RE: Cermark F16
 

That´s it.

I will be changing from P80 to 70, will make a solid wing tube and get another tail pipe.

I agree with Extra300 and it´s much better to fly relaxed than worried.

What do you think about FlyEagleJet F-16 tail pipe? It is wider than Cermark´s one. It would be easier and cheaper for me to get one of that.

Do you think I shouldn´t even try using Cermark´s pipe?

Regards

RE: Cermark F16
 

I have crammed 5 tanks plus a UAT in mine for a total of 104 oz of fluids ( 26 oz are for smoke oil... There is still room for two more 8 oz tanks, but so far that hasn't been required...

RE: Cermark F16
 

Sorry do not have any idea about the flyeagle pipe. On the other hand, if you will be using more than the P-60, i read that it is recomanded to use a different pipe asthe Cermark will not take it. Fyg, i have the P-60 in mine with Cermark pipe, waiting for nice weather and good opportunity to maiden mine.

Regards,

RE: Cermark F16
 

Im on the stock Cermark pipe with my P-70 for now, but will keep an eye on it.

RE: Cermark F16
 

About the Rabbit engine : I'm going to fly mine with a rabit in a couple of weeks (around the beginning of May), I will let you know what are the result, I will also do a full ground test this week end and I may have a great idea of the autonomy...

Aldo, I can tell you that the engine is fitting very well in...

I will keep you in the loop...

RE: Cermark F16
 

Wayne,

Can you post some pics of all these tanks ?

RE: Cermark F16
 

I did a full ground test this weekend, and with my Rabbit on board I got 6.75 minutes at full RPM (with 2 or 3 cool down of a few seconds) until shutdown (because of air bubbles).

It's not a lot, but it's ok.

I guess when in flight, it should be something like 5.5 to 6 minute minutes safe... Of course I will set the timer to 3 minutes for the first flight and then get it longer flight after flight....

A+

RE: Cermark F16
 

Also, what model of servos did you used for the rudder, mine (a whatever cheap Hitec) stripout during my test (I expected it, so I heavily tested it)... There is not a lot of room to fit a servos in there...

Thanks,

RE: Cermark F16
 

Robin,

Hitec 125MG or 5125MG would work.

RE: Cermark F16
 

Hi there,

I have maidened my Cermark F-16 last Saturday and would like to have a feedback on an issue. While the speed in flight was rather on the high side using a P-60 for power, take off roll felt extremely slow and rotation after more then 350 ft. pulling on the stick.
I am using the Cermark pipe, and have installed turbine as per manufacturer's instructions. Also note that all wheels move freely, knowing that i have applied brakes before hitting full throtle and released same when thrust built up.

Thanks for sharing your experience.

Best regards,

RE: Cermark F16
 

350 feet with P60 sounds reasonable to me.

RE: Cermark F16
 

Thanks i3dm, but what i meant was the acceleration of the model seem to be very slow compared to the baby boomerang i had with this same turbine. I was wondering if Cermark pipe had anything to do with this.

Thanks. Regards,

RE: Cermark F16
 

the P-60 left at full thrust will take a couple laps to reach max speed and a 350' take off roll is what i'd expect from it as well.

RE: Cermark F16
 

Mine is taking off exactly lik this, so it's normal.
(and I have a Rabbit (19 lbs thrust)

RE: Cermark F16
 

Don't be afraid to pull up hard on the elevator to get airborne!!!! 350" sounds like a lot for such a light airframe. Mine had an old Simjet 1200 (12# on a really good day!) and it would take off in about 200 ft, almost full up-elevator required. If your model kinda slingshots into the air, you have too much airspeed built up.

The F-16 will not stall on takeoff, just force it up as soon as you see it doing 30-40 mph. Remember to drop the nose some after takeoff so you can build up speed. You can really do some nice scale takeoffs on the Cermark F-16.

Remember this is one of those models that just doesn' takeoff on it's own. If you let it roll down the runway, it will roll forever without lifting up.

