Let's build fixed-wing radio controlled airplanes!

Projects
1

I’ve been wanting to build a Flite Test “swappable” electric RC airplane for awhile, but haven’t managed to build up sufficient gumption to overcome the ridiculous ratio of shipping fees to value of goods received.

For those who aren’t familiar with FT’s airplane designs, they’re made from one or more sheets of dollar store foamcore board, and they all use a standardized, modular “power pod” containing the electronics, motor, battery tray, etc. Typically, to assemble one you need a hot glue gun, packing tape, bamboo skewers, and popsicle sticks. Literally. All the plans for all their planes are available for free from their website, and they have very good videos to walk you through the build process.

Of course, before you can assemble anything, you need to cut/score the foam. If I were doing this by myself, I would order one of their ~$35 “speed build” kits, which include foam that’s already laser cut/scored to the right sizes and shapes. But, since we collectively have access to several laser cutters, I figure we could DIY this aspect of it.

If there’s sufficient interest, I’ll make a shopping list and ask a few of you to review it.

2 Likes
2

When I looked into it, foam board appears to be something that would be on our “not permitted” list for the laser cutter…

3

Ah, that’s interesting. We’ll have to brainstorm some other way to do the cutting quickly and reliably then. Maybe one of these in a CNC? :slight_smile:

4

VHS group project?

5

Those are both pretty cool, but I don’t think either would work well in this instance. The hotwire can’t cut paper, and for the Flite Test models, the paper provides a huge amount of the structural strength, and makes the glue joints much stronger, since the glue impregnates the paper somewhat.

Second, I’m just guessing, but I doubt the omniwheel robot would be accurate enough, even under computer control.

6

OK, since I think we’re likely to have a bunch of beginners (myself included!), and we don’t (yet) have a line on automated foam cutting equipment, I think we should get n/3 3-pack Speed Build kits.

They’re also available for $37 from GreatHobbies. Last time I almost ordered from them, shipping was free for orders >= $100, but their prices were substantially higher than Hobby King, so we’ll probably want to to go with HobbyKing for the electronics, motors, batteries, etc.

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If the project were to go that direction I would vote FT Versa Wing Speed Build Kit.

I think flying wings are alot more suitable for carrying a payload without having to worry so much about balance.

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I like the Versa a lot too, but:

  • Triple the price
  • Probably not as beginner-friendly from a building and flying standpoint
  • Finding a place to legally fly big, fast airplanes is hard; the little/slow ones can be flown indoors in a big enough building, and are less likely to attract complaints when flown in a park.

I think it would be good to do at least two phases:

  1. For beginners, each person builds one of the little guys; maybe we can all go out to a park later and learn to fly together. Hopefully there are a few RC veterans around that could coach us. Even though they’re likely to be three-channel designs, we would want to group-buy 6+ channel radios, for future use. They’re almost as cheap as 4-channel.
  2. Next session, we either pick a bigger, more advanced design, or people can choose from a selection. They’ll use the same TX/RX and ESC as the little guys, but will need a bigger battery and motor.
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Awesome
This is the one that I read about before

I like the idea of building a few of these and doing a contest where we ram them in to each other in the sky. The winner is the one that can fly the longest. Minor repairs can be done with a roll of ducktape.

Fixed wings would be easier to get started, It doesn’t need to be “too” aerodynamic as the motors makes up for the inefficiencies of the design.

its probably hot wire not laser cutter as most foam will be banned on the laser cutter. its not hard to make the shape even without a laser cutter.

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CNC routers are far more effective at precisely cutting foam than hot wire :slight_smile: You can laser foam, you just need to be damn careful with your setup and know what you’re doing.

I’ve always liked the pizzabox planes, stick a motor and a pair of servos on a pizzabox with the rear cut into elevons and away you go. These, like most aerobatic planes (think Extra 300) fly more because they are being dragged through the sky by the motor than from any particular aerodynamic properties. If you break it, all you need to do is order more pizza.

2 Likes
11

I like where this is going! :wink:

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OK, I’ve started a spreadsheet to start brainstorming the parts and costs. I’ve put in a ballpark estimate of 20% for shipping; I’ll get more detailed shipping quotes soon.

At the moment, with 6 attendees (including an instructor), each paying $150 (including an instructor), it looks like we’d be $22 in the hole, I don’t mind eating that.

With 20 people, we could reduce the price to $125 and be only $44 in the hole, or keep the price at $150 and leave over $400 left over for Donatio.

Everyone, please feel free to comment!

13

@Arrgh,

Those flight test swappable are awesome, im building the first one at my hackerspace in Brazil.

That is a really nice project!

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A few thoughts:

  • you’re missing battery connectors - We had used XT-60s for the quadcopter workshop, the battery pack you’ve selected uses something different - not one I’ve used, might be JST?

  • If anyone has plans of trying multi copters, they’ll pretty much need to step up to a computerized radio. With shipping being a big part of the cost, and the cost difference for the 9X radio’s being ~$30, might be worth considering it as an option now.

  • Your battery charger doesn’t include a power supply.

  • item we had the most issues with QC on was motors. I’d suggest more than one spare.

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Thanks for the detailed feedback!

  • I’ve switched the battery for one with an XT60 connector (higher capacity at 800mAh too), and added the corresponding connectors to the list–they’ll have to be soldered to the ESCs. Come to think of it, we need to decide whether we’ll be soldering the motor leads, or maybe we want to get a bunch of bullet connectors.
  • I’ve also put in a choice of $30 (HK 6ch) and $60 (Turnigy 9X) TX/RX kits, and assumed that people will choose them equally
  • It looks like the battery charger uses a generic 12V/2A 5.5mm barrel connector, those are pretty easy to find, I’ve added one to the list
  • I bumped up the min spare count to 2 for the motors.
1 Like
16

I made the TX selection more granular and accurate (everyone pays for their choice of TX); now there are three options: Cheap, Good or None (some people already have one).

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Hey guys. I fly a Bixler (Designed and named after one of the FT founders) I also have made some foamies before.

I also have access to the Coquitlam flying field for flying large models, and I have a drone and FPV rigs that I play with.

For indoors, I have a nano QX that is excellent for learning the basics of RC.

How can I contribute?

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Bixler is actually a Multiplex EasyStar with ailerons :wink:

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Yeah, there are a few pusher-style trainers that are out there. The ailerons are a welcome addition.

It also has a 3D printable mount for electronics that is quite nice.

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Hey @mpede, thanks for the offer! I’ve been wanting to buy a Bix too, but I figured this project would be a good way of motivating myself to actually pull the trigger, as well as try to drum up excitement for a hobby that I’ve been dreaming about since I was a little kid. :smile:

At the moment I’d like curious/knowledgeable people to check out my costing spreadsheet–actually, come to think of it, this is an edit link now.

Edit: Now it’s REALLY an edit link, not just for my domain :slight_smile: