DJI Phantom 3 & Inspire 1 Range Extender – Version E

This version “E” of my original Range Extender (Thingiverse#961197) is a moderate modification, and the primary difference is that the Parabolic Arches on this version are considerably deeper. In general, this makes the ‘focus’ of the Range Extender narrower, or ‘sharper’, while the overall gain is increased. However, this requires the operator to pay close attention to the direction of the quadcopter and to keep the controller and Antennas carefully pointed in its direction. As shown in the photos, this version also fits the Controller very well, with plenty of space to tilt the Antennas and Range Extender to various angles.

This easy-to-print Range Extender will extend the range of your Phantom 3 or Inspire 1 considerably. It slips onto the standard un-modified DJI Controller Antennas and can be quickly installed or removed with one hand – even when your quadcopter is airborne.

The Range Extender was created with accurate, deep parabolic curves, and with the antenna mounts centered at each parabolic focal point to maximize signal gain and overall effectiveness.

The only consideration for using this parabolic reflector effectively (and any other high-gain antenna, for that matter) is that you ensure your antenna is directly facing the quadcopter. Thanks to DJI, that’s pretty easy, even when your quadcopter may be out of your direct sight. Simply note the position of the green line that appears on your DJI Pilot or DJI GO application map that runs between where you are standing and where the quadcopter is currently located on the map, and turn your controller to face directly up that green line towards the quadcopter. That strategy will ensure maximum antenna gain and the longest possible range for both control of the quadcopter and transmission of the FPV feed.

I’ve tested this DJI Phantom 3 / Inspire 1 Range Extender with my Phantom 3 Pro, and it works very well, delivering considerably more maximum effective range. Please note that no antenna range extender works well through heavy cover (such as through dense forests) or from behind large solid objects (such as behind hills or large buildings). Best performance will always be obtained with a line-of-sight signal path between the controller and quadcopter – even when the quadcopter is beyond your visual range. If you pay close attention to the Remote Controller Signal Strength Indicator and the HD Video Link Signal Strength Indicator, you’ll know exactly how strong your signal is, and you’ll be able to determine when you are reaching the limits of your range.

All parts print without support, and require very little post-print finishing. Both the Parabolic Reflector Shell and the Antenna Mounts have been designed to be as thin and lightweight as possible, while still ensuring adequate strength and durability. Total Finished Weight= 50.75 grams.

Please share your Makes and any suggestions you have for improvements.

Print all the parts: 1 Parabolic Base, and 2 each of the Top and Bottom Mounts. I used the following settings on my MakerBot Replicator 5th Generation: PLA; Standard Profile; Infill=25%; Layer Height=0.20mm; Infill Layer Height=0.20mm; Shells=3; Raft=Yes; Supports=No. Print times were approximately: 7 hours for the Parabolic Base (49g filament) and 50 minutes (6g filament) for the Set of 4 Antenna Mounts.

Additional parts required for assembling the Range Extender (which I purchased at Home Depot):

• 4 each #4x3/8” Pan Head Sheet Metal Screws (~$1.18 / 8).

Note: each of these screws must be shortened to ~1/4” by filing or sanding. If the threads are longer than 1/4” they will protrude into the antenna mount – not good!

• 1 each Reflectix Multi-Purpose FOIL TAPE FT210 – 2” x 30’.

Note: Another Thingiverse contributor found 4” wide foil tape on Amazon which would be a perfect size for this project. You may want to consider that alternative although I thought I might have trouble working with such large pieces.

Assembly:

First, cut two pieces of the Foil Tape, each slightly longer than necessary to cover the full width of the Parabolic Base (about 25cm each). Remove a little over half the backing on the first piece. Then, center the first piece near the top of the Base (about 1mm from the top edge); ensure that both ends of the foil are ‘square’ with the top edge of the Base. Then, working from the center towards one outside edge, slowly stick down and smooth the first foil piece down and across to the outside edge. Make sure the foil wraps slightly around the outside edge and leave the excess for now. Try to avoid creases or ‘bubbles’ as you install the foil.

Second, remove the backing from the other side of the first foil piece, and smooth it down over the second side, again taking care to keep it aligned about 1mm down from the top edge of the Base. Again, make sure the foil wraps slightly around the outside edge and leave the excess for now.

Third, follow the same general steps for the bottom half of the Parabolic Base. Try hard to have the top and bottom foils meet as close as possible, but not overlap.

Forth, take some time to smooth the foil across the complete Parabolic Base, removing any bubbles or wrinkles, and sharpening the center spine as much as possible. The smoother the foil is, the better the reflector will perform.

Fifth, take a razor blade or very sharp knife and cut off the excess foil along both outside edges, leaving just enough to smooth around the outside edges with your fingernail.

Now, ‘punch’ out each screw hole from the front (foil) side of the Parabolic Base. You may also want to enlarge each of the 4 Parabolic Reflector holes slightly (to around 3mm) so that the Screws will just barely slide through the holes smoothly.

Then, set one Bottom Mount on a flat surface, smooth, rounded side up, and push the Parabolic Base up to it on the foil side, right side up; push the first Screw (see note above about shortening the screws!) through the back of the Base and up to the Bottom Mount, carefully holding the parts together. I held the Mount down with my thumb and pushed it hard against the Base with my knuckle. It may help to turn the Screw forward half a turn, then back a little bit, then forward again, repeating as you go – this will reduce the effort required to install the screws. Assemble the second Bottom Mount in the same manner.

Finally, turn the Parabolic Base upside down and install the 2 Top Mounts (upside down) in the same manner as above. Assembling the Mounts in this manner will ensure that they are aligned correctly. Take a look at the gaps between the Antenna Mounts and the foil tape and further tighten any screws which are not fully seated. Correct vertical alignment of the Antenna Mounts will ensure that the Range Extender will slide on and off the DJI Controller easily.

Test the Range Extender on your DJI Controller, and make any necessary adjustments to the alignment of the Mounts. You may also need to file the inside of each mount slightly to clean up any stray filament and remove any rough edges.

Have Fun! Fly Safe!