Intro: Make an External Microphone Mount for GoPro HERO3.
When the GoPro HERO2 was released, it included an external microphone jack built in. It was a 3.5mm jack on the side to plug a small condenser mic into. The HERO3 also includes an external mic jack, however it is in the form of a multi use USB port. The user needs to supply a USB to 3.5mm converter cable to use an external microphone. This cable makes it hard for mic users to aim directional or stereo mics effectively without the use of another hand. The following Instructable teaches you how to build a simple rig which allows for the mounting of a microphone to the HERO3.
Step 1: Materials and Tools You'll Need:
The camera equipment I used in this project :
-GoPro "Skeleton Housing" for the HERO3 (To allow access to the USB ports on the camera)
-Olympus ME-51S Stereo Microphone
-GoPro 3.5mm Mic Adapter for HERO cameras (The one I used is exactly 5-1/4-inches long. If the length of yours differs, you may need to adjust the length of the CPVC cable-holding arm for your version of this project.)
-GoPro Tripod Mount
To Build the Mount:
-1/2" CPVC - For the frame. You wont need more than 15-inches in length.
-1/2" CPVC Elbow Fitting
-Machine Screws (1) 1/4 x 20 - about 1-1/2 to 2 inches long, for the tripod screw.
-Tripod Head/Plate (1) - You can use your favorite tripod's head plate, for the purposes of this project I used a small GorillaPod from JOBY.
-Washers (2) - I used 5/8" external diameter x 3/8" internal diameter but anything that fits the machine screw should work.
-Foam - (memory foam, egg crate, packing foam), Just a small piece to keep the microphone from rubbing the plastic.
-Welder cement or PVC/CPVC Cement - Any good heavy duty stuff will keep it together.
-Spray Paint - I used black. Camera equipment looks good in black!
-Dremel with a router bit, cutter bit and sander bit
-Drill with 1/4" bit
-Saw and miter
Step 2: Let's Make!
Make the Frame:
-Cut 2 lengths of the CPVC, one 3-1/4 inches (this will be the camera holding arm) and the other 5 inches (this will be the cable holding arm). I used a saw and miter to keep the edges strait. Sand both pieces to scuff up the surface. This will help you hold them during the drilling and cutting later. It will also provide a nicer paint-able surface if you choose to do that as well.
-On the 3-1/4 inch piece, make a mark at 3/4 inches from one side. Drill a 1/4-inch hole all the way through at that mark. This is the hole the machine screw will go through. You may need to add a little "wiggle room" with the drill bit to make an easy fit. Test it out by sliding the machine screw into it. If it's too snug, insert the drill bit again and run it along the edges of the hole to remove just enough CPVC for an easy fit.
-On the 5 inch piece, make marks at 2-1/2 inches and 3-3/4 inches. Cut a large ovular hole in one side between these marks. Make it about 1/2 inch wide. This is the hole the 3.5mm jack side of the microphone adapter will slide through. I used my Dremel's router bit for this.
About a year ago, I spent the $40 for the Dremel drill press stand and I couldn't recommend it more! It is EXTREMELY useful for projects. I am yet to take the Dremel off of it for any reason. Also, finish it off with a basic foot pedal to control it with. You'll be glad you did!
-Test the cable holding arm of the CPVC by inserting the mic cable as shown in the pic above.
-Finish the frame by gluing both pieces into the elbow fitting. I used a welder cement because PVC cement sets too quickly for my taste. Make sure to orient the pieces to make a backwards L, with the small piece on the bottom and bigger piece on the side. The bottom piece with the through hole for the machine screw should have the through hole vertical, so the screw would run parallel to the side piece. The side piece with the oval hole should have the hole facing inward, toward the bottom piece. As for which ends go into the elbow, the end furthest from the through hole in the bottom piece gets glued and the end closest to the oval hole in the side piece gets glued. I tagged the photos above to make it clearer.
I chose to use CPVC instead of PVC because it's lighter in weight and easier to work with. It's internal diameter is larger then PVC's and will accommodate the 3.5mm jack. You would need to use at least 3/4-inch PVC to fit the same wire. CPVC is available in the same isle as PVC in any hardware store. It has a yellow tint to it.
Step 3: Machine the Screws!
I found that in order to make my tripod screw fit, I had to modify it a little. You may need to do this as well to make your tripod head plate fit back onto the tripod with the new screw in place.
CAUTION: WEAR EYE PROTECTION FOR THIS ENTIRE STEP.
-Use a cutting bit to grind away some of the flanged screw head. The screw will get very hot. Hold it with pliers, gloves, vice grips, anything to separate your fingers and the heat of friction. Rotate the screw to evenly cut away the extra mettle. Stop from time to time to test if you have removed enough material.
The 1/4 x 20 screw size is the standard size for tripod heads. It means the screw is 1/4-inch wide and has 20 threads per inch. You can see in the pic above that I bought 2 inch screws. You'll be removing quite a bit of that length so you can buy 1-1/2-inch screws instead.
-Use the cutting bit to cut the length of the screw down to about 1-1/16-inches. This will be enough screw to fit through the tripod head plate, CPVC, 2 washers and achieve purchase into the tripod mount on the GoPro. If you find the screw is a little too long, simply add another washer to take up the space. In this case, it's better to have too much screw then too little.
Step 4: Put It All Together.
-Insert the mic cable as you did when you tested the length of the cable holding arm.
-Put the finished screw into your tripod head plate and place one washer onto the screw.
-Slide the screw through the hole in the CPVC camera holding arm. Place the second washer on top.
-Screw on the tripod mount and attach the camera. If you have too much space, add another washer.
-Plug in the mini-USB plug into the GoPro and the microphone into the 3.5mm jack.
If you are using a directional or stereo microphone, pay special attention to the microphones orientation. Make sure the left side and right side of the microphone are aimed appropriately.
Step 5: Foam.
If you choose to, you can cut a small piece of memory foam and place it between the microphone and CPVC cable holding arm. This will isolate any rubbing noise from the camera or microphone mount and not transfer it to the audio recording. Cut a small round piece and punch a hole into it. Drive the microphone's phono jack through and sandwich the foam between the CPVC and microphone. Make sure the microphone jack plugs in all the way.
Step 6: Final Touches.
I painted mine black. I used a high quality spray enamel. It should hold up to some wear and tear before a new coat is needed.
Step 7: Conclusion
UPDATE: After using this rig for a few hours while recording some wedding footage, I have learned a few things:
- The sound dampening memory foam is crucial for keeping the sides of the mic from impacting the CPVC cable holding arm. In a rush to assemble my gear, I omitted this detail and ruined some of the audio track.
- If you are using more than one type of tripod or mounting device, you may want to cut multiple versions of the tripod screw. Each tripod and head plate have a different spacing in between themselves. One modified machine screw may not fit all tripods you are using. Also, even if it does fit, you may not want to have to unthread one screw just to rethread it onto another tripod head plate. This can very time consuming as I found out.
- Lastly, if you are using the GoPro HERO3 with the wifi remote or phone app, please shoot test footage with the external mic you are using with the wifi feature enabled. Listen to the audio track for RF interference caused by the wifi signal. I didn’t do this and ruined some very valuable audio. I suggest if you are shooting footage where you need clean audio, use only the buttons on the camera, NOT the wifi feature.