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NACA Foam Leveling Video


Cozy1200

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I didn't like the idea of hand sanding the NACA inlet foam flat. So I built a simple jig and leveled it with a router.

 

There's a video on my website showing the technique. It's 4 minutes and about 10 meg.

 

 

http://www.cozy1200.com/geeklog/article.php?story=LevelRouter

or

http://tinyurl.com/5dttbr

Drew Chaplin (aka the Foam Whisperer)

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www.Cozy1200.com - I'm a builder now! :cool:

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Brace for impact...

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hello guys,

 

I'm wondering:confused: about the right size of a naca inlet to feed my engine and actually I'm finding that a naca scoop is not just a scoop, there is a lot of math behind it.

this guy

http://www.melmoth2.com/texts/NACA%20inlet%20sizing.htm

 

is feeding his IO360 with a 4 inches scoop: his math seems to be reasonably but the scoop seems(to me) to be very small, what do you think about it?

Roads? Where we're going we don't need roads. (Dr. Emmett Brown)

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That should be sufficient as an air intake feeding to the intake manifold.

An inch larger would not hurt.

 

Drew,

I used a router when I shaped my fuselage floor. I had drawn a sort of topographical map in 1/4 inch increments and then cut them out adjusting the depth of cut for each station. I then came back with the Fein fitted with the flush cut blade and did the large blend between levels that way, The rest was done by sanding.

 

...... so how long until you get your own show on the DIY network?

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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I'm wondering:confused: about the right size of a naca inlet to feed my engine and actually I'm finding that a naca scoop is not just a scoop,

 

If you're an EAA member, log in and download this old article.

 

http://members.eaa.org/home/saarchive/eaa_articles/013583.pdf

 

December 1991

 

I stuck with the plans version.

Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

---

Brace for impact...

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That should be sufficient as an air intake feeding to the intake manifold.

An inch larger would not hurt.

 

 

but it could hurt a lot more then you think. when a scoop is sized right there is smooth air flow and little drag. when a scoop is to big for the air flow there will be spill over and backed up airflow which will effect the air flow and pressure that goes into the scoop. it can even reduce the air flow below the required amount.

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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...... so how long until you get your own show on the DIY network?

Me on my own show? Forget it, I want to fly someday. The actual routing probably only took 30 minutes. But because I filmed it, it took an entire evening. Then probably another 6 hours to edit. It's not a good way to make progress on my plane.

 

I figure a couple of these a year is not going to set me back too far. They're kind of fun to make.

Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

---

Brace for impact...

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but it could hurt a lot more then you think. when a scoop is sized right there is smooth air flow and little drag. when a scoop is to big for the air flow there will be spill over and backed up airflow which will effect the air flow and pressure that goes into the scoop. it can even reduce the air flow below the required amount.

this is exactly the problem I was referring to: to build a good shaped naca inlet is not a huge problem, you can find detailed documents from NACA aerodynamic research made in 1948/50(required lenght, depth, lip and so on).

matching the engine air flow requirement to the naca recovery ability is a bit more difficult for me.

the guy with the IO360 has his inlet behind the prop, mine is on the other side.....

who wants to suggest me??

Roads? Where we're going we don't need roads. (Dr. Emmett Brown)

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I hear a bit of Aussie accent

Too right mate, belardy oath... Are you trying to subtly tell Drew to include subtitles next time???

 

Very interesting thanks mate, (and Chasing Mars). I am getting together my order at the moment, and have found a reasonable local source of Divinycell so am actively considering your method, and substituting the PVC. Guess I'll still need the urethane for the spar and nose.

Mark Spedding - Spodman
Darraweit Guim - Australia
Cozy IV #1331 -  Chapter 09
www.mykitlog.com/Spodman
www.sites.google.com/site/thespodplane/the-spodplane

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If you trying to find more information on NACA shapes and sizes.

 

Bferrell has a fantastic website with some great XLS modelling.

 

Brett, you website & wiki are awsome.

 

http://wiki.velocityxl.com/index.php?title=Documents#NACA_Ducts

Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

---

Brace for impact...

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That accent must have been right dinkum strong, because it says the link is no longer available :o

I live in my own little world! but its OK, they know me here!

Chris Van Hoof, Johannesburg, South Africa operate from FASY (Baragwanath)

Cozy Mk IV, ZU-CZZ, IO-360 (200hp) 70x80 prop

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