Brodak 1/2oz Tank Question

The tank is certainly not ideal for an R/C plane. For level stable flight the tank could work ok in the vertical position like the second picture, but it is idealy suited for control line in the horizontal.

Yes that is it for best possible fuel draw will be on it's side.

Here is my solution less weight and can see whats happening.
Brass tube is proportional for engine size.

8cc for TD .010 and 15cc for the thirsty TD .020

I get 11mins with the 15cc / TD .010
Learning that the 8cc is perfect.
15cc is a good duration for the TD .020

Eye dropper bottles off ebay using cork from a wine bottle.

1/2A Nut, what is the clear sealant you used on the cork? Finishing resin? Did you install the cork, then just seal it on the outside? Smear a layer of resin all over the wood before stuffing it in the tank? Can you still get back in there later to access the pickup tube? I often use 1oz round tanks with flop tubes in my .049 planes with good results, using Sullivan tanks and plugs with my own flop tubes. I've also got some of the Cox Int 1oz round tanks on hand to play with. On this .020 bird, I decided to go with the Brodak tank. I'm sure it will be fine for basic loop and roll maneuvers with it's fixed pickup. I've seen another TD .020-equipped plane perform well with this tank and had run times of 5 minutes. That's what I'm looking for. The best orientation was my biggest concern. I am interested in making some of your eyedropper tanks for future projects, though. The stock .010 tank has such a short run and it would be nice to extend the fun a little longer.

I used thick CA speared around the cork to seal the completely after drilling and installing smaller
than .049 size brass tube. After the CA cured / vapors and all, I speared on some around the sides
of the cork and pushed into place followed by a bit more around the top of the cork and lip of the
bottle for good measure. No leaks for over 2yrs now. Epoxy 30min kind would be good choice too.

However I have a new method soon to be tested I have found some rubber stoppers made for
test tubes that will work with less prep and fuss than cutting down a wine cork to fit tight in
the bottle. I have had not problems with the cork type and not having a clunk although it would
be nice knowing there was a functioning clunk for extended inverted flight as that is what would
be needed to do nice passes inverted at all throttle speeds when I vid. I can get away with aileron
induced knife edge pass when the tank is still half full. I had to buy 1 lb of those things just to
get to test the new rubber type stoppers can send you some when they show up. Bit long in the
tooth will have use a razor blade and slice off the tapered end that best fits the bottle. I cut a bottle
top the other day and measured to get the right size rubber stopper.

Yep. That looks like the ticket.

Just used this one to do a engine test 5.2g with a dab of fuel at the bottom. I have used the tin Perfect tanks
back in the day for small RC, the bottles for sure save some weight.

http://www.ebay.com/itm/5-100ml-Plastic-Squeezable-Dropper-LDPE-Juice-Liquid-Water-Bottle-Childproof-Cap-/272575736722?var=&hash=item3f76c7ab92mgrfd9KmMtrn32s0LVfH8dA

I have a lot of these coming in 20cc good for .676oz the perfect amount for very fast 1/2A
any larger and the run time will be taxing on the heart rate and eyes. If with a TD .020 the
run time gives sport flying throttle time about 9 mins.

Another great source for these bottles in 8, 10, 15, 20, 30, and more sizes are from those who 'Vape'. If you know someone who does, they will also be able to help you out. That's where mine came from.

Interesting. I will have to ask around. Thanks.

Spent more time prepping the brass tubes then dealing with the rubber plug.
About 20 mins to set this micro size nylon tank up. 5g  less silicon pickup tube.
Rubber quality is very good (silicon) and formed around the neck of the bottle well for a tight
seal. Much less fuss then using cork which takes more steps to shape and drill out and seal.







Key for good fuel or should I say max fuel out of the tank is slight bend in the pickup line to insure the
pickup tube stays put on the bottom side of the tank. Of course the over fill should just barely miss the top
of the tank for max fill up. Soft rounded off brass tube for zero chance of vibration cutting. Angle cut on the
pickup line to wick up the last drop of fuel. I have used the cork style for some time, all acro no issues.  

That looks great! What capacity is that one? I'm almost ready to fiddle with my tank install on the Sliver project and need to decide on an approach.