RE: Cermark F16
 

I can attest that it will take as much runway as you let it, even with a large motor. (trust me, I've done it!) As Tam says in his manual, "DONOTrocket it down the runway like a heavy jet" (that's what Iwas doing too) Just hold full up as you start rolling, relax it slowly as the nose lifts off and you'll be flying in a few hundred - very scale-like take off. You'll probably be airborne in 200 - 300 ft using this technique. It's hard to trust that much elevator but once you do, you'll get a feel for it. Just another part of the viper "personality"

RE: Cermark F16
 

Although I have not flown mine yet, I agree with you all. Theorically it looks really correct that this plane needs high alpha to take off. It´s easy to understand it if we look to it´s landing behaviour. It needs nose up to have lift with not much speed on landings. The same way, to lift off at not a rocket speed it needs a nose up stance. The only way to get that is to hold much elevator up. And the same way it does not use to wing tip stall on high alpha landing, it won´t on take off. The only care is to let nose go down slowly after take off to allow the plane to accelerate. That´s just my theory opinion, don´t you forget that, I did not try it yet, but I will follow this theory.

Regards

RE: Cermark F16
 

Thanks guys,

Yhis is quite reassuring. Will do as you say and report back soon.

Regards,

RE: Cermark F16
 

Any Updates?

Chris

RE: Cermark F16
 

Bad news.

Lost my Cermark F-16 after only 5 flights (none of which where eventless). Never got bad luck with a plane/jet as much as this one.
Flown on a small runway and guess that CG was still much forward despite some weight put in the tail but i should have removed RX batteries from the nose.
Tendancies: although powered with a Rabbit (after the P-60 for the first 2 flights) F-16 had difficulties to rotate smoothly even after a runof 100 meters.
Difficulty to acheive high AOA or even keep the nose up to bleed the speed. Result landing fast (nose wheel blocked in closed position), hit the runway hard with the mains, dragged the nose and jumped back in the air to overshoot the runway and disappear in the valley. To make things worse, i hit full power hoping to see the F-16 reappear but instead it hit the ground at full power!!!!
One of the worst experiences i ever had in this hobby...

RE: Cermark F16
 

^ Sorry to hear that.

I have a question. Does the Wheels/Gear always stick out like that when retracted? I am asking because I would like to add a simple gear door system and from some of the pics in this thread it would appear as though the tires protrude from the lines of the under belly.

Thanks.

Chris

RE: Cermark F16
 

Christian, here's a couple of pics of my setup. It was very simple and very light. Notice the GIANT Simjet ECU, by far the hardest part to accomodate on that little airframe. :)
Wish I had more, but that's it. I think I had 9411's on elevators and Rudder and 54645MG's on Ailerons.
If you ask me, not worth it to add gear doors. The fiberglass is very thin around the wheel well, certainly not ideal for hinging doors. And no, the wheels are not supposed to protrude any.

RE: Cermark F16
 

BTW, Chris here are some pics of how your YA F-16 went. First is the pic shows how it made it to Tx, then the slow building process...........but it was a lot of fun. I added a functional operating canopy and scale cockpit. Rememembrr the wishbone in the back? Was never able to make it work without crushing the ducting..........so I cut it and added individual elevator servos. I really wish I had kept it for when I got a turbine, but back then it was just impossible to afford.

RE: Cermark F16
 

Thanks for the pics of the Cermark. The reason I want gear doors is because I just hate having those holes there, I don't mind reinforcing that area a bit to make this possible. Other than that, I love how the Cermark flies, based on videos of course. My Super Bee should be right at home in it.

Where are the pics of the YA? (OOPPPSSS...they just showed up..Lol)

I'm very interested in seeing how it ended up.

Chris

RE: Cermark F16
 

Sorry man, looks like Cermark is no longer selling their F-16. There is a Jet Legend for sale here that looks pretty good, and if I'm not mistaken it looks like the one that was built by drdoom (there is a whole thread about the buil-up).