Multicopter Megathread

[straight_stewie]

Just now, Hackentosher said:

As far as I know, nitro is still more power dense than lithium, it's more complicated and less reliable. It's also heavier to carry around a big engine, exhaust, all the gearing, fuel tank, and fuel. But there's something about internal combustion that electric can never capture. 

Not quite. Generally electrics beat nitro in the power/weight department. But it's questionable about whether that affects lugging around the car. Just to lug just the car around, yes, Nitro is heavier. But you never lug just the car around. You lug the car and four or 5 batteries and a charger and some spare parts.

What weighs less, 4 or 5 batteries and a lighter car, or a gallon of fuel and a heavier car? IMO it's six in one and half a dozen in the other in the convenience department. But there is a disclaimer that comes with that: I learned how to work on things by being a warranty certified heavy equipment mechanic for a well known company. I can work on these small engines/vehicles in my sleep. If you're not very mechanical the increase in maintenance going from electric to fuel can be immense.

[Hackentosher]

31 minutes ago, straight_stewie said:

Not quite. Generally electrics beat nitro in the power/weight department. But it's questionable about whether that affects lugging around the car. Just to lug just the car around, yes, Nitro is heavier. But you never lug just the car around. You lug the car and four or 5 batteries and a charger and some spare parts.

 

I'm talking about the weight of the vehicle not what you need to bring to the field lol

[straight_stewie]

26 minutes ago, Hackentosher said:

I'm talking about the weight of the vehicle not what you need to bring to the field lol

Oh yeah. Nitro is heavier and has a smaller power/weight when compared to the fancier electric packages. But I can run my Tmaxx around for 20-30 minutes and still be breaking 50 mph, so I'm happy. It does have some problems during the transition seasons though, and never really got used much in spring or fall. I would really like to switch to gas for that reason (it's much easier to tune for weather), but I am not wealthy enough for 1/5 scale vehicles. 

[KaminKevCrew]

On 12/17/2017 at 9:37 PM, Hackentosher said:

So i've been designing this plane to be 3d printed for the last lil while now, what does everyone think? I know it's not a multirotor, but i think it's in the spirit of this thread. The idea is to have a printed plane inspired by the P-51 and this thing, but with some more modern lines. I know it's missing a tail, but I've just been slowly working on it.

  Hide contents

 

I like it! It looks really sleek. Are you running flaps and/or counterbalances on the tail control surfaces? How big are the control surfaces? (Really, I'd like to see a few different views of this new aircraft.)

 

What airfoil are you running?

On 12/19/2017 at 5:45 PM, Not_Sean said:

hell i'm even loose on Flies, if you got a sick RC project go for it, Ideally not Nitro cars, but electric stuff I'm sure we can all get behind 

lol, pretty much.

On 12/19/2017 at 7:05 PM, Hackentosher said:

Nitro is sick, those engines with those little heatsink are awesome. I stumbled upon a gas powered multirotor project on YouTube a while ago, two engines driving all four props, with collective pitch to adjust the thrust. 

I was watching one of those "drone crash" compilation videos and it had that gasser multi in it. Needless to say, the guy crashed after about 15 seconds, and it was hilarious/sad...

On 12/19/2017 at 7:12 PM, straight_stewie said:

I've been considering fixing my TMAXX 3.3 this year. It needs a new engine and transmission, so I make take this opportunity to go ahead and upgrade. I haven't ran it in about 5 years now.

If you ask me nitro/gas/jet A is preferable to electric if you don't have to worry about noise/fumes. Of course for aircraft you really want to get good at flying them, and good with the engines, independently of each other, before combining the two. Especially for rotary wing aircraft, which are completely reliant on the power plant to stay airborne. 

Aside from the fact that you have extensive experience in Internal Combustion Engines, what about nitro/gas do you find preferable? I personally really like electric. Especially since on smaller models, you can run scale props (something you DEFINITELY cannot do on gas/nitro.) Also, it's nice to be able to run foamies, as people tend to be less scared of a big chunk of foam flying through the air vs. a massive balsa/light ply monstrosity. 

