June 19, 201410 yr Author Well, though this thread is almost dead, I have some new vitality for it. I was waiting for my last order with motors and batteries 3+ months since February and it finally arrived. Then it took some time to actually do something. Main thing I'm happy about is that new batteries and ESC fit into wing root: two more: So, it still goes :)
June 19, 201410 yr what about using a small LPE to power the plane, it would provide sufficient torque and RPMs.
June 19, 201410 yr 1403193976[/url'>' post='1919390']what about using a small LPE to power the plane, it would provide sufficient torque and RPMs. Personally I think that it would be difficult for Whale2 to feed a LPE, unless he used a co2 tank or air hose to feed such an engine. His current setup using the batteries and electric motors is most likely more efficient than a LPE, besides my previous point. Even though I may be wrong. Whale2, I wish you the best of luck with your very ambitios project! John Edited June 19, 201410 yr by John Daniels
June 19, 201410 yr I'm not good with words at the best of times but with this that doesn't matter, there just are none!
November 7, 201410 yr Author Well, the project is not dead yet though moves very-very slowly :) Finished the right wing and re-designed flap deployment mechanism. Some more photos about it (missing half of the flap, aileron and some space between it and rest of the wing, now filled but no photo yet).
November 8, 201410 yr All this non purist thing is TLC fault. They fail year after year at meeting AFOL expectations on several fronts, hence people feel more inclined to look for solutions out of Lego inventory in order of meeting their goals. And I think it is good, Thinking outside the box is always good. No, it's peoples/AFOLs expectations of what LEGO can do that is wrong. It would require a whole new line of parts to make even a simple, _reliable_ RC vehicle. They did that in the past with sets like 8366, but all RC parts we're integrated, not really LEGO as such And it was still a poor performer Even if they offered more powerfull motors/batteries, proper RC, ballbearings etc, the structual integrity of the System/Technic parts are not durable enough Also, flying things are not what parents should buy little Johnny for his six year birthday. And they will if such a product was made Jacking up standard LEGO parts with custom motors/batteries/RC will destroy/wear out the LEGO parts in a heartbeat and TLG would never put such a product in production You know, you can actually scratchbuild RC cars/planes etc. There are thousands of parts out there, you don't need to by a RTR (ready to run), you can DIY it, much like building with LEGO. I know, 'cause that's what I do I'm sure TLG intentionally chose the crappy IR system for their remote controlled sets, just so it's not possible to compete with proper RC. 2,4GHz is very cheap now Good luck to the OP, but I think we'll see real flying cars and fusion energy before LEGO flies proper Allways a good idea to think outside the box, yes, but sometimes you start with the wrong box Imho that is ...
November 8, 201410 yr No matter how long it takes to finish, this is truly a project to be proud of. I'm looking forward one day to seeing where this goes! I don't find any fault with your using non-TLG motors and other parts - a project of that size just can't be supported by anything for sale at the moment. Best of luck, and clear skies!
November 8, 201410 yr This definitely is a first out of Lego. The only worry is that the micro motors will be too slow for the flap and other controls? Can't wait.
November 9, 201410 yr Author Thank for support, guys. I hope this thread does not make anyone upset because of all that non-TLG stuff, however, while it is here I''m going to keep posting my progress. Regarding weight - it should be about 5000g and I expect stall speed to be around 40kph. I'm still not sure if undercarriage will survive it. If not, I'm going to revert to plan B - much simpler design, like biplanes of 20-30s, with single prop, no-retractable undercarriage and fuselage made of technic panels. Actuall I should have started with it from beginning, but it was so sudden and now I have what I have :) Micromotors and their speed - when I tried aileron control (there is a video somewhere above in this thread) it was not very fast, but I used conventional square 9v battery for this and connected to ESC (with BEC, for powering receiver and servo circuit board) it's voltage dropped to about 7v. Main batteries have voltage of 14.4 and, say, 13v under load and this is about two times more than 7v so motors should operate faster than in video. If this would not be enough, more little and light batteries could be installed for this only circuit, up to the level micromotor could sustain.
