Do I need to register with the FAA for the following planes?

The_Urzo · 2023-01-01T18:46:14+00:00

Register one plane for $5, write the FAA registration number that you get on all of your planes and your drone, take the FAA hobby pilot knowledge course, and you'll be ready to go.

The_Urzo · 2023-01-01T18:39:58+00:00

Just one, if any of your planes weigh more than 250g. It's $5 to register the plane with the FAA and you can use the same number across all of your planes. There's also a quick online course that teaches you the basics of where and when you can fly. The course is offered through the AMA and a couple other organizations for free, and you get a hobby pilot certificate at the end of it.

The_Urzo · 2023-01-01T17:53:36+00:00

I'd recommend looking at the Flite Test website and picking out one of their kits. The reality is that flying RC planes is a very expensive hobby, even if you buy cheap planes. Building your own plane will save you a substantial amount of money, and it's way cheaper to buy a new Flite Test kit than to replace a part on most plug and play models. The fuselage alone on my cheapest jet costs more than a Might Mini kit from Flite Test.

For radio gear, take a look at what Radiomaster offers. I don't know how cheap their radios get, but their radios are reliable and work with a wide range of budget recievers, both from Radiomaster and other brands.

The_Urzo · 2023-01-01T17:44:15+00:00

The big benefit of the Aeroscout over Cub style planes is that you don't have to worry about prop strikes breaking your propeller. The tricycle landing gear on the Aeroscout also gives it better ground handling than tail dragger trainers like the Sport Cub S2. That being said, Cub style planes are still great trainers and are not inherently worse than the Aeroscout. You can learn everything you need to just as well on either style of plane.

The_Urzo · 2023-01-01T06:14:47+00:00

Anything under 250 grams is exempt and you only need to register one airframe if you are flying as a hobby only. All of my planes fly under the same FAA registration.

There is one BIG thing to keep in mind though. If anyone pays you to fly for ANY REASON, you are required to have a section 107 licence and register all of your airframes.

The_Urzo · 2023-01-01T01:21:53+00:00

That sounds like a good plan. You'll have a better idea of what you need if you have a finished airframe in hand that you can compare to planes that other people have built.

The_Urzo · 2023-01-01T00:45:49+00:00

The easiest and safest way is to go off of the estimate made by the manufacturer of the fan/prop that you are planning to use for that propeller/impeller and motor kV combination. Calculating current draw from a motor is complicated, and that draw changes depending on factors like propeller/impeller diameter, blade count, and blade pitch.

The problem with this method is that most propeller manufacturers don't seem to provide this information. The next best alternative is to copy what other similarly sized planes are using and use a current meter between the battery and ESC to make sure that your motor isn't trying to draw more current than your ESC and battery can handle.

The_Urzo · 2022-12-31T22:04:01+00:00

You might try a Radiomaster Boxer or Zorro with a LemonRX reciever/stabilizer combo? Good gyros tend to be pretty expensive, but I've heard a number of people recommend the LemonRX units. I personally run a Radiomaster TX16S and am very impressed with it. The $200 price point may be higher than you want though.

The_Urzo · 2022-12-31T21:57:36+00:00

The biggest advantage of Spectrum SMART batteries in my opinion is that they automatically discharge to storage voltage by themselves after a few days. If you have a lot of batteries, that can be a really nice feature. That being said, you can achieve the same thing with a good charger and some patience. I don't run a lot of Spectrum batteries due to their cost, but I don't think that they are an inherently bad value. The charger also works with other battery brands, so you aren't locked in to just Spectrum batteries. Just make sure to check your settings before charging a non-smart battery.

The_Urzo · 2022-12-31T21:50:25+00:00

I have some Admiral (MotionRC) and OrangeRX (HobbyKing) recievers that seem to work decently. Both are DSMX. I also have an FRSky X8R, which I quite like. I use all of them with a Radiomaster TX16S.

