM-N960U using Tapatalk
Yes, Up elevator mixed with the flaperons will help establish the attitude for landing and reduce the need/tempation to "pump" the elevator. Watch the video on Motion where Ryan and Mike fly this bird and they will tell you the amount of elevator mix they use with flaperons. Your mileage may vary (as mine did) depending on the radio system you use.
Battery placement (for CG) will also help or hinder your landing attitude. CG for my set-up is neutral (not tail or nose heavy). If you use a variety of batteries (different weights), you should establish the same CG via battery placement with each one and ensure you place them in the right spot for each flight. If you're starting from scratch, adjust battery placement as necessary to give you the desired result (as usual).
Although I have 3 batteries that can be used, I have narrowed my choice to two batteries that weigh the same to eliminate confusion.

"Spot" landings are not easy with this bird without a LOT of practice. I'm still tying to get it down in the first quarter of the runway. We have 480 ft of smooth concrete and, without brakes, it will roll about 250 ft without power. Slow-flight practice will help you a lot in taming the landings. I need to do more of that myself but, with the short flight times (3 min. + or - a few seconds) it doesn't give me much time. The temptation for me is to watch this beautiful fast bird burn holes in the sky as I rocket around and before I know it, the timer is going off and I haven't practiced.

Good luck.
Sep 06, 2019, 09:25 PM
Nose down, you're gonna stall
rowdyjoe's Avatar
Are there any enterprising modelers out there with a 3D printer who could/would make Ventral Fins for those of us who are missing them? I'd be willing to buy a pair for a reasonable price.

It should be a fairly easy part to produce in ABS (for toughness). I think PLA might be too soft for the abuse they sometimes get. If I owned a 3D printer I'd do the project myself.
Sep 07, 2019, 08:00 AM
Innocent Bystander
Bobaroo's Avatar
It may be stretching the abilities
of some of our 'New and upcoming
AeroModlers' here in our
Highly Technical Age given the extreme
Complexity of those Fins !!


But, 'Old Timers' would use a section of a cereal box turned inside out (So that the Graphics on that 'Lucky Charms' or 'Captain Crunch' box wouldn't become a major distraction)

Using a pencil and a straight edge, these AeroModeling pioneers would Trace out the Trapezoidal shape of One of the fins onto this thin Cardboard sheet. Only one !! More on this Later.

Once the desired shape was carefully applied to the cardboard, these guys would then use scissors (Hand held metallic tool for making cuts on certain substances) to carefully cut out the fin shape from the card stock staying as close to the lines as 'Possible' using these primitive non- computer aided methods.

With this freshly cut Fin Shape successfully removed from the Card stock, these guys were now ready to actually (and this may be hard to even comprehend to some) somehow transfer this shape onto a suitable substance and literally 'Create' a fin shaped object for themselves in their workshop.

I'll post more on the next step in this actual 'Fabrication' business after I do more Research on woodworking.

Definition of a Trapezoid - MathHelp.com - Geometry Help (1 min 40 sec)

https://en.m.wikipedia.org/wiki/Scissors
Last edited by Bobaroo; Sep 07, 2019 at 08:15 AM. Reason: References added
Sep 07, 2019, 08:34 AM
Registered User
subarujunky's Avatar
Quote:
Originally Posted by Bobaroo
It may be stretching the abilities
of some of our 'New and upcoming
AeroModlers' here in our
Highly Technical Age given the extreme
Complexity of those Fins !!


But, 'Old Timers' would use a section of a cereal box turned inside out (So that the Graphics on that 'Lucky Charms' or 'Captain Crunch' box wouldn't become a major distraction)

Using a pencil and a straight edge, these AeroModeling pioneers would Trace out the Trapezoidal shape of One of the fins onto this thin Cardboard sheet. Only one !! More on this Later.

Once the desired shape was carefully applied to the cardboard, these guys would then use scissors (Hand held metallic tool for making cuts on certain substances) to carefully cut out the fin shape from the card stock staying as close to the lines as 'Possible' using these primitive non- computer aided methods.

With this freshly cut Fin Shape successfully removed from the Card stock, these guys were now ready to actually (and this may be hard to even comprehend to some) somehow transfer this shape onto a suitable substance and literally 'Create' a fin shaped object for themselves in their workshop.

I'll post more on the next step in this actual 'Fabrication' business after I do more Research on woodworking.

https://youtu.be/d8DAYzbmuBE
https://en.m.wikipedia.org/wiki/Scissors
Hilarious!

The most basic part and they want it 3D printed.
He could have made the part from scratch In The time it took him to write the post.. lol jk

But seriously, they sell sheet plastics everywhere. Just buy a sheet then cut it out..

