MakerPanel/Field notes & documentation

Maker Panel Specification

The Maker Panel specification defines a modular panel system for maker projects. Inspired by the Eurorack synthesizer standard, MakerPanel adapts the concept for general-purpose control panels. Mount panels on compatible T-tracks, or make your own rails using MakerRail slots. These are different rail constructions, not two names for the same profile.

Design Philosophy

Maker Panel prioritizes:

  • Modularity: Panels can be easily added, removed, or rearranged
  • Compatibility: Standard dimensions ensure all compliant panels work together
  • Accessibility: Open specification allows anyone to design panels
  • Flexibility: Choose compatible off-the-shelf T-tracks or MakerRails made by 3D printing or laser cutting suitable plastic or metal sheet

Visual Guide

Panel Dimension System

Panel widths in horizontal pitch units One HP is 5.08 mm. Bars compare 4, 6, 8, 12, and 16 HP widths: 20.32, 30.48, 40.64, 60.96, and 81.28 mm respectively. 01 / WIDTH IN HP 1 HP = 5.08 mm / 0.200 inches 4 HP6 HP 8 HP12 HP 16 HP 20.32 mm30.48 mm 40.64 mm60.96 mm 81.28 mm 20 HP, 24 HP and beyond →
Build in multiples. Choose any whole number of HP; each step adds 5.08 mm of width.
Compact and standard panel heights One U is 44.45 mm unit spacing. A standard 3U panel is 128.5 mm tall within a nominal 133.35 mm unit space. With 11 mm rails and holes inset 5.5 mm from each edge, mounting centers are 117.5 mm apart. 02 / HEIGHT IN U Compact 3U panel 1U = 44.45 mm 128.5 mm panel Unit spacing 133.35 mm unit space
Panel height ≠ unit spacing. 3U uses a 128.5 mm panel within a nominal 133.35 mm unit space. With 11 mm rails, mounting centers are 117.5 mm apart. Schematic; custom heights are allowed.

Panel Depth Profile

Panel depth measured from the front surface Side section: controls sit in front of the panel, electronics behind it. The rear depth envelope ends 60 mm from the front surface. Allow at least 10 mm clearance behind the panel. 03 / SIDE SECTION Front face Electronics Controls 10 mm min clearance 60 mm maximum from front face
Leave room behind the face. Keep electronics within the 60 mm depth envelope and allow at least 10 mm rear clearance. Side-section schematic, not to scale.

T-Slot Rail Mounting System

Conventional T-track mounting cross-section A screw passes through the panel into a matching threaded T-nut retained beneath the lips of a continuous T-track channel. This is not the flat MakerRail through-slot profile. 04 / CONTINUOUS T-TRACK Screw Panel Matching T-nut Channel / rail Nut retained beneath the channel lips
A captured nut, a continuous channel. Select a screw that matches the nut thread. Cross-section schematic; commercial track profiles vary.

Panel on Rail Assembly

Panel holes aligned with mounting rail centerlines Front view of a 128.5 mm panel overlapping two 11 mm mounting rails. All four hole centers are inset 5.5 mm from the top or bottom and nearest side edge. Horizontal rail centerlines pass through the hole centers, 117.5 mm apart. Width is chosen in multiples of 5.08 mm. 05 / FRONT ASSEMBLY Hole inset = rail width / 2 = 5.5 mm 3U panel 128.5 mm panel 117.5 mm centers Width = HP × 5.08 mm Dashed lines show centers and hidden rails.
Holes on the rail centerlines. The rails sit behind the panel, not beyond it. Each hole center is inset half the rail width (5.5 mm) from both adjacent panel edges: top or bottom and left or right. Center spacing is panel height minus rail width: 128.5 − 11 = 117.5 mm. Schematic; rail-slot details are omitted for clarity.

