RE: Tomahawk Viper Jet
 

Yes, I installed standard type servo's JR8311 in the elevator.
The elevator surface is at least as big as my Ultra Lightning, not happy with 5kg servo's and P-120SE pushing this plane.[&:]
I really dont understand the manual says it is not possible, will stick out of the bottom?
Ofcourse you have to dremel the servo hole in the formes as its made for the mini servo's.
To compensate the heavier weight of the JR8311, I ordered carbon stab tubes. [8D]

RE: Tomahawk Viper Jet
 

nice work Didier ;)

please keep us update with your building stages .

RE: Tomahawk Viper Jet
 

Today I installed the air intake ducts and turbine.
As with all German manuals (only 4 pages), a lot of imagination is required.
But where is the fun if it go's to easy. :D
Luckely the thrustline is perfect. The turbine and thrustpipe are perfect inline compared with his Chinees big brother. ;)
pic1: Intake
pic2: Intake duct
pic3: Thrustline check, all satis!!!
pic4: Turbine mounting rails in progress
pic5: Turbine mounting rails complete
pic6: I thought it was a nice idea to make the turbine and thrustpipe as one unit. This way I get 100% perfect turbine/thrustpipe alignment.
pic7: See above
pic8: And voila! [8D]

RE: Tomahawk Viper Jet
 

very nice work Didier .

the Intake duct inclouding in the kit ?

you are not sleep last days ?:)


i found this video with tomahawk and skygate viper .




[youtube]http://www.youtube.com/watch?v=B5pCutjSPs8[/youtube]

RE: Tomahawk Viper Jet
 

Hey Christian, thanks!
The intake ducts are supplied with the kit, at least I think they are intake ducts as nothing is mentioned in the instruction and pictures. [&:]
Hope it is not a vital part for something else. :D
I noticed at the Jetpower all those Vipers didn't have intake ducts and I really think this looks much better then an open hole.

Xantos,
I noticed that the aluminium bellmouth is "pop-rivited" (don't know the english word) to the inner thrust tube.
As this is a high stress point (heath), I think about to replace this with a bolt/nut connection.
Does your friends have any issues with the thrustpipe anyway as it is build very light and really don't hope the innerpipe is made of titanium.

RE: Tomahawk Viper Jet
 

Hi Didier,
My kit doesnt have the intake ducts , but I dont think they are that critical.
Yes the alu belmouth is pop rivetted to the inner tube, I think the inner is tube is Steel not Titanium :D
Dont think the bell mouth inner tube joint is a high stress point as most of the heat is developed well past that joint.
No we havent seen any problems so far with the thrust tube and we are at the upper end of the scale with a P120
Im plannin to use a Wren 160 detuned however
Xantos

RE: Tomahawk Viper Jet
 

here you can download the font for Viperjet , the name of font is TOPSPEED :D:D:D

[link]http://www.fontyukle.com/tr/1,top+speed[/link]

[link]http://www.urbanfonts.com/fonts/Top_Speed.htm[/link]

RE: Tomahawk Viper Jet
 

any building update ?:)

RE: Tomahawk Viper Jet
 

Hey Christian,
I am on my way to Bahrain and Nepal.
When I'm back, I'll post some pictures. :-)

RE: Tomahawk Viper Jet
 

Is there a US distributer for the Viper?

K.O.

RE: Tomahawk Viper Jet
 

Great service here: http://www.altecare.com/tdviper.htm

RE: Tomahawk Viper Jet
 

FWIW,

I've been flying a Cermark ViperJet MKII for 4 years now, AMT Pegasus HP for power, Eagle tree hits 200MPH TAS, and it has the DS 3421MG in elevator AND rudder.

I run 6VDC and have the servo arm hole @ 5/8" from center, and 1 1/8" on elevator horn. This nets me mechanical advantage near to 100oz each side.

At 100% ATV it is Sooo linear high speed to full 3 point stall with spoilerons, I like flying my VJ more than the BVM KATS, however it sux down the kero,


I also flew it without the OEM ventral subfins for a while as they were heavy and I did not want the tail weight, I then added them back in as thin carbonfibre stock fins to cure a dutch roll wiggle in crosswind patterns, even @ high speeds.

RE: Tomahawk Viper Jet
 

Hi Didier!

Regarding your comment about the Servos. Well, we have decided to use the smaller servos, because it is not possible to use your solution in the kit. It looks as there is no gap between the elevator-skin and the servo. A slight difference in production and it doesn't work for the customer. I think the first production kits had a thicker Airex-sandwich, resulting in less space for the servo. Plus, there is no need to use a big heavy servo in this jet. I have pushed my Viper with all the G-Booster 80 can supply. That is the turbine-range the Viper is designed for, so if there is anyone wanting to put a bigger engine in it, it is to his own risk. I am 100% sure that the small servos work just fine with a 120 size engine. A 160 is double the power the plane is designed for and pure BS in my opinion....

