Jake Ruddy

My Feedback: (40)

<p class="MsoNormal" style="margin: 0in 0in 0pt"><span style="font-size: 9pt; font-family: Arial">Hey guys,

I have mentioned this to a few people and it was suggested Istart a thread on it. Ican not take credit for this since I learned about it from Bob Sensi (Mr Lightening) elsewhere. However, since it is easy to do and the cheapest way of saving weight I think its well worth sharing.

I went from a 40oz tank to a 1 liter water bottle (33.1 Oz). The raw weight savings was approx 5 oz before the fuel weight. If you add in the saved fuel weigh that is roughly 5 oz as well. So for 2 dollars and a little time you save nearly 3/4 of a pound off your flying weight and it cost me about 5 mins flying time.

All you do is use a dremel and cut the top of the bottle cap so the brown fuel stopper will fit snug in the cap.
Then plumb it like you normally would.
The key here is to use a gasoline proof sealant on the threads. DONOTUSESILICONE. For quick and easy I used epoxy.
I used metal compressor plates around the stopper.

Here are some pics of weight compared to the 33oz water bottle and a 24 oz tank. I don't have a 40oz tank here.</span></p>

Rcpilot

My Feedback: (78)

So 4.2oz for the (24oz capacity) tank and 2.9oz for the (33oz capacity water bottle). Thats only 1.3oz difference.

How does that add up to a 3/4 pound savings? You're talking about 12oz weight savings. Maybe I'm just not awake yet....... still working on my first cup of coffee. I don't get your math Jake.

branwell

Thanks Jake,<div style="background-color: rgb(255, 255, 255); padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Arial, Verdana, sans-serif; font-size: 12px; ">
Icurrently fly with a 30oz tank so that will work out perfectly :-)
Do you think standard fuel stoppers (the plastic ones that come with tanks )would work. I cant see why not.

On another note.
Isee you use a 2 line setup with the fill "T ing" off the carb line.
Iuse a 3 line setup with a felt clunk on the carb line.

Thebenefitof my setup is dirt can never get to the carb.
Thebenefitof your setup is asimplerbuild and less weight.

Iassume you use a filter in your fill tank. Have you had any dirt issues? (Iam thinking Iwill go to your setup )


Branwell</div>

gkamysz

My Feedback: (19)

I machined an aluminum stopper with an O-ring groove to seal it. I haven't used it yet.

Jake Ruddy

My Feedback: (40)

You are not awake yet Iwas comparing a 40oz tank to the 33oz water bottle in that example.

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Jake Ruddy

My Feedback: (40)

Yes just the standard brown gas stoppers.

Iprefer the 2 line because it's simple, lighter, and works. I don't use any filters inside of the plane. Ihave a Jersey Modeler Electric 2.5 gas jug that has a filter on board. As long as you keep that filter clean I think you are in good shape.

I typically try and look at the carb screen once a year, since using the Jersey Modeler jug / filter I haven't had a problem.

Flyfalcons

Looks like you also lose 20% of your flight time.

karolh

Very ingenious, I will have to file thisoneaway for future reference until I get into thebigger toys.

Karol

Rcpilot

My Feedback: (78)

Ohhhhhhh. I was looking at your scale and the weight wasn't adding up. Didn't read close enough to see you were using the 24oz tank for comparison.

Flyfalcons has a point. The water bottle is lighter, but at a reduction in flight time. I don't fly planes big enough to require a tank that big. That must be at least 35% size....... 40%? I think a lot of the guys around here are using 32oz tanks in 35% planes.

I can't afford to drink bottled water, so I don't know if there are other sizes available. Can you get a 24-28oz bottle of water at the 7-11 or grocery store? I ran my 20oz tank dry on the last flight. 33oz seams a little too big for my application.

fancman

My Feedback: (16)

Ifor one wouldn't risk my giant scale airplane using a water bottle for a fuel tank. Dosn't seem worth the risk to me. Please let us know how it works out after the stess of a few months of flying. If it were a great idea Ithink there would be a whole bunch of them already in use and fuel tank mfg's already selling them.

bubbagates

My Feedback: (32)

There are at least 2 pro pilots that I can think of. One is Yuri and the other was Chip. I have seen at least 3 of Yuri's planes that are done with water bottles for both gas and smoke. One was a 3 year old Krill Katana that still looked like it was brand new.

