Newbie to 4D VPP (in a flightflex UCANDO)
#1
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Join Date: Dec 2003
Location: Ironhorse,
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Hi, new to this 4D VPP stuff. I'm just setting everything up and haven't flown it yet.
The 411:
Great Planes U Can Do 3D flightflex (put landing gear from a Tensor 4D on it so I can land with the VPP)
Himaxx 2816-890
Some old "Tower Pro?" ESC (Not even sure how to program it, if it is programmable)
VPP101 (http://www.maxxprod.com/mpi/mpi-29a.html) using the 11" blades.
3S 1800mAh
7CAP Futaba (Heli mode)
HS-55 servos
Plane is about 1 lb ready to go. It normally flies great with a 12x6 slow fly prop. Has about 2:1 thrust to weight. I also fly helicopters so I am familiar with 3D throttle/pitch curves. I don't expect any great performance from this set-up, maybe 1.5:1 thrust to weight. I had the plane and thought I'd try it.
First thing I notice is maybe my pitch servo is not strong enough (HS-55). It seems like if the prop is spinning too fast it does not get to full pitch (or full thrust). There is a bit of flex in the whole system, but the servo is mounted basically on the inside of the motor mount stick (so minimal flex from the foam).
I have played around with the throttle and pitch curves to try to keep the RPM down before it gets to full pitch and that seems to be working ok. In throttle hold I get full throw on the pitch. I even set up a throttle/pitch curve to hold the throttle at about 20% and have a normal pitch curve and it gets to full pitch fine.
I guess my question is, are these typical problems with the VPP set-ups? Is a throttle governer mode recommended? Tips? Hints?
Thanks.
The 411:
Great Planes U Can Do 3D flightflex (put landing gear from a Tensor 4D on it so I can land with the VPP)
Himaxx 2816-890
Some old "Tower Pro?" ESC (Not even sure how to program it, if it is programmable)
VPP101 (http://www.maxxprod.com/mpi/mpi-29a.html) using the 11" blades.
3S 1800mAh
7CAP Futaba (Heli mode)
HS-55 servos
Plane is about 1 lb ready to go. It normally flies great with a 12x6 slow fly prop. Has about 2:1 thrust to weight. I also fly helicopters so I am familiar with 3D throttle/pitch curves. I don't expect any great performance from this set-up, maybe 1.5:1 thrust to weight. I had the plane and thought I'd try it.
First thing I notice is maybe my pitch servo is not strong enough (HS-55). It seems like if the prop is spinning too fast it does not get to full pitch (or full thrust). There is a bit of flex in the whole system, but the servo is mounted basically on the inside of the motor mount stick (so minimal flex from the foam).
I have played around with the throttle and pitch curves to try to keep the RPM down before it gets to full pitch and that seems to be working ok. In throttle hold I get full throw on the pitch. I even set up a throttle/pitch curve to hold the throttle at about 20% and have a normal pitch curve and it gets to full pitch fine.
I guess my question is, are these typical problems with the VPP set-ups? Is a throttle governer mode recommended? Tips? Hints?
Thanks.
#3
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Join Date: Mar 2004
Location: Lancaster,
PA
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How much pitch your giving at full throttle, there is to much pitch with the vvp. Throttle governor mode is recommended only if you are over amping your motor. Like WhtBronco said maybe you can get a stronger servo or make the area of the servo more rigid, no flex at all in this area.
Fernando
Fernando