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What is DFC?

Toadster25

Key Veteran

Iowa

I've been flying rc helis for close to 20 years and haven't been keeping up with all the newest and latest stuff lately but keep seeing a lot of talk about DFC and I don't know what it stands for? I'm sure it's a stupid question but I just haven't seen anywhere what it stands for. I've just started seeing this talked about this year.

01-25-2013 Over year old.
rexxigpilot

Elite Veteran

Florida

Direct Flight Control

Realy not much different than a standard flybarless setup, except the links between the swash and blade grips have less flex/movement in any direction other than to create axial rotation of the grip. There is no swash driver. The links do this function instead as they are rigid.

Look at the DFC head/links on a Goblin 700 versus a standard setup on a Logo 700 to see the difference.

01-25-2013 Over year old.
Santiago P

rrProfessor

South West, Ohio

DFC is a misnomer, but more specific, a name cointed by Align to descrive their none-swash-follower heads.

direct flight control...


In a traditional flybareless head, the control link goes DIRECTLY from the swash to the blade grip. The swash follower in not in the way of the control link, it ONLY keeps the swash timing fixed with the head. All traditional flybareless heads are truly direct flight control from swash to grip.

Whats the difference?
DFC setup does away with the swash follower and uses a rigid control arm that moves with the blade grip. So now the blade grip is pushing the swash around through the L shape arm that also serves as the control input.

The problem: ALL modern RC heli heads are design around a floating axle to allow to blade grips to move according to the uneven loads in flight and absorb all sorts of vibrations occurring constantly in a helicopter head. With the axle movement, the control arms are now in continous bending.

yep.

The fix, use kryptonite hard dampeners to prervent the axle from moving to protect the controls arms from bending, but live the vibratory head stresses.

SAB started with it, but IMO I see them slowly phasing it out. Smart guys!

S

01-26-2013 Over year old.
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fastflyer20

Key Veteran

N. Tonawanda, NY

DFC is a marketing technique in an attempt to get us to spend more money

01-26-2013 Over year old.
steph280

Elite Veteran

Irvine, California

Great explanation above.

Just wanted to add the effect of having DFC over traditional fbl head. Because of the lack of swash follower, they are able to shorten the main shaft bringing the head closer to heli frame. So the cyclic becomes noticeably quicker. And fast forward flight is noticeably faster.

I for one love it. There are always nay sayers who hate it, and will bring up endless reasons why you should hate it. It's all personal preference so give it a try then decide for yourself.

Btw SAB wasn't the first one to have this, nor was it Compass. It was minikopter and they still utilize this design.

01-26-2013 Over year old.
Santiago P

rrProfessor

South West, Ohio

Btw SAB wasn't the first one to have this, nor was it Compass. It was minikopter and they still utilize this design.
You mean bringing the head down to improve cyclics? Not sure if Minicopter was the 1st but their machines do have a very low head and still have a follower.


The effect of the lower head works on every helicopter, thats why DFC owners enjoy of faster cyclics. The flip side is, less clearance to the boom, but then the curse of the super stiff head becomes a good thing. Still, SAB (new head), Minicopter, and others have figure out the "low" sweet spot, with a sound design, more flexible dampening choises and still using a follower.

santiago

Team Minicopter - PeakAircraft.com
Scorpion Motors - bavarianDEMON - Team Kontronik USA

01-26-2013 Over year old.
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What is DFC?

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