RunRyder - Header tank mounted on bottom of base plate?

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Align T-REX 600N 700N > Header tank mounted on bottom of base plate?

QuantumPSI
Elite Veteran
Location: Boston, MA

What do you guys think of this idea? I figure this would be the easiest thing to do without having to mod the frame at all.

M

...now where was I, dh/dt = BS-dx/dt
I will fly you forever... till earth do us part

07-18-2007 Over year old.

baddraptor
Elite Veteran
Location: valencia, ca- usa

Not a good place for it. The outlet side of the Header need to be inline with the carb inlet. On the baseplate you couldn't achieve that.

No mods needed, well kind of.
Get a stud the same size as the screws for the laning gear mounting bracket and replace the front screw in the rear mount. Get a hatori or something similar spacer that is threaded with the correct size and screw it (with loctite) on the stud. Now you have a post to mount the header too. It will also correctly orient your outlet with the carb. The header mounting bracket will be upside down, but that doesnt matter.
Then fill with fuel and enjoy.

However, I am with INKSPOT on this,HTs are for PU#$$&#!!!

**Unattended children will be givin a shot of espresso and a puppy**

07-18-2007 Over year old.

QuantumPSI
Elite Veteran
Location: Boston, MA

Quote
he outlet side of the Header need to be inline with the carb inlet.

I've heard this before but don't know why this is the case. Please explain why this is so important. I've been thinking about this for quite some time and if the reason is what I think it is, then the entire equation isn't being looked at properly.

...now where was I, dh/dt = BS-dx/dt
I will fly you forever... till earth do us part

07-18-2007 Over year old.

702nitro
Key Veteran
Location: Las Vegas, NV

I've heard of this before too. Its weird because the outlet from the main tank is way above the carb nipple. I've seen people tilting header tanks forward/backwards just to get the nipples lined up.

Just makes the heli look more goofy

Vibe Fiddy
Atom 111110100
Trex 1001011000n

07-18-2007 Over year old.

baddraptor
Elite Veteran
Location: valencia, ca- usa

Imagine a siphoning effect. The fuel doesnt like to go that far uphill.
This is a simple explanation but you get the point.

The reason my header is pointed up is to get that last airbubble out when filling the tanks. It isnt critical to be perfectly inline, but you want to be close.

**Unattended children will be givin a shot of espresso and a puppy**

07-18-2007 Over year old.

QuantumPSI
Elite Veteran
Location: Boston, MA

Yeah that's what I figured it was, the problem with that is you have the same amount of fuel pushing down.

Think about it, if you have a water hose, put both ends next to each other and let the rest hang. The pressure required to push the water through would be the same regardless of whether or not the hose is level or hanging. Now if the ends are at different heights, then that's not true and if you look at it as just the carb and the header tank then yes you'd have a problem. But when you look at the entire system, main tank, header tank, and carb, it's not a big deal. The header tank is the equivalent of the hose hanging from the two ends. What matters is that the tank and carb are in line and that's going to be satisfied no matter where you put the header tank. Granted, you will have a siphoning effect when the main tank is empty, but don't forget about the pressure from the muffler to help "push" the fuel up to the carb.

Don't mean to argue with you baddraptor, but I don't feel that that is a valid reason all things considered.

Any other reasons to not mount on base plate?

...now where was I, dh/dt = BS-dx/dt
I will fly you forever... till earth do us part

07-18-2007 Over year old.

baddraptor
Elite Veteran
Location: valencia, ca- usa

Your right. On the trex with the tank designed the way it is, it may be a non issue.

Then my only other reason for not putting it there is you wont be able to see the fuel level very easily and it may not be able to draw all the fuel laying on its side.

**Unattended children will be givin a shot of espresso and a puppy**

07-18-2007 Over year old.

QuantumPSI
Elite Veteran
Location: Boston, MA

Yeah, that's my only qualm with the idea... not being able to see it, but I usually land when the main is empty anyway. Guess I'll be the one to give this idea a try.

M

...now where was I, dh/dt = BS-dx/dt
I will fly you forever... till earth do us part

07-18-2007 Over year old.

Dave Yost
Veteran
Location: San Diego Ca, USA

Quote
it may not be able to draw all the fuel laying on its side.

That's the showstopper. If the header in on its side, and you roll hard left, the clunk would be out of the fuel, defeating the purpose. Not to mention you would be pumping fuel up hill out of the header tank to the engine.

I am trying to figure out to get mounted behind the engine in between the frames, on the front of the main tank.

But I think I will be going with the conventional layout for now.

Dave

MA Fury Extreme,Vibe 50, JR 9303,YS,Vblades, Don't blame me, I voted for Jimmy Buffet!

07-18-2007 Over year old.

QuantumPSI
Elite Veteran
Location: Boston, MA

Quote
If the header in on its side, and you roll hard left, the clunk would be out of the fuel, defeating the purpose.

This is only true if the header tank is not full...

Quote
Not to mention you would be pumping fuel up hill out of the header tank to the engine.

Again, this is only true when the main tank is empty...

...now where was I, dh/dt = BS-dx/dt
I will fly you forever... till earth do us part

07-18-2007 Over year old.

SkateFreak
Key Veteran
Location: Cambs UK/Luton

i'd put it this way....

Header tank...

