Synology DS218play 3U 19-inch Rack Mount

Synology DS218play 3U 19-Inch Rack Mount

This rack mount installs a Synology DS218play horizontally in a standard 19-inch rack while using only 3U of rack space.

The NAS is held by an open four-part cage consisting of front upper/lower and rear upper/lower sections. Two pivoting side arms connect the cage to the reinforced front panel, while two crossbars join and stabilize the two front-panel halves.

The design was developed specifically for a Synology DS218play fitted with two SSDs. It has been fully printed, assembled and tested in a 19-inch rack.

Features

• Standard 19-inch rack width

• 3U front panel

• Designed specifically for the Synology DS218play

• Space-saving horizontal NAS orientation

• Reinforced two-part front panel

• Open four-part NAS cage

• Left and right pivoting support arms

• Unobstructed rear fan and connector area

• Captive hexagonal pockets for M4 lock nuts

• Adjustment slots to compensate for small assembly tolerances

• All printed parts fit on a 220 × 220 mm build plate

• Ten individually printable parts

Included model files

Print each part once:

Front panel

• DS218play_Front_Left.stl

• DS218play_Front_Right.stl

NAS cage

• DS218play_Cage_Front_Upper.stl

• DS218play_Cage_Front_Lower.stl

• DS218play_Cage_Rear_Upper.stl

• DS218play_Cage_Rear_Lower.stl

Crossbars

• DS218play_Crossbar_Upper.stl

• DS218play_Crossbar_Lower.stl

Swingarms

• DS218play_Swingarm_Left.stl

• DS218play_Swingarm_Right.stl

The included NAS body shown in the CAD assembly is a simplified reference model used only for clearance and fit checks. It is not a printable part.

Tested print settings

The successful test build was printed on a Bambu Lab X1 Carbon.

• Material: Bambu Lab PETG Basic

• Color: Black

• Material profile: Standard Bambu Lab PETG Basic profile

• Sparse infill: 30%

• Infill pattern: 3D Honeycomb

• Other profile parameters: Standard profile values

• Supports: Manually added where required

PETG is recommended because of its toughness, temperature resistance and resistance to long-term mechanical deformation. PLA is not recommended for permanent use inside a potentially warm server rack.

Print orientation

Front-panel parts

Print both front-panel parts standing upright on their lower edges.

Make sure that the 45-degree slopes face downward. Support is required underneath the mounting tabs and underneath the overhangs above the NAS opening. Supports were added manually for the tested print.

Cage parts

Place each of the four cage parts on its side. No support should be required in this orientation.

Swingarms

Place both swingarms flat on the build plate. The ends containing the pivot and screw holes must face upward. Small local supports may be helpful around these areas.

Crossbars

Place each crossbar flat on its largest side, with the recessed hexagonal nut pockets facing upward.

Required hardware

All M4 screws used in this project are stainless-steel A2 ISO 7380-2 Torx flange button-head screws. Only the lengths differ.

No additional washers are required on the crossbars because the ISO 7380-2 screws have an integrated flange.

No washers are used on the ends of the aluminium axes.

Fit of the 6 mm pivot axes

The Ø6 mm aluminium axes are intentionally designed to fit tightly in the printed pivot holes. This reduces unwanted play in the swingarms.

Depending on printer calibration and material shrinkage, the axes may initially be difficult to insert. Carefully calibrate the printed holes by turning a 6 mm drill bit through them by hand.

Do not use a powered drill and do not use a larger drill bit. Remove only enough material for the axis to move with light pressure and without noticeable play.

Assembly

1. Remove support material and clean all printed parts.

2. Carefully calibrate the pivot holes with a 6 mm drill bit by hand if required.

3. Insert the twelve M4 lock nuts into the recessed hexagonal pockets in the two crossbars.

4. Join and align the two front-panel halves using the crossbars and twelve M4 × 10 flange screws. Initially tighten the screws only lightly.

5. Place the four cage parts around the powered-off NAS: front upper/lower and rear upper/lower.

6. Connect the front of the NAS cage to the front panel with one M4 × 25 screw on each side. Each screw passes through four 4 mm layers: the upper and lower front-panel tabs and the upper and lower front cage sections. Add one Ø12 mm washer and one M4 lock nut to each connection.

7. Position the left and right swingarms between the corresponding front-panel pivot tabs.

8. Insert one Ø6 × 60 mm aluminium axis on each side and secure each end with an M4 × 8 flange screw. Do not add washers to the axis ends.

9. Attach the rear end of each swingarm to the rear cage using one M4 × 25 screw, one Ø12 mm washer and one M4 lock nut per side.

10. Align the complete assembly without mechanical stress before tightening the fasteners evenly.

11. Do not overtighten the screws or crush the PETG parts. The lock nuts do not require high preload.

12. Support the assembly while installing it in the rack and use all six rack mounting points.

13. Route the power and network cables so they do not load the swingarms or obstruct the rear cooling fan.

Compatibility

Confirmed and physically tested:

• Synology DS218play with two SSDs

• Standard 19-inch rack

• 3U mounting space

Other Synology models with the same nominal external dimensions — untested and without warranty

The following Synology models are listed with the same nominal external dimensions as the DS218play in Synology documentation:

• DS212j

• DS213j

• DS214se

• DS215j

• DS216se

• DS216j

• DS216play

• DS218j

• DS220j

• DS223j

These models have not been tested with this rack mount. Compatibility is therefore not guaranteed.

Identical overall dimensions do not guarantee identical enclosure geometry. Foot positions, rounded edges, front contours, case seams, buttons, LEDs, fans and connector locations may differ.

Check the dimensions and all critical contact points on your own NAS before printing. Never force the NAS into the cage.

Official dimensional reference for the tested model:

• Synology DS218play Product Specification

Safety notice

• Shut down and disconnect the NAS before installation or removal.

• Support the rack mount while inserting it into the rack.

• Always use all intended rack mounting screws.

• Check the printed parts regularly for cracks, deformation and loose fasteners.

• Ensure adequate airflow and monitor NAS temperatures after installation.

• Do not use the design for significantly heavier equipment without performing your own structural assessment.

• Use in mobile or frequently transported racks only after an appropriate mechanical evaluation.

• Reproduction, installation and use are entirely at your own risk and without warranty.

Design and AI disclosure

The printable CAD geometry was manually created by Marco Hoppe in Autodesk Fusion.

AI tools were used as an assistant for design review, documentation and replacement of the backgrounds in two publication photographs. No generative AI was used to create the printable mesh geometry.

License and attribution

This design and its documentation are licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license:

CC BY-NC-SA 4.0

Designed by Marco Hoppe (3DmarcoX1C)

© 2026 Marco Hoppe

Synology and DS218play are trademarks or product names of their respective owner. This is an independent accessory project and is not affiliated with or endorsed by Synology Inc.