Official Freewing 80mm A-4E/F Skyhawk Thread

[RanGee]

Great looking A4s guys!

Thanks Ryan!

[AceMigKiller]

Regarding the cheater hole - Go ahead and cover them up if you wish... you'll see no penalty in performance.

Takeoff roll from a paved surface with cheater covered was observed to be no longer than with it open.

Vic

[dahawk]

We had our monthly cub meeting tonight. At the end of each meeting we have a 'Model of the Month' contest. Guys bring just about anything that flies . They describe it, maybe provide a little history of the full scale, etc. Then are told to go out to the parking lot while the crowd votes by a show of hands. Well, tonight, there was my VA-93 A4 pitted up against my buddie's new FW Avanti. and by a show of hands, the A4 won out. Yay ! Another brass tag that goes on my plaque. Freewing all the way !

[Pheonix]

RanGee, what a wonderful job with the new paint scheme. This must have been a tough and time consuming job. I admire your work and others that can air brush so well. Cheers!

[Pheonix]

The 6-year old girl in the photo reminds me of my grand daughter, Milah who is six as well. She loves my planes and goes to the field with me when possible. Kids love planes and I agree that we should share when presented the opportunity. Bless you for taking the time with her.

[TomPatton]

Weathering looks great so far Tom!

Thanks Pat, first time trying the weathering, so I'm kind of muuddeling my way thru it. I think I am going to be pretty happy with it when it's finished though .

[themudduck]

Regarding the cheater hole - Go ahead and cover them up if you wish... you'll see no penalty in performance.

Takeoff roll from a paved surface with cheater covered was observed to be no longer than with it open.

Vic

Hey Vic.... have you seen how the Freewing 90mm F104 has spring loaded "dual-action" speed brakes instead of a cheater hole, these open automatically to let air in to the fan. They open up when you open the throttle when the plane is on the ground. You can see this in the videos (and I've seen it on my plane). I have no idea it they open when the model is in the air.

Obviously its because of negative pressure in the duct - the fan isn't getting enough air and the speed brakes open up in response to this pressure. The conclusion is that the EDF really does need more air, at least when static.

I get what you're saying about the A-4's takeoff performance, but that may not be telling the entire story. To really understand it we'd have to do some kind of test to measure the thrust of the fan, to see if the EDF is actually operating efficiently without the cheater hole. Maybe its starved for air for a few moments... I don't know. Maybe it would be interesting to make a spring-loaded panel (replacing the cheater on the A4) that could let air in only when needed, like the F104's speed brakes.

Or we could just say "screw it, it works just fine with the hole covered up" and not worry about it - the proof is in the pudding. That's OK but I'm just curious about what's happening. At least with the F104, its obvious that fan needs more air. And virtually every EDF out there has a cheater hole. What's the reason for that? Is there a way to measure what's going on - besides just looking at the takeoff roll? Maybe Alpha can tell us, do they perform some kind of air pressure test during the design process to see if the cheater is actually needed? Interesting. :Confused:

[ryramZ]

Playing with some washes. The paint seems to take it well. Very subtle so far.

[RCjetdude]

Looks good Ryan. I just did something similar on my gray A-10... finally. Just kept it very subtle compared to what I usually do but it needed something.

[seaviper]

Looks good sir! I am amazed at all the awesome paint jobs on this forum! You guys have really raised the bar. That's cool though because now I have inspiration to go ahead and start painting my own.

[RCjetdude]

Thanks. Even a little weathering makes a difference. Now, a nice shiny Blue Angels A-4 needs none on the other hand. ;)

[seaviper]

Actually all the birds I have ever been around were rather clean. Even the ones I really didn't want to fly. Most of the smudges or streaks I saw around panel lines were due to corrosion-x treatment seeping out. On the military birds I saw mostly sun damage to paint and the exposed cockpit areas. Not a lot of dirt though. Weathering can be overdone very easily. That's why I am hesitant to weather most of the time. But I will weather the skyhawk. Man some nice planes on this forum!

I like Chris's mechanical pencil technique. Think I might try that for the first time.

[DCORSAIR]

All mine get the natural weathering, fingerprints and smudges......:) I figure I pay alot money for these foam jets, I want them kept shiny and new.................:)

[RCjetdude]

I prefer some to look grungy, some to just show the panel lines and yes, some need to be spotless. Just personal preference.

