About The Project:

The airplane is a home-built, scratch-built Zenith CH 750 STOL. Building from plans/blueprints is a challenging way to build an airplane, since most of the parts you use to build it are not prefabricated. I chose the Zenith CH 750 STOL for its rugged design, its STOL (Short Take-Off and Landing) characteristics and its aluminum construction. Zenith Aircraft Company has designed this airplane so that it can be built from scratch or from a kit by the average person. They provide excellent technical support for both kit and scratch builders. In addition, I'll be installing a 1965 Chevrolet Corvair 164 cid horizontally opposed, air cooled, 6-cylinder engine, with special conversion parts to make it suitable for airplane duty. This is what the airplane will look like when I'm done, although I'll have a different paint scheme:

Follow my progress below!

Tuesday, November 8, 2016

Working on the firewall.

Friends,

For whatever reason, I've decided to shift gears briefly and work on the firewall.  Maybe I just need a break from the tail...I don't know. Anyway, I've ordered a quart of brush-on Zinc Chromate, which I can use in my garage during winter, so I can make progress on whatever I want, irrespective of the weather. Previously, I'd been spraying with Zinc Chromate from a rattle can, but you have to do that outside on a wind-free day, or in a paint booth. In my neighborhood, there's always a lot of wind, and I can't build a temporary paint booth unless I save all the priming to the very end...not gonna happen. I was wasting a lot of primer due to the wind, and that stuff is expensive. The quart jar of primer was $95!

Anyway, I only have a few parts to make in .063" to finish all the aluminum parts for the firewall. I still have to make the landing gear upper bearing out of Nyloil (waiting for my material to arrive), and some small cover pieces in galvanized steel. The center firewall doubler was a relatively difficult piece to make. Since I have hinges at either end of my brake, I couldn't bend it using the brake because I'd need the flanges to hang off the end. So, I used a piece of 1/4" round-over oak board clamped in the vise and hammered it into shape with my dead blow. Here are the results:

Center Firewall Doubler Blank, Part #75F9-5. This took 1.5 hours to make. Looks like a simple part, but making it in a home shop takes a lot of filing and care:

Using an oak round-over board plus the dead-blow in the vise to hammer form this part. I was really worried about cracking the material in the radii:
 

Formed Center Firewall Doubler. The larger flaps at the top should illustrate why this can't be bent in a brake that doesn't allow for overhang on the end:

Most of the firewall parts laid out, the Center Firewall Doubler is nested/slotted into the firewall channel toward the bottom.

Well, that's it for now...still cutting together video for the stabilizer and elevator build. The firewall is a relatively simple structure, so I'm not certain what sort of video tips/tricks I'll have for that, but I'll figure that out once I get into assembly. I still have a couple parts to finish up for it anyway.

Cheers, and good luck with your projects!


2 comments:

  1. Looking great, Greg! As Liz points out when I wonder if I should jump ahead in the plans and make parts using material already on the bench, she just says "they all have to be made sometime!"

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    1. Thanks, Chris! It's great to see it finally coming together after a year of parts. Since my workshop is so limited on space, I just decided to start making parts until I used up a sheet of aluminum, for the most part. With bare sheets getting banged around during storage and constantly playing "musical chairs" with the locations of things, it made more sense to focus on parts. However, I built the complete rudder before I really moved on to mass part manufacture.

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