Wedge shape Metal PERFECT Glow fuel tank

The reason you are confused is because this is a CL fuel tank not a free flight one [Perfect did make FF tanks as well BTW]-and is intended-in normal CL usage-to be mounted horizontally along its longest axis with the narrow tapered portion on the outside of the circle...this is the classic CL 'wedge tank arrangement-due to the rotation of the model, the fuel moves outwards and rearwards within the tank as it is used-and the feed tube is-in the normal setup-drawing fuel from the outer rear corner of the tank.....the feed tube being the one projecting from the triangular surface. The other two tubes almost opposite each other are vents-one of which also acts as a filler-it doesn't matter which-as internally they are mirror imaged-one goes almost to the bottom of the tank, the opposite one almost to the top-the purpose of this plumbing arrangement is to allow the tank to feed and vent when the model is either upright or inverted-if it were not like this, your fuel would run out the vents when flying inverted.

Now for FF use, you will have to mount the tank on its side-ie with the narrow 'v-shape' downwards...ie the word 'Perfect' aligned vertically. with the P lowest...this will allow feed in a steep climbing FF model...the vents will project horizontally....you may well-depending on the type of engine mounting setup-have to give some thought as you how you mount the tank-and perhaps add some local structure to support it. A lot will depend on the engine orientation in the model-if it is upright on wooden bearers-the tank will mount fairly easily...if it is a sidemounted engine, on bearers, you will need to put a bit more thought into the tank mounting...likewise if you're using a radial firewall mount setup.

Personally I would never use such a tank on a FF model-I use Perfect #4, #5 and #6 'Recttanks'-which are made for FF and cover most sizes....or a pacifier or bladder.

ChrisM
'ffkiwi'

PS I'd also give it a through clean inside before using-over the years i've been staggered by what comes out of brand new Perfect tanks....I guess they never clean them after assembly so you find flux residues, metal filings and lord knows what else-not to mention the occasional internal blockage

Thanks, Chris on the advice to fully flush out tanks before use. I was even surprised when opening the noses exposing the crankcase innards on 2 new Fuji .099S-II R/C ABC engines back in the mid 1980's. Their crankcases were full of aluminum shavings from manufacturing, a disaster waiting to happen if I had not done a cleaning prior to use.

I have one of those Perfect wedge tanks installed in my 20" Ace R/C Littlest Stick. It can be made to work for R/C or F/F, if one is careful enough to know what they are doing.

I wanted a tank larger than the standard Pee Wee, because of its shorter runs. Store did not have a suitable sized rectangular tank, only wedges. However, I installed it with the wedge down. This puts both the vent and filler tubes up high, so they still do their functions.

There is some advantage to such as setup. It tends to drain the tank empty as the end of the pickup tubing being in the bottom of the back of the wedge sucks the fuel more completely, whereas with a standard F/F style tank, a slight banking can cause the pickup to be on the higher side of the back, so one doesn't get out the last drop.

Thus, this setup is good to the last drop.



Of course, if you have a deep wedge, then it would not be a good setup, due to the greater lifting distance in suction feed.

Thanks to all for your feedback. I'd like to use the wedge tank since I already have it. But the first thing I will do is test it out in an engine test stand
to see what works.
GallopingGhostler- when you refer to installing the tank with "the wedge down", please clarify the tank orientation using the PERFECT name as reference. I think I understand but not sure.
Here's how I understand it: The fill pipe and the vent pipe on opposite sides along the top wider part of the wedge and the pipe on the bottom of the wedge goes to the engine?

rfara wrote:GallopingGhostler- when you refer to installing the tank with "the wedge down", please clarify the tank orientation using the PERFECT name as reference.  I think I understand but not sure. Here's how I understand it: The fill pipe and the vent pipe on opposite sides along the top wider part of the wedge and the pipe on the bottom of the wedge goes to the engine?

Reason why I did not refer to the "Perfect" name, is because other tank manufacturers like Kap-Pac may lack lettering. And, its been a while, but it is possible that not all Perfect tanks, particularly the smaller ones did not have it stamped on them, or could possibly be oriented differently.

But, yes, see my installation on my Littlest Stick.




I replaced the .020 Pee Wee with an earlier OK Cub .049B on it. Engine is cocked at an angle to avoid drilling a hole in the tank with the engine mount screws.

big big fan of "pacifier" pressure tanks

http://www.texastimers.com/

sells "xsmall" fuel line, that works VERY well with a pinch off timer
http://www.texastimers.com/accessories/fuelline.htm

also carries , T fittings, pressure fittings - and a brilliant diagram of what the setup should look like
http://www.texastimers.com/accessories/pressure_bladders.htm


I know, I KNOW - 1/2A - Cox, cheap old men.
We already HAVE the tank
we dont want to BUY new things

i kNOW

I also know what works, and what people at contests are using for FF.

$6 worth of fuel line, $12 worth of fittings, and my plane flies great. with no issues

Hi rfara,
I agree with every one here.
Is it an A class FF plane (2.5cc) you want to fly?
Or a Cox.049 one?
Huge difference.
The experts here,
Are awesome,
With Respect,
Dave

Very funny.... but also very informative. I'm planning to use a "vintage" K&B Torpedo .15 glow in this A ship (KIWI A).

Thanks for the pacifier tank information. Sounds like that's the way to go to be competitive. I am just getting back intro free flight after decades.

Appreciate all the advice!

Bob

I was looking for an illustration that showed how to mount a C/L wedge tank for F/F or R/C use. At one time, it was either from a book, article or a manufacturer's brochure, etc., perhaps even a SIG catalog. (Some catalogs used to have useful tips inside.)

Above all, the Lord gave us a brain. One thing I learned is that not everything is "cookbook". There is room outside the box. Basic common sense, knowing or having a good feel for the lifting capacity of a particular engine's fuel suction ability, center of fuel gravity that works best, and etc.

Sport flying allows for all possibilities. That's what makes model building unique. Step outside the RTF box, not everything is solved by slide rules and calculators.

It was through model building that made for the best mechanics, engineers, craftsmen, machinists, builders, assemblers, finishers, supervisors, teachers, scientists, etc. Having a practical feel for what works, what doesn't, trying newer materials, etc.

Even on the job, not everything is cut and dried. The one who can come up with a solution and make it works, oft is considered the genius. Failure is not a setback, but a stepping stone to success.

pacifier/bladder

well, as GallopingG said "we got a brain"

I read online all about bladder tanks. but did not see any photos, nor did I really understand it
I knew all the vintage "Perfect" tanks I had were control line, and less than perfect shape.

So I made a pressure tank... with cork, brass tubing, and a "party balloon"

you see, I did not understand it was supposed to carry enough fuel for warm up and a 7 second run.
I thought it was like Control Line, more is better.

I was ready to send 3+ ounces of fuel!! for an .049!

when I got to a contest, and my sorta/mentor saw this? he exclaimed - it will fly to the moon and beyond.


then I saw a small pressure bladder, like the photo on the Texas Timer page, and it all made more sense
lots more sense.


we are all here for learning, friendship and model airplane motors. one size does not fit all
none of us is as dumb as all of us

Hi rfara,
~1974 Dad took me to a FF contest. Flew an 'Inchworm' in towline glider. I flew rubber with the other 6yr old kids.
I remember the noise and javelin launches of power FF. (they had mini-bikes to chase them!)
I bet a K&B Torpedo .15 was running that day...
That is the extent of my FF knowledge.
C/L and R/C got in the way.
Take care,
Have fun,
Dave