 

Of course, I suppose that you're coming from the ground vehicles perspective, whereas I'm coming from an aircraft point of view.

On 12/19/2017 at 7:28 PM, Hackentosher said:

Ooh fun, put an fpv cam on it and bash it around. 

 

As far as I know, nitro is still more power dense than lithium, it's more complicated and less reliable. It's also heavier to carry around a big engine, exhaust, all the gearing, fuel tank, and fuel. But there's something about internal combustion that electric can never capture. 

It certainly is a hell of a lot faster to "recharge" a gas/nitro engine. The nice thing about electric though is that if you want more power/speed, all you have to do is add a battery that has more cells in series (assuming the ESC/motor can handle it.)

 

I got a new Tx in the mail today!!!

It's the FrSky Horus. I'm not sure if I want to sell my X9e just yet, or if I'm even going to keep the Horus, but I had to try it. I love the way it looks, and the size of the thing. Also, a lot of people say that the color screen isn't a very good one, but I disagree. I found it to be quite bright (though I am admittedly in a dark-ish room) and I think it's a much nicer experience than the normal screen on FrSky products (for reference, I owned the Taranis X9s Plus for some time, until I decided that I wanted a tray radio, and I currently own the X9e and the QX7s in addition to the X12s)

 

Also, I like that the 5dB antenna fits on the Horus stock, when it doesn't fit on any of their other radios without some kind of modification. To get it to fit on the X9e, you need an SMA to RP-SMA adapter. On the Taranis, you need to do a somewhat extensive (if relatively easy) mod, and on the X10 you'll still need to mod it, since the recessed SMA (or RP-SMA, not sure) jack is surrounded too closely for the 5dB antenna.

 

I might switch the charging unit in the X12 to one that can charge lipo/li-ion (yes, it does exist: https://www.banggood.com/1A-Battery-Charger-Upgrade-Module-Board-with-7_4V-3600mAh-LIPO-Battery-for-FRSKY-X12S-p-1162880.html)

 

Also, the previous owner (I didn't buy this new) put some tray-style arms on it, so it's pretty comfortable to use. I think I'll probably add one of those real tray radio holder things to it though. If I don't I'll grab a winter Tx glove so that I can use it on cold days without having the Horus freeze my hands.

[straight_stewie]

14 minutes ago, KaminKevCrew said:

side from the fact that you have extensive experience in Internal Combustion Engines, what about nitro/gas do you find preferable? I personally really like electric. Especially since on smaller models, you can run scale props (something you DEFINITELY cannot do on gas/nitro.) Also, it's nice to be able to run foamies, as people tend to be less scared of a big chunk of foam flying through the air vs. a massive balsa/light ply monstrosity. 

 

Of course, I suppose that you're coming from the ground vehicles perspective, whereas I'm coming from an aircraft point of view.

Well, if memory serves correctly, driving the way that I do I can get approximately 15 minutes runtime out of my friends stock Emaxx with a 5000 MaH 6S pack while I was getting 30 minute + runtimes out of my Tmaxx.

From my research, all of Aligns offerings get significantly longer flight times from the equivalent nitro models than the electric models.

Plus, when you're showing it to your friends who don't quite get it, telling them it's "gas powered" (shudder) can reverse their opinion from "you're a child" to "dude that's sick".

 

Quote

It certainly is a hell of a lot faster to "recharge" a gas/nitro engine. The nice thing about electric though is that if you want more power/speed, all you have to do is add a battery that has more cells in series (assuming the ESC/motor can handle it.)

This is a very good point as well. Along these lines, it's also harder to limit a nitro's speed for beginners.

[Hackentosher]

1 hour ago, KaminKevCrew said:

I like it! It looks really sleek. Are you running flaps and/or counterbalances on the tail control surfaces? How big are the control surfaces? (Really, I'd like to see a few different views of this new aircraft.)

 

What airfoil are you running?

