cel

Hello good job. I have interest in a Viper. What are you thinking about it ?? Quality ???
Regards Celso

kasi122

Hi Ian,

Did you fix the tanks a second time or do you think it is good as they are?!

Ian Prentice

Hi
I would say the build quality is good, it seems to be built nice and light , considering it is sprayed out of the mould!
regards the tanks I plan on using the two ply stops provided and maybe 2 carbon tubes fixed along the top of them in the tank recesses, I cant see them going anywhere fast as you have all on to remove them! got to say I am really looking forward to flying it!

sidajili

My JL Viper package arrived today. I bought the Turnkey package with smoke system and T12 pre-installed. Also comes with 4000mAH Li-Po battery. I all i need to do is hook up a receiver and assemble the wings and stabilizers.... very nice. I could not find any manual in my package and the information and pictures in this thread has been very helpful. Would be testing out the Jet in a couple of days. Anyone know the CG of this jet?

sidajili

Hi William,

What smoke oil did you use in the flight video? Did you seperate the Rx battery and Smoke system battery or you are using the single battery suplied for both? Thanks


Sunday.

madmodelman

The cg is printed smack on the mainspar

sidajili

ahh, right! Thanks!

madmodelman

Btw, there is no manual with the kit, I was advised by the factory to use 30mm t/off flap and 60mm landing, I assume this is because the main tanks are ahead of the cg. All other throws are pretty standard,
Gary.

ceffi

Hi all,

this Saturday should be the maiden flight, but the weahter condition is very bad.
Rain and a strong wind.

I installed landinglights in the wings.
I used little reflectors and very strong 5mm LED's. The LED's can be powered with 1S LiPo.

Christian

Chris Pyrah

THISISAREALLYINFORMATIVEBUILD/ASSEMBLETHREAD,ITISMYFAVOURITE
Cant wait for my Viper to arrive

sidajili

I will maiden my viper Sunday morning. I did the CG balance with the header tank full and the main tanks empty. I think the viper will take off nose heavy after the tanks full. Hoping for a successful maiden and will post video.

steve2972

My Feedback: (2)

Good luck on the maiden,looking forward to flight report!

keweiliang

Hi Sunday,
My smoke oil is diesel.There are two2SLIPObatterys in my jetlegend viper jet,each one is 4000mah.One battery suplied RX and smoke system.The other suplied ECU.
My RX is FUTABA 6014HS,directly supplied by the 7.4V LIPO battery,do not need BEC.Btw,the smoke system should be powered by battery directly, no the RX.You just need
to take the smoke system signal line access line the RX.

Regards
William

sidajili

Hi Wiliam,

Thanks for the information. Did you mix the diesel with other oil? Your smoke really looked good.

Never new the throttle cable from the Turbine is able to supply power to the receiver. We just finished the succesful maiden flight and I had a 12 channel spektrum receiver powered by a seperate 3300mA 2s Lipo. I needed some weight to balance the viper. I used extra 2 more batteries (redundant and not used) to balance the cg for the maiden. With the header tank full, main tanks empty and 4 lipo batteries (1 Turbine, 1 Rx, and 2 unused), it was about 100g or so nose heavy. It will be more nose heavy at full tank. The throws were set as follows:

Elevator up anddown 20mmFlap take of 25mm, landing 65mm.

The shock oil on the landing gear on my viper came short. We noticed this only this morning just before the taxi test. We had to improvise and fill the nose gear using brake fluid as this was not expected. I would advice to check that your struts are all firm and refill the oil if neccessary.

We did two flights succesfuly, each lasting about 5 minutes. Tanks were down to just half, so i guess 8-10 minutes flight is possible. I handled the camera while a friend more experienced that me with turbines handled the maiden for me. The bird is all trimmed and I hope to fly it next week myself. Overall, the viper performed great and the flaps were really effective in slowing the bird down.

I will post the maiden flight videos once I get off the camera. The JL Viper is really a great trainer jet. Only took about 4 hours of work to get the turnkey version ready for maiden. I like the fact that the ECU is built into the turbine and there is only one fuel line to connect. Nothing complex! The spark T12 trubine started with no issues. Turbine response time to throttle movements is really good. Am happy with the JL Viper and it looks like this bird and i will be heading to the flying field more often!

Ian Prentice

Congratulations on your maiden !its always nice to get the first few flights out of the way !
Regarding the landing gear ! If it's the same as my JL mig they are pressurised ! There is a threaded hole at the top of the leg that you can top the air up with! I may be wrong as I have not stripped my legs yet !!

sidajili

Hi Ian,

Honestly I wasn't sure whether its air pressurized or oil filled while at the field. There is a threaded hole that i used to fill the oil. I have not filled the rear landing gear yet so I will double check later and confirm.

I will also be working on the wing lights and fitting a gyro to the nose wheel steering before the next flight.

Sunday.

TimWatson

Looks like the quality of jets and the amount of work being done for you is getting better and better all the time

keweiliang

Hi Sunday,
Congratulations�looking forward to your flight video!
My smoke oil is diesel only，no mix other oil.
William

sidajili

Finally got the videos ready. The first and second flight video is posted full time with no edits.

