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polyfractal posted:Thoughts before I start telling other people about it? Useful? Horrible? Worst website ever? ----------------- I need a consult. I recently inherited a pre-rc plane (google tells me it's called a control line plane). I'm considering converting it from gas to electric powered, but I'm wondering if it's possible to convert it to full rc. Right now it only has rear elevator control and both of them are tied together. I could separate them, but how well would a plane control with just the rear. I could probably add a rudder fairly easily, but adding controls to the main wings would require a lot more work. Also, how would I decide how much power I need. I've never flown a plane before so any insight or suggestions would be appreciated.  The plane is 3 feet wide and weighs practically nothing.
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Jun 19, 2012 03:23
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You can actually buy electric control systems to run a control line plane in the traditional manner. http://www.horizonhobby.com/products/control-line-motor-timer-EFLA172 Converting a control line plane to R/C is doable but I would not recomend it as a way to get started. That plane has a pretty flat wing so I would add ailerons to the wing and forget about the rudder as it would be pretty ineffective.
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Jun 19, 2012 21:25
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I wouldn't risk crashing it as my first lesson in flying. I'm probably going to buy the floater that everyone has recommended to learn with. Either that or I'll make one of those foam v planes. I haven't decided yet. Looking at youtube videos it seems like there are small planes that fly using only an elevator and rudder; though adding ailerons would probably be the correct thing to do. I'll have to study some more wind designs to see how I want to implement it.
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Jun 20, 2012 03:10
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Another thing to keep in mind is that control line planes sometimes have one wing longer than the other. It's hard to tell for sure from your picture but it looks like the port wing is short than the starboard. If you've never flown a fixed wing before, a foam 3-channel high wing design with a good bit of dihedral would be your best bet. Something like this is awesome to get started. It comes in RTF and BNF. Flies well and repairs with hot glue and packing tape in a snap. Lots of people have converted it to 4 channel with ailerons fairly easily. http://www.hobbyking.com has similar aircraft to this one for less $.
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Jun 23, 2012 01:33
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Project update: This flies now. Went with Chinese multiwii board. One handed maiden : https://www.youtube.com/watch?v=3LmCBJ2F_i4 Still need to balance props and tune settings. I wasn't patient enough. Had to see if it would fly. No damage on my maiden for once... can't wait to get it dialed in and put a camera on it. ease fucked around with this message at 00:41 on Jun 25, 2012 |
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Jun 25, 2012 00:38
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Get a tupperware or some kind of box to cover your board with. I guarantee that you're going to pancake flip that copter, and if you want the board to survive you need to protect it.
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Jun 25, 2012 01:48
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So it's not nearly as cool as the quads you guys are building, but I purchased a AR.Drone 2.0 and it just arrived. Holy hell that thing is a lot of fun! Even on the stock 8 minute battery, it's really fun flying around. Can't wait for work to lighten up so I'll have time to mess around with a true DIY quad. 
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Jun 26, 2012 19:53
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The automatic levelling of the AR Drone will spoil you rotten.
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Jun 26, 2012 20:38
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I have a few questions about quadrotors that are more theoretical than anywhere close to becoming a reality. 1. Can varying pitch of the propellers (if you are driving all the propellers from a single power source) give you all the steering and maneuverability that changing the power to the motors of a 1 motor per propeller quadrotor? The quadrotor Wikipedia page is a little confusing about this. I'm more wondering if you had a single turboshaft engine running the whole thing would it still be a maneuverable vehicle. 1a. IS there any real way to vary RPM on one propeller in a setup where there is only 1 engine driving all 4 propellers (short of throwing in a CVT)? 2. Why aren't there more ducted fans in quadrotors? I know that fans are generally more efficient than open propellers, but does that efficiency just not scale down as well, is the cost/complexity just not justified at the lower altitudes that these are working with, or am I just completely over-thinking it and propellers are just easier? 3. Not RC related but it is a quadrotor! Man/pedal powered quadrotor. Pretty drat cool if you ask me!
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Jun 27, 2012 01:18
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Essentially all those things are not done because they introduce mechanical bits that can fail or they reduce efficiency. People have made single motor variable pitch prop quadcopters and they work ok but now you have the added weight of a drive system four servos and the VPP systems tend to be much less efficient than boring old fixed pitched props. Electric ducted fans are good at moving small volumes of air at very high velocity. Multirotors need low exhaust velocity and high static trust since the aircraft are essentially stationary.