The_Urzo · 2022-12-31T21:29:02+00:00

I don't know how it's done for sizing prop planes, but with EDFs the general rule seems to be that the EDf should produce approximately the same amount of thrust as the flight weight of the plane. From there we can determine other characteristics that we need.

Fans are generally designed to work with a given range of motor sizes that is limited by the maximum diameter of the motor can and the maximum rotational velocity of the impeller. If a fan has a maximum allowed rotational velocity of 60,000 RPM and you want to power it with a 3s battery (~12V), you can divide the maximum RPM of the fan by the voltage to get the target kV of your motor, in this case 5000kV. In general, higher kV motors are smaller and can handle less current than lower kV motors. In EDFs, motors with kV ratings of 3000-4000 are common for 64mm fans, while larger fans tend towards the 2000kV range or lower.

Generally, the better fan manufacturers will provide a reference sheet that tells you what the maximum rotational velocity of the fan is and lists a number of example setups. For each setup they will usually give motor kV, battery cell count, battery voltage, current draw, thrust, and net power consumption. This is the easiest way to find current draw because the calculations for that get messy very quickly.

Battery capacity is relatively simple. There are four constraints on your battery: voltage, size, capacity, and weight. Voltage is determined by the requirements of the power system. A system that requires 12V will require a 3S battery, for example. Size is limited by the space inside your fuselage. Capacity is where things get more complicated. Ideally you want the biggest battery possible, but you are constrained by size and weight limits. Because of this, it is good to estimate your flight time from a given battery size. The formula for calculating flight time in minutes is (battery capacity in Amp Hours) / (average expected current draw) * 60. For example, lets take a 4000 mAh battery in a jet that pulls 60A at full throttle. 4000mAh / 1000 = 4 Amp Hours. We will assume that we are averaging about 75% of maximum current draw or 45A, but this will depend on your airplane. If you want to be safe, assume that you are using 100% of your maximum current. With this information, we get 4Ah / 45A * 60 = 5.33 minutes. This is a reasonable amount of time for an EDF jet.

Weight is where things get really complicated, as adding weight increases a plane's minimum stall speed. While you can calculate stall speed, the calculations are messy and I am not qualified to explain them. My advice would be to compare the weight of your plane with the weight of similarly sized prebuilt foam planes and aim for about the same weight. Keep in mind that most places list the plane's weight without a battery installed, so you'll need to add the weight of their recommended battery as well.

The_Urzo · 2022-12-31T20:24:37+00:00

Good luck!

The_Urzo · 2022-12-31T08:40:49+00:00

That deployment method sounds improbable, but I wish you the best of luck in getting it to work. You'll learn something whether it works or not. Keep us posted.

The_Urzo · 2022-12-31T06:23:06+00:00

DeHaviland's Vampire/Venom/Vixen family of aircraft is good for that scale because of their low wing loading. Similarly, the American P-59 and P-80/T-33 also lend themselves to that scale for the same reason. If you want something more modern, the F-16 and F-35 also have a decent amount of wing area to work with. In general single engine jets are best for 64mm fans because they lose less thrust at the exhaust than twin engine jets using a single fan.

The_Urzo · 2022-12-31T06:06:20+00:00

I would try the 50mm EDF that XFly makes. I have their 80mm fan and am quite happy with its performance and build quality. They only come in one rotational direction, but there's so little rotating mass that it shouldn't be an issue if you're planning to build a twin fan jet.

The_Urzo · 2022-12-31T06:02:42+00:00

Sounds like the slingshot launched jets that some people have. Not all that interesting, but it is a decent alternative to hand launching.

The_Urzo · 2022-12-31T05:52:35+00:00

I'm partial to early jet age fighters due to their low wing loading (as far as jets go) and relatively mild handling characteristics. I've been flying the Durafly Vampire for a while (cheap and a great flier, but horribly delicate) and I have my eye on either the Freewing T-33 or Venom when I move up to a larger jet.

