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Carbon Fiber VS Wooden Spars

Posted: September 20th, 2017, 2:02 pm
by Raleway
So FFM last year introduced CF officially in their kits. However, with testing, it seemed that while CF provided better airflow and cut the drag better, it was very susceptible to instability and tipping sometimes. In regards to the bonus this year, I would like to ask the Helicopters forum how they feel CF spars will fare against traditional wooden spars especially in the Chinook design that already has many well-known problems, including stability. Thanks so much in advance!

Re: Carbon Fiber VS Wooden Spars

Posted: September 21st, 2017, 12:54 am
by DoctaDave
Raleway wrote:So FFM last year introduced CF officially in their kits. However, with testing, it seemed that while CF provided better airflow and cut the drag better, it was very susceptible to instability and tipping sometimes. In regards to the bonus this year, I would like to ask the Helicopters forum how they feel CF spars will fare against traditional wooden spars especially in the Chinook design that already has many well-known problems, including stability. Thanks so much in advance!
Using carbon fiber would not make your helicopter more susceptible to instability and tipping.

Materials should not play a role in the stability of the helicopter. The most important thing when making a stable helicopter is insuring that each rotor is constructed as accurately as possible, and as similar to each other as possible. In addition, the axis of rotation of the rotors should be parallel. If you are having trouble constructing your rotors to be identical and in line with each other, try using a vane to increase the moment of inertia of the helicopter.

In fact, I think that CF would make your helicopter more stable, as CF is much straighter and much more consistent in its stiffness compared to balsa wood.

Re: Carbon Fiber VS Wooden Spars

Posted: September 21st, 2017, 9:15 am
by daydreamer0023
DoctaDave wrote:
Raleway wrote:So FFM last year introduced CF officially in their kits. However, with testing, it seemed that while CF provided better airflow and cut the drag better, it was very susceptible to instability and tipping sometimes. In regards to the bonus this year, I would like to ask the Helicopters forum how they feel CF spars will fare against traditional wooden spars especially in the Chinook design that already has many well-known problems, including stability. Thanks so much in advance!
Using carbon fiber would not make your helicopter more susceptible to instability and tipping.

Materials should not play a role in the stability of the helicopter. The most important thing when making a stable helicopter is insuring that each rotor is constructed as accurately as possible, and as similar to each other as possible. In addition, the axis of rotation of the rotors should be parallel. If you are having trouble constructing your rotors to be identical and in line with each other, try using a vane to increase the moment of inertia of the helicopter.

In fact, I think that CF would make your helicopter more stable, as CF is much straighter and much more consistent in its stiffness compared to balsa wood.
Not to mention that carbon fiber breaks MUCH less easily than wooden spars do. Additionally, if materials such as CF made your Heli less stable, I'm not sure as to why it would be used in Indoor Free Flight competitions, such as F1D, if that were the case.

Re: Carbon Fiber VS Wooden Spars

Posted: September 26th, 2017, 8:29 am
by andrew lorino
Just a testimonial. Last year, I got the FFM kit, and due to my exceptional time management skills, I had to test it in a room where thick concrete beams crossed the ceiling. Under the circumstances, a collision was inevitable, and I was worried, based on my experience with balsa, that the helicopter would weed-whacker itself to death without time to repair it. Much to my delight, despite the blades constantly ramming the beam at full torque, there was practically no damage to the helicopter.

Re: Carbon Fiber VS Wooden Spars

Posted: September 26th, 2017, 3:57 pm
by Raleway
:( I guess I'm the anomaly when I've snapped countless rotors by flying them haha :(

Re: Carbon Fiber VS Wooden Spars

Posted: September 26th, 2017, 7:46 pm
by daydreamer0023
Raleway wrote::( I guess I'm the anomaly when I've snapped countless rotors by flying them haha :(
Did they snap at the laser cut rib or straight through the carbon fiber rod? Some of the ribs I got were thin, so I would understand snapping, but it would take a lot to snap carbon fiber...though sometimes the carbon fiber would come apart at joints (which was me not putting enough glue).

Re: Carbon Fiber VS Wooden Spars

Posted: October 7th, 2017, 10:10 pm
by Nano1llus10n
daydreamer0023 wrote:
Raleway wrote::( I guess I'm the anomaly when I've snapped countless rotors by flying them haha :(
Did they snap at the laser cut rib or straight through the carbon fiber rod? Some of the ribs I got were thin, so I would understand snapping, but it would take a lot to snap carbon fiber...though sometimes the carbon fiber would come apart at joints (which was me not putting enough glue).
It's a lot more likely that it snapped at a place on a rib or connection rather than the carbon fiber itself (only possible of breaking if carbon fiber is reused and worn or put under an unlikely amount of pressure). To prevent this, spend time making sure every aspect of your helicopter is perfect and try not to break anything. For connections, use CA (cyanoacrylate) glue.

Re: Carbon Fiber VS Wooden Spars

Posted: October 8th, 2017, 2:38 pm
by Raleway
No, the CF split with ribs also broken. I have sat on a rotor once (black chair + CF = out of sight out of mind) and the CF did also break then. However, I would agree that CF is far more durable than wood and can take more punishment- it also seems they spin faster due to a more aerodynamic edge- so I was just wondering :)

Re: Carbon Fiber VS Wooden Spars

Posted: October 8th, 2017, 3:24 pm
by daydreamer0023
Raleway wrote:No, the CF split with ribs also broken. I have sat on a rotor once (black chair + CF = out of sight out of mind) and the CF did also break then. However, I would agree that CF is far more durable than wood and can take more punishment- it also seems they spin faster due to a more aerodynamic edge- so I was just wondering :)
Hm. Well, sitting on a rotor would be a breakage cause as well...

Re: Carbon Fiber VS Wooden Spars

Posted: October 8th, 2017, 4:10 pm
by Nano1llus10n
Well as I said before, "unlikely amount of pressure" could break the CF, which in this case was you sitting/applying pressure on the rotor. And also, CF is a lot more useful as it has a smaller surface area, letting it easily cut through the air.