I like it, it looks pweedy, it helps me gauge how much juice i have left to play with and gives me an extra 2 ounces to play with...

For arguments sake i would mount one as level as possible because most of the time i do fly well into the header tank...
Now if the header tank were to be below the carb and the main tank empty there would be no siphon effect pushing on the fuel and it would be all up hill from there...
that would cause my engine to lean out plenty which i would prefure to avoid... *shrugs*.

even if you dont empty the tank, there will be a point where the fuel in the main tank wont exert enough pressure to push the fuel up high enough and it will lean out before the main empties... (low fuel level in main tank = lower pressure, bottom of the tank = level of backplate... so i guess either way as the end of the tank leans out your a little buggered until you get to a header thats vaugly level heh)

Jst my 2 cents.

-Jvr

07-18-2007 Over year old.

QuantumPSI
Elite Veteran
Location: Boston, MA

Hmmm, fair enough I guess...

I'm going to try it anyway and find out for myself. Will let you all know how it goes... (rainy today, so hopefully tomorrow).

M

...now where was I, dh/dt = BS-dx/dt
I will fly you forever... till earth do us part

07-18-2007 Over year old.

SkateFreak
Key Veteran
Location: Cambs UK/Luton

It'll be interesting to see how it works out.
Let us know, i would be very interested to hear how the engine runs with the header down there once the main tanks out

Best regards

-Jvr

07-18-2007 Over year old.

Zaneman007
Key Veteran
Location: Texas - USA

QuantumPSI,

Let us know how this works out.

I'd rather be flying

07-18-2007 Over year old.

Dave Yost
Veteran
Location: San Diego Ca, USA

Quote
This is only true if the header tank is not full...

I use a header tank for 3 purposes:

1. Keep the Clunk in fuel to prevent fuel starvation during unusual attitudes(3D)

2. Visibility on fuel quantity, you can see that the main is getting empty, and that the header is still full, you have about 3 minutes or so.

3. Increased fuel quantity = more flying time.

I have found that on all four helis I have owned, there is some fuel still left in the bottom of the main tank when it start drawing off the header, especially during allot of 3D. So, if you can't see the header tank, and there is some fuel in the main that is being drawn out intermittently, you could very easily end up with a less then full header tank while some fuel is still left in the main. If you can't see the header, you won't know!? hence, roll left, draw air.
In addition, your fuel line will have to make a 140 degree turn up hill and through the carbon frame. Muffler pressure works, but why make it work harder then it has to?

Unless you plan on setting the timer on your TX religiously, your asking for a flame out.

Let us know how it goes, mine will be mounted on the side, I will post the process tonight.

Dave

MA Fury Extreme,Vibe 50, JR 9303,YS,Vblades, Don't blame me, I voted for Jimmy Buffet!

07-18-2007 Over year old.

Dave Yost
Veteran
Location: San Diego Ca, USA

I forgot one thing, if the header is on its side, then it is not filling from the top, but the side. Hence, the area of the unfilled part of the header tank, is the size of the tank side view. since the tank is rectangle shaped(narrow) the clunk will only have to travel about 1/4 inch to be out of the wetted area. With tank mounted in its standard position, the clunk has to move almost a full inch before it draws air, because the FUEL IS FILLING FROM THE TOP,NOT THE SIDE.

Dave

MA Fury Extreme,Vibe 50, JR 9303,YS,Vblades, Don't blame me, I voted for Jimmy Buffet!

07-18-2007 Over year old.

Dave Yost
Veteran
Location: San Diego Ca, USA

Here we go, just so happens that the canopy mounting stand off's for the R90 3d upgraded fiberglass canopy make a perfect mounting stand off for a header tank. Bonus! The sand off is already taped, and comes with the screws and washers

1. Locate and drill a hole with an 1/8th inch drill bit into the WalMart bling frames.

2. Using two 3.5 MM hex heads and 262 Red Loctite, install the stand off and tank.

WooHoo, looks like it belongs there. (Well, except for the Raptor insignia on the tank

)

Nice little six minute procedure before heading out to the patio for wine with the old lady!

Cheers Dave

MA Fury Extreme,Vibe 50, JR 9303,YS,Vblades, Don't blame me, I voted for Jimmy Buffet!

07-19-2007 Over year old.

baddraptor
Elite Veteran
Location: valencia, ca- usa

Clean set up Dave.
But ya know you could have used the stud that mounts that post instead of the screw in the rear landing gear mount and avoided drilling a hole, right? At least thats how I had mine set up until I decided I couldn't disrupt the clean lines of the heli for another minute of flight time.

Besides, In INSPOTS words... Header tanks are for PU$$!&$

**Unattended children will be givin a shot of espresso and a puppy**

07-19-2007 Over year old.

RPM 1.5
Veteran
Location: Cape May New Jersey

I also added velco to both tanks just for a little extra on mine no drilling needed
Ray

07-19-2007 Over year old.

inkspot1967
rrProfessor
Location: cranston ri.

Quote
Besides, In INSPOTS words... Header tanks are for PU$$!&$

i have never said that before.....lol

Trex700e outrage 12s Solid-G Tyler Bonta Flybarless
Next-D Rave Flybarless vbar
WENZEL CANOPYS

07-19-2007 Over year old.

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Align T-REX 600N 700N > Header tank mounted on bottom of base plate?

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