Si_B

Had all the air pressured up today. Front nose leg is locked but still seems to have more play than I'd like. All works as it should but might drop front retract out just to double check. Other than that, we are getting close to my maiden. Kingtech 80 fired up perfectly this morning and seems to have plenty of grunt.

Jason R.

Best of luck when you maiden it. They do handle very nicely. I like the colour scheme also.

Jason

Si_B

I am looking forward to flying this. Will post back, good or bad.

Simon

scaryxxl

Hi there my friends. I just buy a viper jet all assembled from factory ,servos lights smoke trains etc. And I have some questions.
I have a jetcat p100rx for this plane but I think it will come from factory assembled 2l of smoke tanks and I don't know if with full tank and full smoke oil with lights system etc will enough thrust for the plane.
And also I read several threads about the CG of the plane. Do I have to center the CG as the manual or do I have to move? Thanks a lot for the infon

gsmarino2000

My Feedback: (2)

The P100 should have plenty of thrust; my K100 flies the Viperjet with authority. Like a lot of others on this thread, I run fuel in the two smoke tanks and in one 1.5 l tank in front of the intakes. I'm using the front corners of the engine access hatch for Cg. Measured with the UAT full, fuel tanks empty and gear down. I look for just a bit nose down when supported at the corners of the hatch. That is also a consensus of this thread. The plane is not overly Cg sensitive but I wouldn't go further back than the hatch corners.

Greg

Jason R.

Totally agree with Greg about c of g and engine will be fine. I also fly with a K100 and i carry 3.6 lt of fuel.

Jason

scaryxxl

Thanks a lot guys for the info you all are great!.
I am worried becasue in jetlegend website it says 11kg dry if I put the fuel and 2l smoke oil + lights +etc I don't know the total weight to takeoff.
this is why I was asking you.
also can someone take a photo showing where exactly do I have to mark the cg of the plane?
thanks a lot again!!!

Jason R.

Hi my viper came out at 9.3 kg dry. The C of G can be seen by the red lines at front of hatch.

You can get a pdf file called Bz78178 from post #417 on page 17 of this thread. The file is listed by essyou 35. I hope this helps. Mine is basically set up with this set up except i have 60 mm flap deflection.

Jason

scaryxxl

Fantastic Jason!
thanks a lot !
Hope this viper fly well!.
Is there any image that shows how will come my viper with all installed from factory? to know more or less how it will come?
with lights, smoke system servos valves etc? does it comes with UAT ?
the jetlegend lights system are these one?
https://www.youtube.com/watch?v=BDtrB5LhrI8
thanks a lot.

Jason R.

My viper came Pro wired with lights, but not like the lights in the video you listed. The strobes in the wingtips flash once not twice, the red flasher behind nose wheel is solid on but behind wing on mine. The landing lights are on the undercarriage and are rather bright. It did come with fuel plumbing all done and a uat but i was not fussed on the setup so i replaced the uat and changed the fuel line. Valves were all installed and ready to setup in radio. These are the pics they sent me of mine before they sent it.


Jason

scaryxxl

thanks a lot Jason you are great!

gsmarino2000

My Feedback: (2)

I know that the JL UAT looks a bit crude, but it works just fine. I used it my first viper for ~ 46 flights and never an issue. Mine was cracked in my cornfield landing. Since I just bought a bare airframe on my new one, it didn't come with a UAT so I used a Hanson. No difference in performance as far as I can see, and if you are going to use the stock equipment tray it fits the JL.

Greg

scaryxxl

Hi there I just recived my viper jet from my dealer in Holland. the PNP version

But there is no manual and no spects from lights, smoke pump etc...


the pump works in HV 7.4v??
the lights works in HV 7.4v?? and how can I setup them?
the elctronic air valves works in HV 7.4v?? and how can I setup them??


And also does the lights have 2 switch position or are all on or all off ?
thanks a lot.

Jason R.

Hi scarryxxl,

Not sure about the latest valves and lights but mine are for 6.0v. the lights have one lead to Rx power the other is for landing lights and that connects to undercarriage. If you need more detail on it let me know and i will get the controller out and take a pic and label for you.