Almost any plastic container will do. I've been hoarding film canisters (the plastic ones, not aluminium) for making tanks. You don't need any heavy rubber bungies, just melt a hole slightly smaller than the intended fuel line and it will seal directly against the fuel line it self. The white ones are better than the oval black ones, but they will work too.

I use home made clunks from brass, as I do want do be able to fly inverted etc.

Thank you Todd, it is 15ml / .5072 oz
46mm x 21mm / 5.3g ready to use.  

Kris the tank bung in my design is far from heavy  

The tank will allow inverted flight, last night I sourced some great micro size clunks,
perfect for 1/2A fuel line. All the same I can do a inverted pass with this type of design
as is just not sustained all over the flying field.

Brass and stopper assembly is quite reasonable, just 2.1g  

Yep. I like that. 1/2A Nut. I need to get a few of those bottles and stoppers. This thread was started because I wanted a 1/2oz tank for a TD .020. Not really looking for a 1oz 1/2A tank since I already have a setup that works fine for me in my .049 planes. I always appreciate seeing other folks' methods, though, and I've actually used film canisters before in .049 planes. I never had much faith in the caps staying sealed, so I went back to the Sullivan tanks with my own homemade clunk lines. Weight hasn't been much of a concern for me yet since most of those planes came out tailheavy anyway. Going against the grain, I might still use the Brodak tank in this one. It's ready made and I've had some good feedback here and from others regarding the best way to orient it for efficiency. I made a removeable hatch, so I can always change the tank later if I don't like how it works.

Yes great solution for micro size fuel tanks 5ml / 10ml /15ml / 20ml sizes.
Mecoa sells the TD .020 back plate for that firewall.

https://www.ebay.com/itm/COX-ENGINE-020-TD-Red-Back-Plate-Mount-from-MECOA-K-B-/281011578255?epid=840906737&hash=item416d98658f:g:pT4AAOxyd5tRz9Cf





10cc comparison with a TD .010

Yeah, I'm probably going to use a backplate.it will also het the engine closer to the firewall where I want it. I only have one so will buy a few more from MECOA. Crud, I've made several orders from them in the last few weeks and seem to never get everything I need(several engine projects in the works). That little .010 tank is awesome! I'm actually building an .010 plane as well right now and could probably squeeze that in there.

21M W x 33M L  

5 mins. 10sec / 10cc / cork tank used in this vid
Prop type /size and temp with a peaked NV



AmpAbuser
Published on Jun 6, 2016

NANO II - TD .010 / 2.7x3N Prop /  35% nitro
Best pass this vid:  39,244 rpm  112 MPH
Best pass vid 2:  41.5k 118 MPH
2.2oz RTF / 2ch plane / 15.5in span 28 Sq. In.

1/2A Nut wrote:
Kris the tank bung in my design is far from heavy  

It is more in the commercial 1oz tanks that the bungy is very heavy in comparison to a home-made tank without the bungy, or the Hayes tanks that only has an o-ring.

In your example the bungy is close to 50% of the total tank weight. So not having one would definitely save weight.

Surfer_kris wrote:

1/2A Nut wrote:
Kris the tank bung in my design is far from heavy  

In your example the bungy is close to 50% of the total tank weight. So not having one would definitely save weight.

No Kris in my exampled weight check it was a bung with the brass tubes.

Without the bung you will not need the brass tubes either. The fuel line will simply seal directly against the plastic, if the holes are made with a suitable diameter.

You guys are arguing over a couple of grams of weight!

I do not own any but still curious about proper orientation of the initial metal tank at beginning of the thread

That said... Minnesota modeler first skoole me on the great use of film canisters... too bad they are getting hard to find

and some times the outer diameter is too large to fit IN a wing and too draggy for the side of a profile fuselage

What dose work for me very well and light weight is a combination of balloon inside a part of aluminum cigar tube

I also have had pretty good success with LOW pressure using Kitty Condoms...Red caps designed to cover the nose of a Chaulk tube

Of course inside the fuselage of a RC plane you need a leak proof fuel tank

I even toyed with the idea once to snake a longish section of large diameter fuel bladder materiel down inside leading edge of a wing and one way valve in the end...Fill with fuel and slightly pressurize or not....hoping centrifugal force and suction would use all the fuel

Another bag of tanks came in 20cc size here is the line up for size comparison
to the well known Sullivan 1oz round.