A4Driver45

My Feedback: (7)

Sorry, Viper, not a Vapor....

Jeremy_D

A4,

Have a look at my picture in post 142. It is not a rabbit but a Jetcat but you can see where my solenoids are located. My header and pump are located under each engine mount on the floor of the fuse. Hope this helps

Cheers

Jeremy

A4Driver45

My Feedback: (7)

Thank you, I believe I have found a place for the turbine valves.

Thank you, for for the reply.

R. Kranz

dotdigital

My Feedback: (41)

Hi All, I am flying this bird and just added the factory smoke tank kit to it (with two saddle tanks installed adjacent to turbine). I am very concerned about what these smoke tanks will do for 'resetting' the C/G of the plane into a tail heavy situation. Can anyone with these tanks installed shed light on how and where you found the correct C/G to actually be? My feeling is if you normally locate the C/G with the hopper tank full, main tanks and smoke tanks empty/gear down... you will NOT get a safe reading for a C/G... as once the smoke tanks are filled they will indeed push the C/G aft. I realize this bird has a forward set of kero fuel tanks that makes it a bit nose heavy for take off but once you start loading fuel aft as these two smoke tanks offer- you may get a nasty surprise... which is what I want to prevent...
Anyone with experience on this ??? Please advise!

Thanks...

-Paul.

dotdigital

My Feedback: (41)

I believe the struts have springs inside of them... if so- the low strut just would need a new spring... I had this on a L39 out of the box... new springs fixed it.

essyou35

My Feedback: (11)

Hi, I am using fuel tanks where the smokes tanks are supposed to be, and only using one stock tank in the stock location. The reare tanks drain first, creating a more forward CG as you fly, and then as the main tank empties the cg moves aft. Overall, the movement is much less than the stock location.

Because you have so much fuel up front (nearly 5 lbs of it) if you balance your jet with your smoke tanks full, and your front tanks empty, the CG can never go more aft than that. However, if you balance everything empty (other than hopper) you can have an issue if you fly around and do not use your smoke oil.

So you have a choice, either have a way forward CG to take off with as designed that moved back as you fly (many do it this way). Or you need to ensure you always your smoke tanks in flight (gamble).

I think that with smoke tanks you are better off than those without smoke tanks and using the stock tanks. However, my (ok modelmancan's) modification give you the best option albiet no smoke tanks.

Apparently this bird flies with a HUGE cg range spanning nearly 6 inches. wow.

dotdigital

My Feedback: (41)

I like your idea of using the smoke tanks as the fuel kero tanks and just have one tank 'up front' for the smoke... it makes much more sense to me.... Where is your C/G set with this set up and do you make your C/G test as normal (no fuel or smoke fluid on board, gear down, etc).
THANKS!!!!

essyou35

My Feedback: (11)

Just to be clear Well what you do is use one of the stock tanks, in the stock location, and get two smaller tanks to put in the smoke location, ALL KERO. I suppose you could also put a smoke tank up the in front of the CG as well in the stock location where the other kero would go, that should work finel.

I have not balanced mine yet. Since the rear tanks are behind where the CG should be, one would think to fill them for balancing, but since they empty FIRST, you can balance with everything empty to be safe.

I used two 24OZ dubro tanks in the smoke tank position, and glued a strapping mount down for them, though the tension will be enough to hold them.

Because of my setup, I will start with the CG basically on the spot. Then as I fly, the CG will move forward as the rear tanks empty, then the CG will start moving back again after the main tank empties. I will also balance with gear UP since the front gear will move the CG back but I dont think its enough to matter either way.

The CG still moves but it is much less than the stock CG movement which is just find according to the people on this thread.

I will be using the stock location for the CG to start.


Check his post out here for more information:

http://www.rcuniverse.com/forum/fb.asp?m=11329045

dotdigital

My Feedback: (41)

I will utilize one if the original supplied tanks for kero and other fir smoke.
The rear saddle tanks will burn off first. I think this is how I will give it a go. What do u think?

essyou35

My Feedback: (11)

That will be fine, even if you burned off all the smoke right away. You have so much fuel up front and the rear tanks are barely behind the CG. If you dont burn the smoke, your cg will just move forward but never as much as the stock setup.