Problem with the nose gear before the maiden is here:
[youtube]http://www.youtube.com/watch?v=Zl6U4FvKsIU[/youtube]

Maiden flight video:
[youtube]http://www.youtube.com/watch?v=dY0pE-rnXhA[/youtube]

Second flight video:
[youtube]http://www.youtube.com/watch?v=WnphYnIFBEU[/youtube]

Summary and highlights of the day:
[youtube]http://www.youtube.com/watch?v=iCXAGWZinR4[/youtube]

I am grateful to all the guys here for the information shared.

Sunday.

sidajili

One more modification i need to mention - The turnkey version did not come with a FOD screen for the turbine. Where we fly has small stones on the run way and the risk of getting a piece sucked into the turbine is very high. A FOD screen was fitted onto the T12 turbine and mounted back.

cel

Hello Sidajili. Congrats for your maiden flight, i am happy everything went well. I am interest in this airplane. I would like to know your comments about the airplane ( paint quality, hardware, overal fitting and flight characteristics)Best regards. Celso

sidajili

Hi Celso,

I bought the turnkey version with smoke system, turbine, retracts, servos all pre-installed. Cost wise, I think the turnkey version is the most cost effecttive. Iam personally satisfied with the paint quality and fittings. Am certain most modellers will be more than happy with the painting. This is a high performance sport trainer jet that meets my personal requirements.

1. Quick Build and simplicity: I wanted something good that Ican put together in a short time. I will tell you something. Istill work and have very little time to build models. I can put in only about 4 hours work on a model per week, after business work. I have a JL L39 Albatross with K170F yet to start work on. Ihave a falcon 120 with K80F work in progess for 3 months now and still not finished. I have sky eagle 1:6 MIG 29 VT with dual K170F, work not started. I have flash jet with K140F, work 96% done, yet to maiden since 1 month now. When I bought the JLviper, I planned to start work on it by October. My friend and I unpacked and saw everything so neatly done and wired and we said, hey lets fly this thing. Same evening, we put in a 12x receiver and bolted up the wings, rudder and elevator within an hour. In another hour, the controls were sorted out ready for adjustments. Only 4 screws to fix! Next day, another 2 hours on and the FOD screen was fixed on the turbine, throws adjusted and CG checked. The landing gear is simple, no gear doors or complex sequencer system. The turbine wiring is so simple - ECU is built in and only one fuel line to connect. Two tanks for the fuel and UAT all done neatly. The smoke system has two tanks as well. Brakes and retract uses electronic valves - my preference. Further, the nose wheel steering has a servo directly on it fixed and does not use the cable system. No need for complex power box system, just hook up a 9x or 12x receiver of your choice. Trust me, the JL viper is so simple that I will advise this for anyone moving from electric to turbines.
2. Finishing - look around this thread for the different schemes and you will agree the finishing is good. The videos show this.
3. Performance - My buddy flying the viper for me never went beyong 60-70% of the throttle through out the flight. The weight to thrust ratio is good. This is a high performance jet. 12kg turbine for this weight... too much power to intimidate gravity...
4. Simple to fly: Take off landing just like electric Habu 32. Landing gear high clearance and wide spaced makes it stable during taxi. I did not fly the maiden but I can tell my buddy was in control and enjoyed the second flight. Maiden flights can stretch nerves... I will fly the jet myself next week
5. Simple to transport: Quick disconnect the valves, remove the wings, and this jet fits to a car you can fold the back seats.

Only issues with the JL Viper -

1. No Manual!!! I hate to make guesses and this time, another good product with no manual. I guess JLfeels its really simple enough... I need an 'idiots manual' with nothing assumed for my models especially when lots of $$$ are invested in it. Had to ask around the forum for CG and throw rates.
2. No FOD screen for the turbine. I prefer my turbines protected. Plan to get one installed
3. Icould not see either an electronic or manual fuel shut off valve. Perhaps there's an electronic fule valve for the turbine built in, am not sure. If i find there is none, I will have at least a manual shut off valve installed. I am more comfortable this way.
4. Can't just find any other problem or issues. I am happy putting up this bird in the air successfully just 2 days after un-boxing! And the performance? Exhilarating!

If you are like me looking for quick build, get the turnkey version. I can assure that the assembly and painting is well done. If you like your own thing and want to enjoy the challenge of building and modelling, get the kit version and do your thing. If you prefer a brand of turbine over the Spark 80Nor 120N, get the version without the turbine.

If you are advancing from electric jets to turbine, the JLviper is a good consderation. If you are a pro, the performance from this jet will more than excite you. This jet is a joy giver!

Hope this helps.

Sunday Idajili.

mikedenilin

My Feedback: (67)

Here are some photos of Viper at Kentucky Jet. This plane is really simple to setup. We got it on Thursday and made it ready to fly by Sunday. The T12 turbine is very powerful. This plane has unlimited vertical and you will really need to throttle back otherwise it will disappear on you quickly. I think a P100 or any 100N size turbine would be ideal for this Viper.

This plane is a great step forward to meet pilots, like me, who don't have the time to build or just want to fly.

Mike

cel

Hello Sunday. Thank you very much for your complete explanation about this jet. I am something like you, i do not have much time for building jets. I have spare time on weekends and prefer flying rather than spending hours and hours on building a model. I am really getting in love with this model , as it is beautiful, simple to operate and put together and is also a scale jet. Thanks again and i wish you all the best with this jet. Regards - Celso

cel

Hello Mike. How are you doing ?? I am Celso from Brazil. Do you have videos??? Regards