Mechanical Specifications

Panel Dimensions

Width

Panels follow a horizontal pitch (HP) system:

  • 1 HP = 5.08 mm (0.200 inches)
  • Common panel widths: 4 HP, 6 HP, 8 HP, 12 HP, 16 HP, 20 HP, 24 HP
  • Panels can be any multiple of 1 HP

Height

Standard panel heights:

  • 1U = 44.45 mm (1.750 inches) - Unit spacing
  • 3U Panel = 128.5 mm (5.059 inches) - Standard panel height
  • 3U Spacing = 133.35 mm (5.250 inches) - Nominal unit space (3 × 1U), not rail mounting-center spacing
  • Mounting hole inset = half the rail width from each adjacent panel edge (top, bottom and sides): 5.5 mm for an 11 mm rail
  • Rail mounting-center spacing = panel height minus rail width: 117.5 mm for a 128.5 mm panel on 11 mm rails
  • Custom heights are allowed but should maintain T-slot compatibility

Depth

  • Standard panel depth: 60 mm from front surface
  • Recommended clearance behind panel: 10 mm minimum

Measuring Tool

Use the MakerPanel / MakerRail measuring tool to check panel and rail dimensions before fabrication or assembly. This printable OpenSCAD example provides panel and rail gauges; set part to "makerpanel" or "rail" and adjust verticalUnits and horizontalPitch for the size you need.

Maker Panel Rack System

T-tracks and MakerRail slots

T-track describes a conventional rail with a continuous channel, typically an aluminum extrusion. Matching T-nuts are retained by the channel and can slide along its length. Select a track profile and hardware that fit the panel mounting points; commercial T-tracks are not all interchangeable.

MakerRail uses discrete through-slots separated by structural ribs. The reference rail is a flat slotted profile, not an extruded T-channel. Compatible twist nuts engage the slot edges; the ribs interrupt travel between slots. Allow clearance behind the rail for the nut and screw, including room to insert and turn the nut.

This slot-based construction supports three fabrication routes:

  • 3D printing: Print the rail profile as a solid part. Choose material, orientation, and wall construction appropriate to the load.
  • Laser-cut plastic: Cut the 2D profile from laser-safe plastic sheet suited to the application and cutting equipment.
  • Laser-cut metal: Cut the same 2D profile from suitable metal sheet with equipment or a fabrication service rated for that material and thickness.

The reference library provides maker_rail() for 3D geometry and maker_rail_2d() for 2D profiles. makerpanel/rails_laser.scad is the SVG/DXF export entry point. See the OpenSCAD workflow to get started.

Hardware compatibility is not profile equivalence. Check the actual nut body, screw thread, slot opening, rail thickness, and rear clearance. Test a sample joint before fabricating a complete frame; changing the material or manufacturing process does not guarantee the same strength or fit.

MakerRail Rack Specifications

Rails are designed to work in both orientations (horizontal cross beams or vertical side rails):

  • Slot height: 6.2 mm (0.244 inches) - Accepts 3mm panels with clearance
  • Slot width: 19.125 mm (0.753 inches) - Half of 1U minus support width [(44.45 - 6.2) / 2]
  • Support width: 6.2 mm (0.244 inches) - Structural support between slots
  • Support spacing: 44.45 mm (1.750 inches) - 1U intervals, creates two slots per U
  • Rail material: Laser Cut Metal or Plastic or 3D Printed
  • Rail height: 11mm

Design rationale: Slots spaced at 1U intervals (44.45mm) work for both vertical structural support and horizontal panel mounting. For horizontal rails, panels mount across multiple slots. For vertical rails, the 1U spacing provides consistent mounting points.

Rail Configurations

A rail consists of alternating slots and supports, with supports spaced every 1U (44.45mm). This creates two slots per 1U interval. Optional mounting holes can be added on either side for structural assembly.

The same rail design works for both cross beams (horizontal) and side beams (vertical): - Cross beams: Panels mount horizontally across multiple slots, aligning with HP widths - Side beams: Vertical mounting uses 1U-spaced slots for consistent panel positioning

Rails are used for sides and cross beams, while panels are mounted between cross beams.

Rail as cross beam (horizontal orientation)

MakerRail used as a horizontal cross beam Flat rail with separate elongated through-slots and solid ribs, not a continuous groove. Callouts show the listed 19.125 mm slot width, 6.2 mm slot height, 6.2 mm support width, and 11 mm rail height. Schematic, not to scale. 06 / HORIZONTAL MAKERRAIL 19.125 mm slot 6.2 mm slot height 6.2 mm support 11 mm
Open slots, solid ribs. These are through-openings in a flat rail, not T-track channels. Nominal dimensions from the specification; schematic, not a cutting template.

