Re: CEF speed contest Design Discussions

roddie Mon Nov 25, 2013 8:01 am

Cribbs74 wrote:Don't over think it Roddie, all you need is a tank that will work.

I will probably use a tanked bee myself, but If I was going to run an external tank I would open it up, clean it out, solder the pickup and press.

This tank doesn't have to last forever just a few runs. If you want to have a real reliable tank then modify it later on.

Ron

You're right Ron... I tend to over-think everything... (it's a cure for boredom) plus... I'm real excited for everyone, regarding this contest!

It would be cool during the official flight; to "bust a couple of confetti-filled Helium balloons on strings" if there's any fuel left after the 10th lap... (bio-degradable confetti of course...) lol!

(where's the balloon-bust emoticon?)

roddie Mon Nov 25, 2013 4:00 pm

It's "tank time"! I bought a couple sm. (4" x 5") sheets of Tin (Hillman Brand) and it's amazing that it's "packaged" as being .008 mm... I didn't even notice this until I got home... I glanced at the store; the .008 spec. and assumed it to be in "inches"... (which it is...) You have to wonder who's in charge over there at Hillman... I digress Huh...

I took Phil's advice and got a coil of 1/8" Copper tubing from "Auto-Zone". I didn't buy any solder/flux... because I have several types here in the shop. What I don't have; is a good iron or design templates yet... but I'm working on it. My Brother say's he has a "good" iron I can have... and I've been researching uni-flow racing tank design principles/construction options.

I know that this will take a lot of patience and perseverance on my part... being my 1st attempt... but anyone who builds their own tanks, had to start somewhere. The .008" Tin is pretty thin... but the tank will be less than a cubic inch in size... so it should be fine.

Question: Concerning the storage of "profile" (exposed) tanks that could be easily removed after a flying season; should they be flushed with a solvent or alcohol and sealed in a bag w/desiccant; in order to slow their degrading? or will it "just happen" no matter what?

CEF speed contest Design Discussions - Page 7 11-25-10

CEF speed contest Design Discussions - Page 7 11-25-10

pkrankow Mon Nov 25, 2013 4:13 pm

Just drain the tank when you are done for the day. Flush with alcohol every now and again as needed. The real problems start happening if the tank is left full of fuel. The oil can congeal after a time, which is the real source of the green gunk.

When you see green gunk forming fill with denatured, let sit for a while and flush with more denatured. If you are flying regularly this will be about never. It's when the plane is left sit for months and years at a time the problem happens.

Phil

pkrankow Mon Nov 25, 2013 4:18 pm

Oh, PUNCH the holes for the tubing with a proper diameter nail that you filed the head cone shape. This will make spigots that will accept solder nicely.

Phil

roddie Mon Nov 25, 2013 4:50 pm

pkrankow wrote:Oh, PUNCH the holes for the tubing with a proper diameter nail that you filed the head cone shape. This will make spigots that will accept solder nicely.

Phil

Thanks Phil... yes; an "awl" has also been suggested. It makes sense for a stronger solder fillet to support the tube(s).

Thanks also for the tank maint. tips...

Roddie

Kim Mon Nov 25, 2013 5:04 pm

pkrankow wrote:Oh, PUNCH the holes for the tubing with a proper diameter nail that you filed the head cone shape. This will make spigots that will accept solder nicely.

Phil

Holy Hoot !!! THANK YOU...and curse my cursed need to make everything "Big Machine-Like"!

DON'T drill it.....PUNCH IT DUMMY ! I now retreat back into the darkness, thankful for yet another bit of light from this forum...

Dense as Plutonium Kim

roddie Mon Nov 25, 2013 6:27 pm

Kim wrote:
pkrankow wrote:Oh, PUNCH the holes for the tubing with a proper diameter nail that you filed the head cone shape. This will make spigots that will accept solder nicely.

Phil
Holy Hoot !!! THANK YOU...and curse my cursed need to make everything "Big Machine-Like"!

DON'T drill it.....PUNCH IT DUMMY ! I now retreat back into the darkness, thankful for yet another bit of light from this forum...

