I bought a Tomahawk Viper at the Jetpower show .
The build is very straightforward and very quick , really limited to radio and turbine installation and painting and I guess like most German kits deficient in instructions.
I have come to the point of gluing the ventral fins but have no clue where they are to be glued.
Has anybody built a Tomahawk Viper ?
I would like to know the measurement/location of the ventral fins from the rear of the fuselage and also would like to know whether the ventral fins are parallel to each other or at an angle
Xantos

Hello Xantos,

Do you have pictures of your plane ?

Thanks
Jean-Philippe

Take a look at Viper Aircrafts web site:

http://www.viper-aircraft.com/home_f.html

In the gallery there are some pictures of the Viperjet including a good tail shot showing the location of the fins.

PaulD

HI Xantos!

There is an english manual,send Thomas an e-mail.... Guess what:The only part missing is mounting the ventral fins . Damn, I knew I missed something...

We glued two short carbon pins in the fins, drilled the matching holes to the fuselage. They are parallel to each other. Just compare to pics of the fullsize.

We glued them after painting with contact-glue (UHU foam-glue). YOu can get them off easy, but they won't come of during flight.

BR,

David

Thanks Guys for the Inputs.
I looked up the Tomahawk website and found that Ventral fins seem to be a recent addition because there seemed to be many more Vipers without the ventral fins.

I finally called Thomas and got the details. so for those who might be building the viper here are the measurements.
The ventral fins are 40mm from the rear of the fuse at the step where the steel tube at the rear ends.
The two fins are 90 mm apart at the root where they are glued to the fuse and 140mm apart at tips.
I was planning to put in a Wren 160 but I saw one fly with a 120 yesterday and have changed my mind now , the 160 will be tooo much for this airframe.
The performance is marginal with a P80 but just right with a 120.
Xantos

Hey Xantos.

Thanks for the great information.
I will power mine with a P-120SE.
I ordered and payed the Viper at the Jetpower show but heard they will be available in januari......[]

Hi Didier,
Youll be happy with the Tomahawk Viper.
It flies great and builds very very quickly , you'll probably spend more time painting
I'll post some pics soon

Xantos

Hello All

Thomas told me the delay is very long !
You say that the building is very fast..what do you mean by "fast" ?

And does anybody of you have the electrical landing gear from GZ retract ?

Thanks
Jean-Philippe

i have a 2.5 meter one here didier
perfect for your Ollie

Hi Jean
By Fast I mean , Most of the work of gluing formers is done already,
The fit is very good and most of the work is limited to radio and turbine installation and painting
One of the Vipers here has the GZ electrical retracts and is working well so far .
I usin the pneumatic set made by Airtech Germany.
Xantos

Xantos,

Do you have any more info regarding the GZ retracts?

I am hoping to have this option in my Tomahawk Hawk but can't find anything about them!

Are they reliable? What size battery do they run off? Does the anti stall mechanism work? Does the unit sequence the gear and gear doors? Does he have the electronic brakes?

Rgds,
Mark

Haha, my OLY already gives my Ultra Lightning a great pushhhhhhhhhhhhhhh!!!!
I must say I'm very impressed with the big SM Viper and yes indeed the SM Viper desirves at least a P-200SX or AMT OLY.

Xantos, post some pictures of your Viper, will be great.

Hello Mark,

Xantos and i fly at the same field, a common friend of ours has the TH viper with electrical retracts, he has had around 10 flights so far and they seem to be working fine. He runs a 4s lipo around 3000 Mah which take care of the retracts and brakes. I do not know about the anti stall mechanism but will check with him. His viper does not have gear doors fitted.

Best regards
Chaitanya.

There is a nice video of the Viper on the Tomahawk site.
Looks very neutral to me.

http://www.tomahawk-design.de/html_e/videos/index.html

Very cute model.
Would go well with a Wren-70 or SS even.
Looking forward to seeing one in the UK.

Is there a wing-tip option ?

Hi Mark,
I havent played around too much or set up the GZ retracts but from what Ive seen they seem to be fairly reliable, they run off a 2 cell lipo.
The anti stall mechanism works well , if you mechanically obstruct the strut you can see the anti-stall mechanism work.
The brakes are electrical as well and completely propotional , I guess there is some kind of solenoid in the brake drum as opposed to a O ring in a pneumatic system.
As a system it seems to be working well so far barring a few issues we have had with poor electrical contact at the control unit , we had to wiggle the contacts on a few occasions to get it to work .
A Wren70 or a SS will fly the airplane BUT with marginal performance, with a P80 the vertical performance was very limited, IMHO it needs a 120 !
No wingtip options are available
Xantos

But obviously difficult to land short.

Mike

The flaps are not the biggest in the world.
I'm convinced with crow the airplane will be slower at final.
I'm a BIG crow fan, it works on all jets very good.

The little Viper landed much slower than that at JetPower. Just think the landing captured on video was not Thomas's best []

Hi Guys,
Landings are the best part about this airplane, it possibly the easiest jet to land
Im comparing with a Bobcat, Kingcat,Bandit and Rookie. It is not as speed critical on landing as these others.
The KC ,BC and especially the Rookie are fairly speed critical on landing and have a nasty bounce if induced by wrong speed on landing whereas the Viper is very tolerant.
You can come in 2deg nose down with full flaps and flare just before touchdown and the airplane sticks to the runway without a bounce.
You can really grease this one in !
The standard flaps slow the airplane well enough (with a P120 SX), probably wont need the crow.
Xantos

Jeanfi

I will pickup some models soon and will send you some pics of the kit

JPZ

here is some pictures .

best German quality

Looks good . Keep en coming.
Thanks

Christian.

Looks great, hope to get mine next week.
One question, I see on the picture the engine mounting is already glued in the fuselage.
Do you have any idea how to drill the holes for the engine mounting? It looks like a "mission impossible" job.
Or do you need a 90 degrees drill?

Thanks

this pictures is not from my viper , i wait my in few weeks .

here is the engine instalation manual from Thomas ...........

Turbine-installation
For a light and strong fuselage we decided not to go for a turbine-hatch. The canopy is big enough to work on most of the parts. There are two ply-plates supplied to mount the turbine. With a Booster G-80, the plates should be mounted on the rails of the turbine-mount. Make up your mind to either use wood-screws or bolts with blind-nuts in the turbine-plates. Mount the tailpipe to the turbine-plates. Again, using the Booster G-80, the distance between the rear turbine-case and the front of the tailpipe should be 20-25mm (4/5 to 1 inch). It might be necessary to sand the rear of the fuselage to accept the tailpipe. We cut it to about 5mm, just enough to fit and secure the nozzle provided with the tailpipe. Use small button-head screws and cut them inside the fuselage.