Sent from my SM-N960U using Tapatalk
Sep 07, 2019, 08:54 AM
Innocent Bystander
Bobaroo's Avatar
...
Sep 07, 2019, 12:24 PM
Nose down, you're gonna stall
rowdyjoe's Avatar
Quote:
Originally Posted by Bobaroo
It may be stretching the abilities
of some of our 'New and upcoming
AeroModlers' here in our
Highly Technical Age given the extreme
Complexity of those Fins !!


But, 'Old Timers' would use a section of a cereal box turned inside out (So that the Graphics on that 'Lucky Charms' or 'Captain Crunch' box wouldn't become a major distraction)

Using a pencil and a straight edge, these AeroModeling pioneers would Trace out the Trapezoidal shape of One of the fins onto this thin Cardboard sheet. Only one !! More on this Later.

Once the desired shape was carefully applied to the cardboard, these guys would then use scissors (Hand held metallic tool for making cuts on certain substances) to carefully cut out the fin shape from the card stock staying as close to the lines as 'Possible' using these primitive non- computer aided methods.

With this freshly cut Fin Shape successfully removed from the Card stock, these guys were now ready to actually (and this may be hard to even comprehend to some) somehow transfer this shape onto a suitable substance and literally 'Create' a fin shaped object for themselves in their workshop.

I'll post more on the next step in this actual 'Fabrication' business after I do more Research on woodworking.

https://youtu.be/d8DAYzbmuBE
https://en.m.wikipedia.org/wiki/Scissors

One could also trace the shape onto light ply, cut the shape out, paint, drill and install it ....IF one had a place and tools to do it. Many do not.

BTW ....you should have shaved before you had your portrait made and the orange suit went out of style with Disco.
Sep 07, 2019, 12:49 PM
Innocent Bystander
Bobaroo's Avatar
Quote:
Originally Posted by rowdyjoe
One could also trace the shape onto light ply, cut the shape out, paint, drill and install it ....IF one had a place and tools to do it. Many do not.

BTW ....you should have shaved before you had your portrait made and the orange suit went out of style with Disco.
Hey Now !!! That's not me ... SillyHead,... That's a internet harvested picture of a Hero from our Space Program !! Cheers !!

And .... I typically go 'Shirtless' in photos !!!
Sep 21, 2019, 09:02 PM
RC Junkie!
The Slayer's Avatar
Does anyone have a technique for stripping the paint down to the bare foam with out damaging the foam?
Sep 23, 2019, 05:20 PM
Nose down, you're gonna stall
rowdyjoe's Avatar
I have very little personal experience painting foam planes so, when I do, I follow the example of folks who have successfully painted quite a few. Generally speaking, most of them remove all stickers and paint over the existing/factory paint. Some use a primer and some use a base coat of the final color. There are a number of videos on Utube.
Last edited by rowdyjoe; Sep 24, 2019 at 12:14 PM.
Sep 24, 2019, 11:48 AM
Mach One
captain MoMo's Avatar
Quote:
Originally Posted by The Slayer
Does anyone have a technique for stripping the paint down to the bare foam with out damaging the foam?
I have used some tape to pull off the paint. On mine, regular masking tape was good enough. Some have used duct tape but that may pull off some foam as well. I have not seen anyone use stripping agents recently but I am sure that is also done by some.
Latest blog entry: ESC and BEC Steup
Sep 24, 2019, 12:04 PM
Registered User
Quote:
Originally Posted by captain MoMo
I have used some tape to pull off the paint. On mine, regular masking tape was good enough. Some have used duct tape but that may pull off some foam as well. I have not seen anyone use stripping agents recently but I am sure that is also done by some.
I stripped the factory paint off my first F-4 Phantom. I tried the tape method. I used very powerful tape when I tried it. The only problem I had with it taking foam off was when I was trying a second time to get the areas of the paint that didn't come off on the first attempt. If any of the tape touches bare foam when attempting to remove paint that didn't come off the first time, foam will definitely come off. For that reason, I soon tried acetone after watching a few youtube videos of others using it to remove paint. Going with the acetone is very messy and can cause serious gatoring, especially if the foam is exposed to the acetone for too long. Also rubbing a piece of clothe soaked in acetone back and forth or in circular motions will expedite the foam to gator. So when choosing the acetone route, for best results, make sure you wipe in one direction only and try and limit the time the foam is exposed to the acetone as little as possible. It does take a little time for the foam to react to the acetone, but when it does, you'll know because the foam will start to become sticky to the touch and then you'll start seeing the gatoring effect.


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