Viper Driver

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One of these years I will start early enough to be finished before the season starts. At my rate, I should be firing up the CAD program tonight to have next years plane complete on time. Maybe I could design between rounds?

rchotdoger

Awesome build,
This has encouraged me to pick up the knife and sanding block again. I am still mad at myself for selling my pattern ship last year. If you don't mind, i was wondering what airfoils you were using. I have a couple of ideas but wanted to make sure that i was on the right track.
-Casey

Doug Cronkhite

My Feedback: (34)

If you stick with the NACA 00 or 63 series you can't really go wrong. 0012 or 63012 works just fine. 12% thick, the only real visual difference is where the max thickness occurs along the chord. For our purposes, they'll pretty much fly the same.

Viper Driver

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I am using a modified NACA 64012 for the Lightning. The only changes I made were to the trailing edge thickness

Viper Driver

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Odds and ends...

I use a Dean's Ultra connector as an external arming plug. I want a jack that I can remove the plug to take the speed control out of the airplane. I have not found any suitable jacks for this application and the one I have on my current airplane is marginal (it can be removed, but needs a little glue to stay in). Here is what I built out of some 1/16" ply, 1/8" lightply, and a 2-56 blind nut. I will use a shorter screw that the one pictured, that is just what I had on hand. This assembly is glued to the fuselage side, and then a hole is cut out of the side in the shape of the jack.

Mastertech

My Feedback: (31)

Please build a second one for me. We can install it tomorrow in the rain.

JRgraham

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Hey nice work on that plug box! Maybe just a teeeeeny tiny wrap of carbon fiber around the box when your done? The fuse is seriously looking great too.

Viper Driver

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JR,

That was my thought going in, but once I put the box in the lightply, it was plenty strong. It binds the entire jack together.

Jeff

mithrandir

My Feedback: (2)

Fiberglass might be better... carbon is conductive....

Viper Driver

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I use 3/8" dowel hard points for the control horns. To cut the holes, I use a sharpened piece of brass tube in my drill press. Once the holes are cut the dowels are epoxied in. After that cures, I use the Dremel router attachment, with the bit set flush, to shave off the excess dowel. Once that is complete, I use the drill press to drill the hole in the hard point for the control horn.

It is getting close to time to put away the 60 grit and get this thing fine sanded, glassed and painted/monokoted!

JRgraham

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Thats what we wana hear!

Doug Cronkhite

My Feedback: (34)

Just curious Jeff.. is there a requirement for E-power to have an external arming plug now or is this just a personal preference?

rcpattern

My Feedback: (45)

Doug,

It's personal preference. I know Jeff puts his canopy on with screws, so its easier to have the arming plug. My canopy just pops right off, so its just as easy to take off the canopy. After seeing Lightning number 1 in person, its a shame these forums can't do the plane justice it is an absolute work of art, and I expect number 2 to be even better,

Arch

Mastertech

My Feedback: (31)

FAI has the requirement, I suspect AMA will soon. It's actually a smart thing to do IMHO.

Tim

rcpattern

My Feedback: (45)

I don't believe it has to be external to the plane though. I know very few FAI guys that have external plugs. I think you can take the canopy off to do it.

Arch

Mastertech

My Feedback: (31)

As I understand it, and I'm apt to be wrong, it has to be external. New rule for this year IIRC.

Tim

rcpattern

My Feedback: (45)

Interesting...

I'll have to look into that. Certainly wouldn't be the first time I've been wrong,

Arch

Viper Driver

My Feedback: (1)

I do not know the status of the rule requiring arming plugs, but I like the ability to disarm the motor without having to remove anything. As Arch stated, I do use screws to hold my canopy on, so an external plug it the only way for me to accomplish this. It is also nice for an unfamilier caller to have a simple way to "shut off" the motor. I guess my career in the flight safety field is showing.

rcpattern

My Feedback: (45)

I've just been using a throttle cut after I land. Then you can just turn the RX power off and the motor can't do anything as it is essentially shut off. Never had an issue. I had gotten the idea from Dave Lockhart. I guess theoretically the motor still has power so it could go, but never seen an issue, but that doensn't mean it can't happen. Takes about 2 seconds to pop off the canopy on my Wind's, so its very easy to disconnect the packs.

Arch

Viper Driver

My Feedback: (1)

The check cowls are made from ¼” balsa; this leaves plenty of meat for sanding to the desired shape. There is quite a bit of shaping that goes into getting them to fit the contours of the fuselage. The pictures show them squared off, but they will be rounded off during final sanding.

Viper Driver

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The Lightning fully assembled for the first time:

Mastertech

My Feedback: (31)

Sweet !!!!!!

Final weight projection?


Tim

tschmidt

My Feedback: (1)

Great work Jeff!!

Todd

Viper Driver

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Based on comparisons with the prototype at the same stage, I am estimating 10 lb 10 oz. Weight has been under the curve for the entire build, but I can't get lazy now. That "I have plenty of weight to spare" starts to creep in. I have a fairly detailed spreadsheet with weights for almost every piece that has gone into this airplane, although I admit to gluing a few in prior to weighing.

alawel

My Feedback: (3)

Looks good Jeff. Wish I were close enough to see it in action.

Alan