QRM [DIY quadcopter]


Last year me and a friend of mine started building a quadcopter from scratch. We wanted to build the machine and the electronics ourselves. We experimentad a lot, but up until today we did not yet succeed in getting the bird in the air with the home build electronics. We keep having some trouble reading the data of one of the sensors, thus the PID loop doesn’t work properly. More information about out QR1 quadcopter can be found on QR1 quadcopter

We recently bought the Hobbyking control board for quadcopters, and mounted this on the QR1 frame. It flew good, and we both wanted a proper quadcopter for flying purposes only. We recon the Hobbyking control board with other KK microcopter firmware will do the job perfect. We wanted the quadcopter to be small, and started designing a mini quadcopter.

We used the same parts lots of other folks use in there quad, listed below:
Motor: 18-11 2000kv Micro Brushless Outrunner (10g) 
ESC: Turnigy 6a Brushless Speed Controller
Props:5x3 Propellers (Standard and Counter Rotating) (6pc)
Prop adaptors: Prop adapter w/ Alu Cone M5x2mm shaft (Grub Screw Type)
Turnigy nano-tech 850mah 2S 25~40C Lipo Pack
Control board: ]HobbyKing Quadcopter Control Board V2.1 (Atmega168PA)

We ordered all the parts for an amazing 110 euro’s, you almost get it for free.

After deciding which parts to use, we started designing the little monster. We came up with a design that we could machine out of 1,5mm aluminium, for prototyping purposes. We plan on making the final design out of a carbon fiber sheets. The quadcopter is only 176x176mm and will have a RTF flying weight of about 325grams. We gave it the name QRM, meaning Quad Rotor Mini.

Below are some images of the prototype machined out of 1,5mm aluminium. The LiPo battery in the pictures is a 3S 800mAh battery, and will be replaced for a 2S 850mAh equivalent.




And a Youtube video!

Larger images are available on:

Gallary Dennis Martens - QRM quadcopter

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  • Thanks for the positive reactions, and the other comments!

    To all of you who commented about the total weight of this machine, we use the 5x3 two blade props. (not the 3 blade, or the 5x2 blades) The total weight will be around 325grams maximum with the aluminium frame and steel bolts. We did a lot of reading and got to the conclusion that everything below the 400 grams with this setup would be able to fly.

    However, we are aware that a lighter quadcopter has numerous advantages, and the final QRM will weigh a lot less. When the design is finalized we will machine it out of 1.5mm carbon fiber sheet, and use nylon bolts. This will spare about 50 grams on the total design. We will also have a look if we can lose extra weight by making some changes to the design. The arms can each spare about 3 grams, which is a total of 24 gram. We think we can get the total weight down to 250 grams, without huge compromises to the current design.

  • Can only agree with the rest of the comments.

    Looks really beautiful but sadly it is to heavy for that power choice.

    I have experience with the same motors and props and more than 250g on 2S is not a good idea. (Even 250g is to much in my opinion but at least if flies)

    Right now I just fly with 3S 460 mAh on my silver hornet (240g AUW), the 2S batteries is only used for indoor hovering tests. http://wiki.openpilot.org/display/Doc/Silver+hornet

  • Using these motors with a 2-cell: http://www.dealextreme.com/p/a1510-2200kv-outrunner-brushless-motor...

    You might get away with a 6" and a 2-cell, 3S might be too much for them.

  • Hey Steve, what motors are you using for the hex?  My mini is so small, with a 9" (23 cm) motor-motor distance, that's why I'm getting the 3-blades to get more prop surface area.  I think the minimum I can go is the 6x3, for the short armed version.  But in the frame is ready for X8 or Octo configuration, in the future.


    The long armed version is a little better, with a motor-motor distance of 10 inches(25cm):


  • I am personally not a fan of the GWS 5x3 tri-blade. They are flimsy and typically very unbalanced. I had them on a mini quad and on my mini hex. I recently switched the hex to use APC 4.75" which come in pusher as well. More expensive but I am getting a much more stable flight: https://twitter.com/#!/Hovership_rc/status/154713002715774976

    Twitter. It's what's happening.
    From breaking news and entertainment to sports and politics, get the full story with all the live commentary.
  • Nice frame.  One thing though, if you're going to drop down to a 2s battery, you're probably going to have to go to increase the size of the propeller.  I don't think the 5x2 are going to lift  325g with that motor.  You might get away with 6x3, but check out my blog to see the props, I've ordered for my Firefly Mark One:


  • Stunning frame design! Are you planning on releasing the plans?

  • That's a very nice frame!

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