Do you have any experience with the 8311 you are using? I only used it in a pattern-plane and had three or four gears destroyed. Didn't have that kind of experience since I quit rc-parachuting.

BR,
David

RE: Tomahawk Viper Jet
 

Is this build thread going anywhere!!

RE: Tomahawk Viper Jet
 

Hello David.

I hear a lot of comments that it is not possible to put a standard sized servo in the stabs.
Maybe I'm lucky with my kit but the standard servo installation was not to difficult to install.
Yes, we have a couple of Flashes flying with JR8311 servo's and it works perfect.
I believe if you say the smaller servo's works in the stab but the surface of the elevator is bigger then the elevator surface of my Ultra Lightning!!!
It gives me at least more confidence to put 8kg servo's in the tail then 3,5kg servo's.
I will use a P-120SE as I have this engine spare. I guess I can expect good vertikals. ;-)

@Silmaril: My Viper is at the painter at the moment.

RE: Tomahawk Viper Jet
 

Sorry, Just looking forward to this thread as it will decide whether or not I buy this Viper myself......thanks Didier!!

RE: Tomahawk Viper Jet
 

Hi
Mine is at the painter too so its been a little slow.
I've got the JR 3401 metal gear Servos for the elevator right now but looking at the possibility of squeezing in 8411s 0r 8511s
I have a Wren 160 detuned to 27lbs in mine.
Xantos

RE: Tomahawk Viper Jet
 

Xantos

The 8511 will not fit as this is the bigger case like the 8711.
We have a special on the 8411 servos at £60, so they are perfect!

regards

Dave

RE: Tomahawk Viper Jet
 

Thanx Dave,
I'll try squeezing in a 8411
Will order 2 x if its possible
Xantos

RE: Tomahawk Viper Jet
 

[quote]ORIGINAL: Xantos

Hi
Mine is at the painter too so its been a little slow.
[>:]

RE: Tomahawk Viper Jet
 

This Viper is awesome.
I've seen a couple of these flying at Jetpower and it looked great.
Now you also have the 2m Skymaster Viper ARF and according to Ali (Als hobbies) this baby Viper flies awesome as well.
Some facts or at least my opinion.

-Both Vipers fly's great judged from video's and heard.
-Tomahawk Viper: This is not a chinese ARF but the best of the best quality molding and very light. It's more a "sportscale" plane, no geardoors or other scale details. Needs some improvisations of the builder as the instruction manual is poor. Need to be painted.Relatively expensive
-Skymaster Viper 2m: Skymaster is good quality and "ok" moulding quality. Its a ARF and very complete. Very nice paintjobs on Skymaster jets. A little more scale details like geardoors and cockpit etc. Not very expensive.

Maybe Ali can jump into it as he is dealer of both Tomahawk and Skymaster.

RE: Tomahawk Viper Jet
 

Hi Didier
As you mention I am a dealer for both Tomahawk and Skymaster, and proud of both lines. I think its quite well documented around here how happy I am with the Skymaster 2M. Regards the Tomahawk model.. Well I really cant tell you much other than what has been mentioned on these pages. The reason being that I have not flown one as yet. :(
The truth of the matter is that the Tomahawk is, as you mention a kit that requires building and painting. At this time, all my builders ( and more importantly my painter) are back logged for quite some time. The painter has at least 5 projects in the line waiting for some bench time.
I can say that the construction of the T Hawk viper ( particularly the moulding) is above and beyond the skymaster version. Stronger, neater and a near perfect finish in the mouldings ( From what I saw at Jet power anyway) Also the T Hawk viper is designed around a set of trailing link gear which I am sure will make it more suited to grass use, although the 2M I am sure will not struggle. Plus there is bound to be a set of riling links that will drop fit the 2M.
I look forward to getting some stick time on a T Hawk viper one day to make it a true comparison.
Regards Al

RE: Tomahawk Viper Jet
 

www.vogelsang-aeroscale.com

RE: Tomahawk Viper Jet
 

Good job Didier, but I wanted to ask:(the few instructions, Thomas writes that the model weighs Tail)
Putting the turbine in this way, as you are with the cg?? or however you are obligated to put in that position because of the reference thrustpipe. Thanks Davide

p.s.: sorry for my bad English!!!!

RE: Tomahawk Viper Jet
 

Could someone help me out? I need to know the combined intake surface area (in cm2) of the Tomahawk Viperjet and the exhaust diameter.

I have a Schubeler DS94HST fan that was destined for an Aviation Design Scorpion (EDF version) but the vendor has let me down and will not be delivering it.:( Painful story behind that which I wont both going into. [:@]

I need to know the intake/exhaust size before I place the order for the Viperjet to ensure the EDF system will work efficiently. Any help would really be appreciated.