November 17, 201410 yr Author Potentiometer for control surfaces integration. Extensive use of a file makes it possible to fit it into 1x1 space :)
November 17, 201410 yr It's rather depressing to see this kind of budget and so many parts (all these micromotors!) pumped into something that, with all due respect, has no right to work. Most RC planes and drones stay under 500 grams and use super-efficient motors and lightweight bodies. My Parrot drone is dead simple and very light, but its main structure is made of carbon fiber tubes. You want to go 10 times that weight with plastic, loosely connected bricks. I would say your project is good, you're just developing it on the wrong planet - it's more likely to work on the Moon, with gravity six times lower (but then there's no atmosphere, damn you Moon). If you ever actually try this thing, I fear damage to Lego pieces will be catastrophic. I doubt it will leave the ground or even move, but how are you going to stop these motors and propellers from simply tearing the nacelles to shreds? Once they develop any significant thrust, what is keeping them attached to the rest of the structure? A few Lego bricks? Drones use several thick solid steel screws for that. I'm afraid they will simply burst through the structure forward and that's it. Not to mention stuff like balancing the whole plane out, so it doesn't go upside down in the air, testing landing gear's placement and strength, and so on. Professional builders of RC planes usually get a few crashes when developing something new - in your case, every single crash means going back to step 1, only with many pieces damaged beyond repair (these poor micromotors)! Edited November 17, 201410 yr by Sariel
November 17, 201410 yr Author Well, 500 g is a bit exaggerated. There are several commercially available models with comparable wing area that weigh about 3000 - 3500 g, so I'm of course out of typical envelope, but not that far. Airspeed should compensate this, however, making handling harder. And as it was said in very first post, almost all parts are glued except some covering for allowing to assemble and service some inner parts.
November 17, 201410 yr Airspeed is surely great, except it comes with added structural stress. And sorry for stupid question, but how is the aerodynamic profile of your wings? Any test on thrust and drag?
November 17, 201410 yr I am surprised you are using micro motors for the flaps,would using m motors not be better since they would be faster,you may find that micro motors slip when raising the flaps.
November 17, 201410 yr Author Ha-ha, sarcasm detected :) Well, *some* tests were made, but you convinced me to make more. Thinking on setup. I am surprised you are using micro motors for the flaps,would using m motors not be better since they would be faster,you may find that micro motors slip when raising the flaps. Flaps are operated via mini-LA. With, say, 10% of efficiency of mini-LA, there should be about 8 N*cm to deflect the flap. Seems enough to me. Ailerons are on direct drive - there's no space for M-motors in the wing. Torque on ailerons should not be that much on speeds up to 80-100 kph.
November 17, 201410 yr "...has no right to work" is what people would say of the 747 if they saw one in the 1920s is what people would say of electric lightbulbs when they were invetned - but as Edison said "I have not failed 10,000 times I just found 10,000 ways that do not work.... getting it airborne is possible - keeping it airborne is the next episode of this adventure...
November 17, 201410 yr "...has no right to work" is what people would say of the 747 if they saw one in the 1920s Yes, and you know why? Because it was not possible with 1920s' technology. Just as it is not possible with current Power Functions technology. Also, as somebody already pointed out, the Wright brothers started dead simple - here we have fancy stuff like retractable landing gear while the model itself has never been airborne. I'm really afraid this is one of these 10,000 lightbulbs that won't work. I'm really not trying to be sarcastic, sorry if I sound like that. Just trying to spare the author harsh disappointment and a lot of wasted money. Edited November 17, 201410 yr by Sariel
November 17, 201410 yr getting it airborne is possible - keeping it airborne is the next episode of this adventure... Like pushing it from top of a skyscraper? It will remain in air, at least before it hits the ground :)
November 17, 201410 yr Author I admit I started too ambitious, but now I'm way too far from start and there's no big deal in falling into '10,000 wrong bulbs' category :)
November 17, 201410 yr I belive that there's a way to make a LEGO-based plane, and that you are very close to it. But as many people said here, things like retractable gear, and all other features of real planes make it only more impossible. ;)
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