Rise of the Clones (APM2.x series)



The name 3DR, 3D Robotics, and ArduPilot are trademarks of 3D Robotics.  

The design is Open Source and licensed under the Creative Commons and GPL v3 license.

A misconception is out there that cloning the Ardupilot is not liked.

This is not right, there are a few companies that make Ardupilot gear, and who give back to the community, either in support of developers, or simply adding improvements and Publishing the results for all to see.

What are not appreciated are those who take, but do not give. Who either simply take the Schematics and PCB drawings, directly use these, make equipment, and do not offer support channels or worse, those who make derivatives, and do not feed back to the community.

Recently Hobby king released the HKPilot mini, a welcome derivative to the APM series of boards, this is great news, but there is a catch.  Hobby King did not want to release the drawings.

Here is an email exchange that I have had with them regarding this issue.(please note I have been corrected, the copyright is owned by 3DRobotics)


Me Mar 11 11:47:

Where are the design files for this product? it is Open Hardware, you must publish your design files. This product is copyrighted to DIYDRONES*, and is licensed under the Open hardware licence. This requires you to publish the Eagle drawings.
Under the licence, any derived product MUST be published with the SAME open hardware licence.

Howard T., Mar 14 10:39:

Hello Philip,

Thank you for raising this matter to our attention. For us to help you with your inquiry, we will escalate this matter to our Product Specialist for further assistance. Rest assured that your concern will be addressed shortly. Thank you for your patience and understanding.


HobbyKing Support Team



Ian, Mar 14 18:20:

Hi philip , 
Thanks for contacting the HobbyKing Support Team.

You may contact DIYDRONES for the design schematics. We are not the owner therefore we cannot supply you with the design

Thanks for emailing support. 
If you have any other questions, please let me know. 
Best Regards. 
HobbyKing Product Specialist 

 After other exchanges, including posts on the product page they posted the following.


   Proficnc 11 points - 11/03/2014

   design files please


      Eagle CAD files will be uploaded shortly in compliance with the user agreement

      proficnc  11 points

      Thankyou :)

Which was great…. Except they did not post the files.

After another day of many people sending support requests, finally they sent an Altium file (Just PCB, and with exploded polygons).  This File was a modification of the Altium file I had posted on DIY Drones of an early 2.5 revision (mistakes included J ) which does appear to be the board that they have built.

But the problem? According to the licence, they MUST abide by the licence.

  • ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
  • Attribution — You must give appropriate credit, provide a link to the license, andindicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

So that means that Altium is OK, as that is what they used. But they MUST include the FULL design file. That is Schematic, Lib files, everything needed for others to go straight into production with this file, and it should have this license clearly marked, and it should show it is a derived work.


* The name 3DR, 3D Robotics, and ArduPilot are Trademarks of 3D Robotics.  

The design is Open Source and licensed under the Creative Commons and GPL v3 license.

The Pixhawk / PX-4 has the open Hardware licence, please see the link below for details...


1. Documentation

The hardware must be released with documentation including design files, and must allow modification and distribution of the design files. Where documentation is not furnished with the physical product, there must be a well-publicized means of obtaining this documentation for no more than a reasonable reproduction cost, preferably downloading via the Internet without charge. The documentation must include design files in the preferred format for making changes, for example the native file format of a CAD program. Deliberately obfuscated design files are not allowed. Intermediate forms analogous to compiled computer code — such as printer-ready copper artwork from a CAD program — are not allowed as substitutes. The license may require that the design files are provided in fully-documented, open format(s).


If you do not wish to release your drawings, then you must start with a clean slate, the reality is, if it is compatible with APM/PX4/Pixhawk, it is most likely a derivative. (Exceptions would be TauLabs/OpenPilot; APM code will run on their boards, but only after significant modification to the code)

Why is this important?

DIYDrones is a community where people with a common interest share their ideas, and inventiveness. It is important that the work done by those in the Development process is recognized for its worth. When someone comes along and taps into that knowledge, makes a gain from that, and does not return to the community, it takes away from why we are all here.

I have heard people say “I do not want to open source my product based on APM, because people will copy it…..” the reality is, without the open nature of the project, this person would be unable to economically design their project in the first place, so feeding back to the community is a small price to pay.

For those interested, have a look at the git-hub repositories, there are a number of hardware suppliers supported by the code base, and the development team, these manufacturers get direct support from the whole team, because they are OPEN with their code additions, and also with their hardware.

When purchasing hardware, consider this,

  1. does the company you are purchasing from directly support the product?
  2. does the company seek to improve on the product, and release this information for the community to use?
  3. do profits from the sale of the product go towards creating better outcomes for the community in the longer term?
  4. does the company have quality control?
  5. does the company have engineering on hand to help with your log analysis?

This Blog will be moderated. All posts will require approval. 

Views: 5289

Comment by William Premerlani on March 23, 2014 at 7:02pm

Philip and Craig,

Just want to point out a couple of highlights in the development of the UAVDevboard.

The first version of the UAVDevboard was in production at SparkFun on 3/10/06, and was documented here.

We are now up to the 5th version.

The UDB team was developing many of the ideas presently being used by the community in general and ArduPilot in particular. For early developments see this discussion and this discussion for example, and for later advances see this summary.

Regarding ArduPilot, Chris and Jordi started out with thermopiles, but quickly realized gyros and accelerometers were better. To get a jump start, Chris sent Jordi to my house for a week for me to bring him up to speed. We spent 2 days going over the math, 2 days writing software, and 1 day testing. ArduPilot was born and 3D Robotics was kickstarted in my family room.

And lets not forget the Paparazzi Project in 2003, which predates both ArduPilot and UDB.

