Kitfox V new project build

[jmodguy]

As far as avionics, does anyone have advice as to where to start for designing electrical schematics? I have some manuals Ive been reading through, but man it is tough to decipher them when I dont have the physical product(s) sitting in front of me.

Start with the basics, i.e. the aircraft electrical system. Battery, starter, alternator etc. Next radios and lighting, Then move to the EFIS/autopilot.

Congrats on the Series 5 score. I built from a 5 project and they fly just as nice as a shiny new 7.
Check the wall thickness on your spars. if they are .050' your gross wt will be 1420, if .060, then 1550. Your build manual should have the details.

[Eric Page]

Check the wall thickness on your spars. if they are .050' your gross wt will be 1420, if .060, then 1550. Your build manual should have the details.

I don't believe that's correct, at least not for all Series 5 Kitfoxes. As Debra explained it to me, there were a number of early Series 5s that were shipped as 1,400# aircraft. Some, including mine, had the thicker spar tubes but lacked other modifications that were part of the 1,550# upgrade. Debra could not divulge what those other modifications were, but comparing the Series 5 and Series 7 build manuals, I believe one of them may have been a change from AN to NAS shear bolts to attach the wing struts.

The upshot is that some early Series 5 aircraft like mine are penalized with an extra ~20# of aluminum in the spars, from which they gain no benefit. Debra told me that my kit was six serial numbers short of the cut-over to 1,550# MGW. If I had been a SkyStar customer at the time and found out that this issue affected my kit, I would have been mighty upset. But, that company is long gone and the current Kitfox operation bears no blame.

Bottom line: if you call Kitfox and give Debra your serial number, she can tell you whether your kit was built for 1,400 or 1,550#.

[Eric Page]

...does anyone have advice as to where to start for designing electrical schematics?

A good place to start for a solid foundation in light aircraft electrical system architecture is The AeroElectric Connection, by Robert L. Nuckolls III. The book covers the waterfront on aircraft electrical systems and includes a bunch of sample designs for various types of airplanes and engines. It's available for free download, and large-format versions of the system schematics are available in DWG format and in PDF format.

Mr. Nuckolls helps builders with questions on the AeroElectric List forum. He has also written a number of articles for Kitplanes magazine.

[TRegli]

Start with the basics, i.e. the aircraft electrical system. Battery, starter, alternator etc. Next radios and lighting, Then move to the EFIS/autopilot...

Jeff,
Thanks for the response. Definitely doing my research on this as I want to make it look clean and simple.

As far as the spar thickness, I measured my spar and it was the thinner .052. So I believe this makes it automatically the 1400GW model.

Thanks for the help!

[TRegli]

It looks like you have the same Whelen wingtip lights and landing lights that came with my 1999 model V Outback, which I also picked up second hand...

Phil,

I have definitely am considering upgrading to the 3 in 1 LEDs as well as the landing lights. Did you use just generic LED offroad lights? I have wired these to my Tacoma and the wiring is pretty straightforward with great results.

I will get the full glass doors (make them myself out of lexan) because I really enjoy high visibility and will be flying in the woods/mountains of Norcal and Montana.

It came with the round cowl and a 912 FWF. I won't use the round cowl as I don't like the looks. But I plan on using as much as I can from the FWF. Do you know if the FWF between the 912ul and 912uls are the same? I imagine I will find out as I go.

That information on the manual for garmin was super handy! Thanks!

Tyler

[Jerrytex]

Mine has the .52 spars as well and according to the serial number it's 1400#. (1200# with the shorter wings) I went ahead and replaced the lift strut bolts with the NAS higher sheer strength bolts. Figured it Can't hurt. Also extended the baggage area around a cross bar because the baggage area on this model was very small. Pretty easy mod. Just requires a new, or modified baggage sack and some aluminum angle. Also did the razor back and the longer turtle deck which required welding tabs. Added the larger elevator too.

I plan on making my gross weight limit 1320# so the 1400# is not a problem. Can always go up in weight, just not down... so if the LSA rules change, I'll go to 1400#

I switched from the 912 UL to a ULS.

I am using the Round Cowl.

Most of the firewall forward is the same. However, the motor mount is different for a ULS and will have to be replaced. If you use a ULS, the starter is longer and will hit a brace on the original motor mount. If the ULS has a heavy duty starter with the lugs, you'll have to replace the motor mount, and cut off one of the lugs to make it fit.

[TRegli]

A good place to start for a solid foundation in light aircraft electrical system architecture is The AeroElectric Connection, by Robert L. Nuckolls III. The book covers the waterfront on aircraft electrical systems and includes a bunch of sample designs for various types of airplanes and engines. It's available for free download, and large-format versions of the system schematics are available in DWG format and in PDF format.

Mr. Nuckolls helps builders with questions on the AeroElectric List forum. He has also written a number of articles for Kitplanes magazine.

Eric,

A good friend of mine (Bearhawk builder) loaned this same book to me last week. It has already been very helpful in clarifying and simplifying the electrical process. Seeing other builder's panels and even small glimpses of behind the panel has also been very helpful.

Tyler

[TRegli]

Wanted to give a quick update of my project andask some more newbie questions while I am at it...

Also, special thanks to themodel V builders on this forum who are making detailed posts about there build(EricPage and AlexM).To start,
I wanted to square off the top of my older model 7rudder because I like that sharp look + a little bit more rudder authority. Itook some imposed measurements. Drew up a mold on CAD, 3D printed the mold, andvaccum bagged some CF:
Picture1.pngPicture3.pngPicture2.pngPicture4.png

The final product actually fit way better than I expected. I hysoled the piece in and then sanded and filled with more hysol to get a smooth finish. I decided to go with this method rather than cut and weld new tubing in for a couple reasons:
1. I am way better and more familiar with the engineering and mfg methods used for composites compared to structural 4130.
2. I did not want to cut into a perfectly sound frame and risk messing it up.
3. I believe I saved a decent amount of weight using the carbon method, which IMHO is very important given it is the longest moment arm on the aircraft.

I have also started working on Carbon Fiber fairings for my wing struts. I used a NACA0021 airfoil and made a mold to which I layed up the laminate over. So far the results have been okay due to some warping in the molds, but a little finish work should fix it. The weight savings and speed savings will be tremendous compared to the PVC extruded fairings:
Picture5.jpg
I took off the old door fiberglass and windows(if anyone wants them, they are up for grabs) and started putting on .063tinted lexan:Picture6.png
Question for all the lexanwizards out there... with the new lexan clecoed onto the frame, I get bucklingin between the attach points. Will this be held down by the VHB tape duringfinal install or do I need more holes/screws OR do I need to find an oven tocook the lexan so it conforms? All advice is appreciated


Picture7.png
I have also started on all my electrical schematics as well as avionics layout, I have the new S7 elevator ready for covering, new fuel tanks are on order, and have started on a milliondifferent paint schemes but so far this is my favorite (yes it will be a painto paint, but as they say, a moment of pain for a lifetime of glory):

Picture8.png
Thanks again for everyones input and advice!

Tyler

[WurlyBird]

Tyler, I like the look of your fairings. I have been working on a mold to make my own. How did you make yours?

James

[alexM]

That is a fancy paint scheme. I lack the talent to come up with something that nice.

As for the doors, all I know for sure is that the Lexan is mounted to my doors and sometimes they look perfect and other times have huge puckers in between the fasteners like you're showing. And the only difference is the weather. I've got plenty of experience with VHB but I don't know why it is called for here, since it seems like I would want it to slip as the the steel frame expands and contracts.

But I haven't reached the stage yet where I need to flex some neurons to solve the riddles, so maybe the light will go on when I get there.