N1UT - construction is in progress
Elevators, trimmer
Elevator -----
---- this portion is under construction

Elevator trimmer.
Trimmer mechanism has been designed based on FUTUBA Servos and on specially designed by Umbrella Technologies, Inc. Servo control unit UNET-servo. This unit is a standalone DSP-driven controller with ability to be adjusted by programming Zero position, +/- angle for deflation and travel speed.
SERVO - there is a wide spctrum of servos on the hobby market priced from $12 and up to $150 for 2BB metal gear one. Choose the best one with at least 3kg torque and 2BB. Plastic will work, but I think that after a year or so it needs to be replaced.
Trimmer tab - should be mounted on ball bearing hinges, but it is possible to install it on plastic hinges (310 series). Surface of the tab is an open issue. Based on comparison by surface and simple calculations it should be 11" by 3" or 33" sq. Trimmer surfaces are manufactured by cutting of elevator surface and installation of ball bearing support. It is rigid and virtually backlash-play-free.
Linkage adjustment - the maximum angle for trimmer tab should be around +/- 20 degree. Servo works well for +/- 30 degree, so make servo arm shorter and tab arm longer to satisfy these requirements.
Servo control unit - I use one with precision positioning (256 steps for full travel !), which is controlled by a push button and has programmable Zero position, angle, and travel speed. This unit has been designed by Umbrella Technologies, Inc. and named UNET-servo. It could be connected to UNET network in the future to provide remote access to start moving and to provide data for displaynig current trimmer angle. To order UNET-servo module send an e-mail to UNET master. Specify type of controller and quantity. Same control modules could be used to control both elevator trimmer servos or another UNET-servo module could be used for aeleron trimmer as well. This unit has dual outputs for same servo phase control and one output for negative phase. UNET-servo is a universal module, and you need to have two of them, one for aelerons and another one for elevator trimmer. Price depends on features and scalability. If you do not need UNET™ network features, it will cost less then $100 a unit (!). Ask them, they could quote you differently. Do not shoot the messanger.

Elevator trimmer Preparation for installation of servo mechanism into elevator
Elevator trimmer Servo in cradle
Elevator trimmer Ball bearing bracket hard point installation
Elevator trimmer View of trimmer tab slot and servo cradle
Elevator trimmer Servo with arm and link attached
Elevator trimmer Servo cover plate installation
You need to firmly connect the cover plate to the hardpoinds and
be sure that everything is aligned well.
Elevator trimmer Assembled trimmer
Elevator trimmer Assembled trimmer and torque tube
Look how wires go through elevator and torque tube
Elevator trimmer Torque tube and wire attached to terminal header
Wires should be gently come out from torque tube.
Be sure that everything is aligned well.
Elevator trimmer Servo almost the best fit for this application - Futuba FP9304
Speed - 0.22 sec / 60 degree
Torque - 69 oz-in / 5.0 kg-sm
Size - 1.59 x 0.79 x 1.40 in / 40.5 x 20 x 35.5 mm
Weight - 1.76 oz / 50g
SRP - $150.00 (but you can find cheaper in your local hobby shop)
Elevator trimmer Animation - principal; explanation
More pictures coming soon! Come back to see and learn more.





This is neither the official Velocity Inc. site nor even the unofficial Velocity site.
This web page simply describes our experience of a Velocity Elite RG
construction project as it progresses.


Umbrella Aviation