Rivian R1 B-Pillar Molle Mount

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B-Pillar Molle Panel

This idea came up in one of the Rivian community group discussions.  Folks were looking for a way to mount their walkie talkie as high up as possible to get the best reception during off-roading.  This idea of having a simple molle panel on the b-pillar was floated around as a possible solution.  It provides a generic mechanism for mounting whatever you might need there.  It's also right next to the door, so it's relatively easy to retrieve items instead of having to crawl into the car.

I also wanted this to support the BuiltRight Composite Tech Plate.  There’s a photo at the end showing its size. It uses slightly different dimensions than my panel so a couple of adapters have -builtright versions.

The clip mechanism is the same one I used in my cup holder models, which has been shown to be pretty strong and secure with the latest locking pin design.  The attachment assumes a 3mm thick molle panel.  The BuiltRight version is 4.5mm thick.

Get Started

I highly recommend starting with the rivian-b-pillar-molle-recommended.3mf collection for the panel and adapters to use.  This uses the double clip, which provides greater stability, and includes the necessary adapters to attach the panel to the clip.  It also includes the twist lock nut and cup adapter so you can print the -slide versions of any accessories and then use them on other cup holder clip locations as well.

Accessories

Now that I've iterated on a couple of radio mount accessories, I've had some time to use them.  I HIGHLY recommend locking a twist-to-cup-adapter to the molle panel itself and printing the -slide version of any of the accessories.  This allows you to move the adapter between the molle panel and any of the normal cup holder locations, like the new stable window clip.  The twist connectors are generally fine, but the nub on them does wear down over time, so it's best to not lock/unlock them a lot or they start to loosen.

I've moved all of the accessories into their own page since they're not specifically for these molle panels.

Installation

To install the clip, just follow the progression of photos:

1. insert top of clip horizontally into gap between panels

2. rotate down to pull the upper panel away, but don't let the clip slide into place yet

3. tuck the bottom of the clip into the lower panel above the seat belt adjuster

4. now slide the whole clip up and …

5. let the top part slip into place

6. the upper and lower panels should both be flush with one another again

Once the B-pillar clip is installed, you can then attach the panel:

1. Use the attachment clip by inserting it into one of the holes in your panel

2. Slide the attachment horizontally into the slot on the b-pillar clip

3. When it hits the end, push extra hard to “snap” it into place.  There are friction bumps to hold it tight.

4. Optionally, insert a locking-pin vertically into the small square holes on the b-pillar clip to prevent the attachment from accidentally coming out.

Removal

To remove the clip you mostly just need to get the top out:

1. use a second clip or a trim removal tool to pull the top panel out again similar to installation steps 1+2

2. pull top of clip out then it should be able to slide down to release the bottom

You might see a slight indentation left over on the soft headliner where the clip was, but rub it with your finger to smooth it all out and it'll go back to normal.  I've inserted/removed mine a dozen times now with one of the clips installed for a couple of weeks and there's no sign it was there once I remove it.

Printing

The .3mf includes my PrusaSlicer settings with all of the following set.

• I've printed these using PETG to test, but you should use something thermally-stable like ASA.

• 0.20mm layers is what I use/test.

• The clips and attachment need to be printed on their side for maximum strength.

• 4 perimeters

• gyroid infill pattern at 15%

• I added “helper discs” on the clips to keep the thin side from detaching from the plate during the print.

• Enable supports for the attachment.

• The twist-lock-nut should be printed on edge with snug supports on build plate only for proper strength.  I also reduce the overhang threshold setting to 10 degrees, but you do you.
  

  

Changelog

2025-12-09

• Added new adapters rotated 90 degress on the Y axis.  This should let you mount things when your molle panel is oriented 90 degrees from expected.

  • twist-to-cup-adapter-90deg

  • attachment-90deg

  • attachment-builtright-90deg

 2025-10-26

• Moved all of the accessories into their own page for easier discoverability.

• I've also removed the -twist versions of any of these accessories, as those were really specific to just this molle panel and no longer recommended.  Use the twist-lock-nut and twist-to-cup-adapter to get a normal cup holder mount on a molle panel and use that.

2025-10-15

• Added rocky-talkie-5w model.  This is a cradle for the 5 Watt Rocky Talkie radio.

• Added recommended .3mf collection using the panel/adapters I would use.

2025-08-23

• Added mic-slide model.  Renamed mic-mount to mic-twist.  This mic mount is still largely untested, as I don't have anything with a standard mic clip.

2025-08-18

• Updated Motorola belt clip model.  V7 is great.

• Added BuiltRight versions of the attachment and twist-lock-nut connectors that should accommodate the standard size of BuiltRight panels, like the linked Composite Tech Plate.  They're 4.5mm thick and use ¼" corners instead of being 3.0mm thick and 5mm corners.

2025-08-17

• Added a cup-holder mount version of the motorola belt clip experimental model

• Added a twist-to-cup-adapter to convert a twist-lock connector to cup holder connector

• Added a cup-to-twist-adapter to convert a cup holder connector to a twist-lock

2025-08-13

• Updated twist lock connection mechanism for easier printing.  Supports now interface flat surfaces.  This means the orientation/shape of the lock nut changed slightly and they're not compatible with previous versions.  They'll likely lock, but won't stop at the perfect location so they won't be perfectly vertical.  This results in new versions of the following:

  • twist-lock-nut

  • mic-mount

  • cobra-ctw285-twist

• I've also updated the corners of the attachment and the twist-lock-nut to start from the build plate at a 45 for easier printing.

• We've been experimenting with a belt clip model for the Motorola Talkabout T470.  We're on v5 now, but it should be very close to final.

2025-08-12

• Updated twist-lock-nut to print easier (on edge) and not require supports except for next to the build plate.  It also includes a small bumb to help keep it locked in position so it doesn't accidentally rotate and unlock.  We'll see if this is enough …
  

  

2025-08-08

• Added b-pillar-double with two clips for extra stability if you want that.

• Added a generic belt-clip-ctw285 model.

  • It is designed to be generic for any belt clip, but is somewhat specific to belt clip size so that when it's fully inserted it doesn't slide around and locks in place.  This first model is based on my Cobra CTW285 radio belt clip.  These are the reference dimensions:
    

    

  • (A) Belt Clip Gap: ~3mm

  • (B) Belt Clip Nub Distance: ~33mm

  • (C) Belt Clip Width: ~25mm

  • (D) Belt Clip Nub Width: ~7.5mm

  • If you want a custom size let me know.

2025-08-07

• Added a cradle for my ancient Cobra CTW285 radio using a new twist lock nut.  It slides in and locks into place using the belt clip included with the radio.

• Added a 2x3 molle panel in case you don't want it as tall.

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