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: 5308

Comment by Thomas J Coyle III on March 20, 2014 at 8:28pm


You gotta tell it like it is. Nice exposé:-)


TCIII ArduRover2 Developer

Comment by Craig Elder on March 20, 2014 at 8:29pm
Well said Phillip.
Comment by frederic reblewski on March 20, 2014 at 11:34pm

how is a derivative defined? I did not know that type of license so I read it ( following the link ) to better understand this post. it does seem to be very focused on musical, literary or artistic material. it is difficult to understand the extent of the concept of "adaptation" for hardware. when does a design including the licensed design becomes a "collection"? 

on your point itself, I understand the frustration about people who develop "adaptations" and do not apply the license terms. that is not right. but there is something I do not understand. you seem to think that it is not OK to "just" take the files, manufacture the product and sell it. first let's make sure we are on the same page. if the quality of the product or the support are bad that approach will fail anyway. but if somebody is doing it seriously, it seems to be in the letter and the spirit of the license. One could argue that manufacturing the product and selling it at a low price is indeed giving back to the community.

may be you feel that this is unfair competition to 3DR, as 3DR has to spend resources to create part of the technology and is so much involved in the development of the community. I am sure that the companies that have to develop their product from scratch having to pay for 100% of their R&D and marketing feel that 3DR is distorting their competitive landscape. it is a global deal. open source gives you a lot but you have to feed some competition.

anyway do not worry, sooner or later somebody will put a 9 figure check in front of Chris to acquire 3DR and DIYDrones. nobody will ever offer that for a clone maker!!

Comment by Jethro Hazelhurst on March 21, 2014 at 2:15am

Thank you for the well informed article Philip, a very balanced read.

Comment by Ted Van Slyck on March 21, 2014 at 3:14am
Thank you for putting the pressure on Hobbyking to comply. Does the Creative Commons actually apply internationally? Is it enforceable in any way?.

Comment by Roberto Navoni on March 21, 2014 at 3:57am

Hi Philip, 

i agree with your vision about the hardware ... i think that VRBrain project is an example of original project that support the APM firmware , but try to have different approach . We start 3 year before of 3DR to support STM32FX micro controller and port all code to 32 bit with our team and engeneer . 

So we can reply to this answer : 

When purchasing hardware, consider this,

Does the company you are purchasing from directly support the product?

* YES We have direct support with DIYDRones , Virtualrobotix and other friend community as Italian Baroen Rosso  :) 
Does the company seek to improve on the product, and release this information for the community to use?
* Yes sure we have our code repository and wiki that support the project with more info specific for our platform.
- Do profits from the sale of the product go towards creating better outcomes for the community in the longer term?

* Yes sure we try to improve our product by feedback from the community.
- Does the company have quality control?

* Yes sure our company have ISO 9000 Quality process control :) 
- Does the company have engineering on hand to help with your log analysis?

* Yes sure we have support for decode log from VRBrain to understand where is the problem .... 

But Philip , 

the problem is another ... how is possible using money from hardware  support the DEVTeam ?  I understand that all is opensource but is not good that only how sell board can take money profit from the community . 

I think that we need to implement a Foundation as Linux or Openstreetmap or wiki that can support the development of the project  also using money from company that would invest in the project.

At the moment there isn't a good coordination between 3DR and other company different from 3DR that would invest money in the project. I think that one problem could be also the licence of the code. 

Is not trasparent how are pay and who aren't pay inside the community for this huge work ... could be nice to understand how many money is put inside this project in trasparent way.

For Example could be nice have a virtual wall where you put the open project and need of support ... by guys or with money ... and the company that want support that development can put it's money on that task to accelerate it :) 

This is my 2 cent on this discussion .



