Garmin Varia RCT715 Adapters

Description

Garmin just released a new version of their popular Varia Radar system: the RCT715. This product diverges from the rest of the Garmin line, in that it no longer has the quarter turn mount, and the existing mounts out there for the other Varia Radars are not compatible with this new release.

This package of parts is intended to provide multiple mounting means for this new radar/camera/light system.

Solutions

The base of every solution here is the “GoPro Adapter.3mf”. Pair this with a number of other parts, some purchased, and some 3D printed.

1. “FSA GoPro Metal Mount.3mf” with
   1. Aluminum Tripod Mount
   2. Aluminum Mini Tripod Mount
   3. Aluminum Rotational Mount
2. "FSA GoPro Plastic Adapter.3mf"
3. Bup Labs Bike Mounts for GoPro

In addition to the mounts, I've designed an alternate cap for the SD card that includes a loop for a strap: “RCT715 Cap with Tie.3mf”.

Non 3D Printed Parts Required

1. x2 M3x10 machine screws (Philips or Hex)
2. (Suggested) two washers for M3 screws
3. (Suggested) Loctite or other thread locker 

Printing Parameters

I've prepared and included a project that contains all parts in the suggested print orientation. You will need support material.

• I highly recommend that you use PETG on all of the parts except for the "RCT715 Cap with Tie.3mf”.
• Use at least 6 wall thickness, if not 10 or greater. You need the FSA mounts to be solid around the bolts. You also want the fingers of the “GoPro Adapter.3mf" to be solid.
• I use gyroid 20% infill.
• I suggest a 0.15mm layer height (or smaller) for the “GoPro Adapter” to capture the slope on the back side.

Assembly

General Assembly

1. Take the GoPro Adapter, and ream out any of the holes that are undersized due to shrinkage during printing.
2. Using a T10 bit, remove the two screws on the factory mounting bracket. This is located behind the rubber wedges that would normally hold your Varia to the seat post. Save these screws.
3. Take the latching portion of the mount and snap fit it to the GoPro Adapter. This only goes on one way.
4. Using the thread locker, washers, and M3 screws, tighten together the GoPro Adapter and latching portion of the mount .
5. Follow the instructions below based on your mounting type.

FSA Solutions

1. Remove the saddle by removing the two M3 bolts going to the rail clamps.
2. Remove the top rail clamps, but leave the bottom clamp.
3. Place the 3D printed FSA adapter on top of the bottom clamp, and push through the bolts.
4. Start, but do not tighten the top clamps.
5. Install the saddle at the desired location and pitch.
6. Tighten the M3 bolts. The 3D printed part will clamp between the top and bottom clamps, and the seat should still be secure on it's rails.
7. Install either the metal GoPro tripod adapters or the 3D printed GoPro Adapter.

Bup Labs Solution (Cover photo solution)

1. Follow the installation instructions for mounting the mount to the saddle.
2. Remove the clasp from the tether.
3. Loop the tether, using the fatty side, to the saddle rail.
4. Instead of using the glue-on loop, loop the thread side of the tether twice around the mounting post of the Varia. There should be just enough room to loop it twice.
5. Install the Varia to it's quick release.
6. Install the GoPro Adapter to the Bup Labs mount.

DISCLAIMERS

I have not yet printed and tested the following models:

1. “RCT715 Cap with Tie.3mf”

I have printed and fit tested:

1. “FSA GoPro Metal Mount.3mf”
2. "FSA GoPro Plastic Adapter.3mf"

I have printed, fit, and road tested:

1. “GoPro Adapter.3mf”

Notes/Commentary

I have ridden thousands of miles with printed plastic parts on my bikes, without failures. I've got other models that use this same GoPro mounting system (in PETG) and have had no issues with it keeping shape or breaking. 

I rode hundreds of miles with PLA mounts and adapters on my bike as well, but these did not hold up quite as well as the PETG, but should work as long as you do periodic inspections.

In the pictures, the white plastic is PLA, and the black is PETG.

I'm also providing the Fusion360 file. Be warned, I don't know how to use components yet, and all of these objects are in a single file so I don't have to deal with the 10 file limit in Fusion360 for makers. I also haven't yet made it work by parameters.

EDIT 9/14/2022
I've now ridden at least 500 miles with this device (both paved and gravel), and driven 100's of miles with it on the bike on the back rack on my car. I've still not seen a failure. Your mileage may vary.

EDIT 10/04/2022
I've now ridden this design to it's failure. I took it on a gravel road, which was more washboard than road, and after 10 minutes of riding roads so bumpy my hands were going numb, it broke.

A print of 100% infill might fix this issue, or increasing the perimeters. I'll also look at beefing up the area of failure.

I'm also linking a video of the failure point, as seen by the camera. You can see why the mount broke.

EDIT 10/25/2022

I've beefed up the fins that interface with the GoPro mounts a bit, and uploaded it as a version 2. I'm also getting this printed in carbon fiber nylon, to try next season.