adavis

How on earth to you get a usable clunk working in a Dubro 1oz tank?

Many Thanks,
=Adrian=

Half-A-Hec

I replace the fuel line supplied with 1/2A size fuel line. It has a smaller diameter and therfore flexes better in the tank.

Hec

adavis

Sorry guys - I've got DuBro on the brain.

Of course I ment a Sullivan 1oz tank!!

ptulmer

My Feedback: (5)

It's pretty difficult to use 1/2a fuel line with their clunk. I use a couple of wheel collars and a piece of 3/32 brass tube to make a clunk. It ain't purty, but who cares? Nobody will know what's in your tank but you! I have also replaced their 1/8 tubing in the top with 3/32. So far, so good. No leaks yet.

eroc144

My Feedback: (1)

Yeah, the clunk does stick kinda straight out from the stopper, doesn't it? Kinda like... well, nevermind. I've got a bunch of these tanks and have never had a problem with fuel draw - I generally orient the holes so that the main fuel line is at the bottom of the plane, and centrifugal force keeps the fuel there in most cases anyway. Should be fine unless you're pulling significant negative g's.

I've had some success using smaller diameter tube, but then getting it on the clunk can be "challenging" at best. Another option is to use tubing with a smaller wall thickness - One of the major brands is noticably thinner, but I forget which one off the top of my head. Last option is to use the brass tube instead of the fuel line, and then connect the brass tube to the brass fuel line via a small piece of fuel tube. This puts more weight and stress on a focused piece of the fuel line and lets it flex more freely. Make sure you use the wire ties to attach the fuel tube to the brass tubes!!

EG

flyswatter

I agree with eroc. Think about it guys. Do any of you have a clunk in your blackwidows or golden bees? The fuel suspended in the system is more than sufficient for most aerobatics. With the little tanks, I think we just need to insure no kinks in the pickup line and that it terminates at the bottom of the tank. That is the way I do it anyway.

Andrew

Patricks use of tubing and wheel collars works well. If you have a clunk with a barb that's too large, you can cut it off and solder a smaller tube into the clunk. The 1/2A tubing from Sullivan is usually flexible enough to allow the clunk to move around. I've used the silicon insulation stripped off General Silicones Ultimate Wire, 14 awg (most hobby shops that cater to e-flyers and car folks will carry this wire for battery hookups). Rather than have a piece of brass tubing extend thru the stopper, I will work short piece of brass tube into the fuel tubing and use it as a stint to keep the tubing from collapsing, then just pull the tubing thru the tank stopper. It allows the clunk tube to flex right at the inside of the stopper.

ptulmer

My Feedback: (5)

Andrew, I can't remember which of you guys that came up with the wheel collar idea, but it works like a charm. You only need enough fuel line to make a hinge. Flyswatter can't fly inverted, so take what he says with a grain of salt. Actually, the Norvel short tank will do any manuever you want to until the last tenth of a tank or so.

FS, you want proof of my setup? Think back to the reedie race. I couldn't shut that thing down, no matter what I did! Run it down to the bottom and you can invert to shut the engine down. Like Bobhh did right before he started laughing about my little "blimp" racer.

flyswatter

pt:
To me, putting in a flexible feed in a little tank is usually more trouble than it is worth. But if a flexible feed makes you guys happy, I say go for it! But tell me, do you really put in a flexible feed in the little 0.6oz bubble bottle tanks?[sm=eek.gif] If you do, then you are almost a better man than me!

ptulmer

My Feedback: (5)

FS, look in Randy's "Killer Buzz"! It depends on the need. I like that insulation that Andrew uses. Just too darn lazy and forgetful to remember when I get to the hobby shop. Or really looking forward to seeing the lil' hottie at the Pizza Hut next door...[X(]

eroc144

My Feedback: (1)

Don't Cox motors w/attached tanks have clunks? Them's pretty small tanks! Anyway, if I recall, the Cox tubing is VERY flexible. Andrew - where do you get the Mega Wire?

EG

Andrew

I got mine at the LHS (since closed, unfortunately) -- I didn't intend to use the insulation, but they didn't have any flexible small tubing so I thought I would give it a try. It's fuel proof and very flexible, but a little difficult to remove. [link=http://www.willstech.com/listings.html]Here is a site[/link] or try www.hobbypeople.net.

If your LHS supports either electric flight or cars, they should carry hookup wire.

flyswatter

eroc:
Maybe yours have flexible tubes with clunks - mine just have fixed, bottom feeder pickups. I have never seen a flexible pickup in a Cox attached tank. Maybe it is just the ones I have opened up? Maybe they were stiff with age?

ptulmer

My Feedback: (5)

Ahem! At least something you have is.... stiff with age, that is. There was a Cox with a clunk. (dragonfly?) But not the BW's and similar style tanks. The fuel pickup comes off the backplate. You can't make that style with a clunk. FS, we going to the HS anytime soon? (heck's bells, I'd settle for LD)