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Jun 27, 2012 02:06
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Since we are talking theoretical multirotor physics, here's a question I was idly thinking about earlier. I know you can't have a gas powered multirotor since the engine can't change RPM fast enough to compensate for the inherent instability. Would it be possible to have one large gas rotor, helicopter style, stabilized by four small electric rotors on the edges? Main gas rotor provides lift while the small electric rotors provide counter-torque, stability and maneuverability?
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Jun 27, 2012 04:00
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https://www.youtube.com/watch?v=uGZqF7R4I80
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Jun 29, 2012 17:48
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 Is it okay?
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Jun 29, 2012 21:05
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Haha yeah it's fine, just a little crunched nose. Replaced the Chinese motor shaft with one from the LHS and it's still perfectly straight lol
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Jun 30, 2012 04:52
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Neatened up the wiring : Took me a while to figur out the art of PID tuning and I've got a pretty stable setup now. It's much easier to fly than when I was figuring things out. Check out this guys tri, i think his settings are similiar to what I was trying to learn to fly on. https://www.youtube.com/watch?v=GcpHA-U4-XA Also, Gaui props are the poo poo. I've had a ton of prop strikes on everything from grass to a piano and they dont break, just bend. ease fucked around with this message at 18:15 on Jul 1, 2012 |
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Jul 1, 2012 17:13
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And video rx/tx ordered. Decided to go 5.8ghz. I need to get a cheap camera for now, any suggestions? This is the package I bought : http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200774928836#ht_1864wt_1344
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Jul 5, 2012 20:03
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This thread needs more people posting than me. Apparently someone flew a delta wing up pretty high with balloons and flew down FPV style :  http://www.rcgroups.com/forums/showpost.php?p=22114016&postcount=9531 On my FPV note, I actually cancelled that ebay auction and ended up buying a used fatshark setup instead. Came with bluebeams and a nice sony ccd. Going to upgrade my tx to the 600mw RMRC one.
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Jul 9, 2012 14:58
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Make sure that the video transmitter is compatible with your receiver. Fatshark's tx/rx operate on different frequencies than the chinese ones. All the transmitters on RMRC look like they're fatshark compatible. Fatshark Frequencies: quote:5740, 5760, 5780, 5800, 5820, 5840, 5860MHz chinese frequencies: quote:CH1---5705---MHz
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Jul 9, 2012 17:08
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ease posted:This thread needs more people posting than me. Here have a dead-stick landing from ~2000ft AGL. https://www.youtube.com/watch?v=TCNlUgRJ5Mc
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Jul 9, 2012 21:53
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^-  Richie SpiceI have an unused HK KK board I'll ship to someone for for the cost of shipping (small flat rate box). First person to reply here gets it. http://www.hobbyking.com/hobbyking/store/__21977__HobbyKing_Multi_Rotor_Control_Board_V3_0_Atmega328_PA_.html ease fucked around with this message at 00:11 on Jul 10, 2012 |
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Jul 10, 2012 00:08
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ease posted:^- I could use that for my quadcopter project.  PM me
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Jul 10, 2012 00:15
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So I work at an ecommerce company that carries GreatPlanes stuff and they made a purchasing error awhile back by buying some of these before they figured out they couldn't reliably ship them safely. They have been sitting in our warehouse for over a year now and the decision came down to just give them away, so I went ahead and snagged one because why the hell would I pass up on a $1000 remote plane? So, my choices are to either turn this thing into a weird wall hanger in my basement or to actually try and get it flying. For the record, I have never flown anything more complicated then $40 remote control helicopters before. Thoughts? Opinions? Anubis fucked around with this message at 16:45 on Jul 10, 2012 |
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Jul 10, 2012 16:38
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Wall hanger. You WILL crash that and it WILL magically transform into a hundred thousand matchsticks.
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Jul 10, 2012 17:23
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Learn to fly it, get a cat. Cat pilot.
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Jul 10, 2012 17:41
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Slanderer posted:Learn to fly it, get a cat. This is obviously the correct answer. Step one is apparently going to be getting it home. It's a rather large set of boxes so I'm going to maybe have to get my 8' trailer just to bring the box in.
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Jul 10, 2012 20:47
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Time for some updates in this thread! I haven't posted in here in way too long, even though I haven't been working on my quads for at least a month. I got a lot to catch up on, so let me start with Product Reviews. DuraTrax Ultimate E-Clip Tool Ok, this isn't a big review, but I found this guy handy. Regular e-clip tools werre all way to big for the clips on my motor shafts. Working with those e-clips using pliers sucked--I'd have to seriously deform it to remove it, and when getting it back on, I was liable to lose it. While spares from rctimer definitely helped, it wasn't ideal. I found this guy through a google product search, but all the retailers I found were sold out (not sure if this is still true)> However, I was able to get it from ebay!. While it may not really be worth the full $20, it's sturdy enough, pretty small, and using it means I don't have to worry about an e-clip slipping out of my pliers and springing up into my eye again. Hobbyking Alloy Transmitter & Gear Case. Carrying and transporting my transmitter (Turnigy 9x) has been annoying--the handle is awkward to use when you got other stuff in your hand, and when I'm grabbing for it, I'm more likely to pick it up by the antenna instead. Sure, I have a neckstrap, but I try not to wear it, since it's pretty dorky. It obviously doesn't fit great in boxes with other stuff, and the screen is easy to scratch. This case is cheap, light, and sturdy. With the exception of the same standard "locks" that you find on art supply cases, footlockers, and other non-critical storage, it doesn't actually feel cheap. The cutout fits my transmitter well, and there are different sized cutouts in the foam you can remove for even bigger transmitters. There are also cutouts you can remove for smaller stuff (receivers, I guess?). It goes really goddamn well with a similar aluminum toolcase I got from harbor freight. I actually have to recommend that guy as well, if I can find it again--big briefcase size, with the same locks and shoulder strap as this case. The "bottom" compartment comes with both flexible dividers and a pelican-style breakaway foam insert (for those who aren't familiar, it's a foam insert that fills the entire case, and is partially perforated so that individual small squares can be torn out, and you can make form-fitting compartments for specific equipment. The top side of the case comes with both an egg crate foam insert, as well as a removable insert with pockets/holsters for lots of tools. The entire case has enough storage for me to hold all the hand tools I need for repair, maintenance, and most rebuilding, 5-6 spare batteries, all of my electronic tools (programmer, ESC programmer, tachometer, power monitor, cell voltage checker), spare parts, and anything else I need to fix just about any damage. Combined with my transmitter case, I have just about everything I need for an afternoon of loving around with my quads at CMU. KK2.0 Control Board This new version of the KK board replaces the piezo gyros with MEMS, adds MEMS accelerometers and an LCD screen, and gets rid of those lovely goddamn potentiometers. Ignoring the new features entirely, the addition of the backlit LCD is a huge improvement, as it allows digital control over the PI controller variables, instead of gains being crudely set by trimpots (that were also annoyingly multiplexed for other settings). Although the manual is utter poo poo, setting the hardware configuration for your multirotor is easier with helpful diagrams displaying motor numbering (and maybe direction, I forget). If you need something more exotic, you can also go to the mixer and configure it manually, but I didn't need to do that. Tuning the PI controller was really easy, and gives you more control than with the KK board (since here you can configure the P and I gains and limits for all 3 rotational axes). Otherwise, it's still pretty lovely. The "autolevel" is barely that, due to the lack of an actual sensor fusion algorithm. Coming from the ardupilot, which I'm told uses a direction cosine matrix algorithm, it's pretty much crap. Schematics haven't been released (although it's not really that complicated, so a full schematic could be generated pretty easily. Someone already has their own code running and drawing to the LCD), and the firmware is closed. It doesn't help that rcgroups is even more fanboyish and unreadable than usual with regard to the KK2.0, with the general opinion being that "pro's don't need autolevel anyway! it's for newbs! / "HOW DARE YOU CRITICIZE HIM!?!? YOU ARE BUYING THE HARDWARE NOT THE SOFTWARE" / "Well, I've never used an actual non-poo poo controller, so this MUST be the correct way for autoleveling to work, right? It's not autoHANDHOLDING!" And so on. As it stands, the autolevel sorta helps for landings, at least when you're far enough away that you need some help, but otherwise it basically overdamps the controls. So, yeah. Until someone gets around to writing decent firmware, it's only useful as an improved KK board--and it does this job very well, at only $30 from hking. Admittedly, there is another feature I haven't gotten to try "height dampening", but I assume it's a pretty piss-poor attempt at making an altitude hold based only on the accelerometer, with the same shittiness that is present in the autolevel. Turnigy 7 in 1 Mega Meter Not too much to say, as I haven't gotten to use mine much. Another rebranded item, but it's pretty legit in it's plastic case. It's tiny, light, and replaces a bunch of instruments (but I haven't done any head-to-head comparisons). In theory, it is a cell voltage monitor, internal resistance meter, tachometer, servo/ESC tester, thermometer, and power meter. It comes with 2 sets of half-finished leads that you can solder your battery connector of choice onto (XT60 baby!), as well as the temperature probe. Although it's not really a probe, since it's huge. I'm pretty sure it's just a standard 3-wire semiconductor temperature sensor. Along with the big to-92 package, it's probably only roughly-accurate without calibration, which is a shame. A thermocouple probe would have been a lot easier and more accurate, especially since it could be taped to the side of a pack to monitor the temperature with a lot less thermal resistance...but that would have required additional conditioning circuitry, so I'm not surprised it isn't here. The menu is pretty frustrating to navigate, if only because it has 3 instead of 4 buttons. Otherwise, it's probably pretty good value at just under $40. Okay, I think that's enough for now. I was going to give my mixed-opinions on this prop balancer, but that can wait until another time.
