FlyerInOKC

My Feedback: (6)

Great video I downloaded it for future reference.

the Wasp

My Feedback: (1)

Lonnie, thanks for the video. but what was he spraying on it ? a spray glue to stop the air from seeping threw the foam?

Gary, cool, thank you too, but stop talking like that, I'm starting to get anxious LOL

Jim

Glowgeek

CA accelerator to make it set instantly. Also sold under the names CA activator and CA kicker.

1967brutus

Interesting! What is that "craft foam"?

I use Balsa, but basically do the same

Glowgeek

Bert, it is EVA foam. It's easily cut to irregular shapes with scissors,it's flexible, waterproof, paintable and can be glued with many common adhesives. The melting point is somewhere between 170°f to 213°f so care must be taken.

1967brutus

OK... EVA foam does not immediately ring a bell, I'll look into that.

For now, I feel more comfortable with Balsa, as it does not have a melting point

Glowgeek

Oh yeah, I forgot, you're an engineer. IIRC it's Ethelyne Vinyl Acetate.

ETA: Your baffling job on that R5 looks great.

Jesse Open

Dave,
Of the two, Iron Bay and Cline, which one was your favorite?

1200SportsterRider

I guess it would be the Cline because the fuel line attachments are standard sized and the Iron Bay because the fuel line attachments are brass. The Cline elbows can pop off with a little rough handling. They don't pop off from pressure. Difficult choice.

FlyerInOKC

My Feedback: (6)

Is that the stuff from Hobby Lobby and Michael's that comes in a 8.5 X 11" sheet? I have used to frame jewelry for the wife.

Glowgeek

The very same.

the Wasp

My Feedback: (1)

we have a Michael's here some 2 miles away, slick!

Jim

Jesse Open

Still have a few of both?

the Wasp

My Feedback: (1)

this guy wants to brake the Moped Land Speed Record. LOL you should see his bike. he cast his own cylinder, makes his own pistons, the last I knew of it he was talking 20,000 RPM. but here, if accurate he is only turning 11,000+. so I don't know what's up. but the subject says "SuperCharged" I think it really means "modified"

Jim
If it ant modified, it's going slower.

1200SportsterRider

I'll take a look, I think I have one of each.

Well, I have three Cline's and one Iron Bay. All used.

Hyjinx

Nice looking work Brutus. I don't run my radials inside cowls but have one coming up that way. Was thinking aluminum flashing material. Maybe even vanes mounted inside the cowl diameter projected down between the cylinders. Well done.

acdii

Whats interesting is the full scale planes when flying have the cowl flaps closed, only open when on the ground.

Glowgeek

Yes, closed down but not fully closed off. The low pressure formed by cowl flaps and air dams provides an enormous amount of drag and turbulence at speed.

From what I've read wrt the Corsair is that the cowl flaps were manually adjusted and the oil cooler flap was thermostatically controlled. The cowl flaps could be adjusted by the pilot in flight to help control engine temps and fuel efficiency however, in the event of an impending dogfight the flaps were fully opened to prevent overheating. The flaps generally were only fully closed on the ground after a cool down period.

FlyerInOKC

My Feedback: (6)

Speaking of cooling issues, I have a Sopwith Baby project yet to build. The designer came up with an interesting feature to address this issue. This model's design has an engine 1/16" plywood cooling duct extending from the top of the firewall to the bottom of the fuselage. The baby is a slow flying and with a detailed dummy engine and a tight cowl the old 1960s .60 engine was an overheat risk, the cooling duct prevented this.

Glowgeek

That's fine, as long as the exit opening of that "cooling duct" is shaped in such a way as to form a low pressure area. For example: protruding from the cowl further at the leading edge of the opening than the trailing edge of opening. As a general rule, it doesn't matter so much where the exit opening is pulling air from within the cowl e.g. top, bottom or sides, it matters how it is pulling it.

Not like this

Like this.


Over the course of the last couple of years I have converted almost all of my cowled glow aircraft to gassers. Much higher temps to deal with. Inlet baffles and a better way to eject hot air became mandatory. Inlet baffles alone did not solve the overheating issues on a couple of them. Some form of air dam to create a low pressure at the outlet opening fixed all my heat related issues.

These tiny louvered vents are quite handy, and cheap, for creating low pressure at the air outlet(s). They can even be trimmed to use only one louver as an air dam if so desired.
https://www.espritmodel.com/cooling-...-x-16mm-2.aspx

FlyerInOKC

My Feedback: (6)

Agreed, you need a little bit of lip on the engine side of the outlet to develop the low pressure area to pull the air away from the engine compartment.

1200SportsterRider

I buy this foam core board at Amazon, it is 24 x 36 x 3/16", I use it to back 1,000 piece puzzles after assembly to make picture I can hang. I plan to build a plane out of it too.

Light but strong.

FlyerInOKC

My Feedback: (6)

What is it?

1200SportsterRider

It is Foam Core Board, the same as Mudducks were made of. This is my second one, the first was the original 108" version.

acdii

I use that for mold making because it can be waxed.