Cornell Motor/Battery box rebuild

Continued work on rebuilding the Cornell's motor/battery box. I started with fuse work yesterday. You may recall that with Cornell 3 I replaced the box with a pedestaled motor mount and angled the battery. This worked fine, but changed the CG a bit. In this rebuild I wanted to preserve the original design of a firewall motor mount and battery box. It came out pretty good, but took a lot of time.

Building the box from popsicle stick wood.

Cut some gaps into the framework to lighten it up.

The remaining original box on the left had the corner sanded down, likely to fit under the cowl. I did the same to the right side, which is the rebuilt side.

Installed.

Under the battery shelf, the side supports sheared off.

I supported the battery shelf with popsicle stick wood cross bars.

I fit the hatch and realized I had placed the top of the firewall too far aft. Here its moved forward about 2 mm and fits nicely.

The box is done. I need to re-cover the bottom of the fuse with sheet balsa curved to fit, then do all the cote work, remount the motor and ESC, and rebuild the cowl (they are still out of stock expected Jan 2012). I won't touch the NIB Cornell as its for when they stop making replacement parts.

Burning, searing, stinky stuff

Working on the fuse frame, realizing a large portion, about half actually, of the battery/motor mount is missing. So I've been cutting and gluing. Have you ever smelled cut wood with CA, epoxy and modelling plywood? Its an acrid burn that melts your eyes and blisters your nasal passages. And my wife says it makes the house smell like "New House"... Smells like burning down the house to me.

Using popsicle sticks to rebuild the front upper cross support of the fuse. I had the old fuse and saw that the crashed one is missing the upper part of the firewall, so I scavenged it from the old one. I had to cut it out and shave it down, and that's when my eyes melted and my nasal passages blistered. I actually took it outside so I could breath, even though I was using a mask. It killed...

This is all that's left of the battery/motor mount box, the right wall and the bottom. I did some patchwork to the mount (the X).

The fuse. This is going to take a lot of time. Especially with melted eyeballs...

Rebuilding Cornell, what, um, #5?

Today I restructured the internal main spar of the wing and a part near the trailing edge at the fuse, strengthening them and then recoting them. I forgot to take pics, but it was pretty straightforward. I had to remove cote and sand away the field repair I had done, then run some popsicle stick across the section between the wing stringers. Came out pretty good, actually! I also recoted the area around the wheel well I had to fix when a previous hard landing wrenched the gear. In reinstalling the gear I gave them a little more forward sweep to help with the tipping problem on landing.

Just to the right of the star is a long patch along a section, and then a small square at the leading edge all the way right.

New cote around the wheel on the left.

Forward sweep of the gear.

I did some repair work on the hatch, though I have a new one coming. I think I can actually get this one back up to speed. I fabricated a forward bulkhead as you can see, and CA'd some cracks. I will use some packing tape to seal over the cracks after sanding them, and the hole, then spray paint it gloss black.

I ended the evening with removing cote over the damaged sections of the fuse, including one contribution by a naughty, naughty cat, to expose the damage.

The fuse was fractured through and through here, where the crack is. I repositioned it and CA'd it, as well as associated cracks elsewhere along the fracture line. This is post CA.

The battery section and motor mount were sheared off, and I will be repairing them tomorrow. Here's the forward section of the fuse. 

The floor of the forward fuse is fractured. The front "wall" is broken.

Another view of the cracked bottom of the forward fuse.

The right horizontal stab, post a previous repair, cracked again.

The rudder is cracked at the lower opening of the cote, and the top is, well...

My darn cat must have chewed... I was looking at this wondering how the heck the damage got there from the crash when I realized this is a post-mortem injury! Damn it, Neko!  Its a good thing you're cute....

So I will make these repairs and start on the battery box/motor mount.

It's in the box!

And I am keeping it that way! NIB, baby! My Eflite PT-19 Cornell from Chief Aircraft came courtesy of my friend in the Brown truck!

Piratey Squadron adding another Stearman?

I loves me a Stearman... and Alien Aircraft has a new 863mm one coming out on Sept 16th! They haven't announced the price, but looking at their other models the kit should be reasonably priced at less than $100. After the Eflite Pulse XT, I think this one in yellow is next!

Where am I going to put all of these planes?

UPDATE (9/16/11@1845 hrs) whoa... nice, but it turns out its a build, not an ARF. I have a psychological issue flying planes I have spent hours building... I will get one though, perhaps my first build, eventually.

Hot diggety-dog!

I found one, I really, really found one! I search regularly for the Eflite PT-19 450 ARF to have in reserve as its been discontinued and I can't find it, but I found one at a fair price! I found it at Chief Aircraft and they have one in their Florida store. Psych! This one is staying in the box for as long as it needs to, until I can no longer get replacement parts. Awesome!


Its been 20 minutes and they haven't called to say, "Oops, its a stock error." Yay!

Come in, Major Tom!

She was in a nice descent on base and I started my turn to final. And then she wasn't there anymore. We all stood there kinda stunned. The Cornell simply stopped flying and just as suddenly was gone. Major Tom stopped responding to Ground Control...

I had been toddling around in a holding pattern waiting for Greg to bring his Ugly Stick in for a landing. He cleared the threshold and I turned to base. I was just starting a turn to final when she just disappeared. She had plenty of speed, and hadn't done anything quirky. Her battery was fresh, she hadn't been up long (still over 4 V on recovery). She disappeared in a hurry. I was dumbstruck. A lot of people were watching and it was clear I wasn't doing anything other than a nice gliding turn. When Kenny, Susanne and I found her (using the motor sound to track her), she didn't look too bad. The wing is a little tweaked. The motor mount and battery box are bits and pieces, but I think enough remains to rebuild it. I won't make the mistake of angling the battery as I did before. If it's too much trouble then dammit, I'm buying another expensive fuse! She just flies too sweet. I won't be using the AR6100E I had in there... curious as she wasn't more than 500-600 feet away, and I've never once had an issue with this receiver. I may put an HK Orange Receiver and Satellite in her, since I have never had a problem with one of them... Don't know. We can't think of anything else it might have been. Its nigh on impossible to stall this plane.. There was nothing else wrong that I can see so far. Has to be the reciever.

Bummer.

UPDATE (9/10/11@2057hrs): Ordered a new hatch and noticed that the cowl's will be available in Jan 2012!

UPDATE (9/12/11@0800hrs): Dick Clarke pointed out that I am using a Spektrum AR6100e, a park flyer receiver. I need to change these over to the new AR600 series full range receivers. I have flown this receiver without problems at great distances, but I wonder if the odds eventually caught up with me, even though it wasn't all that far away?