 

 

I got a new Tx in the mail today!!!

It's the FrSky Horus. I'm not sure if I want to sell my X9e just yet, or if I'm even going to keep the Horus, but I had to try it. I love the way it looks, and the size of the thing. Also, a lot of people say that the color screen isn't a very good one, but I disagree. I found it to be quite bright (though I am admittedly in a dark-ish room) and I think it's a much nicer experience than the normal screen on FrSky products (for reference, I owned the Taranis X9s Plus for some time, until I decided that I wanted a tray radio, and I currently own the X9e and the QX7s in addition to the X12s)

 

Also, I like that the 5dB antenna fits on the Horus stock, when it doesn't fit on any of their other radios without some kind of modification. To get it to fit on the X9e, you need an SMA to RP-SMA adapter. On the Taranis, you need to do a somewhat extensive (if relatively easy) mod, and on the X10 you'll still need to mod it, since the recessed SMA (or RP-SMA, not sure) jack is surrounded too closely for the 5dB antenna.

 

I might switch the charging unit in the X12 to one that can charge lipo/li-ion (yes, it does exist: https://www.banggood.com/1A-Battery-Charger-Upgrade-Module-Board-with-7_4V-3600mAh-LIPO-Battery-for-FRSKY-X12S-p-1162880.html)

 

Also, the previous owner (I didn't buy this new) put some tray-style arms on it, so it's pretty comfortable to use. I think I'll probably add one of those real tray radio holder things to it though. If I don't I'll grab a winter Tx glove so that I can use it on cold days without having the Horus freeze my hands.

Thank you! I think i mentioned that I was going for like a modern P-51 feel with it, thus the airscoop that probably wont do anything but create drag within the fuselage. I would like to add flaps, but I don't know how necessary or worth it they will be considering how small the aircraft is. The wingspan is only 630mm, so I don't think it'll need flaps, however I'd like as much scale details as I can in a small, printable, package. I would also like to add custom retracts, but I want to finish the rest of the design and control surfaces first. Speaking of control surfaces, I have no idea what I'm doing in terms of aerodynamic design, so the ailerons are 1536mm^2, the elevators are 815mm^2, and the rudder is 382mm^2. Those are all arbitrary and I sized all of the features and control surfaces by appearance and gut instinct... soooo we'll see how that goes. I have a feeling the roll will be super duper twitchy, pitch will be fine, and yaw might be a lil sluggish. I've also never really flown rc planes, but I could handle it if it was FPV, so I'd really need to be on my feet when flying it in the goggles. I'd be lying if I said I wasn't scared of a maiden, I will probably want to have a flight controller running inav for some stability and OSD.

 

As I mentioned, I have no idea what I'm doing, so I did the standard flat bottom, curved front top. Here's a cross section.

Spoiler

I also like how the Horus radios look, but I think you're the only one that likes the x12. But hey, if you do, more power to you. Fly what you like.

 

Aren't the batteries burried within the Horuses (Hori?)?

[straight_stewie]

6 minutes ago, Hackentosher said:

As I mentioned, I have no idea what I'm doing, so I did the standard flat bottom, curved front top. Here's a cross section.

I seem to have missed something important here. You might want to take a look at the University of Illinois' Airfoil Page (many RC airfoils are located here, as well as real world and experimental airfoils), as well as Airfoil Tools

[Hackentosher]

11 minutes ago, straight_stewie said:

I seem to have missed something important here. You might want to take a look at the University of Illinois' Airfoil Page (many RC airfoils are located here, as well as real world and experimental airfoils), as well as Airfoil Tools

Well, I said I don't know what I'm doing, but I do have a basic understanding of Bernoulli's principle. I've also been running some tests in Autodesk Flow Design, a virtual wind tunnel, and I've noticed some weird turbulence after the tail, not sure what's going on there. I can attach some screenshots from that.

 

I'll check out those airfoils, but I'm not sure how I'd do that in CAD, it was a pain in the ass to get the fillets just right for the one I have.

