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A Yolo Wizard posted:Theres no way thats going to be cheaper than the hking one with good shipping (I got a pair super quick at $36 w/ my platinum account) i tried. ordered it a month ago. usps hosed up and accidentally returned it (?). wasted half a day in line at the post office because they send poo poo w/ signature required (why? they've never given a straight answer on that). finally get up to the window and "uhh, it's not here.. looks like it got put int he wrong spot and sent back." i'm done with hobby king, the extra $15 is more than worth my time and sanity. CheddarGoblin fucked around with this message at 04:33 on Apr 19, 2016 |
# ? Apr 19, 2016 04:31 |
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# ? Jun 11, 2024 20:11 |
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n.. posted:i tried. ordered it a month ago. usps hosed up and accidentally returned it (?). wasted half a day in line at the post office because they send poo poo w/ signature required (why? they've never given a straight answer on that). finally get up to the window and "uhh, it's not here.. looks like it got put int he wrong spot and sent back." Yeah, I agree. Hobbyking has great prices but I just won't deal with their shipping bullshit anymore. One time things came just fine but twice I have ordered from them and had the items get sent to some weird rear end DHL? shipping depot in an industrial district instead of my local post office like every other item I ever ordered from amazon/ebay/alibaba/banggood/etc. Also, they do the annoying "legitimate" business thing and list the EXACT cost of the items and detail that it has lipos, etc. So you're paying extra fees to pick stuff up as well. It's shady as poo poo but I like that other less reputable places will just say "hobby parts, $5.00" and bypass all that.
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# ? Apr 19, 2016 05:00 |
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bring back old gbs posted:
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# ? Apr 19, 2016 05:44 |
Anyone try Liftoff?
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# ? Apr 20, 2016 07:22 |
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Is sealing up a 250 quad, to reduce wind turbulences, worth the additional weight of the plastic?
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# ? Apr 20, 2016 14:35 |
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What does everyone thing about some of the toy-grade quads? My friend showed me his Syma X8C over the weekend and it seemed really cool as an "intro to quads", especially for ~$80. Flight time was good even when pulling his gopro around. Obviously you guys seem to be into rolling your own, but are the toy grade ones a good place to start?
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# ? Apr 20, 2016 14:53 |
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dreesemonkey posted:What does everyone thing about some of the toy-grade quads? My friend showed me his Syma X8C over the weekend and it seemed really cool as an "intro to quads", especially for ~$80. Flight time was good even when pulling his gopro around. Yeah Symas are fine to get your feet wet. $80 is a lot for a toy grade though unless it's one of those FPV Hubsan ones Hubsan x4 and Blade Nano QX get recommended often but neither of those will come close to lifting a gopro
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# ? Apr 20, 2016 14:56 |
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Combat Pretzel posted:Is sealing up a 250 quad, to reduce wind turbulences, worth the additional weight of the plastic? Probably not, unless you're racing at 60mph+ on the regular.
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# ? Apr 20, 2016 15:14 |
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bring back old gbs posted:Yeah Symas are fine to get your feet wet. $80 is a lot for a toy grade though unless it's one of those FPV Hubsan ones The X8C is more or less a feature-stripped Phantom clone, so it's quite big. It also has a crappy camera already attached, but a phantom gopro mount slides right on. I have seen those small quads and they're really neat, but I'd primarily like to get some video/stills up in the air if possible so that's why I was leaning towards the Syma (possibly). https://www.youtube.com/watch?v=3DeSyUhbSCM
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# ? Apr 20, 2016 15:29 |
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MrYenko posted:Probably not, unless you're racing at 60mph+ on the regular. I'm not even sure that's true. I'd like to see some testing.. but those flat arms out in the wind are really awful for aerodynamics. If you want to close in your airframe... I'd probally suggest the fabric route, versus plastic. It's good for keeping thing clean, but I suspect not a lot else. Have i complained recently about choosing brushless motors? And props. And gettting combinations right. The motors and escs that came with my hex were, lets say laughable. 1000kv motors, 30amp ESCS. With the equipped props they never draw more than say 19amps. But they also stop making more thrust at like 15amps. Hovering they seemed ok, but when one motor cut out, and it fell (I assume due to overheating..) ... well I figure it's time for new motors. I ordered a set of these: http://www.hobbyking.com/hobbyking/store/__67016__Quanum_MT_Series_2227_800KV_Brushless_Multirotor_Motor_Built_by_DYS.html To replace the 2212's that are on the airframe now. 200kv less, and a much bigger motor, it should be able to sustain the amp load without cooking. I also have some really shallow blades ordered. 12x3.8's. Along with some 11x4.7's. I'm hoping some more swept area will let me make some more lift with lower amp draw. We shall see....
