Archive for July, 2008

Panel planning

Sunday, July 27th, 2008

I bought a copy of DeltaCad and spent the weekend teaching myself to use it well enough to create a design for my instrument panel. Unfortunately I can't put a picture of it here for reasons not worth going into. But it's pretty cool.

Designing a board

Sunday, July 20th, 2008

Your humble author apologizes for the lack of blog-updating. Working sixty hour weeks is incompatible with airplane building! Also, the garage is a furnace this month. However, I did manage to sneak in some time this weekend playing with electronics. I'm designing an annunciator light controller for the panel, which has turned out to be a fun way to exercise the very rusty hardware skills I haven't used since I became a full-time software weenie.

I soldered up a little microcontroller board I bought as a cheap mail-order parts kit:

Then I breadboarded a prototype circuit to verify that the basic design was sound. For this part I raided some old boxes of electronic junk I've been hauling around for at least a dozen years. You just never know when you'll need a 10uF cap on a Saturday night!

Then I spent an afternoon routing a little board. When I used to get paid to design PCBs, I had access to some pretty nice CAD tools. Not so much anymore – the free ExpressPCB software is much less capable, but I got the job done eventually. Next time I might try Eagle, but I think that all the free board layout tools pretty much suck in different ways.

I still haven't settled on the actual annunciator lights I want to use, but at least by next week I should have all the parts I need to make a board to control them.

Ordered propeller

Thursday, July 10th, 2008

Last night I sent Van's a big chunk of change for a propeller – specifically, a Hartzell C2YR-1BFP/F7497-2. That's an aluminum constant-speed prop with a pair of 72" blended-airfoil blades specifically designed for the two-place RV's, and will look something like this.

I kind of wish I'd ordered the prop sooner, since it has a 12-16 week lead time and I find myself with the following chicken-and-egg scenario: In order to finish the FWF plumbing and wiring I kind of need to have the baffles in place, for which I need to have the cowl fitted first, which means I need the prop to fit the cowl. Actually I guess that's a whole series of chickens/eggs. Theoretically you can fit the cowl without the prop if you make some kind of spacer, but even Van's suggests you wait for the real thing to arrive if you have a constant-speed prop like I will. Apparently there's something different about how the spinner is mounted…? We'll see.

Meanwhile, I suppose I will continue to work on interior fuselage systems, when I have time.