 

edit: I just clicked those links, holy crap I have no idea what I'm looking at. 

[straight_stewie]

Just now, Hackentosher said:

I'll check out those airfoils, but I'm not sure how I'd do that in CAD, it was a pain in the ass to get the fillets just right for the one I have.

Which CAD are you using (all autodesk products have special tools to make them out of splines by importing csv or xlsx...)? I'd love to see the images. I also have an Autdesk CFD 2018 student subscription if you want me to take a deeper dive into some things for you...

Pre-Post Edit: AutoDesk makes an airfoil generating tool that they distribute for free. 

[straight_stewie]

10 minutes ago, Hackentosher said:

edit: I just clicked those links, holy crap I have no idea what I'm looking at. 

Sorry for the double post  It's a one time occurrence, just to give you the notification.

In the database you are looking at a collection of coordinates (an x,y value pair). Some tools exist that eat those, mostly you just import them into excel and then use that.
In airfoil tools you are basically seeing an airfoil generator that follows the NACA 4 and 5 digit algorithms. It also includes a database of every airfoil generated by a user.

[Hackentosher]

2 minutes ago, straight_stewie said:

Which CAD are you using (all autodesk products have special tools to make them out of splines by importing csv or xlsx...)? I'd love to see the images. I also have an Autdesk CFD 2018 student subscription if you want me to take a deeper dive into some things for you...

Pre-Post Edit: AutoDesk makes an airfoil generating tool that they distribute for free. 

I use Fusion 360 because I think it's better and more intuitive than Inventor. I'll give that airfoil generator a shot. 

[straight_stewie]

Just now, Hackentosher said:

I use Fusion 360 because I think it's better and more intuitive than Inventor. I'll give that airfoil generator a shot. 

I haven't started on Fusion 360 yet. I'm still using inventor. I think that airfoil generator takes the NACA 4/5 digit code and outputs a sketch file, so you still have to know what numbers to put in. 

Actually, airfoils are quite an interesting subject. They are the third most interesting subject in academia to me, right after propulsion and control systems.

[Hackentosher]

1 minute ago, straight_stewie said:

I haven't started on Fusion 360 yet. I'm still using inventor. I think that airfoil generator takes the NACA 4/5 digit code and outputs a sketch file, so you still have to know what numbers to put in. 

Actually, airfoils are quite an interesting subject. They are the third most interesting subject in academia to me, right after propulsion and control systems.

Give it a shot, it's a little different than Inventor and it takes some getting used to, but I think it's more intuitive, although sketch tools are less powerful. Now what are these NACA 4/5 codes? Also the way I modeled the airfoil was to sketch the overall wing, extrude it to thickness, and then fillet it to shape.

 

I'm so excited for college

[KaminKevCrew]

8 hours ago, Hackentosher said:

Thank you! I think i mentioned that I was going for like a modern P-51 feel with it, thus the airscoop that probably wont do anything but create drag within the fuselage. I would like to add flaps, but I don't know how necessary or worth it they will be considering how small the aircraft is. The wingspan is only 630mm, so I don't think it'll need flaps, however I'd like as much scale details as I can in a small, printable, package. I would also like to add custom retracts, but I want to finish the rest of the design and control surfaces first. Speaking of control surfaces, I have no idea what I'm doing in terms of aerodynamic design, so the ailerons are 1536mm^2, the elevators are 815mm^2, and the rudder is 382mm^2. Those are all arbitrary and I sized all of the features and control surfaces by appearance and gut instinct... soooo we'll see how that goes. I have a feeling the roll will be super duper twitchy, pitch will be fine, and yaw might be a lil sluggish. I've also never really flown rc planes, but I could handle it if it was FPV, so I'd really need to be on my feet when flying it in the goggles. I'd be lying if I said I wasn't scared of a maiden, I will probably want to have a flight controller running inav for some stability and OSD.

 

As I mentioned, I have no idea what I'm doing, so I did the standard flat bottom, curved front top. Here's a cross section.