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# ? Apr 20, 2016 15:53 |
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Fabric is a clever idea. Weighs way less than 2-3 perimeters of 3D printed plastic.
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# ? Apr 20, 2016 17:17 |
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The biggest issue for quad aerodynamics seems to be that they can fly in any direction. With planes and boats there are body lines that give away direction of travel because the aero/hydrodynamics? are built into their basic function. How do you do that to a quad that can go full throttle and instantly change directions?
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# ? Apr 20, 2016 17:41 |
bring back old gbs posted:The biggest issue for quad aerodynamics seems to be that they can fly in any direction. With planes and boats there are body lines that give away direction of travel because the aero/hydrodynamics? are built into their basic function. How do you do that to a quad that can go full throttle and instantly change directions?
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# ? Apr 20, 2016 18:02 |
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Nerobro posted:I'm not even sure that's true. I'd like to see some testing.. but those flat arms out in the wind are really awful for aerodynamics. They certainly are, but any effort at cleaning up a quad that I've ever seen has dramatically increased not only the cross sectional area as it applies to forward flight, but also the area of structure under the rotors. My gut feeling is that at the low speeds that quads generally operate at, you'd be better served trying to minimize structural size and mass, rather than attempting to improve the C/D.
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# ? Apr 20, 2016 18:41 |
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Combat Pretzel posted:Is sealing up a 250 quad, to reduce wind turbulences, worth the additional weight of the plastic? No.
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# ? Apr 20, 2016 19:04 |
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MrYenko posted:They certainly are, but any effort at cleaning up a quad that I've ever seen has dramatically increased not only the cross sectional area as it applies to forward flight, but also the area of structure under the rotors. My gut feeling is that at the low speeds that quads generally operate at, you'd be better served trying to minimize structural size and mass, rather than attempting to improve the C/D. I've got ideas for taking care of that. I've outlined them earlier in the thread. There are "unstallable" airfoils, that still provide the drag reduction of an airfoil. Heck, just some standoffs to raise the prop disk, and a "nose fairing" would more than halve the drag of the arms. It's fairly easy to design a fairing that's aerodynamic in at least two directions.. the two that matter for a quad are forward, and "up". The warpquads with the vertical stack of battery, flight controller, camera.. are going the right direction with that.
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# ? Apr 20, 2016 19:12 |
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Nerobro posted:I've got ideas for taking care of that. I've outlined them earlier in the thread. There are "unstallable" airfoils, that still provide the drag reduction of an airfoil. Heck, just some standoffs to raise the prop disk, and a "nose fairing" would more than halve the drag of the arms. It's fairly easy to design a fairing that's aerodynamic in at least two directions.. the two that matter for a quad are forward, and "up". The warpquads with the vertical stack of battery, flight controller, camera.. are going the right direction with that. That's fine, but you need all 3 dimensions for a racequad. The biggest factors are props and weight with CG trailing at a distant third. Aerodynamic efficiency on something where 90% of the surface presented to the airflow is the props is largely relevant, more so when it comes at the cost of weight & strength. This is still worth reposting, though: http://fpvlab.com/forums/showthread.php?37954-World-speed-record-with-250mm-(or-under)-size-quad This is made for straightline speed only, but it's still interesting.