I would love to find a smallish 65oz tank for my DA170 along these lines.

Rcpilot

My Feedback: (78)

Will a 2-liter Coke bottle work?

Jake Ruddy

My Feedback: (40)

Well that is dependant on what you use really. I had a 40oz tank in my 35%er and could fly upwards of 25 mins. Losing 5 mins and the weight was fine with me. Most people with 35% frames use a 32 anyhow. If you need more time you could use 2 20oz coke bottles and still loose weight.

Jake Ruddy

My Feedback: (40)

This is not a new concept, people have been doing it for a couple years, at least, to my knowledge. Yuri had 2 "Smart Water" bottles in his back upKatana last year. There are a bunch of people using this, I just haven't seen much talk about it on RCU so I thought Iwould share it here.

Idon't see how the fuel tank mfg's could really get involved? Are they going to make any money selling cheaper (if they could) and are you going to pay for shipping or walk down to the corner store


RCP, not sure what sizes are out there, coke bottles will work as well.

Jake Ruddy

My Feedback: (40)

That will work but probably a bit too bulky.

The best option would be 2 1 litre bottles to give you 66oz. The fujis are sqaure and would probably easily sit side by side, Just plumb them like a header tank.

Flyfalcons

What's the savings over an equivalent size tank?

Jake Ruddy

My Feedback: (40)

I don't have the sizes here to compare however as a guess I would say</p>

2oz on a 24 oz tank
4oz on a 32oz vs a 33oz tank
hard to say for 40-50oz
I bet 6-8oz on a 60oz tank.</p>

It's not dramatic, but if you think what CF parts cost vs the weight savings this one has a lot of bang for the buck.</p>

bubbagates

My Feedback: (32)

Probably not enough room for it, they are fairly round and large. Ijustcalled B&amp;B and got a 64oz rectangular tank which will fit nicely
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2Brave

My Feedback: (28)

I'm glad to have found this forum. I've seen pro's use a clear water bottle as your saying. The benefits are really great since you can clearly see what's going on with the interior of your tank. I've had a few issues where the tygon tubing had gotten stiff over the season and this lead to dead sticks. Since then I am going to use Viton tubing
http://www.amazon.com/Black-Viton-So.../dp/B000FMYY8M
for my pick up lines. Also very easy to keep an eye on fuel level on those cloudy days. Just good assurance to be able to keep an eye on everything as opposed to those fogged tanks.

flatspinjim

My Feedback: (3)

I've been using the Fiji one liter bottles in my 35% planes for over a year now. I would never go back to a Dubro or such. I'm building a 42% Dalton right now and will be running a DA 200. I'll run 2 Fiji water bottle tanks, one for each carb.

karolh

I just came across this thread and found it to be quite interesting as I do like the idea of having a see through fuel tank, but tell me how do you seal the brass tubes in the cap to make them leak proof.

Karol

flatspinjim

My Feedback: (3)

I just run a 2 line system. Get a fuel jug fitting that goes right through the cap, no stopper. I use Seal All to seal it. You can find it at Home Depot. For the vent I use a Sullivan fuel nipple at the top of the tank, sealed with Seal All too. Takes about 5 minutes to make one.

2Brave

My Feedback: (28)

Ok, I need some help here...... I attended the Toledo show and ran across a vender that actually made an aluminum version of the screw cap that had the holes drilled into the screw cap assembly. It had a rubber gasket that sealed everything nicely and it was annodized red. Very sharp and clean. I have noticed that there is sometimes seepage around the plastic screw caps even when the correct petrolium silicon is used. Has anyone seen this cap??

ghoffman

My Feedback: (3)

http://aztechaero.goods.officelive.c...ccesories.aspx

They have a nice CNC aluminum pop bottle stopper assembly.

2Brave

My Feedback: (28)

Oh nice... I completly forgot about these.... However, I did actually finally find the other manufacturer here's a link to them as well. $2 cheaper if your interested.... Thanks again.

http://www.foxmanufacturing.com/inde...oducts_id=1516