My point is, in my opinion, much of what is out there, including ArduPilot, did not start from scratch, but was built on the work of others. I just don't want us to loose track of that.

Best regards,


Comment by Craig Elder on March 23, 2014 at 8:01pm

Bill, yes what you say is an important part of our history and a successful collaboration not to be overlooked.  We all all greatly indebted to you and your work on the DCM.  Thank you!

Comment by Gary McCray on March 23, 2014 at 8:21pm

@ Georacer, I am not "fiercely" discouraging people from buying clones.

I am simply and validly pointing out that it is truly not in the best interests of even the non-3DR employed developers to spend our time dealing with their problems.

The reason virtually all of us don't buy them and don't use them is that most of them are "problematic".

They are often not "cloned" properly, not tested before being sent out and often have not even been verified to be fully operational at all.

Thus they often don't work whereas if there is a problem with a 3DR board it is generally something actually broken that 3DR will fix or replace.

None of the clone makers have shown any propensity to do that.

This allows us to spend our time on real problems rather than chasing a manufacturers problems and lack of assumed responsibility.

Feel free to use clones, just please don't expect us to troubleshoot them for you.

Even if you have a legitimate (non-clone) problem, we can't tell that and have to end up chasing our own tail to even figure out whether the problem is legitimate or one caused by the cloner.

Since periodically (far too often) users don't bother to mention it's a clone (until we actually figure it out for ourselves) we really, really dislike clones and also are not all that happy with those people who think we should treat them as if they weren't.

Life isn't long enough to spend fixing drek, especially for free.

Basically if you buy a clone and it works, great, if it doesn't, consider it a lesson learned and stick it in a drawer.

Best Regards,


Comment by Gary Mortimer on March 23, 2014 at 10:09pm

+1 on Bills and all the other devs contributions. UAVDevboard is a thing of beauty.

It does sometimes feel as if people think this is new technology only just released and don't realise the number of air frames and autopilots that have given themselves back to mother earth  to get us where we are now. The very reason you can now argue about low price clones. I contend that the napkin based dreams of 2007 and the start of DIYD have been achieved and are only getting better and faster.

Gary is right it sticks in the throat a little when folks ask for help with their clones created by companies that don't give a stuff about the end user. The rudeness with which that help is asked for can be astounding. Generally from people that start there post or email with something like this is my first RC aircraft, I have bought a 3m predator clone and the largest engine and prop money can buy. 

I can't code and all the little plastic bits with wires coming out of them mean nothing to me. But what I do know is that I can take the box and attach it to any model aircraft and make it fly it. All for less than $500. Its not the only show in town but its the one I have been hanging out with for six years now.

Comment by Philip on March 24, 2014 at 12:54am
Absolutely :)
Thank you
Comment by Georacer on March 24, 2014 at 6:49am


I value your response, given the time you have spent educating new users and documenting existing knowledge. I understand that you are reluctant to provide troubleshooting services for cloned boards, since the community time can be better spent doing research and bug fixes.

What I don't understand is which board distributions you consider "official" and worth community time. Is the 3DR version the only one worth our time? Are there other boards that you approve of? Do you have a set of prerequisites a clone should have to be considered support-worthy?

I am basically referring to the APM2.5/6 hardware package.

Comment by Gary McCray on March 24, 2014 at 8:08pm

Hi Georacer,

There are actually quite a few people who have developed derivatives of the APM and now PX that actually offer some enhanced or interestingly repackaged capabilities.

Generally these people are actively engaged in on-going development and more than happy to field questions about their own products and variations.

We love those guys, that is really what open everything is all about.

It is the simple snip and rip that is the problem, copy it as cheaply as possible, do no support and try to undercut the people who developed and support the original.

Even then we don't care much if you buy it, we just don't want you to expect us to support it, it isn't fair, they pay nothing and shift the burden of support over to us.

It would be like expecting Ford to do warranty work on your Chevy, it just doesn't fly.

Basically if the people you buy it from don't offer real support (or even in many cases a realistic way to return it to them if it flat doesn't work - you are on your own buddy).

You can pretty much guess the ones we don't buy, almost all of them are cheap and come direct from China with no support other than referring you to our web site and a return policy that more often than not proves to be non-existent.

Don't get me wrong, 3DR actually resells some stuff direct from China, but 3DR also stands directly behind them and will do their best to help you solve any problems you have with them.

Flight control boards are not on that list though and likely never will be.

For us developers users and 3DR to make this work we have to go for the utmost synergy and that is really what this whole issue is about.

This trinity gets my time, my effort and my dollars and I get back my time spent on the leading (and bleeding) edge.

That's where I want to be.

Best Regards,


Comment by Philip on March 24, 2014 at 11:24pm

Just to let you all know, ARSOV RC has released their Pixhawk derivative. Thanks Phillip and Nick 

Comment by Emin Bu on March 25, 2014 at 3:09am

GARY, and others involved ,can you please explain how do you know who is using clone or original when asking for help?!

Also,why 3DR keep APM 2.6 price point at 239$(more expensive than Pixhawk) ,by now they already made profit on 10 000 boards sold, enough to pay for all developments...put it down to 100$(production cost must be less than that) and no one will buy clone..

my FCs(APM2.0 and Pixhawk) are original but it is not always easy to pay for shipping almost as much as some clone boards price....

Also,can you do something on software side, some kind of protection, password or clones not be able to update firmware?(maybe I do not understand what open source is...)

Also,can someone convince me once more that 3.1 firmware is not written to disqualify clones or some bad components inside them?

sorry if my questions are not on technical level u would expect,but most of the users are not on that level too...

Comment by Nick Arsov on March 25, 2014 at 8:43am


Could you please fix the AUAV-X1 and Arsov tags of this blog post?

Best regards



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