Comment by Philip on March 21, 2014 at 7:03am
Hi Roberto
Great response, and VR is a great example of development and ingenuity
VR's hardware is truly a clean sheet approach. In doing so, they still help with the development process for APM and Pixhawk

Thanks Roberto
Comment by hal on March 21, 2014 at 7:30am

Lets hope 3dr does not sell out when the big check arrives!  As with any industry that starts it will go through phases. Once the market starts to mature and saturate with companies it will begin a slow but steady combining of companies as the few successful ones have enough money to either buy their competition, or acquire the competition when they go bankrupt.  3dr has the advantage of being one of the first, and one of the most widely supported.  Open sourcing their products may end up being a competitive advantage because who would pay money for a company that anyone can copy the products, and not pay royalties based on patents?  Most takeover targets have patents or a technology the other company wants.  HK is both a good and bad for the industry.  They do drive prices lower, but some of the business practices are less than honest, and most of us know the quality control is horrible.  Will they get in trouble for not releasing the files?  Probably not.  And if they do, they would have already made their profit and moved on.  From other posts the board is considered "old design" already and not benefiting the community anyway.  But having HK customers which is a massive number of people buy and receive an ardupilot comparable controller will eventually drive more people to this site, into the community, and probably add to the repository in a good way.

Comment by Rob_Lefebvre on March 21, 2014 at 8:31am

if the quality of the product or the support are bad that approach will fail anyway.

No, it won't, and there are two reasons:

First, a certain segment of the population wants the lowest possible price, with no consideration for support or quality. They just want bargain basement pricing. There will always be a market for this.  A lot of the time these products end up in a drawer after they can't be made to work.  Sometimes they're just tinkerers, and they're not actually that concerned with having a workable system at the end, and that's fine.  But sometimes it's people who want a workable system, but just don't have a lot of money, and that's not so good.  It's a false economy. But there will always be a market for drawer stuffers. Unfortunately, sometimes these products smear the entire project. The users think they are actually getting something exactly the same as a higher quality product, with the exception being that they aren't paying what they deem an "outrageous markup". When the cheap product fails, they believe it's because the entire project is worthless, and spread the word about that. This is how these products can not only hurt the project and community by stealing sales while offering nothing back, but they actually damage the reputation of the entire project.

The second reason why there will always be a market for these products, is because some of these bargain basement cloners actually put the 3DR logo on them. Then you get buyers who can't figure out that something priced at $60 cannot possibly be the same as something priced at $200, even if they have the same name printed on them (in the wrong font...). This is the worst kinda of cloning, because it is actually illegal.

Amazingly to me, it appears to me that a company in the US is actually selling these products which are misusing the trade-name.

And don't even get me started on, the third type of cloner... The one that sells a product that is nothing but a simple clone, offers nothing back to the community by way of support or contributions, but engages in a campaign of false criticisms, libel, misinformation, etc. towards 3DR and the developer community for the supposed purposes of making themselves appear superior, and increase their sales.

Comment by crystal garris on March 21, 2014 at 9:11am

well this raises an interesting problem in my mind and apparently in the mind of legal professionals. This may lead to a loophole that HK may very well be able to exploit. The central problem is this:

#1  the definition of a derivative work: (from copyright website)

"A “derivative work” is a work based upon one or more preexisting works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which a work may be recast, transformed, or adapted."

#2 how transfer copyright works:(from this pdf)

"Any or all of the copyright owner’s exclusive rights or any 

subdivision of those rights may be transferred, but the trans­
fer of exclusive rights is not valid unless that transfer is in
writing and signed by the owner of the rights conveyed or
such owner’s duly authorized agent"

If you don't see the logic loop, I'll explain it.

lets say I wanted to create an interface device between my original copyright protected work "the techpod" and 3dr's original copyright protected work " the APM"

legally speaking it is now a composite work with derivative rights going to both original copyright holders. the problem is both parties now have rights to said derivitive. the only way forward is a mutually signed contract just as is explained above. In this case the creative commons license agreement is invalid in this particular case. No one can compel you to distribute your work without written signed consent. Check marks on web sites and EULE will never stant of to right of copy in court.


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