I am building my first 3D-printed RC model airplane.
This will be a "Plane Print" design, and will have a 67½" length.
https://www.planeprint.com/learjet
David printed all the parts for me (I paid him for this) and helped me acquire all the parts needed for assembly. I had the twin 70mm ducted fan (and speed controls already), and test-fitted that they would fit. They do.
After considerable reading, planning and preparation, I started on the fuselage. The design uses small alignment tabs that really help parts fit together properly. I'm using fast, medium and slow CA glue, using my judgement as to which glue is suitable for the task at hand.
Looks incredible. Good luck and thanks for sharing.
looks like quite the build hopefully goes well. I've always wanted to try 3d printing myself. maybe one day ill get a printer.
Working on the elevator ....
David helped me to understand the placement of parts, since we are using an updated version of elevator control; two servos instead of one. There is a separate PDF of alternate instructions for this.
I glued the stabilizer and elevator halves together, but so far, nothing else is glued.
I had to carefully drill/enlarge the holes in the two-part hinges so the wire (that connects the elevators and stabilizers) would flex freely.
I filed the connecting wire to a smoother point, and heated the tip (held briefly to a soldering iron) so I could slightly open the channels through stabilizers and elevators, because it was too tight to assemble.
In order to assemble the parts, I installed the hinges without glue, so the everything would be easier to adjust and align when pushing the connecting wire through the assembly. I will then carefully remove the wire, and drop a small amount of glue into the hinge recess areas.
There's only a few minutes of work here, but hours of thinking and planning.
Coming along nicely Michael
Opposite rotating servos are used for the elevators, one in each stabilizer. The servos are screwed onto 3-D printed mounts, and then glued to the servo hatch cover. Some trimming of the mounts was necessary for a proper fit in the servo bays.
I'm enjoying the assembly/construction. It's challenging and new to me (building a 3-D printed model), but it's fun, and it looks like it's going to be a nice model.
The instructions call for a slop-free connection between the servos and the elevators. I used a ball-link connector with a z-bend tipped wire.
The rudder is secured with screws and small plates over a carbon tube hinge line.
The tail is finished. It's an elegant design.
What a beauty!!
Rudder servo assembly installed.
Nacelles assembled and installed.
Nose gear assembly includes an steerable electric retract and a steering servo with linkage. It works well.
The assembly fits snuggly onto 4 carbon fiver tubes, and it is secured by screws from inside the fuselage.
I have left out a servo and mount for landing gear-door operation, as I am not adding that option to my model.
So far, my method of building for each step is: 40% time and effort for thinking and planning; 40% testing and fitting; and 20% assembling, securing and gluing.
Landing gear installation is complete, except for wiring (it's all tested for good operation).
Correction from the last post: The nose gear assembly is screwed in place from the front; the retract must be removed temporarily to enable this.
Wings assembled. Everything, including servo installation and linkages are exact/precise fits.
FMS 70mm fand installed; proper rotation (wiring) tested prior. Again, precise fit.
The detail & precision is amazing
According to the instructions, the battery tray may be installed forward or rearward of where indicated, in order to achieve proper balance with a battery pack. It looks like I'll have to move the tray forward by a few inches.
Other than that, basic assembly/construction is finished. Wiring, radio, stabilization, etc. installation, fine-tuning and programming is next, and maybe a bit of decoration before a maiden flight.
Wiring complete, some white paint, some black paint, dual rates set up, stabilizer set up, and balanced.
Ready for a maiden flight.
I recommend a bit of paint on the tip tanks and rudder before flight. The visual aid has saved my Albatross from lost orientation.
Here are some photos from the maiden flight today.
A heart-stopping moment when it looked like it tip stalled.
Some of us thought he had bought the farm.
Michael (Sully) was able to re-gain control and brought it in for a safe landing.
The real reason: one of the two fans stopped working.
The photo sequence for the first take-off.
Frank
The landing sequence.
Yes that was Rob Pike for the trim levers.
Frank
Congratulations! ;D
That must have been a beat away from a heart attack. :-X
Takeoff pictures look great.
Good photos, Frank. Thanks.
Absolutely no damage to the airframe; one EDF unit needs to be replaced.
Hopefully, ready to fly in a day or two.
2nd and 3rd flight of the Learjet 35 today. Two new X-Fly 70mm EDFs.
Here's one of the flights:
Fantastic flight! Great landing too.
Congratulations, Michael. I bet that was a more relaxing "Maiden" than the first one.
What was that wiggle dip on approach? Did your throttle hand push full rudder? ;D
Robert
Quote from: piker on July 10, 2025, 11:43:44 PMWhat was that wiggle dip on approach? Did your throttle hand push full rudder? ;D
I don't know. I'm thinking about it.
It looks like it happened right after it sounds like you throttled right down. I wonder of one fan slowed faster than the other, producing a yaw effect.
Anyway, nice recovery.
Quote from: piker on July 11, 2025, 11:25:42 PMI wonder of one fan slowed faster than the other, producing a yaw effect.
You're the second person to suggest that. I was using 2 different brand speed controls, so it's a possibility.
I replaced the 70 amp speed controls (which got really hot) with matching 100s.
No issues now. 4th and 5th flights were better. I even did a roll!
Nylon sticker windows added (Thanks David).
Flew beautifully - congratulations Michael!
The view from my office today just happened to be a Lear 35 with extra long tip tanks. ;D
What a coincidence. Here's the view in my basement.