Fuel tank options

Stuka Stunt Main Forum · 10 of 10 known posts recovered

Dzlstunter · Dec 25, 2000 02:53 PM

LAST EDITED ON Dec-25-00 AT 04:12 PM (EST)

I am building a stunt model (Freebird) which shows a chicken-hopper style tank on the plans. I have used clunks in the past, and had already bought a nice new uniflow tank for this model. Then I saw the plans, and saw the diagram for the tank construction. It seems easy enough as tanks go, but is there any advantage of this style over the uniflow which I already have?

John Miller · Dec 25, 2000 03:34 PM

#1 source

Hi John

I've heard that a good chicken hopper tank can cure some run problems. I've never run one myself, but several of the guys have reported good experiences with them.

John

Jim T. · Dec 25, 2000 07:44 PM

#2 source

I havn't seen the Freebird plans. Is the uniflow shown going to the front outside corner or back near the fuel pickup? In fact, where is the fuel pickup? A standard uniflow should work fine.

Jim Thomerson

Dzlstunter · Dec 25, 2000 08:17 PM

#3 source

The uniflow line is shown running down the outside of the main tank on the inboard side, then through the back into the hopper tank which is located at the rear outboard portion of the main tank and from which, of course, the pickup tube exits.

olivertiger · Dec 26, 2000 01:35 AM

#4 source

I too have the Freebird plans and intend to build 'as per plan' Tony Eifflander the designer and part of the PAW dynasty flee the 'bird to victory in the British nationals and if it's good enough for him then it's good enough for me.

Are you intending to put a diesel in the plane? I am going to put a PAW .40 in mine

I have seen a Freebird with a plastic clunk tank and a ST .51 it flew just fine.

Dzlstunter · Dec 26, 2000 09:23 AM

#5 source

It looks like the PAW40 for me in this one. But I would like to know what the advantages of the chicken-hopper are supposed to be. I thought there was some general agreement that as far as metal tanks go, uniflows are the established preference in stunt.

LNeumann · Dec 26, 2000 11:12 AM

#6 source

You are right, the uniflow is the mostly accepted "standard" tank. The advantage of the chicken hopper, I think, is in the fact that you have a smaller tank nearly always full (the "hopper"). This is more useful in the more violent maneuvers of combat, and the like, although most of these are on pressure feed now (where permitted). You can make a uniflow out of the chicken hopper and have the best of both worlds, but they are best suited for profile installations. It kind of hurts the looks of the plane on a full bodied ship when you see that hopper sticking out the side of the fuselage. Now, if you decide to go to a full body installation and you built something with cheek cowls and enclosed the hopper in the cheeks...well, there is another idea for you. But a straight uniflow should work just fine.

Leonard Neumann

FKrueger · Dec 26, 2000 01:31 PM

#7 source

I have started a Freebird from Tony E's plans. It will have a PAW40 and also a chickenhopper tank. I hope it is finished in 2001. I have 2 planes under construction at once!

I have used chicken hopper tanks on virtually all my recent profiles with excellent results (very steady runs). If Tony recommends the tank, I'll try it. It's removeable if you don't like it! I you look carefully at Tony's drawings, you'll note that his chicken hopper design is a uniflow (most that I've seen, are uniflows). The small hopper is actually the fuel tank. The main part is a reservoir that keeps the hopper tank replenished. Tony's tank is completely enclosed in the fuse, nothing protrudes.

Fred Krueger

olivertiger · Dec 27, 2000 05:42 AM

#8 source

Hi Fred what do you intend to cover your plane with?

I am considering silk or silkspan.

How far have you got with the construction of your 'bird

Vernon

FKrueger · Dec 28, 2000 12:04 AM

#9 source

LAST EDITED ON Dec-28-00 AT 00:05 AM (EST)

Vernon,

I am building this from plans. I modified Tony's plans by making the fuselage profile with a turtle deck. I kept all internal structures and moments the same.

At the present, I have all parts cut out. The fuse doublers are glued on. The main wing structure is completed, including the rear geodetic spar. I built the wing using Tom Morris' 'lincoln log' method. Unfortunately, I did not add trailing edge material where the hinge points are, so I will have to remove the trailing edge shear webs in a few places and put them back after adding small balsa blocks.

I plan on using silk span as the wing does not have leading edge sheeting and I think Monocote type materials are too flexible for this wing.

I just got a Great Planes hinge slotting tool for Christmas. The Freebird and a KA-10 will be the first uses. I dread doing hinge slots so this should be a great tool.

If you want, I can send you a small drawing of the fuse profile.

Fred