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# ? Apr 20, 2016 20:36 |
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ImplicitAssembler posted:That's fine, but you need all 3 dimensions for a racequad. The biggest factors are props and weight with CG trailing at a distant third. Aerodynamic efficiency on something where 90% of the surface presented to the airflow is the props is largely relevant, more so when it comes at the cost of weight & strength. Imagine getting a free 20% more thrust. That's what you're going to get with good aerodynamics on the arms. You can trade that for smaller props to make the thing more agile. Making the fuselage .. wing-ish.. would give you more more thrust to throw at corners without needing more horsepower. ... I'm going to need to break out the math on this, aren't I?
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# ? Apr 20, 2016 21:35 |
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Nerobro posted:Imagine getting a free 20% more thrust. That's what you're going to get with good aerodynamics on the arms. You can trade that for smaller props to make the thing more agile. Sure, break out the math. Better yet, build one and prove it. You may be able to get 20% more thrust in some situations, but it will come at a cost in others and most definitely will come at the cost of more weight and less durability. Again, look at the fpvlab thread and see how much trouble he has getting it to work for a quad flying in a straight line.
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# ? Apr 20, 2016 22:10 |
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I Want to Believe this can be put into practice. I guess those clear plastic waterproof frames are pretty close.
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# ? Apr 20, 2016 22:20 |
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ImplicitAssembler posted:Sure, break out the math. Better yet, build one and prove it. I've got some testing equipment .. I can do that. I "should" do that. I'm not talking 20% more thrust in "some" situations, i'm talking 20% in ALL situations. If you're getting 20% more thrust, you can afford some weight. Arm fairings don't need to have any effect on durability. An aerodynamic fuselage definitely leads to "more things to break" I have checked that FPVlab thread. I like it a lot. He's doing a lot of things right.
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# ? Apr 20, 2016 22:48 |
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Nerobro posted:I've got some testing equipment .. I can do that. I "should" do that. I'm not talking 20% more thrust in "some" situations, i'm talking 20% in ALL situations. If you're getting 20% more thrust, you can afford some weight. Arm fairings don't need to have any effect on durability. An aerodynamic fuselage definitely leads to "more things to break" Well, you could probably become pretty rich if you can come up with a practical design that offers 20% more thrust. You have access to a a wind tunnel? Aerodynamics software?
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# ? Apr 20, 2016 23:09 |
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I don't think that current race quads are lacking top speed, maneuverability or power to an extent that aerodynamics would really add much. Most races seem to be lost at the moment through attrition in that most pilots are crashing out and not finishing or not posting the best times before they wipe out. Maybe one day people will get so good at flying the the things that a little bit more straightline speed matters or endurance formats will become a thing and aerodynamics might make a difference. But at the moment everyone is flying grossly overpowered carbon bricks on short racetracks for a few mins at a time. I don't see fancy cowlings etc trumping durability any time soon.
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# ? Apr 20, 2016 23:17 |
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Well I'll be damned, by some miracle usps pulled through and delivered my teensy cam/vtx from HK. This is hilariously fun. Need to figure what the best motors i can use with the beef's brushed board are for maximum oomph, because it flies weak af like this.
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# ? Apr 20, 2016 23:27 |
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Nerobro posted:Imagine getting a free 20% more thrust. That's what you're going to get with good aerodynamics on the arms. You can trade that for smaller props to make the thing more agile. --edit: Or would the peaks need to be angles forward (and backward respectively) to deal with wind facing the drone during flight? Combat Pretzel fucked around with this message at 00:21 on Apr 21, 2016 |
# ? Apr 21, 2016 00:14 |
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n.. posted:Well I'll be damned, by some miracle usps pulled through and delivered my teensy cam/vtx from HK. The black edition 8mm from micro motor warehouse
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# ? Apr 21, 2016 01:13 |
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Well that was easy. Thanks.