Jason

scaryxxl

hi there Jason
yes will be fantastic if you can post a pic for me!
thanks

gsmarino2000

My Feedback: (2)

No manual is typical for jets. This forum is better than any manual IMO, however it does take some time to dig through it. I don't have the lights, but I run everything on my jets and gas planes with redundant 2S LiFe. The voltage on LiFe is enough lower that it's within the range of nominal 6V NiCd and NIMH packs.

Greg

Ceeray

Hi. Just wanted to comment here.. 2 years ago I was thinking about buying my first turbine jet. I ended up getting JTM viperjet which is similar sized as JL.

In overall it is a great looking model with gear doors and all but needs more building.

And wing structure is NOT strong enough.

There is only 4-5mm wide balsa main spar , chinese soft wood, between airex wing surfaces.
I lost my model at beginning of flight 15. After a several spins I leveled out and started to make snap roll. I barely touched the controls as wing blew up with a quite spectacular bang.

I managed to shut down the turbine before impact. Plane and some other stuff a total loss. Turbine and radio gear salvageable, now in repairs.

It flew really nice until then. But wing structure is not strong enough for turbine use.
What kind of wood is used in JL viper and has anyone tried snapping it?

Mine had a little excess speed at start of snap, 100kts...

gsmarino2000

My Feedback: (2)

Ceeray,

Sorry about the loss of your JTM Viperjet. I have had no issues at all with the Jet Legend version, however I normally fly pretty smoothly. I will say that there are quite a few of these flying and they have a very good reputation for structural quality. The wing skins are a foam composite, but the interior wood appears to be good quality and the overall structure seems quite solid.

Greg

Ceeray

I btw just bought a set of pull-over-products wingbags and tail covers before losing the plane. They might fit JL right on if someone needs. Out of Europe shipping might get too bad.. pricewise.

Jason R.

Here is the unit i have in my viper for lights. Mine worked fine for about 5 flights then the landing lights stopped working, I contacted supplier and they sent a new one to me and the same happened to it. I thought that i would try the throttle selector side as if using AB ring. I swapped a couple wires around and it has not missed a beat since, a little over 100 flights on it now.



Jason

AlW

My Feedback: (17)

A couple of months ago I had the chance to get a first hand look at the inside of a Jet Legend Viper wing. One of my flying buddies destroyed his Viper and one wing was all that remained in one piece. We took that wing and sectioned it into eight or nine pieces using my band saw. I am a retired structural engineer with (36) years experiance with Boeing and I can tell you that the Viper wing is well designed. The quality of the wood was good and the spars and ribs etc all had good glue joints where they interfaced with the skins. I paid particular attention to the structure supporting the mainl wheel retract and found it to be well designed using good quality aircraft plywood. The wing is quite heavy and some weight could have been saved by using lighter structure outboard of the retract area where the landing and flight loads are reduced. All in all I was very happy with what I saw! I recently completed my JL Viper in the Ferrari scheme so I had a personal interest inlooking inside this wing. Al

barger

Thought you guys might enjoy this more than my neighbours ....kingtech k100g on diesel and jet legend smoke pump burning straight diesel


https://www.youtube.com/watch?v=NlRy-3OHBfU

essyou35

My Feedback: (11)

Well Ive had my viper for over 3 years now. Lots of flights (500?)

Unfortunately tonight I went to take off and it would not steer and it ran into some tall grass. While its not destroyed, the front gear pin sheared off. I have no idea what happened.

I decided I can no longer keep up with my jets. For the first year or two this jet didn't need much but it starting to require more work. Further with every single little part having a $40 EMS overhead charge I cannot afford it anymore either..



Look for it on the classifieds I sells things cheap. Usually gone in a day or two.

barger

That sucks....why dont you sell off some other stuff and stay in it.?

scaryxxl

Hi there all my friends! tomorrow will be the maiden flight hope all will go fine...
One more question the break valve form jetlegend factory is it possible to setup it like ABS system not 0 to 100% I want to be a gradual brake not so hard.
please If someone can help me will be fantastic

thanks a lot