To dfc or not to dfc

[Heli biggie]

I think I found the wobble in my head of my trex600 efl pro. Should I upgrade to a dfc head? It says I need to buy blade grips seperate. Can I reuse my stock ones? And can I use my stock swash?

[fastblackbird1]

I like my trex 600 ESP DFC

wha I changed for the conversion

main shaft 600 ESP DFC ( I don't know what shaft you will need for your)
DFC head with swash plate, cause the other swash plate doesn't has same linkage ball size as DFC swash plate. ( this is in my trex 600 esp with a nitro swash plate, so I don't know if all swash plate has same linkage ball size)

also I running 105mm tail blade with not issue

[fastblackbird1]

[Luvmyhelis]

When I did the DFC style mod to one of my 600s I went with the Compass 6hv head. Much better all around. But I have since equipped others an RJX non DFC version after crashing, and have setup two more with them. And really do like the way the RJX head flies. I am so not a fan of the Align DFC version.

[Smoggie]

You can use the stock Align swash, the DFC head kit comes with the required new balls that simply replace the stock balls.

The Align DFC head is rigid, it uses 'dampers' are rock hard plastic, so not really dampers ar all. This 'theoretically' might cause some issues but in practice it seems to work perfectly, at least at my skill level.

[Solmanbandit]

I tried the DFC on my 450 and did not like it. One of the things that I did not like is that it tore up my servos when it crashed. Not just stripped, but burnt out two 5065 Hitec servos on my 450. For my 500 and 600, switching to the Ikon is what turned my my heli's into awesome flying machines.

[Smoggie]

I hear claims that the DFC head puts more stress on servos, but being a mechanical engineer by profession I've looked long and hard at the standard and DFC head arrangements and cant see any reason at all why this would be the case.
In both designs the servos are directly connected to the swash by rigid pushrods and in both cases the swash is connected to the grip control arm, and thus the blade, by another rigid pushrod. So there is no 'give' in either arrangement. The stress on the servos must be identical in both cases.

The only difference between the two is how torque is transferred from head to swash, and the servos play no part in that.

If you crash you have to except that there is a good chance of damaging servos regardless of your rotor head type. If you don't want to break servos, don't change head design, just avoid crashing

[Solmanbandit]

I hear claims that the DFC head puts more stress on servos, but being a mechanical engineer by profession I've looked long and hard at the standard and DFC head arrangements and cant see any reason at all why this would be the case.

Under normal use, I don't see why it would be any harder as well.

If you crash you have to except that there is a good chance of damaging servos regardless of your rotor head type. If you don't want to break servos, don't change head design, just avoid crashing

There is a difference between replacing some gears and having to replace the whole servo. With a standard FBL, the link rod is more likely to bend or give way under extreme loads like in a crash. DFC from my experience transferred the whole load to the servo, thus burning 2 servos in one crash.

[Heli biggie]

1st off I love the brid fast! I bet it looks great in the sky, 2nd thanks alot for all the input. I have a dfc head and ikon on my 450 and love it, more percise I think. I wish i ahd 2 more ikons..... I was told today by helidirect support that if you get the dfc swash also, in a crash the links will pop off causing less wreckage. Compared to keeling the stock swash.

Originally Posted by Solmanbandit

Under normal use, I don't see why it would be any harder as well.




There is a difference between replacing some gears and having to replace the whole servo. With a standard FBL, the link rod is more likely to bend or give way under extreme loads like in a crash. DFC from my experience transferred the whole load to the servo, thus burning 2 servos in one crash.

[Smoggie]

Originally Posted by Solmanbandit

With a standard FBL, the link rod is more likely to bend or give way under extreme loads like in a crash. DFC from my experience transferred the whole load to the servo, thus burning 2 servos in one crash.

If the force was big enough to bend a rod there is still the servo to swash link to bend. Or use plastic arms if it's something you worry a lot about.

[Solmanbandit]

If the force was big enough to bend a rod there is still the servo to swash link to bend. Or use plastic arms if it's something you worry a lot about.

Either way, that was my experience with DFC and wasn't impressed by it. I also did not notice it flying any better than with a standard FBL head.

[Phoinix]

Did any of you guys fly the DFC head at low rpm - 1200?
I'm thinking of replacing my modified Flybared head into DFC, but I'm worried about the damper stiffness and low rpm wobble.

[Ah Clem]

I have converted an Align Trex 600E and the very similar Chaos 600E to FBL using the Compass/TracX heads. These are driverless heads, but not DFC. You can run softer dampers in them if you want to run lower headspeed, as they actually flap:





They are a direct replacement for the heads on the older Trex 600E and 600N (not requiring a shaft change, etc.). I don't recall which generation of Trex 600 the EFL is, at the moment.

[Phoinix]

Thanks, do you have a part number maybe?

[Ah Clem]

Looks like it is out of stock at the moment:

http://www.prostarhobby.com/product-p/08-850x.htm

Also upgraded a Trex 550E:



And a Kyosho Caliber 700 (550 sized model):

[Phoinix]

Thanks for posting. I see the pitch horn/link connection is still rigid flap-wise (the same way as DFC), or an I wrong?

Besides that, any issues during use?

[Ah Clem]

"I see the pitch horn/link connection is still rigid flap-wise (the same way as DFC), or an I wrong?"

Yes, you are wrong!

The black rod between the blade grip and the swashplate ball is actually a hollow tube, designed to flex as the the head flaps. The tubes will shatter in hard crashes and so are easier on servos in an impact (sadly, I have tested this theory several times). There is a bolt to hold the tube to the yoke at the blade grip and a threaded stud at the bottom where the ball link threads on. Note that the shank of the ball link is supported by the tube.

The new Avant head uses a similar design (flexible drive tubes instead of rigid links).

"Besides that, any issues during use?"

None. I have eight or nine of these in service now (I have lost count).

[Phoinix]

Thank you for the information. If only I could get my hands on one of these.

[Trexwilly]

I converted mine to DFC, mine is an older 600CF so I had to wait till they made DFC shafts for the nitro because of the third bearing block thing...

[ReadyToCrash]

align has anounced the end of dfc. the new 700e will use a non-dfc head.