Rail as Side Beam (vertical orientation)

The same MakerRail turned vertically A vertical rail has the same discrete through-slots and intervening ribs as the horizontal rail. The slot long dimension is 19.125 mm and short dimension 6.2 mm. The overall rail width in this orientation is 11 mm. 07 / VERTICAL MAKERRAIL 19.125 mm Slot long dimension 6.2 mm support 6.2 mm slot opening Same profile. Either orientation. 11 mm rail
Rotate the rail, not the rules. Use the same slotted profile for side beams and cross beams. Diagram shows orientation only; verify slot pitch against the reference design.

Pattern repeats every 1U (44.45mm) with two slots per U interval

Mounting Hardware

MakerRail screw, panel, rail and twist nut Exploded side section: screw head at the front, then panel, flat slotted rail, and a matching twist nut behind the rail. The nut engages both slot edges. Leave room behind the rail to insert and turn it. 08 / MAKERRAIL HARDWARE Matching screw Panel Flat slotted rail Twist nut Allow space behind the rail to insert + turn
Clamp across the slot edges. The panel is in front of the rail; the nut sits behind it. Match screw thread, nut body, slot opening and rail thickness. Exploded schematic, not to scale.
  • T-slot compatible nuts (M5/M6 twist nuts or drop-in style)
  • Standard M3 or M4 screws for panel attachment
  • Panels should include mounting slots or holes compatible with T-slot spacing (25 mm centers)

Panel Material

Recommended materials:

  • Aluminum: 2mm-3mm thickness (most common)
  • FR4/PCB: 1.6mm thickness (for electronic panels)
  • Acrylic/Polycarbonate: 3mm thickness (for transparent panels)
  • 3D Printed: PLA, PETG, or ABS (ensure adequate rigidity)

Electrical Specifications

Power Distribution

Maker Panel does not mandate a specific power distribution system, but common options include:

  • Bus strips behind panels (e.g., +12V, GND, -12V for analog circuits)
  • USB-C PD distribution
  • Individual power connections per panel

Connectors

Recommended connector types:

  • Qwiic/StemmaQT: For I²C low-current signals
  • Screw terminals: For power connections
  • USB-C: For highspeed data and power connections

Design Guidelines

Clearances

  • Minimum edge clearance: 2 mm from panel edges
  • Mounting hole clearance: 3 mm diameter minimum for M3 screws
  • Component clearance: Ensure no component extends beyond maximum depth

Labeling

  • Use clear, legible labeling for controls and connections
  • Recommended minimum font size: 8pt for labels
  • Consider silkscreen, engraving, or UV printed labels

Aesthetics

While aesthetics are subjective, consider:

  • Consistent visual design across your panel set
  • Alignment of controls and indicators
  • Professional finish (smooth edges, no sharp corners)

File Format Standards

When sharing panel designs, include:

  1. Mechanical drawings: KiCAD, DXF or SVG format
  2. 3D models: OpenSCAD, 3MF, STEP, or STL format
  3. Electrical Schematics: KiCad format
  4. Bill of Materials (BOM): Markdown tables
  5. Assembly instructions: Markdown

Compliance Checklist

To be Maker Panel-compliant, your panel should:

  • [x] Use width in HP units (1 HP = 5.08 mm)
  • [x] Include T-slot compatible mounting points (M5/M6)
  • [x] Not exceed 60 mm depth from front face
  • [x] Have 2 mm minimum edge clearance
  • [x] Include clear labeling
  • [x] Provide mechanical drawings in open format
  • [x] Document any electrical specifications

Variations and Extensions

The Maker Panel specification is intentionally flexible. Variations are encouraged as long as they maintain basic compatibility:

  • Custom heights: For specific applications
  • Extended depth: For complex assemblies (document clearly)
  • Integrated systems: Multi-panel assemblies
  • Powered rails: Custom power distribution systems

Reference Designs

See the Gallery for example panels that follow this specification.

Questions and Clarifications

For questions about the specification or to propose extensions:

  • Open an issue on the GitHub repository
  • Contribute to the discussion in existing issues
  • Submit pull requests for specification improvements

Version: 1.0
Last Updated: February 2026
Maintained by: Ranch Hand Robotics and the Maker Panel community