I also like how the Horus radios look, but I think you're the only one that likes the x12. But hey, if you do, more power to you. Fly what you like.

 

Aren't the batteries burried within the Horuses (Hori?)?

If the wingspan is going to be that small, I would recommend avoiding retracts (hell, landing gear of any sort) and flaps. The added servos/linear whatevers (The proper name escapes me at the moment) weight will really kill how easy it will be to fly. 

 

Yeah, the battery is mounted internally on the Horus, but it's not really any worse than my current radio, the X9e. Besides, I've been thinking about using a pack of 18650 cells in parallel with a step up converter so that I can have constant voltage to the radio (of course, I'll have to set up a total runtime timer to keep track of battery levels, as the radio will only see one voltage.)

 

Not many people like the Horus, but I think that's mainly because most people looking at FrSky gear are looking for something inexpensive. While $500 for a new Horus isn't cheap, it's not exactly expensive when compared with other vendors (Spektrum DX20, the JR android based monstrosity that has almost 65,000 steps of resolution on each axis of the gimbal, or any jeti radio). Also, I'm a pretty big guy - 6'6", around 285 Lbs. So I tend to like having a wider radio, as I have very broad shoulders. Plus, I'm a pincher with not particularly flexible fingers, so it's impossible for me to comfortably operate a radio without a neck strap. As such, I have no issues with the Horus. Also, since I was planning from the get-go to take advantage of the external antenna on the Horus, I'm not bothered by the placement of the internal ones. 

10 hours ago, straight_stewie said:

This is a very good point as well. Along these lines, it's also harder to limit a nitro's speed for beginners.

Were those packs NiMH or Lipo? Also, lipo tech has definitely taken a few strides in the past could of years. 

 

The other nice thing about electric vs. Nitro/gas is that when you drop the throttle all the way down, the prop no longer has any energy, almost instantly whereas with nitro, it takes a couple of seconds (at least) to kill the motor. Also, electric has instant power adjustments. 

8 hours ago, Hackentosher said:

Well, I said I don't know what I'm doing, but I do have a basic understanding of Bernoulli's principle. I've also been running some tests in Autodesk Flow Design, a virtual wind tunnel, and I've noticed some weird turbulence after the tail, not sure what's going on there. I can attach some screenshots from that.

 

I'll check out those airfoils, but I'm not sure how I'd do that in CAD, it was a pain in the ass to get the fillets just right for the one I have.

 

edit: I just clicked those links, holy crap I have no idea what I'm looking at. 

Would you mind showing us the elevator? Also, keep in mind that the wings will create some turbulence that will interact with the tail. Also, I would definitely recommend starting with an airfoil that has been tried and tested. It will be a LOT easier to get something that's flyable. If you want anything close to scale speed, I think you're going to want to shorten the one that you're currently using. The bump on it looks more similar to a Cub than a P51 to me. (And cubs are actually really annoying to fly well because of how much lift the wing generates.) 

8 hours ago, straight_stewie said:

Which CAD are you using (all autodesk products have special tools to make them out of splines by importing csv or xlsx...)? I'd love to see the images. I also have an Autdesk CFD 2018 student subscription if you want me to take a deeper dive into some things for you...

Pre-Post Edit: AutoDesk makes an airfoil generating tool that they distribute for free. 

I didn't know about that tool. I'm definitely going to have to look at it!

8 hours ago, straight_stewie said:

Sorry for the double post  It's a one time occurrence, just to give you the notification.

In the database you are looking at a collection of coordinates (an x,y value pair). Some tools exist that eat those, mostly you just import them into excel and then use that.
In airfoil tools you are basically seeing an airfoil generator that follows the NACA 4 and 5 digit algorithms. It also includes a database of every airfoil generated by a user.

That sounds like a big database!

8 hours ago, Hackentosher said:

I use Fusion 360 because I think it's better and more intuitive than Inventor. I'll give that airfoil generator a shot. 

Fusion 360 also has some nice cloud/collab functionality that (to my knowledge) is missing from other Autodesk products.