[The RC Geek]

Hey Guys,

Got video posted last night. This was the 4th flight on the airplane and also has the cheater grate taped over.


Chris

[The RC Geek]

Hey Vic.... have you seen how the Freewing 90mm F104 has spring loaded "dual-action" speed brakes instead of a cheater hole, these open automatically to let air in to the fan. They open up when you open the throttle when the plane is on the ground. You can see this in the videos (and I've seen it on my plane). I have no idea it they open when the model is in the air.

Obviously its because of negative pressure in the duct - the fan isn't getting enough air and the speed brakes open up in response to this pressure. The conclusion is that the EDF really does need more air, at least when static.

I get what you're saying about the A-4's takeoff performance, but that may not be telling the entire story. To really understand it we'd have to do some kind of test to measure the thrust of the fan, to see if the EDF is actually operating efficiently without the cheater hole. Maybe its starved for air for a few moments... I don't know. Maybe it would be interesting to make a spring-loaded panel (replacing the cheater on the A4) that could let air in only when needed, like the F104's speed brakes.

Or we could just say "screw it, it works just fine with the hole covered up" and not worry about it - the proof is in the pudding. That's OK but I'm just curious about what's happening. At least with the F104, its obvious that fan needs more air. And virtually every EDF out there has a cheater hole. What's the reason for that? Is there a way to measure what's going on - besides just looking at the takeoff roll? Maybe Alpha can tell us, do they perform some kind of air pressure test during the design process to see if the cheater is actually needed? Interesting. :Confused:

The cheaters are there usually because the inlets are too small to feed the fan sufficiently. A properly designed and sized inlet system does not need a cheater and is far more efficient. But, it requires that the inlets themselves have sufficient area to feed the fan. For the scale purist like myself, the existence of the cheater kind of kills me a little inside, haha! So, being that this A-4 is a large model for the 80mm fan I had a feeling that the inlets themselves would be sufficient.


Chris

[The RC Geek]

Actually all the birds I have ever been around were rather clean. Even the ones I really didn't want to fly. Most of the smudges or streaks I saw around panel lines were due to corrosion-x treatment seeping out. On the military birds I saw mostly sun damage to paint and the exposed cockpit areas. Not a lot of dirt though. Weathering can be overdone very easily. That's why I am hesitant to weather most of the time. But I will weather the skyhawk. Man some nice planes on this forum!

I like Chris's mechanical pencil technique. Think I might try that for the first time.

Just be careful with the pencil on bare painted foam as there's a good chance it may poke through the paint pretty easily. The pencil works great when you have a hardened surface. Since this airplane has the recessed panel lines, I actually intend on doing a wash similar to Ryan (though, I've gone back and forth about just filling them all in, haha!). I plan to take my acrylic raw umber and thin it down, spray it over the entire airframe and then wipe it all off (in the direction of the airflow on flying surfaces, vertically on fuselage). This will leave the thinned paint in all of the recesses. I'll then go back and add oil streaking with the unthinned acrylic pigment. The panel lines are too large for scale as a whole (though not bad), so thinning it down will help tone down the prevalence of the wash. Applying an unthinned acrylic would make the panel lines too dark in this case based on the panel line size.


Chris

[RanGee]

RanGee, what a wonderful job with the new paint scheme. This must have been a tough and time consuming job. I admire your work and others that can air brush so well. Cheers!

Thanks!
About 20 hours into that

[Callie Graphics]

Hey Guys! We got a bunch of new sets added to our website yesterday. Sure is great seeing these schemes come to life as you all receive your models!

We would love to include your completed models photos to our product pages. If you'd like your model showcased, feel free to e-mail a pic to: info@callie-graphics.com

You can see these sets and more at: https://callie-graphics.com/collecti...ted-descending

Just be sure to select the 1/9th scale option for this model.

[themudduck]

Hey Guys,

Got video posted last night. This was the 4th flight on the airplane and also has the cheater grate taped over.


Chris

Very nice job on the video presentation Mr. Geek, and that's some smooth flying as well. Love it! Now all you need to do is spend a few hours on the weathering, airbrushing, and decals! :)