3D Printable Nose Landing Gear - Version 4
After countless hours and 4 distinct versions of the landing Gear assembly for the RC L-1011 Airliner, The final design going into to airframe #1 has been completed.
About The assembly:
Nose Gear Steering Servo: FrSky HV5301
Forward Bay Door Servo: FrSky 5701
Main Gear Structure: Taulman 910 Alloy
Frame Mounting Structure: 20% Carbon Fiber Nylon 6:6
Estimated 3D Print Time: 16hrs
The frame mounting structure is bolted directly to the 4 gear bay spars in 4 places. The spars are sandwiched between the two carbon fiber nylon Trunnion Mounting plates
Design Details Video From Nose Gear Version 1
In this quick video, I provide some information regarding the design of the nose gear structure. The prototype you will see is the first version of the gear structure and the housing used to mount into the airframe. The most changed parts of this design have been to the mounting structure. As you can see from the images above, it’s no longer a unibody insert. This change was made due to discoveries made in several test prints with different materials.
3D Stress Simulations From Version 2
Aft Quartering Nose Gear Assembly Safety Factor Simulation
Nose Gear Strut Side Loading Safety Factor Simulation
Nose Gear Strut Backstop 3D Animation Displacement Study
Nose Gear Strut 3D Displacement Study Animation
Why did the gear mount design change?
In an effort to reduce weight, and print time, the mount received several material reduction changes. The side effect of these changes created unacceptable printing problems near the end of the print. As you can see in the images below, the version 2 structure is thin enough, on the vertical axis, to move side to side when the 3D print head lays down a new layer. This movement made print accuracy virtually impossible near the end of the print.
3D Printing Problems
The photos below show the intended version 2 mount design (3D Model) and the actual print.
3D Rendering of Landing Nose Gear Mount - Version 3
The Finalized Airframe #1 Gear Mount and Bay Design
What are the key differences in the final vs original designs?
The nose gear mounting structure is no longer a unibody design. It is now individual key parts that can be 3D printed flat, which increases it’s vertical strength and reduces printing time significantly.
The bay door hinges are no longer 3D printed, instead the hinges are made of the same laser cut 3mm birch ply and inserted into the lower gear bay spars.
The gear actuation is no longer controlled by a rotary servo, instead it is no controlled by a linear servo.
The upper drag link mount is now a separate fixture bolted directly into the upper bay door spars. It also serves as the servo mount which actuates for the forward pay doors
Check out the first version of the nose gear assembly here >
This post will be updated as the build progresses
