While developing our payload drop hook (thing 1259564) for our DJI Phantom 3 quad copter, we realized that we needed landing gear extensions to provide clearance for the folded-up drop hook. We didn't want to re-invent the wheel, so to speak, so we chose Tanemahuta's "Phantom 3 Gimbal Guard to go" (thing 909566) design as our mounting base on which to mount our landing gear extensions. Many thanks to Tanemahuta for his design.

So, to use our Phantom 3 landing extensions you will need the following:
2- H5 labs landing gear extensions (this design)
1- http://www.thingiverse.com/thing:909566 (P3 Gimbal Guard to go)
4- 4-40 x 1/2" long screws
4- 4-40 nuts

Please reference the print settings for information on what we found worked best for us in printing the landing gear extensions.

To assemble:
Press fit the landing gear extensions onto the P3 Gimbal Guard to go. align them so that they fit centered over the two beams that run next to and parallel to the original Phantom 3 landing gear bars (these run front-to-back). Reference attached photos for details. Once aligned, use a 7/64" drill bit to drill the four holes in the P3 Gimbal Guard to go - use the holes in the landing gear extensions as guides for drilling (reference attached photo to see how we drilled these holes using this method). Then, insert the 4-40 nuts in the indentations on the bottom of the landing gear extension arms. Finally, insert the 4-40 x 1/2" long screws so that they first pass through the holes drilled in the P3 Gimbal to go and then into the landing gear extensions (it's a good idea to use a small dab of removable loc-tite on the screw threads). Reference the attached picture showing the completed assembly.

When ready, simply attach the modified P3 Gimbal to go to your Phantom 3 and you're good to go.

UPDATE (2/8/2016): Added two new styles. Style 2 moves the landing gear legs to be inline with original lading pads. Style 3 is based on style 2 and a bit more radical (and most likely a more challenging print) in that it twists the landing gear legs 45 degrees out, which should keep it completely out of the camera's view. I have not attempted to print either of these new designs yet. I would appreciate feedback from anyone who tries to print and use these at it may be awhile before I get to it (strong gust of wind took out my Phantom 3, so I've a good many repairs to make :-). Best of luck to all.