Dense as Plutonium Kim

I would have drilled the holes... and probably with a drill press! Question is... can I solder with a butane lighter... tongue

pkrankow Mon Nov 25, 2013 6:58 pm

roddie wrote:
Kim wrote:
pkrankow wrote:Oh, PUNCH the holes for the tubing with a proper diameter nail that you filed the head cone shape. This will make spigots that will accept solder nicely.

Phil
Holy Hoot !!! THANK YOU...and curse my cursed need to make everything "Big Machine-Like"!

DON'T drill it.....PUNCH IT DUMMY ! I now retreat back into the darkness, thankful for yet another bit of light from this forum...

Dense as Plutonium Kim
I would have drilled the holes... and probably with a drill press! Question is... can I solder with a butane lighter...

I have soldered with a butane lighter before, but they were lose wires twisted together with a bit of slder twisted onto it...it isn't a question of "can it be done" but "can it be done well enough for this"

You can also use a lump of metal on a stick heated by some external source, such as done in YE OLDEN TIMES

http://www.maniccollector.com/antiques/brassblowtorch.htm

End grain works pretty good because it deforms easily allowing the nail to go somewhere while supporting the metal.

Yes, I tried drilling on an early tank...all my early tanks leaked. Most of my recent tanks leak too, but not around the tubing!

The EASIEST way to make a tank that is leak free is to form a band into the triangular (or whatever) profile, make sure the ends are square and even, then clamp over sized pieces to the ends of the tank, and while clamped solder the ends on. Carefully grind, file, or sand the excess away.

My attempts at making formed end caps resulted in leaking corners typically.

If Kim were a source of plutonium his passport would be revoked lol!

Phil

roddie Mon Nov 25, 2013 11:13 pm

Ken Cook mentioned the "Pittsburg seam" used in the old "Perfect" tanks, as a reliable seal. It's like a "lock-seam"... you'll see it in this link... (scroll down a bit) Which is fine for joining the main body... but you still have to deal with end-caps... which are... well... "end-caps"... which present their own challenges with sealing tightly.

http://www.tpub.com/steelworker2/22.htm

Roddie

JPvelo Tue Nov 26, 2013 12:00 am

Got the cheek blocks installed, not the easiest thing to do with all those angles to work around.
CEF speed contest Design Discussions - Page 7 WF8soZO

CEF speed contest Design Discussions - Page 7 WF8soZO

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CEF speed contest Design Discussions - Page 7 AvfZvSX

My removable landing gear system:
CEF speed contest Design Discussions - Page 7 YGFLhCJ

Not only will this let me replace a bent gear, I plan on making a Tee Dee mount firewall. I want to be clear that a Tee Dee is not approved for the contest, just something I want to do for fun after I get an official time posted.

Jim

**RknRusty** Tue Nov 26, 2013 12:09 am

Very nice, those wings are awesome. I can't wait to see it in its full paint and markings.

OVERLORD Tue Nov 26, 2013 1:02 am

I like it Jim, with wheels and engine on, looks very cool.

Lieven

batjac Tue Nov 26, 2013 1:49 am

Well, since I tend to bounce around a lot, I stole some time from other projects to cut some wood. This is the fuselage cut out in 1/8" balsa. I'm going to laminate skins of 1/16 ply on each side to make a really strong sandwich a 1/4" wide instead of making the fuse of 1/4" and using ply nose doublers like usual. I had to draw the wing three times to get a semi-scale shape and still meet the 45 square inch rule. To make the wing bends, I used an X-Acto blade and cut along a score line almost, but not quite all the way through. Then I bent the balsa up to the angle I wanted and applied CA to glue the wing to the angle I want. It's quite strong and I don't have to reinforce it other than using four pieces of 1/16 ply cut to the dihedral angle and glued in. I also had to draw out the stab/elevator three times to get a semi-scale shape with enough area for what I thought would be stable control.
CEF speed contest Design Discussions - Page 7 DSCN0848_zpse72c5a43

CEF speed contest Design Discussions - Page 7 DSCN0848_zpse72c5a43

CEF speed contest Design Discussions - Page 7 DSCN0849_zps7ae6cbf5

Here's the full scale plane I'm modelling after. It's a Hawker Sea Fury called September Fury:
CEF speed contest Design Discussions - Page 7 Sea-Fury-September-Fury-600x399_zps5a92beb0

CEF speed contest Design Discussions - Page 7 Sea-Fury-September-Fury-600x399_zps5a92beb0

The Furious Mark

JPvelo Tue Nov 26, 2013 12:40 pm

RknRusty wrote:Very nice, those wings are awesome. I can't wait to see it in its full paint and markings.