8 hours ago, straight_stewie said:

I haven't started on Fusion 360 yet. I'm still using inventor. I think that airfoil generator takes the NACA 4/5 digit code and outputs a sketch file, so you still have to know what numbers to put in. 

Actually, airfoils are quite an interesting subject. They are the third most interesting subject in academia to me, right after propulsion and control systems.

I 100% agree with that. It really makes me want to be an aeronautical engineer, but I've been leaning towards mechanical and electrical otherwise. There are so many cool options in engineering, it's hard to decide!!!

[straight_stewie]

9 hours ago, Hackentosher said:

Give it a shot, it's a little different than Inventor and it takes some getting used to, but I think it's more intuitive, although sketch tools are less powerful. Now what are these NACA 4/5 codes? Also the way I modeled the airfoil was to sketch the overall wing, extrude it to thickness, and then fillet it to shape.

NACA 4/5 wings are wings that have a 4 or 5 digit number describing the wing shape. You can plug those numbers into an equation and get out the airfoil shape. There's a wikipedia link that describes it in better detail: Wikipedia NACA Airfoil. 

Btw, the best way to model an airfoil is to take those coordinate charts, convert them into a CSV file, import them as a spline, and then extrude. You can scale the wing by scaling the wing chord line.

 

8 hours ago, KaminKevCrew said:

I 100% agree with that. It really makes me want to be an aeronautical engineer, but I've been leaning towards mechanical and electrical otherwise. There are so many cool options in engineering, it's hard to decide!!!

I tried it. I got kicked out of school. I wish they had offered a minor in aerospace engineering. I wanted to do CS for aerospace applications, but to get the aerospace knowledge I had to have aerospace as a major. I think all universities will be the same: They will not offer a minor in aerospace.

[Hackentosher]

Printed the first two thirds of the fuselage, have some changes to make. Namely, camera hole, revise the battery plank thing, add motor mount for the front bit, make the motor hole smaller (it's 35mm right now, way too big for a 22xx motor), maybe move the scoop forward so that it could cool the ESC and do something other than create drag, add a hatch for the battery and electronics, and maybe revise the shape of the nose because it looks a little weird to my eye. Also it's in two different colors because I ran out of black oops. However, the yellow lets you see some of the internal structures better so happy accidents.

 

As I was gluing it together, I was thinking I should have the pieces of the fuselage interlock and then glue them, but it's ridiculously strong just glued edge to edge with CA. Here's some pictures.

Spoiler

 

[KaminKevCrew]

6 hours ago, straight_stewie said:

snip

Yeah. That's why I've also been considering doing a double major.

3 hours ago, Hackentosher said:

Printed the first two thirds of the fuselage, have some changes to make. Namely, camera hole, revise the battery plank thing, add motor mount for the front bit, make the motor hole smaller (it's 35mm right now, way too big for a 22xx motor), maybe move the scoop forward so that it could cool the ESC and do something other than create drag, add a hatch for the battery and electronics, and maybe revise the shape of the nose because it looks a little weird to my eye. Also it's in two different colors because I ran out of black oops. However, the yellow lets you see some of the internal structures better so happy accidents.

 

As I was gluing it together, I was thinking I should have the pieces of the fuselage interlock and then glue them, but it's ridiculously strong just glued edge to edge with CA. Here's some pictures.

  Hide contents

 

edge to edge CA will likely be stronger actually. When you start adding notches, you become reliant on the strength of the layers of plastic to hold together, which aren't particularly strong. Also, of all the other designs I've seen for models, everyone just glues it all edge to edge, and that works fine. If you really want some kind of interlocking, I would add some longitudinal splines internally that kind of lock one section against the walls of another. It might be good to add some mounts so that you can screw in a motor mount (even consider making accommodations for threaded brass inserts, so that you can screw that in and out repeatedly). That will make the build much easier. I would also definitely recommend making the battery tray accessible through a hatch of some sort (you can buy neodymium magnets that can be inserted into either side to create a very secure mount.) so that you can easily remove/replace the battery. Usually this is done on the top/bottom or side, as it's much easier to do up a battery strap from that angle vs. the front or rear.