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# ? Apr 21, 2016 02:09 |
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dreesemonkey posted:What does everyone thing about some of the toy-grade quads? My friend showed me his Syma X8C over the weekend and it seemed really cool as an "intro to quads", especially for ~$80. Flight time was good even when pulling his gopro around. The Syma x8c is a great quad. I highly recommend it for outdoor flying and aerial photography. It's extremely easy to add a bunch of accessories and you can have a really decent camera drone for around $150 if you don't mind tinkering with some DIY stuff. Add a Runcam HD with a home-made "credit card mount" (check youtube) and you'll be pretty happy with the results. I also added a Boscam TS351 5.8ghz transmitter and ordered an Eachine VR-007 for FPV flying. I also just installed a 2.4ghz signal amplifier for increased range, but haven't been able to try it out yet. My next quad is going to be a Phantom. You outgrew the toy quads really quickly... The Shep fucked around with this message at 03:02 on Apr 21, 2016 |
# ? Apr 21, 2016 02:52 |
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ImplicitAssembler posted:Well, you could probably become pretty rich if you can come up with a practical design that offers 20% more thrust. 20% better than conventional race quads. Not 20% better than a good prop, nacelle, and strut. I'm clever, i'm not able to bend the laws of physics. :-) Cheap wind tunnels come in the form of the tops of cars. If I need to simulate the drag/thrust on a airframe strapping it to a car and giving it a go is a fair shot. mashed_penguin posted:I don't think that current race quads are lacking top speed, maneuverability or power to an extent that aerodynamics would really add much. Most races seem to be lost at the moment through attrition in that most pilots are crashing out and not finishing or not posting the best times before they wipe out. I can't say you're wrong. But there's a whole lot of noise about "this one is faster" and "this one has a better power to weight ratio." It really works out to "free power". Even it weighs more, I bet the return in thrust will be more than the weight of arm fairings. Combat Pretzel posted:Do you think something like this to wrap around the arms would help something thrust-wise? That's kinda the idea, and that's better than a flat arm. But if you're doing something like that, you might do an actual airfoil and do even better. Below a 3:1 aspect ratio, airfoils really don't stall. If you did a teardrop shape, with the tail going towards the rear of the quad, in addition to getting less drag from the flat arm, you'd also pick up some forward thrust. The actual angle of the airfoil would need to be a compromise between the airstream coming off the props, body angle of the quad, and incoming air stream. My bet.. is somewhere with a chord angle of about 30 deg off of vertical would be the right sort of idea. But that would be found out through testing. The ideal test rig, would be a tubular armed quad, where an airfoil could be slipped over the arms, and the angle changed until best performance is found. Just to emphasize the point. The Cd of a flat plate (standard quad arms) is 1.28. A round nose bluff shape (like a mario bullet) is somewhere around .3 An airfoil is more like .05. Figure any potential thrust your motor makes is "gone" when applied to the flat plate of the arm, a round nose bluff shape would get you back 3/4 of that thrust. An airfoil shape, would get you back more than 90% of it. On a tough race quad, with wide arms, and small swept area that would be a LOT of thrust. For example, if in free air, you're making 600g of thrust on a 5x4. That means you've got 18 square inches of swept area. (excluding the motor area in the middle) On a ZMR250, that arm is eating two square inches of your swept area. That works out to something like 70g of lost thrust due to prop-wash blocking. "any" kind of fairing would get you 52g back. Or 200 some grams for the airframe as a whole. This all doesn't consider the effects at speeds beyond a few miles an hour. Any sort of aerodynamic advantage matters more as speeds go up. ... I want my motors for my hex. :-(
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# ? Apr 21, 2016 03:13 |
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Nerobro posted:Cheap wind tunnels come in the form of the tops of cars. If I need to simulate the drag/thrust on a airframe strapping it to a car and giving it a go is a fair shot. And just how will you measure the drag?..and you're going to do this for all attitudes? Nerobro posted:For example, if in free air, you're making 600g of thrust on a 5x4. That means you've got 18 square inches of swept area. (excluding the motor area in the middle) On a ZMR250, that arm is eating two square inches of your swept area. That works out to something like 70g of lost thrust due to prop-wash blocking. "any" kind of fairing would get you 52g back. Or 200 some grams for the airframe as a whole. Except that you still have the low pressure that the prop creates in front, a gap behind the prop and the arm,etc, so s straight calculation of Cd wont work.
