kodlovag

Some real progress today. I finished the control system of the aircraft. I had serious problems how to control the rotor tilt and the landing legs. I desperately wanted to add a PF servo to have RC controlled functions, but it simply cannot fit. When I gave up and dropped the servo, things simplified a lot. Now the rotor tilt is manual function, controlled by the pilot. And the best idea today was to use the old 9V System battery box. Much smaller, than any PF battery box, and finally something that could fit easily. Now I only have to finish the chassis, and make a display stand. I will also check the feasibility of HoG controls. And finally some pictures of the finished control system. The big 4 x 8 box supposed to be the old 9V System battery box.

Oh, this plane is huge. I think you can easily fit all the mechanism into it.

I'm not really familiar with these superhero things... And there were more than one batwings. Probably you are referring to this one, below. But I hope my aircraft is not so futuristic, because it is not permitted by the rules. Actually, there is some similarity in the shape. As the Batwing is the earlier, maybe it inspired the designers of the Volante Vision Concept. But I think it is just an accident, and maybe the similarity is only from specific viewing directions.

Slow progress

I made the prototype of the control mixer from real bricks. It works, but the small gears within the differential gear are so slack, that the flaps tilt down by ~10degrees from horizontal in center position, and the elevator movement becomes asymmetric: 10 deg up and 30 down. I have to find out something to center it well... Furthermore I spent the whole weekend on arranging the PF parts and the control mixer in the plane, and failed. I tried to pack everything behind the seats, and it is just impossible. Any attempts have some serious drawbacks. Then yesterday I have the idea to put the control mixer at tail, directly next to the flaps. Then it is no more a problem that the output axles points sideway, it's just the perfect direction. A long control rod for the elevator will be needed, but all of the somewhat useful early attempts also required long control rods. Additionally, the servo now can be placed behind the seats, there is a lot of free space here, and the M-motor should fit too.

Wow, good idea. Simple and effective.

I forgot to write, but I ended at the same conclusion. I need the display stand, because without the servo, the landing legs won't be able to hold the weight of the aircraft. But I want to add the battery box to the plane, to keep some playability.

I searched the web for tank subtractor, and I found good references at Sariel's web page. These subtractors are very similar to my preliminary idea. However, mostly using the old differential, which I have only one. But I learned the principle, and I think, finally fully understood the differential gears, and could create my own optimized solution. Looks rather simple and elegant, only drawback is that the outputs to the flaps are pointing sideways. But any other solutions with outputs backward are far more complicated, because the elevator input cannot be attached in a compact way. One side I'm happy with the control mixer, on the other side I have serious problems. I put the M-motor, the servo, the IR receiver and the battery box to the LDD model, and they occupy more space, than available in the aircraft. And the control mixer uses the same space, as the servo. So some of the functionalities have to be sacrificed. I really want the motor to drive the propellers, so I also need the battery box. If I drop out the servo, than the IR receiver is not really necessary either. But without the servo, I have no idea haw to make the rotor tilt mechanism working on both sides. Still the best idea to drop the servo... And I still have no chassis in the cockpit. Sigh. More sigh. Finally, this is how the aircraft looks now.

Nice truck, compact and detailed. My favorite size range.

Thank you. I was not even thinking in existing airplanes, concept aircrafts are more interesting. The ones, which can be there in the near future. Furthermore it has the advantage, that you do not need to exactly copy the shape, that anybody can recognize it; it's enough that it looks good and provides a plausible way to fly. The canopy was the very first part I selected for the aircraft. This sets the scale of the aircraft. I continued to develop the plane. I worked on it until late night, so I had no time to take an image and share it, so no new progress picture today. Currently I'm working on shaping the circular rotor hole on the back of the plane with the vertical stabilizers. The plane starts to look better, than I ever expected. It's actually quite interesting that I previously considered the bent liftarms are totally useless, while in this design I already used many bent liftarms. I also have a new idea. The plane only have one pair of flaps(?), so the elevator and the aileron should be combined. Now I'm thinking on a mechanism how to combine controls. Normally, in model airplanes this function is done in the controller by electronics, but of course the PF controllers can not do any similar. But I think that the aileron and elevator controls can be combined mechanically by differential gears too. I hope this can be done in limited size, because I'm running out of space. The PF electronics occupies a lot of space, and I don't have BuWizz to save space. The planned functions for the final model are: Spinning rotor and propellers, PF M-motor Tilting front propellers with synchronized landing legs, PF servo Speed control and fine tilt control with the train's PF speed controller Mixed aileron + elevator, manual (HoG + pilot handle) Rudder, manual (HoG + pilot handle) Uh... Long list. I'm back to work...

I think designers are forced to use the new molds, or at least new colors of an existing mold, in every new sets. This is pure business. It is not good for the business, if the lego fan can copy/rebuild the exact same stuff from his/her existing bricks. And therefor the new bricks (molds, colors) are usually used at critical places. And we have to buy the new sets. And TLG following this rule since, well... maybe the beginning.

I had the exact same idea, about covering the gap with cheese slopes. I used that technique in one of my inverse corner modular, and it was possible to completely cover the gap. But my facade used hinge bricks for the diagonal, but this modular uses these new rounded 1x2 plates, and this diagonal technique shifts the stud positions by half. Whatever I'm trying looks just even worse, than the original gapped design. Furthermore the height of a level is 9.something studs, should be increased to 10. The whole upper part of the building should be rebuilt to correct the gaps. I really don't like the upper part of the building. I gave it a chance, but now I also have a failed attempt to correct it. :( Maybe someone else come up with a feasible solution.

I upgraded the propeller tilting mechanism. Now turning the front propellers to vertical direction for takeoff and landing, also automatically opens the landing legs at the end of the wings.

I think the selected architectural style is good. My problem is the realization, which is IMO very very weak.

I'm following my usual building method, starting with the LDD design. This is what I have so far. Selected the propellers for the front and the back. There is a mechanism for turning the rotors from vertical to horizontal powered by a servo motor, and the driving axles for the rotors. Currently I'm trying to shape the wings, it will be harder, than I expected.