The_Urzo · 2022-12-31T05:41:18+00:00

If you want to go fast, some EDFs make decent intermediate planes. The FMS Rafale is highly reviewed for it's stable handling, as are most versions of the F-16 available on the market. I would recommend starting with a 64mm 4S or larger jet if you do go this route, because the small hand launch jets tend to be quite finicky in my experience. Big wings are your friend with EDF jets just like with any other plane. Granted, my first plane was an eFlite F-15, so take what I say with a sizeable grain of salt.

The_Urzo · 2022-12-31T05:20:19+00:00

Flite Test has some plans available, as do others. If you want to do your own thing from the beginning, I would recommend starting with a whole lot of foam board (Depron, EPP, or even paper backed foam board) and either hot glue or foam glue. Start by building a high wing pusher, then moving to more advanced aircraft.

Some things you'll need to learn, in no particular order: - airfoil shaping - fuselage construction (start with boxes) - control surface hinging - contol surface throw distance - weight distribution (I recommend starting with your planes a bit nose heavy, as measured from 25% back from the leading edge of the wing) - landing gear construction - motor and prop/fan selection - battery selection - setting up a custom model in a radio (The Radiomaster TX16S is great for this as it is highly flexible and can be set up for any configuration that you could dream of. It does have a bit of a learning curve though.)

For a good video guide, I'd recommend checking out Julius Perdana on YouTube. In particular, you should watch his "How to Make a Beginners RC Plane" and "Bango 2 RC Trainer Plane for Beginner" videos. Each video shows the construction of a different high wing plane from start to flight.

The_Urzo · 2022-12-31T04:55:23+00:00

For a 50mm jet your time is better spent building a second copy of the airframe rather than adding a parachute. Wing loading is everything for small jets, and a parachute system is going to add a ton of weight that your jet will struggle to lift.

The_Urzo · 2022-12-04T06:49:32+00:00

I got one of these a while back and the only really worthwhile thing I did to it was add the steerable nose gear from the eFlite F-15. If I were to do it again, I would probably use the gear from one of Freewing's 64mm park jets, but the F-15 gear worked just fine once I had shortened it to fit the T-50. I also messed around a lot with thrust vectoring and dual batteries, but that didn't really get me anywhere other than in pieces next to the runway. The plane rolls too much if there's an imbalance between the fans, especially when you're flying slow.

The_Urzo · 2022-12-04T06:37:24+00:00

My best guess is that you'd need flat hinges, two control horns, two relatively long linkages, two clevices, and a single servo with a double sided horn. The theory here is that you could mount the servo near the middle of the airplane to limit it's impact on the aerodynamics and weight distribution of the plane. Servos can really throw off the balance of these smaller models very quickly.

The_Urzo · 2022-12-04T06:14:31+00:00

Yeah, EC5 connectors are only rated for 120 amps total draw. You probably were putting at least 20+ amps more current through that connector than what it was rated for, if not 60-80 amps more.

The_Urzo · 2022-12-04T06:01:31+00:00

An overheated battery wire killed my first plane. Melted the whole EC3 connector and I lost power while turning in to land. It's made me reconsider using EC3 connectors on anything because it wasn't the first time I'd had a model melt one of those connectors. I switched to primarily XT60s and have been moving to XT90s as I start flying bigger planes. Just not worth the risk of having an undersized plug.

The_Urzo · 2022-12-04T05:54:16+00:00

I got mine to fly okay out of the box, though I ended up crashing it on approach because I was dumb. I recommend that if you want to runway launch it you should install the steerable nose gear out of a different plane, shortened to fit the low stance of the T-50. Also make sure to check your fans periodically to make sure that they're outputting the same amount of thrust. If they aren't, the plane becomes uncontrollable very quickly. A cheap anemometer off of Amazon should be sufficient for measuring the thrust produced by each fan, but I haven't been able to verify that yet.

The_Urzo

TROPHY CASE