Aviatik 30.27

fli48rc · 28-04-2006

Austro-Hungarian Prototype Fighter. 2 were built, but failed the field testing.. took over 45 minutes to climb to 10K. Short kit offered by AerodromeRC. AUW 27.1oz, works out to 10.6 oz/sq ft. Used the following hardware - MPJet Brushless, CastleCreation 25 ESC, Hitec 6 Rx, 4-Hitec HS55servos, TP 1300mah Lipo, APC 10x7 Prop.

**Bunkerbarge** · 28-04-2006

Lovely looking plane Mark. You don't say how yours performs though.

Looking at the length of the fuselage I bet it takes a bit of controlling.

How long does yours take to get to 10K?

fli48rc · 28-04-2006

Thank you for the nice comment. I haven't had the chance to maiden it yet, I actually just finished the rigging yesterday. I am not sure you can see clearly, but both ailerons are drooping just a tad. I am not happy with the very loose connections, and am going to replace the structure with a Dubro Micro connection setup and then recenter the servos. I kept putting pressure on them while I tried running my flying wires through the very small eyelets I used for mounting. I expect it to be a hand-full, and climb very slowly.. though I will have to call the local FAA first to get clearance over 300'

**Bunkerbarge** · 28-04-2006

Mark,

I don't know what your level of expertise is with these models so if I sound condescending I apologise. If you do not have a lot of experience I know that these models are very difficult to fly so I would wait for some suggestions from our resident expert Barry before committing to the air.

I would hate to see such a superb model damaged, but I can't wait to see a shot of it in the air.

fli48rc · 28-04-2006

I certainly didn't mean to have my response sound like I was taking offense. I appreciate any and all comments. I was wondering if the Aviatik would act like a Camel, with all the weight up front.. Though the CG is spot on, using my homemade CG machine. I will send an update and hopefully a pic of 30.27 in the air.

**Bunkerbarge** · 28-04-2006

No problem I didn't think you were!

I can see the plane being a bit of a handfull though with such a short fuselage. The rear controls will probably be very responsive as the rotating moment is relatively small to the point where the slightest touch will have an immediate effect.

Don't take your eyes off it for a second!!

**wonwinglo** · 29-04-2006

Mark,nice project my guess is that she will be a tad skittish in flight,I would have opted for just a few degrees of dihedral,large frontal area will fly nice and slow,wing section looks fine,short nose so you have managed to keep the tail very light,if you can incorporate some aileron differential that will help adverse yaw effect,cranking horns forward is easy method.
You would be better with some equal up aileron,but not too much rather than aileron droop which will cause power stalling effect.
I like the turned engine cowling effect,how did you do that ?
I like your model subjects Mark,let us know how she flies please.

fli48rc · 29-04-2006

The short kit comes from AerodromeRC, here in the States. The designer tries to keep his planes as true to scale as possible, so no dihedral, though I certainly could of built some in I guess. When you say aileron differential, what exactly do you mean? The total throw is about 3/4" up and down from center. I like to use my transmitter to add about 10% rudder, to start, to my aileron control, and tweak it as needed.

As far as my "swirling", after finding an actual picture of the original 30.27, I realized that the engine cowl was swirled, or should that be "swurled" because its Austro-Hungraian? I had watched Peter Rake swirl one of his planes in another forum, so I PM'd him for any tips. He was very nice and responded quickly. Basically I took my Dremel tool, took a old cutting wheel and CA'd a small circular piece of green scouring pad on to it. I had previously found a couple of throw away aluminum cookie sheets at a local grocery, so I swirled the sheets. I cut a template from paper, determined the size, and then cut the aluminum 1/8" larger. I applied this to a piece of 1/64 inch ply by just bending over the edges. Between the aluminum and the ply I came up with the plans requirements of 1/32 balsa sheeting.

Sorry about the run on post!

**wonwinglo** · 29-04-2006

Mark,differential on ailerons is a way of making your ailerons much smoother in operation,as you know the downgoing aileron creates lift on that side thus raising the wing,if the other aileron goes up it drag that wing down,what we need to do in effect is gear our ailerons so that the up side is greater than the downgoing aileron,by doing this we avoid what is termed 'adverse yaw' which in extreme cases can reverse the effect of the ailerons,to sum up to fly a model smoothly especially these small models we need to take care of this effect by adding some differential,the easiest ways are to use special bellcranks in the wings,or even easier to simply rake the aileron horn 'forward' so we get the desired more up than down when the servo is in operation.
Another interesting point is that although some aircraft appear to have flat wings with no dihedral in fact the designers do incorporate a few degrees on most machines not noticeable to the human eye,it just gives the aeroplane a more stable sit in the air especially on long cross country flights,on your next model that appears to have a flat wing as scale,try adding a couple of degrees without going overboard and see the difference it makes to the way that it flys.
The swirling or machine effect looks most realistic,the most famous swirled machine was the 'Spirit of St Louis' which had the nose cowlings done in this way.

fli48rc · 29-04-2006

Thanks Barry for the info on my aileron setup... I will make sure more up than down! My next build is a 1/12th scale SE5a, from AerodromeRC... got that built in dihedral!! and 4 working ailerons. Thought I might go with a NightFighter color scheme, but I really do like the C1096 "Maybe", flown by Lt HJ "Hank" Burden in the 56th Squadron in early 1918.