Carsten. Congrats on the maiden. Looks like the canopy blew out. There is a lot of pressure inside the fuz when flying, especially with the P200 speeds. I added some epoxy all the way around mine. I also cut a circular hole about 1.5inches diameter at the rear end of the fuz just below the rudder to release some of the pressure. I also opened up the holes in the rear thrust tube former as much as possible. This was originally done in an attempt to prevent the gear doors opening when flying using the standard door cylinders.

Regards
Jim

Thanks Jim,
yes, that might have been the problem in a nutshell!
I didn't make any "flat out full throttle" passes, only time the left stick was in "on" position was in a climb, so I didn't go too fast (I think )

As I have a large thrusttube, that closes the rear of the fuselage completely, the only escape for the incoming air, is thru the thrusttube !
So the 1.5" inch hole you have made, that is between the rudder and the exhaust ?

Another one is if the inlets are too small for the P200, but I guess that is not the case ? (could have "sucked" the canopy glass in), one of my friends have problems in a Dragon, when the fuse is closed up (hatch over the front wheel), the fuse is sucked in at full throttle

Yes. The hole is just above the exhaust. There is a triangular flat part there & I cut the hole in the middle. If your gear doors are opening in flight, it is unlikely to be a suction effect on the canopy. I think if that was so, the gear doors would stay shut. If they were open & there was a suction effect, you would think enough air would get in through the gear door openings. Was it sucked, or was it blown?

Regards
Jim

Better keep this thread family friendly
Well, my first flight, one of the main retracts didn't close fully, making the wheel rest on the wheel door, so effektively the fuse was "open".
On the second flight, I think we saw once or twice one of the door not shutting completely, but that was at low throttle/speed, I _think_ that the doors was shut most of the times !?
Anyway, I will assemble the plane again, have the gear retracted, and fire her up, full throttle, and see what happens....

Just removed the rest of the canopy glass from the frame, the glue Skymaster uses, must be expired....it is very very bad, the glass comes off almost just looking at it, dammit I didn't check that better before the maiden

Sandor, have you soon looked thru your boxes , I need to go flying [8D]

Hi All
I recieved my Viper approx 6 weeks ago and have not seen this posted before there is a blind nut in the fin approx 25mm from the front carbon post and also a corasponding hole in the fuse the photo and the arrows should be self explanitory this provides 2 hold down points and makes the rudder very solid it is not mentioned in any instructions ( this may be a new mod)
Also if you trim approx 2 mm off the trailing edge of the fin as per arrow at the hinge line you do not need to use mounting blocks for the hinges as the hinge centre point is corect and all the paint lines line up. hope for those that are interested the photos are self exsplanitory.

Cheers Bronte

Hi Bronte. This is a new mod. Skymaster will be constantly improving the Viper based on the experiences of us who fly them. I am sure the gear doors will also soon have modified cylinders. Enjoy your Viper,It is a winner.

Regards
Jim

Bronte, I received my Viperjet at the JepPower fair in september. The T nut was also on mine, makes the vertical sit very secure!
However, the trick with removing 2mm on the lip at the rudder, would not help me, I had to mount blocks of varying thickness to align the rudder correctly to the fin, otherwise the top "horizontal part" of the rudder would not "lay flat" on top of the vertial stabilizer.
But, whatever you do, make sure there is wood inside the surfaces for the horns! The last 3 we have here in Denmark had none (or only some), and glue that canopy glass securely, and don't trust the chinese glue used

I just had the parts on a weight:

Fuse: 13.3 Kg (incl UAT, 125 mL)
Hor stabilizer: 0.8 Kg
Right wing: 2.5 Kg
Left wing: 2.5 Kg
Wingtube: 0.3 Kg
2 x Pilot/"bathtub": 0.8 Kg

Total dry weight: 20.2 Kg
add 4.2 ltr fuel, weight 3.4 Kg

Total AUW is 23,5 Kg (approx 52 lbs)
This gives me 1:1 in thrust/weight right from takeoff, nice!

John, I follow the fishing technique but not good results so far...... any advice? or do you guys have some sort of drawing? are you guys doing the airlines too in that way? I didn't used a chain... instead a wool line with a nut at the end..... I am a good fisherman but I don't seem to get this one.

