I've just finished framing up a Lanier Shrike 400, having first reviewed all previous shrike postings to these forums. I am concerned about balance -- that the plane will build nose-heavy. In Joe Beshar's original construction article (Flying Models, FEB 1998) he located the servos behind the wing TE, but also used a higher rear fuselage deck to clear them. In the current Lanier design, the deck tapers all the way back to the stab.

The best option I see is laying the elevator servo on its side behind the existing hatch, and installing the aileron servo behind the wing TE and letting it protrude up thru the hatch. This should let the batt pack move rearward enough to balance.

Regarding those pesky front and rear spars that penetrate thru the fuse... have any of you trimmed them out? Most of the wing loads are carried by the top and bottom LE and TE sheeting, so removing the spars inside of the fuse might be an option if the fuse can be kept rigid.

Also, any recent experiences/opinions on hand launching this plane vs a bungee pedal launcher???

I'd appreciate comments/gear layout photos from any of you who have actually built and flown this plane. Thanks!

Craig, I've never built the kit, but I scaled down my larger sized Shrike to S400 size. I had the same problem with the balance and actually increased the height on the rear fuse to put my servos back there. Mine had CF spars all the way through the fuse so to clear the battery, I moved the wing up some on the fuse.

<img src=http://www.ecis.com/~cobrajet/Shrikesml.JPG>

I built the S400 Shrike. Fast, great flying plane once balanced properly. I originally balanced the plane per the plans, but after 2 handlaunch attempts the plane was uncontrollable and went right into the ground both times. Moving the battery to move the CG forward about 3/16" helped a lot. The plane was now a fast stable flier, and the handlaunches were very easy. A bungee launcher is totally unnecessary. Once you get it balanced and flying well mark the battery position carefully, as this plane is very CG sensitive.

My Shrike had a 6v S400, a 6x3 Graupner folder, and 7 and 8 cell 600 batteries. Hitec 555Rx, and S-81 servos.

As far as the spars go I trimmed the forward and rear balsa spars flush with the fuselage inside walls, and left the main spruce spar intact. You mention the wing loads being carried by the sheeting and this is true, if the sheeting is properly secured to the fuselage sides. I trimmed the covering and squeezed a bead of epoxy all around the outside wing/fuselage joint after covering, and forced it in with an alcohol-dampened finger.

I put the aileron servo behind the main spruce spar, and the elevator servo was laid down on its side at the rear of the fuselage behind the aileron control horns. This set-up keeps all the pushrods very short. I also attached the Rx to the underside of the top hatch with velcro, this leaves a large space for the ESC and battery up front.

Good luck!

GregG/Paul:

Thanks for the info!

Paul:

Thanks, Paul! You've described exactly the layout I'm thinking of. I was also going to use a DD 6V S400 and 7-8 500AR/600AE cells. With your 7 and 8 cell packs, approximately how much space is between the rear end of the packs and the main spruce rear spar? You're absolutely correct about getting a good fuse/wing sheeting bond. I've installed some strategically placed pieces of balsa tri-stock internal to the sheeting to reinforce the skin/fuse joint (I actually notched out rib 1 here and there for the tri-stock). Good idea too, in placing the receiver up under the hatch and out of the crash-crush-zone in the nose!

What was your finished weight w/batts???

GregG:

Thanks for the info! Good looking plane... what's powering that yellow Sonic-tronics folder???

Originally posted by Craig Logan
GregG:

Thanks for the info! Good looking plane... what's powering that yellow Sonic-tronics folder???

Just when I thought no one was looking! You caught that one didn't you. That is a 8 X 4 SonicTronics repitched to <b>8 X 8</b>. I used a S400 with 2.33 Graupner gearbox and 8-600Ae pack. That larger prop and the gearbox in the nose forced me to use that large spinner to blend the fuse size and to move my radio gear as far back as possible for balance. With the geared setup, it had enough power to go vertical from launch for a ways and top speed was a knee shaker for me back then.

I almost forgot the wing part. The stock Shrike had in my opinion too thick a wing profile. Being this was all scratch built, I chose a NACA semetrical airfoil and thinned it down to 6%. I then used a hotwire to cut blue foom cores and vacuum bagged the whole thing. This probably enhanced the top speed quite a bit!

I did this plane in at a local contest. You know the story, many people watching and the showoff in me took over. I wanted a really dramatic takeoff so I threw it as hard as I could. There was a loud clunk and I could feel something thud inside the fuse just as I gave it a Herculean Heave. Must have torn loose the battery pack as she became very unmanagable in the air. It did a huge loop (despite my full down elevator application!) and ended up behind me in a splintered pile! Lucky for me no one was behind me or got hurt! You would think that I would know better by now.

Like Greg, my Shrike is also gone now. I like to do terminal dives, and then pull out at the last minute. I forgot my elevator was switched to low rate and I hit the ground almost straight in. It hit really hard, I had to go back to the pits to get a screwdriver to dig my engine out of the ground.

Craig,
My finished weight was 18oz. if I remember correctly, but I can't recall how much space was between the battery and the rear spar.

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