Mode Zero

hi Guys

I'm building a Veron Deacon which shows a C of G around the 60% mark.

Is this a trait of FF models or is the plan wrong?

It's the way these free flight models with a large lifting-section tailplane were rigged. The (what Americans call) horizontal stabilizers on these planes are so big, in comparison to the wing, that they're close to tandem wing designs.

For radio control, I think it's better to move the c.g. forwards - at least to 50% but preferably 33% of the wing chord.

I would also change the lifting section tailplane to a flat plate and reduce the tailplane area somewhat. It's not really necessary and if you want to stay true to the original design you could keep the area the same, but unless you're a real stickler for authenticity you could still change the lifting section to a flat plate.

If you're not too bothered about modifying the design a little to make it fly better as a radio plane, the other two changes that help are to reduce the dihedral to about 2/3 of the amount shown on the plan, and increase the fin area somewhat.

Like I say, none of the changes except for moving the c.g. forward are really necessary - but they do make flying the plane under r/c guidance easier and more satisfying.

Hmm - well my experience is quite different - but then I like to fly my deacon in the traditional free flight style (short powered climb followed by long floaty glide) rather than powered cruising. My CG is at 3 3/4 inches back i.e. 47%. This required 3/8" packing under the trailng edge of the tailplane to get the glide right. It flies beautifully and has more than enough decalage to recover positively from spirals.

I did try 33% but had to add 4oz lead to the nose and more than 1/2" tail packing. This adversely affected the climb and gave a poor glide.

My tailplane is as per plan and works fine as is the fin.

I built my Deacon as per plan initially but from memory, I ended up moving the CoG forward about 10mm & packing the tailplane TE up about 4-5mm. It putters around nicely with a very tired Taipan 1.5cc diesel - very much radio interfered free flight, using the "trim tab" rudder & and bang-bang rudder only.

How you set up the model depends very much on how you want to fly it. If you wish to fly it more like a "conventional" r/c aeroplane (say rudder, elevator & throttle) then follow Martin's advice. If your preference is less guidance & more f/f, then make the changes minimal along the lines of what Paul & I did.

Whichever way you go, the Deacon & its little brother the Cardinal, are great flyers - have fun

Thanks for all the advice guys. I will be flying the model on bang bang S/C using an old RCS transmitter converted to 2.4ghz (when I can spirit a compound escapement up from somewhere). lol

I have not flown S/C for nearly fifty years. My old routine was to test fly over long grass with just a few seconds worth of fuel which worked pretty well. They pretty much flew themselves with the odd button press from me.

Hi,
I have an Elmic compact I could part with, or a sequential one if that's what you prefer. You understand that Phil's emulator jobbie is much more reliable and less fuss than original gear but if you really want authenticity then send me a pm.
Gary

Yes they had a large tail plane which had a lifting section. Great for long glides but another reason was to stop ballooning when the model built up speed as the tail would lift the tail, which works providing the speed is not excessive. I moved the CG fwd an inch which helps it in a wind. Great to fly.