Just be careful to check the balance with fuel full and the smoke empty to see what effect that has. I think it will still be OK though.


There is room underneath the intake lip of the turbine for another smaller tank, that sits right on the CG. A 24 oz tank will fit. If I do smoke I will just use that and I wont have alot of smoke but enough. I am not sure how much smoke 24 oz will make though.

dotdigital

My Feedback: (41)

Thanks for the assistance. A 24 oz tank might give u about a two min thrill with smoke but depending on pump speed too.
Again, thanks!

essyou35

My Feedback: (11)

BTW I am VERY Jealous you liv ein Florida. Always fantasize about moving down there. I put off buying my YA f-18 just so I can take a trip there soon and get out of this cold!

dotdigital

My Feedback: (41)

I recently moved down here from North East and its paradise. Great jet field to fly too at Markham Park.

dotdigital

My Feedback: (41)

Does anyone on the thread have the Smoke system pump sold by GJC? I just got a smoke kit from Mike.. there is no info on how the pump connects, voltage reqd, etc and they (Global Jet) have no info on it at all. I d like to know what a safe voltage is and how the two leads get connected.
Thanks!

-Paul.

essyou35

My Feedback: (11)

There are people with the smoke system, I dont have it.

Does anyone have an opinion on the robart air quick disconnects? I have used them all last year and only had them come apart once in flight for no explained reason.

Being air up and down I wondered if maybe something better is needed....

Jeremy_D

Get the Jetlegend Air wire set. It works great with no leaks

essyou35

My Feedback: (11)

Does the valves the sell for it have the smaller nipples for the airlines or do you need an adapter?

Also what PSI do you pump your gears up to?

SKYPILOT

My Feedback: (9)

Guys, I put my Viperjet in the AMA show. I'll load pics tonight when I get back from the show

madmodelman

This has all been expained earlier in the thread.

Jeremy_D

100 PSI and yes it includes the smaller nipples. $38 from JL according to their website

SKYPILOT

My Feedback: (9)

Well,

The AMA show was fun, it seems like a good time was had by all who attended. I managed to be awarded second place with the Viperjet. I entered in sport jet.

I'm having trouble getting pictures to load from my I-phone, so will have to try from my laptop after work. The Viperjet seemed to be a hit with the crowd and their were two present, the other one was in a booth and not entered. It was in the red and silver scheme and seemed to also get a lot of attention .

dotdigital

My Feedback: (41)

This is the revised set up I have decided to fly on... I ve removed the stock pair of tanks and installed the saddle tanks (smoke kit) and have these saddles tanks holding KERO fuel and DRSIN FIRST... then the front tank is a Dubro . Sitting atop the front kero Dubro are two smaller tanks which will provide the SMOKE fluid feed to the smoke pump. The entire set up essentially HUGS the C/G forward and aft minimizing any dramatic C/G shift during flight and also eliminates the very nose heavy original tank set up.

essyou35

My Feedback: (11)

Looks good, I need to get those smoke tanks because they fit better and probably bigger than the 24 oz tanks I put in there.

I would be a little concerned about that tank on top of the intake.. are you sue it will hold it during high G or a hard landing if it is full?

dotdigital

My Feedback: (41)

The top smoke tank is only 12 oz and is secured with rigid foam blocks above and below sealed with silicone glue for a very secure fit... it wont budge. I may remove it and go with a bigger second smoke tank on top if I see I need more smoke time, there is room for a bigger tank.
All in all this solves many issues over C/G on this great flying bird. My original maiden had the stock tanks and C/G set- took way to long to rotate and would tuck in on the turns due to nose heavy tendency till fuel began to burn off... Id hate to even think about having to land this thing with a nearly full front tank set up in an emergency.

essyou35

My Feedback: (11)

how many oz are those smoke tanks?