Bicycle Aero Bar Rail System for Headlight, Watch, ... (Customizable)

Rail system to mount headlights, GPS-watches, cameras or other equipment to ski- or s-bend-style aero bars.

The design is based around a regular alloy curtain rail with 14 x 8 mm outer dimensions. The OpenSCAD customizer allows the adaptation of the design for use with rails of similar dimensions. The customizer allows for control of virtually all other relevant parameters as well.

For anyone without OpenSCAD or customizer experience: Just open the .scad file with OpenSCAD and select “Customizer” from the “Window” menu. Note that this model depends on the BOSL2 library. Make sure it is installed on OpenSCAD's library path.

You have to cut the alloy rail to the width of your aero bar setup of course.

When used in warmer regions make sure you print it in a more heat tolerant material like PETG.

The rendering options "rail" and "assembly" are for illustration/design purposes only.

The design consists of several parts:

Plug:

This is the part the rail mounts to and which sits partly outside the bar. Even if this design is based around the aforementioned rail the plug can be configured to accept a tube (e.g. 25 mm PVC) if you so desire. Note that for screws larger M4 the plug becomes to small to encompass the rail properly. Therefore I recommend to stay at or below M4.

Cap:

This is the opposite part of the plug which sits inside the bar and where the clamping screw screws into. The design allows you to choose between an embedded nut or a brass insert

Wedges:

The wedges sit between the plug and the cap. By tightening the clamping screw the cap and the plug pull together. This forces the wedges to the outside - clamping the whole assembly firmly to the bar. I chose a wedge-based design to avoid any problems with part cracking often happening with spring-based designs.

Mount:

Optional mounting disc which can be added to the rail as a way to mount GPS-watches, cameras or battery headlights to the rail if some sort of rubber strap or so is provided.

T-Nut:

A T-nut for the rail used to mount anything to the rail, including the "mount" or a dynamo headlight mount as shown in the pictures.

Printing Instructions

I printed everything in .25 mm layer height.

Plug:

I printed the plug with the rail part on the print bed to get a better surface finish on the visible parts. This requires supports for the rail slot. If you flip it over no supports are required as long as you use three or more separators.

Cap:

The cap can be printed without supports as long as you use three or more separators.

Wedges:

The wedges are the most challenging parts to print:

• Print them upright
• Add a small brim
• Add supports to the bottom inverse cone parts using the paint on supports within Prusa Slicer by using the "Smart Fill" tool, as shown here: 

Mount:

The mount must be printed with supports if you don't want the screw holes and screw recess to look awful.

T-Nut:

The T-nut can be printed without supports.

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2023 (c) Uli Franke, Elektronik Workshop