Radiomaster TX16S Mark II Foldable Transmitter Tray (V2)

A foldable transmitter tray designed specifically for the Radiomaster TX16S Mark II.

The project was developed to improve comfort during long flying sessions while remaining lightweight, portable, and secure. The design incorporates foldable arms, four-position adjustable armrests, and a dual-retention system that securely holds the transmitter without requiring any modification to the radio.

The overall concept was inspired by commercial transmitter trays available for FrSky radios. All parts in this project were independently designed and modeled from scratch specifically for the Radiomaster TX16S Mark II.

This project is not affiliated with or endorsed by FrSky, RadioMaster, or any other manufacturer.

Designed and tested with the Radiomaster TX16S Mark II.

Compatibility with other TX16S versions or RadioMaster transmitters has not been verified and may require modifications.

Suggestions and feedback are welcome.

A video demonstration showing transmitter installation and the retention system in operation is available here:

Lock bending demo video (Hot water method):

https://youtu.be/NC_5m5iTE_o

RECOMMENDED PRINT SETTINGS

Material:

•  PLA

•  PETG (recommended!!)

Profile A - Standard Parts

Recommended for:

• Hub_Front.stl

• Hub_Back.stl

• Bottom_Support_L.stl

• Bottom_Support_R.stl

• Bottom_Support_Join.stl

• Hand_Rest_L.stl

• Hand_Rest_R.stl

• Hand_Rest_Holder.stl

• Hand_Rest_CuttingTemplate.stl

Settings: (default Strenght Orca Slicer profile)

• Layer height: 0.20 mm

• 6 perimeters/walls

• 6 top layers

• 5 bottom layers

• 20% infill

Profile B - Critical Parts

Recommended for:

• Lock_Flat.stl

• Lock_Holder.stl

• Spacer.stl

• Strap_Hook.stl

• Strap_Hook_Pivot_L.stl

• Strap_Hook_Pivot_R.stl

Settings:

• Layer height: 0.20 mm

• 3 perimeters/walls

• 2 top layers

• 2 bottom layers

• 100% infill

IMPORTANT ASSEMBLY NOTE

The Strap_Hook_Pivot_L and Strap_Hook_Pivot_R parts must be permanently bonded to their corresponding Strap_Hook components.

Assembly procedure:

1. Enlarge and thread the pivot holes using an M3 tap. The parts are supplied with a 2.5 mm pilot hole specifically for M3 threading.

2. Apply cyanoacrylate (CA) adhesive to the M3 screw threads before final assembly.

3. Tighten the screws and allow the adhesive to fully cure.

A strong and permanent bond is required between these components, as they are subjected to load during normal use of the tray and neck strap.

Do not leave these joints loose or removable.

DESIGN INSPIRATION

The overall concept was inspired by commercial transmitter trays available for FrSky radios.

Although inspired by those products, all parts in this project were independently designed and modeled from scratch specifically for the Radiomaster TX16S Mark II.

Several design elements, dimensions, mounting methods, and retention features were developed and adapted to suit the TX16S Mark II platform and the requirements of FDM 3D printing.

ADJUSTABLE ARMRESTS

The tray features adjustable armrests with four selectable positions, allowing each pilot to find the most comfortable setup.

The adjustment mechanism uses 3 mm carbon fiber pins glued to hand rest part and inserted into the selected position holes of the holder. Once installed, the pins provide a rigid and secure assembly without requiring tools.

TRANSMITTER RETENTION SYSTEM

The TX16S Mark II is secured using a dual-retention system designed to prevent accidental movement while still allowing quick removal when needed.

Lower Retention Clip

The lower retention clip supports the transmitter from underneath and prevents it from sliding forward.

A small retaining tab helps prevent accidental movement while still allowing the clip to flex slightly when transmitter removal is required.

Upper Retention Bars

The upper locking system uses two short sections of 3 mm carbon fiber rod inserted into the printed supports.

The rods engage the TX16S Mark II carrying handle and prevent the transmitter from being lifted out of the tray during normal use.

Together, both retention points provide a secure hold while maintaining quick and easy transmitter access.

See the video for more details.

IMPORTANT - HEAT FORMING REQUIRED

The part named "Lock_Flat.stl" (Lower Transmitter Retention Clip) is intentionally supplied as a flat print.

This approach improves printability and strength while eliminating the need for support material.

After printing:

1. Heat the marked bending area using hot water (I used this method), a heat gun, or a hot air station.

2. Bend the main section to form a litle bit more than 90-degree L shape.

3. Heat and bend the small front retaining tab.

4. Allow the part to cool completely before installation.

The front tab helps prevent accidental transmitter movement while still allowing the clip to flex slightly when radio removal is required.

Do not overheat the part, especially when printed in PLA.

REQUIRED HARDWARE

Fasteners

• 8 x M3 nuts

• 6 x M3 x 17 mm screws

• 2 x M3 x 7 mm screws

• 2 x M3 x 9 mm screws

• 2 x M3 x 14 mm screws

Pins and Rods

• 2 x 5 mm diameter x 19 mm long pins/shafts (Or m3 thread)

• 8 x 3 mm diameter x 10 mm carbon fiber pins (armrest adjustment mechanism) (Or m3 thread)

• 2 x 3 mm diameter x 30 mm carbon fiber rods (upper transmitter lock) (Or m3 thread)

PRINTED PARTS

• 1x Bottom_Support_Join.stl

• 1x Bottom_Support_L.stl

• 1x Bottom_Support_R.stl

• 2x Hand_Rest_Holder.stl

• 1x Hand_Rest_L.stl

• 1x Hand_Rest_R.stl

• 1x Hub_Back.stl

• 1x Hub_Front.stl

• 1x Lock_Flat.stl

• 1x Lock_Holder.stl

• 6x Spacer.stl

• 2x Strap_Hook.stl

• 1x Strap_Hook_Pivot_L.stl

• 1x Strap_Hook_Pivot_R.stl

• 1x Hand_Rest_CuttingTemplate.stl

ADDITIONAL MATERIALS

The supplied Hand_Rest_CuttingTemplate.stl can be used to cut custom armrest padding from foam, EVA foam, leather, cork, rubber, or any other suitable material.

Alternative you can print Hand_Rest_CuttingTemplate.stl in TPU if you want.

PRINTING NOTES

• Print all parts in the best orientation (supplied orientation is not the best).

• No supports needed.

• Use ironing for a better Surface finish

• Clean any stringing or printing artifacts before assembly.

• Minor fitting adjustments may be required depending on printer tolerances.

• Test-fit all moving components before final assembly.

FEEDBACK

If you build one, please post a Make and share your feedback.

Field testing results, photos, suggestions, and remixes are always appreciated.

Happy flying!