LEDs

Underground Whoop League (UWL) requires pilots to put LEDs on their drone to make racing more exciting and spectator friendly. This page contains all the information you need to meet this requirement.

RULES

Rules for Regular LEDs

Most pilots will choose to use an LED harness to get to spec. The most common would be 1206, 603, or "Headlight" LED harnesses from Tiny Whoop. When you're using traditional LEDs like this, whether by using a pre-made harness or by making your own, these are the rules you will follow.

-Must have 4 LEDs

-LEDs must be visible from all angles and regardless of the whoop's orientation

-At least 2 LEDs must be pointed in exact opposite directions of each other

-Typically will be placed on the outside of the ducts (looks cooler) or between the ducts (more durable)

-May use more than 4 LEDs

-When frames are painted or dyed to be UV reactive, UV Leds may be used to help make the frame glow or "pop"

-LEDs that are built into the flight controller or other components do not count towards your LED requirement. LEDs must be external to your electronics and fixed to your frame/canopy. Sorry, but no free floating "whiskers".

Rules for COB LEDs

COB LEDs are growing in popularity due to their cool look. Typically these are a little heavier and so pair well with analog builds. Even though a COB strip is comprised of many LEDs, 1 COB strip is considered to be 1 LED under most circumstances

-COB strips shorter than 3" (6 segments) are treated as 1 regular LED

-When using COB strips of 3" or more, only 2 are required. However, in this case, the strips must be placed on the outside of the frame. They must be centered between the ducts and touch all 4 ducts. See the picture with the white cobs for reference.

-A single COB strip may be used to meet your LED requirement if the strip is placed on the outside of the ducts and wraps at least 3/4 of the frame. See the picture of the blue cobs for reference.

Example of Two COB Strips

Example of One COB Strip

Bonus Tip

It isn't uncommon for LEDs to go out on race day. 1206 LEDs are more durable than 603, and COB strips are even more durable. For this reason it's recommended to come prepared for this occurence. Some people like to put more than 4 LEDs on their whoop so that, on the off chance one goes out, they are still in spec. Another option that's even better is to have a backup whoop. If you are attending a big, multi day race, it might be a good idea to bring a couple extra frames with a harness pre-glued to make a repair as simple as a frame swap and soldering 2 wires.

INSTALL INSTRUCTIONS

LED Harness

Installing a 1206 or other LED harness from Tiny Whoop is a pretty simple process. The harness will come with 4 LEDs attached to a power lead with a positive (red) and negative (black) wire. Cut the power lead down to the desired length and solder it to the same pads as the battery lead (VBAT and GND). I usually like to solder my battery lead to the bottom of the flight controller and use the top side of the pads for the LED wires. However, if your battery lead is on the top side of the flight controller, it is still easy to solder the LED harness on top of the battery lead wires (you don't actually have to make the LED wires touch the flight controller; touching the exposed part of the battery lead is enough). Once you have soldered the 2 LED wires to the flight controller, they should be working and now only need mounted. It is safe to plug in a battery to your whoop to test that the LEDs come on when powered.

Mounting the LEDs to your frame is as simple as gluing them. You can use welders glue, hot glue, or my personal recommendation, E6000. Aside from the glue, the only other thing you need is something to hold the LEDs in place while the glue dries. Some people use tape or other methods, but I personally have found baby clothespins from Amazon to be perfect to pin the LED to the frame while the glue dries. So my process is to apply E6000 to the frame with a toothpick, push the LED into the glue blob, and then pin it there for about 30 minutes with a baby clothespin. This is an extremely easy rocksolid way to mount your LEDs securely.

Once everything is soldered, glued, and dried, you'll want to coil the excess wires under the canopy and potentially use a couple more dabs of E6000 on the frame to keep the excess wire from uncoiling, getting loose, and potentially finding its way into a propeller. If you plan to mount the LEDs on the outside "corners" of the ducts, the regular harness is perfect. However, if you plan to mount the LEDs between the ducts, much closer to the flight controller, the standard harness will give you way more excess wire than you'd want, so for that reason I would suggest the "shorty" 1206 harness.

DIY LED Harness

Ask someone smarter than me haha. All I know is that the LEDs will need the appropriate resistor to keep the LEDs from burning up but not dimming them too much

COB LED Harness

COB LED strips work very similar to a DIY LED harness, just without the need for the resistor. You'll need to cut 4 strips to length and peel back enough of the strip to expose the positive and negative solder pads. Solder a wire to each (magnet wire is popular for a lighter weight harness). Repeat this for all 4 strips (or 2 or 1, depending on your configuration(. What you essentially need to do at this point is attach the ground wire from all 4 strips to the same (or I guess different if you really wanted) ground pad. And the 4 positive wires to the same power source (I like to use VBAT). I find this can be really tricky and difficult to maintain, so I prefer to solder/splice all 4 positive wires from the COBs to another wire, and all 4 negative wires from the COBs to a different wire. Then use heat shrink to cover the spliced area. This essentially consolidates all of the COBs into a single power lead, creating your harness.

At this point, with a finished DIY COB harness, you can solder it up the same way that you'd solder your LED harness. You can use 5v or VBAT, but 5v puts extra strain on your regulator and kind of makes your COBs a little too bright. I find it much easier to solder to the battery lead/other side of the battery lead pads simply because it's easy and those pads are usually open and not being used by anything else.

At this point, you can use the sticky side of the COB strips to stick them to your frame and probably mix that with E6000 and baby clothespins using similar methods as what's used to mount a regular LED harness.

If you want to use COBs but are pressed for weight, you can also peel back the protective gel layer and save tons of weight. However, this will potentially make your COBs much less durable so do this at your own risk.