Xcompact project. Portable and flexible DIY frame.


Hello everyone,

I would like to share with you my latest project. Currently I am at the crossroads and would appreciate any feedback.

The main goal was to design a truly portable drone that fits into a backpack. I was unhappy with the foldable frames on the market, as they were all too large. The ones which fold in horizontal plane still have a problem with landing gear, and in umbrella-type frames you need to sacrifice the space for electronics. I ended up with such requirements:

  • Compactly folding core

  • Arms fixed with a screw (no plastic clips)

  • Detachable legs  

I've decided to use two 16 mm tubes as a frame core in order to make it strong and flexible. I've made two modules for front and rear arms. PMMA plastic is used to reduce the prototype costs (however, 3mm plates are surprisingly strong), later I am planning to switch to carbon fiber. The most compact folding is achieved when arms are above each other.


Firstly I was attaching legs to the core tubes (PVC plastic). But then I realized that they can be fixed with the same screw as arms.  And this shortens the assembly time. Legs can have different length, mine are short just because I ran out of tubes.


Following the modern trend I added a vibration isolated plate. The number of damping balls can vary depending on the load. Some balls have flexible position in order to fit to different core sizes.


My current frame size is 710mm and it folds into ~ 370x170x120 mm, which is less than 8L volume.


While the weather was not good for flying I decided to collect my thoughts. The frame is portable and also turned out to be quite flexible. Several holes can be drilled for the arm-fixing screw -> several square frames can be build from the same parts.

I started to dream about "Lego" for drones. The main point about "Lego" is that from the same parts one can build various things. There are some plastic analogues like RotorBits, however I was considering only carbon fiber and aluminum parts. Currently with my friends we are working on such set of universal parts for multirotors. Here are the characteristics we implemented in the kit:

  • Frame size D: 400 - 800 mm (8 - 18 inch props)
  • Folded size: L x 160 x 120 mm (L ~ D/2 + 60)
  • Variable arm angle, > 10 different square frames
  • Detachable legs
  • Arms and legs are fixed with an M4/M5 screw 
  • Quad or X8 configurations
  • Vibration isolated center plate
  • Different camera layouts
  • Optional: Retractable landing gear, vibration damping motor mounts, prop guards, integrated PCB

Personally I am really happy with the result.

Even my large 710 mm drone fits into a backpack. The frame is easily customizable: in order to change the size one simply slides the arm-modules, also variable parts can be attached to core tubes or to the center plate.

At this point I would like to hear your opinion. Did you also think about a truly portable DIY drone? Which characteristics would be the most important?


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  • Greetings Denis Krylov,

    I met your Xcompact project today. It is wonderful.
    You are very smart.

    Do you have any updates?

  • Gleb,

    I design the parts with solidworks and export an STL file.

    Then on the printer I use Repetier Host with Sli3r.

  • Hi Vince,   What is a program do you use for the 3D printer? I also bought the 3d printer for $350 a month ago. And just as you're doing a new project with using the 3D printer. 

  • I guess $500 will get an OK printer. All my drone parts can be printed on a really small printer even though i made myself one of the biggest.

    here is interesting link about new plastics

    3D printing filament

    3D Printer Filament Comparison | MatterHackers
    Filament Comparison Guide: Everything you need to know about 3D printing materials from the professionals at MatterHackers.
  • Nylon sounds interesting. What is the price for such 3D printer?

  • I am totally converted to 3D printing. Parts can me made light by selecting a 'fill density' and skin layer thickness. By having a thick part that has a 30% fill density is rigid and light. The fill is achieved with a grid or honeycomb pattern. 

    Now its possible to print in nylon and polycarbonate for seriously strong parts.

  • Joseph, yes 3D printed parts are perfect for prototyping in general. In my case I was lucky to have an access to a laser cutter, where I made a lot of attempts with plastic plates. And for the blue clamps on the arms I have used a standard one + some drilling.

    So prototyping is done and now I am working towards a small scale production.

    Also I hope to have an animation soon, my friends are helping me with that. 

  • My understanding is the value of 3d printed parts is that advantage of rapid protyping. design it, build it, tweak it then have the parts CNC'd or molded to get the optimal strength and weight.

    I think the cost of machining with a mill would be prohibitive. 

    I really like the all tube frame,  Can you provide pics of how the folding system works?

  • Oh, that is really sad!
    Your project is great! It shows the strong sides of 3D printing.
    I will definitely think about using some printed parts in my design. However, I don't want to sacrifice the portability. Xcompact frame for 17 inch props will fold to ~400x170x120 mm.
  • Gleb, will try to upload a vid of it flying soon.

    Dennis, the props are 17". I was getting 30 minutes airborne with the sony NEX on full 3 axis gimbal.

    I dont know how much it is to get parts printed but suspect its cheaper than CNCing, anyway the printers are very cheap now and you will never regret getting one.

    I just printed bits to join carbon tubes. Newer printable plastics are very rigid and can even get carbon fill.


    Mine can be folded with arms attached to 700mm x 300mm or arms removed to 500mm long. Gimbal just unclips  and is on a single plug with all video and power etc. Legs fold under. The arm units are floating on sorbathane. I printed plugs so the end units detach without wires.


    The sad end to this story is that all my drones, 3D printer(self design), PC containing my designs has been stolen from my workshop.

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