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Jul 16, 2012 15:54
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So.. I found out last night that a MSR and MCX will carry video camera.... I need to order one of those keychain cameras and buzz my back yard. OH yeah, and i bought a MCX2. Because I melted the rotors, and body on my MSR, and MCX. Don't leave them in your car people. :-) Nerobro fucked around with this message at 16:03 on Jul 16, 2012 |
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Jul 16, 2012 16:00
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Nerobro posted:So.. I found out last night that a MSR and MCX will carry video camera.... I need to order one of those keychain cameras and buzz my back yard. Wait, it melted in your car? Wow, why the hell would they make it with ultra-low melting temperature plastic? That's just asking for trouble.
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Jul 16, 2012 19:34
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Slanderer posted:Wait, it melted in your car? Wow, why the hell would they make it with ultra-low melting temperature plastic? That's just asking for trouble. Yes, both canopies, for my MSR and MCX melted in my car. And the rotor blades for my MCX. That said.. sit a car in the sun all day on a 105 deg day.. and it's hard to blame the plastic for becoming.. uh.. plastic.
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Jul 16, 2012 19:40
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Here's my latest plane. It's the Pitts Challenger. My buddy is down the street from RCFoam.com's warehouse so he hooked me up with some free Depron! Specs: 30" wingspan 34" length 705g AUW with 1300mah 794g AUW with 2200mah Turnigy 2826/6 2200kv motor with 7x5 prop ~350 watts Rangelink 200mw 5.8ghz vtx module with CCD Killer camera The motor is way too inefficient in this set-up, only getting about 5 mins off 2200mah! I have a similar size 1000kv motor and 9x7.5 prop that should work well. I also added some landing gear for the maiden.       https://www.youtube.com/watch?v=T59-LPM-1d0
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Jul 20, 2012 16:48
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This is pretty cool: https://www.youtube.com/watch?v=FX_YU9V5VHA
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Jul 27, 2012 15:48
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polyfractal posted:This is pretty cool: https://www.youtube.com/watch?v=FX_YU9V5VHA ahhh variable pitch on a F3P... Yeah that plane can fly backwards.
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Jul 27, 2012 17:20
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So, inspired by this thread I have been building a quadcopter slowly over the last few months and finally have something that looks like a flying machine. So far its only got one motor+rotor so it obviously doesn't fly yet. Its a 14"x7 prop so its a lot larger than most setups I see. What kind of amperage to lift numbers do you guys usually see? Right now I get about 180 - 140 grams of lift per amp and I'm wondering if that is comparable? Right now I'm using a 3S battery and max out that single prop at 3.4 amps for 470 grams of thrust (138gm/amp). Am I right in thinking that a large prop might be more efficient for moving the most weight? If anyone has any questions about my setup ask away. Hopefully I'll get the rest of the parts in the mail this week. EDIT: Added some raw motor data that I collected below. pre:PPT(uS) RPM Thrust(g) Volts Amps g/Amp RPM/g RPM/Amp RPM/V 1300 1212.5 40 12.3 0.25 160.00 30.31 4850.00 98.58 1350 1425 70 12.3 0.33 212.12 20.36 4318.18 115.85 1400 1650 90 12.2 0.44 204.55 18.33 3750.00 135.25 1450 1815 110 12.2 0.54 203.70 16.50 3361.11 148.77 1500 2050 140 12.2 0.71 197.18 14.64 2887.32 168.03 1550 2225 170 12.1 0.88 193.18 13.09 2528.41 183.88 1600 2490 220 12.1 1.2 183.33 11.32 2075.00 205.79 1650 2725 270 12 1.5 180.00 10.09 1816.67 227.08 1700 2975 320 12 1.9 168.42 9.30 1565.79 247.92 1750 3200 360 12 2.35 153.19 8.89 1361.70 266.67 1800 3387 420 11.9 2.8 150.00 8.06 1209.64 284.62 1850 3635 470 11.8 3.4 138.24 7.73 1069.12 308.05 
Serjeant Buzfuz fucked around with this message at 23:21 on Jul 31, 2012 |
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Jul 31, 2012 22:56
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Those numbers look ok. For reference, I'm using these guys, well, actually I think I'm using the cheaper (and identical) ones ordered directly from RCTimer, but still. If those numbers are right, it has a nominal 433gr (goddamnit how I hate that this isnt in Newtons), but that's at 50% throttle. At 100% it gets like 1000gr. What's the maximum power rated for that motor? If you aren't hitting that, you might consider switching to 4s, or a different prop (at a possible sacrifice to efficiency). This tool seems to be the go-to reference for getting approximate figures for different prop configs: http://ecalc.ch/xcoptercalc_e.htm?ecalc I have no idea how accurate it is, but it makes a pretty chart, so it at least has that going for it. As for the prop mount, that's a pretty clever idea. However, I'm not sure that will eliminate the ground effect, since the prop is still going to be creating a region of turbulent air between it and the scale. Regardless, I wouldn't worry about that too much, since we take what tools we can get. Then again, I don't really know what I'm talking about for the most part.
