Now AliShanMao is having 700 size DJI arms made. The multirotor world has gone DJI crazy....... http://www.youtube.com/watch?v=mCqEH5-or1I&hd=1
Do you think those arms are a direct hole-for-hole match with the original DJI arms? I'm thinking they may not be, otherwise why sell a frame with them?
Whether the holes are the same or different, I think the reason for the new frame is the added stress from having motors mounted 700mm apart. The original frame likely will not handle that stress load. Plus, the reason for the longer arms is to lift more load - bigger motors, bigger props. A bigger frame gives you somewhere to mount all your goodies. Just my thoughts on the subject
Impossible to say unless we get our hands on one, or if they volunteer the info. But, if I was making them they would be exactly the same just for the sake of being universal. I would think you would sell more that way overall than if it was proprietary. I could see people just wanting long arms on a regular DJI 450 with all the small stuff still (motors, props, center section) just to get the GoPro a clean view.
I agree with you on the "universality" of keeping them the same. However, from an engineering perspective the mounting points should be scaled up with the length to help distribute the additional loads.
Good point, I did notice that the triangle matches the actual DJI format (The vertical part is straight), but the end that mounts to the frame is oval which matches the HK style arm. And it is hard to tell, even in HD, but it looks like the brass inserts are missing from the white arms? And there are some inserts missing from some other arms he pans the camera over to. I wonder if the inserts are pressed in after the arms are molded. If that is the case then there could be problems.
I disagree. In my experience the stock DJI frames are much stronger than the arms. Even my own experience flying dual 6400 mAh batteries and having a propeller failure in flight resulted in a broken arm but no damage to the frames. From a engineering point of view the way the arms mount to the frames there is a super sturdy box made in the center frame area as each arm mounts with six shoulder screws. Keep in mind I am referring to the original DJI frames, arms and screws. I have seen that some knock off kits use regular cap head screws that do not have the shoulder which may allow for more flex in a crash. I bet you could put meter long arms on the stock DJI frames and not suffer any frame failure as long as they are mounted with the DJI type screws and the arm mounting holes meet the original DJI pattern.
