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paulc
11-07-2008, 08:46 PM
Hi Guys,

It's a MkIII that I’ve hopped a bit! The kit came to me in very basic form, welded fuselage and wing kit, that’s about it. The rest I have had to make myself including all the moulds for the fairings and cowls which I flopped off a friends Kitfox II parts. The windscreen is slanted at a shallower angle which I think looks good and my mate reckons he picked up 5 knots (we'll see). All the panels doors turtle decks etc are all fiber glass skins, there are no metal skins/panels at all except for the floor panels.

Some extra stuff I did:
· Aluminum clad each side of wooden Aileron hanger ribs
· All fiber glass panels, skins, and cockpit, instrument panel
· My own molded fiber glass wing tips (didn’t like the droopy type.)
· Galvanized tin fire wall, my own.
· Rotec R2800 installation
· 13 gallon wing tanks x 2, again my own glass work.
· Two piece fiber glass wheel pants
· Static port wing mounted with Pitot tube
Stuff intend to do:
· Round off vertical and horizontal stab and elevator to more 1930'-40's look
· Lengthen undercarriage to clear 76" prop. (Stinson look)
· Fair undercarriage with fat airfoils (Fiber glass)
· Bull nose spinner (Radial Cessna 190 shape)
· Oval shaped Sky Lights
· Fair main wing struts with fiber glass airfoils
· Side and top grills / vents in boot cowl.

84KF
11-07-2008, 09:00 PM
If I had that engine I would mount it on my living room wall and just stare at it for hours... and hours...and hours. It's just so beautiful. :)

DesertFox4
11-07-2008, 10:09 PM
paulc
Wow!!
That engine would make any aircraft look beautiful but it is especially at home on a Kitfox . No wonder Dan Denney wanted radials on the first Kitfoxs.
Nice project Paul. Also what part of the world are you in? MkIII's are not generally found in the US of A.;)

paulc
11-08-2008, 06:21 AM
The Plane is at our shop, located in Melbourne Australia. I bought the raw kit of a local guy who visited me to buy an engine I reversed the deal and bought his plane instead!

The kit was of course shipped in from the states. Here in Australia the Kitfox was later copied and was sold as a "Skyfox" CA 21 then CA 22 then finally a trike version called a "Gazelle". The were essentially all MkIII copies, but were never sold as kits and only factory built. The story goes that they were to be built under license in Oz but our authorities CASA back then would not allow this, so the mark three, they (Skyfox) had was copied and re engineered here as an Australian design. It was a little heavier in construction the Flaps were deleted via a solid mixer bar and the flap lever became a spring pulled trim for the elevator pushrod. The rudder was taller and no ribs were ever used in the tail. The airfoil was a mark three wing except the spars were extruded with the I beam integral with no riveted insert. Struts were heavier too and always air foiled.

The Ailerons were segmented at each hinge point (gave trouble) and were internally balance at the leading edge the air foil was flat bottomed like the Mk3.

Word had it that when finished copying the Mk3 "SkyFox" had the cheek to send back the Kitfox III and never even paid for it!!!!

Joe Meyeres
01-20-2009, 05:37 PM
Hey Paul,

I have heard you talk of your Kitfox before, but never saw any photo's. Very nice build! Can't wait to see it when it is done!

Joe Meyeres

paulc
01-21-2009, 02:39 AM
Thanks Joe, but I'll be working to get it even close to your bird, you've set the bar pretty high bud!

You should do that write up. I'm sure others will get a lot out of it.

Av8r3400
01-21-2009, 08:44 AM
What are you fine craftsmen doing for a Rotec engine mount?

paulc
01-21-2009, 02:09 PM
My engine mount was made by Rotec and supplied with the engine. They do engine mounts for all the Kitfox types. They can also supply you the drawings should you wish to make the mount yourself. In the case of the Model 3 and 4 there were no mods required to the cowls or airframe.

Slyfox
01-21-2009, 04:11 PM
I would like to know how much the engine weighs?

Joe Meyeres
01-21-2009, 04:23 PM
As I recall the engine weighs 232 lbs with all accessories installed. This includes a starter, alternator, engine driven fuel pump, carb, one mag and one electronic ignition system. You can go on to the Rotec Website at www.rotecradialengines.com (http://www.rotecradialengines.com) to verify that and look at all the specifications. They are very helpful in providing data for the do it yourselfers or if you like, they can also provide numerous other accessories including prop's, engine instruments, engine mounts etc...
My experience in dealing with this company is that they are a top notch organization. Very helpful, very friendly and they build a dynamite product.

Slyfox
01-21-2009, 04:59 PM
so what have you done to compensate for the extra weight up front, just thinking because I think mine came in around 125 pounds(engine complete without exhaust). This being for a model 4.

Av8r3400
01-21-2009, 05:15 PM
Does the 232# include the oil tank and related hardware?