 

For the air vents, I would suggest using a NACA duct instead:

 

 

NACA ducts are great because they are VERY low drag. They're not great for things that need massive amounts of airflow, like a jet turbine, but they work quite well for something like cooling a battery compartment or whatever, as they have ample airflow for something like that. Plus, they can be relatively compact. Just something to consider.

 

Oh yeah, and for that battery tray, it would be really cool if you could put a slit at the bottom of it to loop a battery strap through.

[straight_stewie]

@Hackentosher Which end of the fuselage is the front? If it's the black side, that looks very, kerbally

[Hackentosher]

29 minutes ago, straight_stewie said:

@Hackentosher Which end of the fuselage is the front? If it's the black side, that looks very, kerbally

The side with the big motor hole lol 

[KaminKevCrew]

8 minutes ago, Hackentosher said:

The side with the big motor hole lol 

To be fair, one side has a big motor hole, and the other side has an even BIGGER motor hole....

[straight_stewie]

15 minutes ago, Hackentosher said:

The side with the big motor hole lol 

Bidirectional aircraft!

[Hackentosher]

2 hours ago, KaminKevCrew said:

Yeah. That's why I've also been considering doing a double major.

edge to edge CA will likely be stronger actually. When you start adding notches, you become reliant on the strength of the layers of plastic to hold together, which aren't particularly strong. Also, of all the other designs I've seen for models, everyone just glues it all edge to edge, and that works fine. If you really want some kind of interlocking, I would add some longitudinal splines internally that kind of lock one section against the walls of another. It might be good to add some mounts so that you can screw in a motor mount (even consider making accommodations for threaded brass inserts, so that you can screw that in and out repeatedly). That will make the build much easier. I would also definitely recommend making the battery tray accessible through a hatch of some sort (you can buy neodymium magnets that can be inserted into either side to create a very secure mount.) so that you can easily remove/replace the battery. Usually this is done on the top/bottom or side, as it's much easier to do up a battery strap from that angle vs. the front or rear.

 

For the air vents, I would suggest using a NACA duct instead:

 

 

NACA ducts are great because they are VERY low drag. They're not great for things that need massive amounts of airflow, like a jet turbine, but they work quite well for something like cooling a battery compartment or whatever, as they have ample airflow for something like that. Plus, they can be relatively compact. Just something to consider.

 

Oh yeah, and for that battery tray, it would be really cool if you could put a slit at the bottom of it to loop a battery strap through.

That's good to know, but I also kinda want it to line up right. I added a motor mount like a miniquad arm, so four slots that fit the standard bolt pattern, but 3mm thick and fileted into the body so hopefully it'll be strong enough. I'm working on the hatch right now, just sliced off the top third of the fuselage, I think I'll hold it down with some notches and a magnet. 

 

As for the duct, I'm going for form over function in a sense because I wanted to take the design element from the pt1 because I think it looks cool. 

 

Next steps for the middle will be finishing the hatch, and then adding wheels to the wings. I'm thinking about just connecting them straight to a servo for just a quick and dirty retract. Then a steerable wheel in the back that stays down. 

[Legolessed]

Well the wait for the rain to clear was worth it. I get to fly in the snow!!!!

[Hackentosher]

Holy crap US people: helination is having a 50% sale on select items, namely the brother hobby tornado 2000kv (my 6" build is coming back baby :D) and the og red butt is now $10 on emax USA. 

[straight_stewie]

1 minute ago, Hackentosher said:

Holy crap US people: helination is having a 50% sale on select items, namely the brother hobby tornado 2000kv (my 6" build is coming back baby :D) and the og red butt is now $10 on emax USA. 

I just saw that literally 30 seconds before you posted this  
 

I was looking for Blade Nano CPS parts. I could practically build one out of their discounted spares for half what I just paid for it.