Thanks Rusty, I got some pointers from Larry Renger over on stunt hanger. Had I known how much work it would add to a "simple" profile I would have thought twice. It was getting the correct angle on the four cheek blocks that takes awhile to wrap your mind around.

Jim

JPvelo Tue Nov 26, 2013 12:47 pm

Mark,
I like your ply dihedral reinforcements. You do much finer work than me. I just slapped mine with epoxy and fiberglass.

Jim

Kim Tue Nov 26, 2013 1:07 pm

JPvelo wrote:

Not only will this let me replace a bent gear, I plan on making a Tee Dee mount firewall. I want to be clear that a Tee Dee is not approved for the contest, just something I want to do for fun after I get an official time posted.

Jim

A man has GOT to have options !!!

duke.johnson Tue Nov 26, 2013 2:10 pm

Mark
Cool plane man. Hope you put the flame paint job on it, should make it go faster. Very Happy

roddie Tue Nov 26, 2013 2:21 pm

Jim, The Corsair looks SWEEET! Thumbs Up

I love seeing all the photos of the entries so far...

I am "pencil sketching" full-size plans for mine as I go... and will "ink" them later, if the model flies well. Is anyone else doing this as they design/build? I already see several other contestants designs that I'd love to build!

Roddie

CEF speed contest Design Discussions - Page 7 11-26-10

CEF speed contest Design Discussions - Page 7 11-26-10

pkrankow Tue Nov 26, 2013 2:43 pm

roddie wrote:Jim, The Corsair looks SWEEET! I love seeing all the photos of the entries so far...

I am "pencil sketching" full-size plans for mine as I go... and will "ink" them later, if the model flies well. Is anyone else doing this as they design/build? I already see several other contestants designs that I'd love to build!

Roddie

Nice..."sketch"

Phil

OVERLORD Tue Nov 26, 2013 2:52 pm

Roger, that's a good idea. I followed the evolution of your plane and I noticed you started with a drawing before building as did Rémy. I think that avoids overlooking certain details or oblige you to find solutions for problems that would otherwise only show up during construction. I didn't make any drawings as I am a bit spoiled: I have got a laser printer/copier and can enlarge plans and copie them several times so I can cut out each part in paper and use it as a pattern. It also makes it easy to slightly enlarge f.i. the wings to meet the required surface. On the other end it still remains a bit design as you go along.

Lieven

JPvelo Tue Nov 26, 2013 3:30 pm

I'm more creative than analytical so I like to blow up a 3 view on a copy machine and cut parts as I go. That way I can wing it (pun intended) with the construction.

Jim

roddie Tue Nov 26, 2013 3:41 pm

Thanks guys, All I had to go by were 3-view drawings, viewed on my laptop screen... along with the min. contest "length" requirement, to start planning the fuse... which is 12" L. without the engine. I started with basic straight-line angles; knowing I could add contours to the top and bottom to create a convincing profile "illusion" after the flying surfaces were decided on and fitted. I ended up having to lengthen my wing by 1.5"/panel.

**Cribbs74** Tue Nov 26, 2013 5:07 pm

Ok,

I've searched and can't find the rules. I know they are out there somewhere..... Sorry to be so daft Jim.

If you bump them up I will attempt to sticky them with my limited mod skills.

Ron

JPvelo Tue Nov 26, 2013 5:19 pm

Cribbs74 wrote:Ok,

I've searched and can't find the rules. I know they are out there somewhere..... Sorry to be so daft Jim.

If you bump them up I will attempt to sticky them with my limited mod skills.

Ron

They are on the sidebar with the P-51graphic.
Sticky is a great idea as well.
Jim

**Cribbs74** Tue Nov 26, 2013 6:55 pm

Shoot...... I'm an idiot. If it was a snake it would have bit me endlessly!

Embarassed

I thank the good Lord for humility! Keeps me in check. lol!

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