Regards,

Gonzalo

I have read that most guys are not bothering with the bypass set-up. With the internal fuse pressure issues would it not make sense to install one?

PaulD

We were commenting on that just the other day Paul. I have fitted the bypass with my 160, but i think the supplied bypass would be too small for the oversized turbines some of the guys are using.

Duncan

I'm gonna fit a bypass to mine. Not to that stage yet now, but I'm gonna do a simple mold and carbon/glass layup of a bypass for a p200

Should be a bit better for the blowing out of doors.

If you don't want to build one yourself, I saw BVM has a bypass available for a P200

Hi ,Duncan :

Do you still have door problems with the bypass???

Regards

Mine isn't finished yet, but last night i moved the mounting point for the gear door ram and have changed the rams to BVM one's. Time will tell if it's going to work, but it looks promising

Duncan

Thanks Duncan .

Before purchasing a bypass from BVM, check to see if their system will fit/work in a Viper. I have a P-160 in my Viper and in one of my conversations with a tech at BVM, he gave me the impression that the BVM bypass would be somewhat difficult, if not impossable to install in the Viper without major modification. This is simply a heads up and not fact and I am not quoting anyone as saying it wont work. However, you may want to research before spending the money.

On a seperate note.... I have about 20 flights on my Viper now. Each one gets better and more fun. I have had no gear door issues as some have. I am not running a bypass. I still need to increase aileron travel to get better vertical roll rate.

Just my 2 cents!

Enjoy and happy holidays to all Viper flyers, builders and soon to be builders!

Matt

i am not using bypass as well with for than 50 flights...

Still at the building-stage, but I'm going to create my own bypass for a P200. Just because I can

No, really, because then it will be a good fit I hope, and because I've never done it before Should be a good excercise

Finished the rudder and elevator-halves. Had some trouble with paint letting go on one half (I think they forgot to degrease between layers), but I think I'll just get it to a painter and get touched up, no biggie.

Started fitting connectors for air and servo's to the fuse yesterday. Noticed a crack in the paint near the wing-root of the right wing that got me concerned, skin does not feel nearly as strong on that wing as on the other. [:@] Don't know what to do with that one yet. []

Other than that, it is a great looking airplane, cant wait to fly it. [8D]

Hi Matt,

What do you think is the issue/solution for others door problem .

Thanks.
Juan

Hi all,
finally I found a way through the wing for the lights and servo cable. As I thought the passage for the lights was simple but for the servo wires I had to use a little chain (no way in other ways) because in my Viper (we all know they are not all equal) there is a very tiny passage on the middle of the wing.
I have done a scheme hoping it will help[sm=thumbs_up.gif]
The question marks are "obscure lands"

Ciao
Alessandro

Alessandro, you lucky one

I didn't have that hole, I made a small hole right after the wing-tube to reach the leading-edge area.

Who know what my second wing will bring

Perhaps you will be lucky on the other wing.
Obviously I spoke too soon . I didn't found [sm=what_smile.gif] the "tiny passage" in the second wing and I had to do a third hole. So here it is the "unlucky scheme"

Ciao
A

Guys,

I built the following tool to make the holes.... it work so so nice almost like cutting a cake! I call it the retractable cutting tool. I made it of brass tube and shape the cutter with my dremel. My good friend John Dento gave me some insight of how to do it!!! Thank you John!!!

First you use the first part with the cutter and cut the wall of the servo box. You attached the second tube extension via the 3mm screws and cut the next former. Now you attached the 3rd extension and cut the last former. Then you use the fishing method and you are ready to pass the servo wires as well as retract tubes and break line! super nice!!! The first former is the one that it takes some time.... the last former is very thin.... piece of cake. Nothing to worry structually as the former are quite big for the size of the holes. I would love for SM to put the holes as I did. I didn't like the idea of the retract lines, break line and servo wires to go so close to the retracts.... now, I am happy!... second wing coming up.

Enjoy the pictures,

Gonzalo

I am so doing that, brilliant Gonzalo.

Alessandro and Gonzalo,

Thanks for the brilliant and usefull tips. [8D]

PaulD