The Mission:

I am building an airplane. I really can't tell you how weird it sounds to me to hear those words in my head as I type. I am keeping this blog as an adjunct to my written log, which is required to comply with FAA requirements for Experimental Aircraft construction. My son Doug is my partner in this project. There are two goals: to build the best, safest, and yes, COOLEST, airplane we can, and to allow Doug to acquire some truly awesome experiences, not to mention building skills. Thanks for viewing.



How to use this blog

The most current post is displayed on this opening page. To access the older posts, click on the "Blog Archive" on the right hand side. The drop down menu is arranged by the month and lists the posts, by title and by date posted, in reverse chronological order.

I will arrange the hypertext links to other websites I find interesting better some day, but they are at the bottom.

If you navigate to my first post, there is a link to my luthiery pages. I miss working with wood. Aluminum is nice, but it's boring. Give me a highly figured maple any day!

Sunday, January 22, 2012

Baffling

For the past several work sessions, I have been working on the baffling.  The design  of this airplane's cowling has three "ducts", if you will, at the front.  The bottom duct, sometimes referred to as the "scoop", directs air into the filter air box and then to the fuel injectors where, mixed with fuel, it goes in to the engine for combustion.  I'll do that assembly later.  The other two ducts, on either side of the spinner, direct air over the cylinders to cool them (it's an air cooled engine, like an old VW).

To keep drag down, the ducts are small, so its necessary to use the air ultra efficiently.  The baffling accomplishes this by routing the air, without leaks, directly where it needs to go.  The key is WITHOUT LEAKS.  Also, the oil cooler, also cooled by the directed incoming air, needs to be positioned just so, to receive enough flow.  Finally, there are three blast tubes to direct some air over the primary alternator, the magneto and the electronic ignition.

Photos follow:


Starting the baffling construction

Left side cylinders and start of oil cooler positioning

Overhead shot

The baffles aren't yet trimmed down to fit the upper cowling

Forming the left inlet ramps

Another view of left inlet ramp

Checking fit with lower cowling

Starting to look good

There are primary and secondary bends to get the ramp lined up

Right inlet ramp

Holding upper cowling a fixed distance above lower to mark baffling for trimming

Epoxying the upper cowing inlet ramps (pencil marks show center baffle position)

More epoxy and filler will be used to smooth the ramps

Oil cooler, mounted as high as practical

Mounted high to stay out of the way of airflow over rear cylinder

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