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Aug 1, 2012 01:46
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Are you sure those amp readings are right? The lift/amp ratio is twice my setup, but the main thing I'm concerned about is you're only running at 40W. What are the motors rated for? Running at a lower power can be more efficient, but it's going to be really sluggish and lack power.
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Aug 1, 2012 06:16
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TheLastManStanding posted:Are you sure those amp readings are right? The lift/amp ratio is twice my setup, but the main thing I'm concerned about is you're only running at 40W. What are the motors rated for? Running at a lower power can be more efficient, but it's going to be really sluggish and lack power. This motor is rated to go up to 9 amps according to my spec sheet, so I'm well below the maximum envelope. The battery I have on the way is a 5s which is the maximum this motor is rated for. As for the amp readings, I ran the negative side of the battery through a calibrated Fluke 77IV measuring amperage. It read amperage down to 100th of an amp but I rounded down due to the fluctuation during the motor test. As for the accuracy of the lift readings, they are doubtful at best. However, on a chart all the readings line up nicely so I'm inclined to think they're accurate enough for this bench test. If anyone has a better idea on how to test actual thrust, I'd love to hear it.
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Aug 1, 2012 18:45
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Gunktacular posted:Am I right in thinking that a large prop might be more efficient for moving the most weight? That's a 14" prop in the picture? I think the MR prop rule is use a smaller size for more responsiveness and a bigger size for more power, just because of the momentum. Isn't a 14" prop going to be needing like a 60a + ESC?
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Aug 1, 2012 21:23
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ease posted:That's a 14" prop in the picture? I think the MR prop rule is use a smaller size for more responsiveness and a bigger size for more power, just because of the momentum. Its a 14" diameter prop in that picture, and its definitely running at less than 60amps. However, this is my first foray into r/c aircraft so I might be doing something entirely wrong. My motor is only a 360kv type, so higher torque and slower speeds? My RPM readings are above and should be extremely accurate. Motor: http://www.myrcmart.com/rcx-d501014...vtm2ah9u46nrfe4 Prop: http://www.myrcmart.com/rcx-eprop-14x7e-airplane-propeller-motor-shaft-adapter-rings-5pcs-p-4188.html Also, anyone know where to get cheap cw/ccw pairs at 14"? I can't seem to find any at a reasonable price.
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Aug 2, 2012 17:13
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Multirotors with large props are slower to respond to the constant correction being fed from the controller. This is not to say it won't fly, but you may find that for example it becomes unstable while descending rapidly (this is kind of a worst case scenario). Smaller props can change speed very quickly. This is another reason it's good to use reflashed ESCs, since the stock firmware designed for fixed wing aircraft can introduce several ms of lag. Source: my own experience with 10" vs 8" props on a VC-450 frame, and rcexplorer.se's latest design: rcexplorer posted:Let me present the next evolution in my tricopter adventure. I call it the Tricopter V2.6HV where HV stands for High Voltage. This version uses a 4S LiPo battery, shorter arm and smaller props to achieve increased stability, improved maneuverability and almost no wobbling during decent.
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Aug 2, 2012 22:34
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My quad changed frames from a Talon to a DJI : Youtube video pending upload : http://youtu.be/Up2cg6CmEZ4 Maybe you guys can help me trouble shoot the crash at the end. It's not a big deal, only broke a prop, but I'm curious why the quad can't right itself after a free fall, and instead it flips over. Second time I've done this on my Crius Multiwii.
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Aug 2, 2012 23:15
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