Joe Meyeres
01-21-2009, 07:28 PM
What I did was weighed the airplane to configure my weight and balance. I found that I was on the fwd edge of the center of gravity for flight with my battery mounted behind the baggage compartment on the provided tray. What I "needed" was to balance the airplane so that a 100# pilot could run the airplane out of fuel and still be within the cg in order to make his/her emergency landing if needed. (This would be the worse case scenerio.) So I built a shelf and mounted it on the tubing above the tailwheel. On it I mounted a 5# lead weight. I also made provisions to add a second 5# weight to that shelf. Went out to fly and found that it worked OK but it needed just a little more. (In slow flight with full up elevotor trim it still took substantial backpressure to hold level flight.) I hated to add any more weight to the airplane, but decided it was worth it especially since I already pre-planned it. So I added the second 5# weight to my shelf. Remember... anything put in the airplane (basically aft of the panel...ie fuel, pax, baggage...) is going to improve the CG, but you have got to watch the gross weight.:eek: On my airplane, two 170# (high school weighted) adults, full fuel and 40#'s of baggage... I am about 100# over gross but there is no way I am close to the aft CG. Now I decide what 100# I can live without. :)

Joe Meyeres
01-21-2009, 07:44 PM
No, the 232 does not include oil tank. Mine is mounted on the tubing fwd of the instrument panel and is velcro strapped to the frame with 1 inch velcro belting. Virtually no weight for mounting hardware that way.

If anyone wants photo's I would be more than happy to provide them.

paulc
01-23-2009, 04:16 AM
Allbee what does a 912 come in at installed, after all those hoses, water, radiator, starter, exhaust, oil tank, belt driven alternator? Do these come as standard or do you have to pay extra? Aside from making your wallet light what lbs does all this add to the airframe?

I bet is gets pretty messy under the cowl with all that junk in the trunk, good thing for cowls eh, covers the mess.

paulc
01-23-2009, 05:11 AM
Allbee, 125 lbs you say, hmmmmm?

I found this from the Rotax site: http://www.rotax-aircraft-engines.com/downloadarea/912/techdata/Techn.Data_912_S_ULS.pdf

912ULS Raw Engine= 125lbs
Oil Cooler = 1.2 (dry)
Water Radiator = 2.2 (dry)
Clutch = 3.7
Air Box = 2.8
Filters = .7
Exhaust = 8.8
Air Hood = 1.8
Pumps = 1.8
Prop Govenor = 5.9
40 amp alternator = 6.6
Suspension Frame = 4.4
Fky dat = 1.1

And I reckon you need these too:
Coolant = 9.0
Oil = 8.0
Various rubber hoses = 6.0
Various Fittings, clamps, brakets = 2
Sub Total =191.0 lbs

Now just in case they rounded down instead of up, lets just to be sure add 5% = 200. 5lbs

Joe Meyeres
01-23-2009, 05:58 AM
Don't forget the standard 912 is only 80 HP where the Rotec is 110 HP.

Slyfox
01-23-2009, 08:05 AM
No way to the 200 lbs. Why do I say that? because you can delete almost all of your list. The engine at the 125lbs. comes with everything except the exhaust, weighs about 5lbs. The radiator, about 3 lbs also, expecially if you use the aluminum one. Hoses, you need two aluminum ones to the radiator, they were so light, I won't comment on what the weighed. I had to put on a very small amount of hoses, maybe 2 lbs worth because the rest came on the engine. Look at the list of what comes with the engine, the mags are part of the engine, altenator is part of engine(you have up to 18amps), the oil tank is part of the engine. I put on the K&N filter, these things are light. No prop governor, electric.

Water in the system is about a quart and a half. Oil is 3 quarts. The mount was supper light. clutch is part of the engine. Oil cooler was supper light.

Like I said, dry weight on the aircraft is 650 do the math yourself.

paulc
01-23-2009, 03:50 PM
This is directly from the Rotax site.

The raw engine weighs 125 lbs then if you need any thing from the accessories list you pay extra money for it then add its weight to the core 125 lbs, pretty simple stuff.

I'd suggest you don’t know what the all up weight is of your engine install is?

But why are we talking 912 anyways? Way off topic.

Slyfox
01-23-2009, 06:01 PM
you brought it up.

Paul Z
01-25-2009, 02:51 PM
I found the link it is on the Rotec Page, customer project Neil Rings Project.
http://www.rotecradialengines.com/customers/NielRing.htm

paulc
01-25-2009, 05:20 PM
Hi Paul Z,

I had not seen that! Very good that’s the same as mine. The tube is all 1/2" x .049" 4130. If one is making it themselves care needs to be taken to correctly set the offset between the top cups and the lower pins, there is a slight stager. In that PDF the rubber cushions are not shown but the measurements have included there presence.

It’s the perfect mount for this engine because the geometry clears the starter and 40A alternator with out having to cut the tubes on either side.

To convert mm to decimal inches divide mm by factor of 25.4 eg 100mm divided by 25.4 = 3.937”