NightSwan

Hmm.. even better!

jclittle

My Feedback: (99)

Eagle Driver

Vertical

snobird

My Feedback: (36)

Mine landed perfect without half a fin and no rudder.. try it a little nose heavy until you get used to it...

Matt Chapman

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Well after lots of delays...work....life....my Viper is VERY close to being ready to fly. I had the help of a BVM rep today getting the first run on my P-160. VERY cool indeed. (my first jet)
While i dont have the cockpits fitted yet, Im wondering about the CG. I'm running two Duralite 4300mhr packs and a large pack for the engine. both the flight packs are up in the nose gear area and the engine pack is at the aft bulkhead of the nose gear area. (for now) I measured the required 220mm to 250mm Cg range. Being by myself, this was tricky, but it would appear as if im in need of about 28oz of weight in the nose. Seems like a lot to me... just under 2lbs... hear others are not using any weight...

Whats all of your experiance out there? (gear down, UAT full, ECU under the aft cockpit, 3 batteries up front) What has your experiance been with factory CG location?

Out doing shows the next two weeks, so no first flight until then, but will have time to button up the small items and get the plane balanced.

Look forward to the input.

regards,

Matt

heraldoboldrin

I dont know my CG as i bought the jet used.. but i have two big NIMH batteries 330mah each in the nose and a 5400 lipo battery for turbine in the nose too..
The turbine is in the maximum front position.. touching the air intake..

CraigG

My Feedback: (40)

Matt,

28 ozs does not sound right. I have two 2300Mah A123's and a 10cell Nicad up front and mine balances right in the middle of the cg range. The cockpits and a pilot will definately help but not 28ozs worth. Because of the curved bottom of the Viper, it is difficult to place balance points and it is definately a two person job. I suspect your initial balance may have been off.

Craig

jclittle

My Feedback: (99)

Matt, I heard from John B that you were getting close! My CG is exactly in-between where Anton recommends in the manual. All batteries are up front (2 - 5200 mA Li-ions and 1 - 2750 mA LiPo), gear down, UAT full, and all turbine related equipment is under the turtleneck just behind the cockpit. With this set up I needed to add 3 oz in the nose. Definitely fit the cockpit before doing final CG, this along with a pilot will make it nearly right without adding any additional weight. I made a stand to balance my larger planes without a helper, photo is attached. Set your elevator movement to 25mm, this is perfect for landing with minimal expo. The Viper will balloon on you with too much elevator and expo.

Did you do the mods that were recommended in the various build threads? Specifically the rudder? I also added additional glue to the windsheild as I had one come out in flight several months ago. Not the canopy but the windsheild.

Enjoy your Viperjet! Its a great flying jet.

jclittle

My Feedback: (99)

A video of my ViperJet, complete with deadsstick landing at the GA Jets Super Jets South last week. Filmed by Jim in Kentucky (thanks Jim).

http://www.youtube.com/watch?v=bZoNtumTfIA

norbert montenegro

Very good video,congratulations.
Norbert

Ali

My Feedback: (5)

My latest little viper mod, and an oldie that is really worth making sure you do........
I found the canopy frame very flexible one the lower cross braces of fiberglass were removed. This made handling it when it was off the model tricky and after a few " Harder" flights ( Especially those with snap rolls ) I found the rear edge of the canopy frame starting to open out. I didnt deal with this quick enough and ended up with a tiny hair line crack in the very top of the frame where it had opened out more and more.
My fix was to put a cross brace in. What I used was a 3mm carbon push rod with a threaded adapter at both ends, with a clevis attached. This was I could adjust the length of the cross brace a little to get it just right. I then cynoed, and rocked powdered the very top domed part of two fiberglass servo arms into the corner of the frame as attachment points. Job done! The frame is allot stiffer now, nicer to handle when off the model and can not open up in flight.
The oldie to make sue you look out for is to make sure that you gently heat the flap faring attached to the flap surface which lips below the top surface of the wing, then while warm flew it gently so it rolls under more and clears the top skin of the wing. From the factory these tolerances are a little close and I have found in flight that with a little wing flex the flap can actually catch the wing as they raise. On more than one occasion I have had it where one flap has caught and not gone fully up. Causing the model to roll a small amount in flight, ruin that flight, stall the servo and damage the wing skin a little. A gentle warm with a heat gun ( Go easy as its thin glass in that area ) and a tweak down has it sorted.
Hope these mods are of some help

extra 300

My Feedback: (3)

Ali,

Thanks for the mods. Could you please provide a photo for the canopy mod although your explanation is quite clear would like to see exact location of cross brace.

Thanks,
Best regards,

Ali

My Feedback: (5)

Not a very good photo I am afraid but it will hopefully give an idea, if not I will take another later on.

extra 300

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Thanks Ali,

I think i get the picture. Do you think that a carbon fiber layer with resin on the inner side of back former of canopy to stiffen it would do the work??

Thanks, Regards,

Ali

My Feedback: (5)

yep I am sure that would help but the carbon rod is just as if not more stiffening as well as being super quick to do.

Also another bit of good news for all you Viper jet owners out there... I have had Pull Over products in Germany make me a gorgeous set of padded and lined custom bags for the wings and tails to help protect your pride and joy.

Two piece wing bags securely clip closed and even have a slide of wing tip protector.

extra 300

My Feedback: (3)

Very interesting. What's the budget??

Regards,

Carsten Groen

The bags are great Ali, I got myself a set for my Viper at JP also (and when I saw the quality, I ordered a set for my Eurosport also )
Regarding the canopy brace Al, what have you done in the front of the canopy ?
There is a cross brace in fiberglass when the canopy is delivered, I looks like on your pictures that it is removed ?
I'm afraid that removing it will make the canopy blow of in flight ?

gonzalom

My Feedback: (1)

Hi Ali,

Thoese bags for the Viper looks super! where can I get a set?

I finished some new helo projects and now I am full throttle to get my Viper in the air!

Regards,

Gonzalo

Ali

My Feedback: (5)

Gonzalo Hi
I am selling these bags and have just last week sent a set to Rob Lynch in Florida.
Regards Al

Email me direct for costings [email protected]

extra 300

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jclittle,

Great video. I noticed that you're gears retract slowely (very realistic) what valve system are you using?

Thanks, Regards

extra 300

My Feedback: (3)

Can anyone advise how slow can the Viperjet land?? What about the stall characteristics??is it safe to fly out of a 300 feet paved runway?

Although they might have nothing in common, how would you compare the Viperjet landing compared to a Boomerang XL landing.

Thanks for your input and experience.

Best regards,
Dany

jclittle

My Feedback: (99)

I'm out of town at the moment but I'm 99% sure its a UP3 valve.

heraldoboldrin

Dany

I never see a Jet with better landing caracteristics than Viper.. with a P160 i use more or less 300 feet to take off, but i never push it to the limit, like giving 0% to full power in 1 second...
Go on with the viper.. you cant find better and so beautiful jet

"Thanks again Ali.. mine has 45 perfect flights in my hand"

regards

Heraldo, from Brasil

jclittle

My Feedback: (99)

As others have said it lands very nice and easy, I personally would not fly it from a 300 foot runway as it does have a tendency to float. Our strip is 1000 feet and I use just over half most of the time.

Carsten Groen

Ali,
have you done somthing with a brace in the front of the canopy ?
There is a cross brace in fiberglass when the canopy is delivered, I looks like on your pictures that it is removed ?
I'm afraid that removing it will make the canopy blow of in flight ?