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# ? Apr 21, 2016 04:21 |
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ImplicitAssembler posted:And just how will you measure the drag? quote:..and you're going to do this for all attitudes? quote:Except that you still have the low pressure that the prop creates in front, a gap behind the prop and the arm,etc, so s straight calculation of Cd wont work. I don't know if I have a spare quad arm hanging around.... we'll see. I need to get my friend over, we have some other testing to do as well.
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# ? Apr 21, 2016 04:37 |
I'm slowly getting everything together, got the d4r-ii fitted (had to remove the case and direct solder everything), converted a dell server psu to be used as the power supply for the icharger 206b, bought 2 Tattu 3s 1800mah batteries (a graphene on the way too). Still waiting on my fatsharks (ebay seller lagged on shipping them out, got an in transit notification but no tracking #). Things I still need to figure out: 1. Setting up failsafes in both cleanflight and the d4r-ii (I would appreciate any tips on this, I don't want my little quad to fly away ) 2. Continue figuring out my Taranis 4. Figure out how to route my long rear end d4r-ii antennas so they don't get diced 3. Crash immediately, break everything and QQ about it Google Butt fucked around with this message at 07:22 on Apr 21, 2016 |
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# ? Apr 21, 2016 07:19 |
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Oscar Liang has the answers to most of your questions: http://blog.oscarliang.net/failsafe-rx-fc-naze32-frsky-d4rii/ As for the antennas, I route mine through a couple of thin straws. Others use zip-ties as guides
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# ? Apr 21, 2016 07:32 |
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Zip-tie plus heat shrink tube is a good way to do it. On my new build, I put the antennae in a plastic tubing as well for extra protection in case it gets bent into the choppy zone. You can scavenge the plastic tube form air dusters or empty pump spray bottles.
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# ? Apr 21, 2016 08:07 |
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Nerobro posted:That's kinda the idea, and that's better than a flat arm. But if you're doing something like that, you might do an actual airfoil and do even better. Below a 3:1 aspect ratio, airfoils really don't stall. If you did a teardrop shape, with the tail going towards the rear of the quad, in addition to getting less drag from the flat arm, you'd also pick up some forward thrust. I still need to make the counterpart. The other one was symmetrical and less work. There's only so much airfoil you can emulate before things get way too big. The edge has already only distance 3-4mm to the prop. Combat Pretzel fucked around with this message at 09:17 on Apr 21, 2016 |
# ? Apr 21, 2016 09:14 |
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Speaking of enclosed frames, has anyone been following the X PlusOne? 60+ mph is pretty impressive. Admittedly, it's flying like a fixed wing to achieve those speeds.
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# ? Apr 21, 2016 11:38 |
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Finally had my first extended acro session today without instantly something going wrong. Certainly much more fun, but throttle management is a pain in the rear end in the driftuuuu style rear end-out banked turns, because the quad belly is like an airfoil pushing everything up.
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# ? Apr 21, 2016 12:08 |
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Combat Pretzel posted:Kinda like this then? I guess I could fillet the edge to make it teardrop-ish. A quarter or half inch spacer under the motor would really help that situation. And even your first design would have a huge affect on drag. I appreciate your modeling.
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# ? Apr 21, 2016 14:35 |
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Is this a custom frame?
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# ? Apr 21, 2016 17:16 |
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# ? Jun 11, 2024 20:11 |
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It's a Shendrones Krieger frame: http://www.shendrones.com/krieger
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# ? Apr 21, 2016 17:53 |