3DP File

What are 3DP files and how to open them

Are you having problems opening a 3DP file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your 3DP files.

What is a 3DP file?

3DP files have multiple uses, and 3Digi Parameters is one of them. Read more about the other uses further down the page.

3Digi Parameters

3Digi Parameters (.3dp) files store flight-controller tuning parameter sets used by the 3Digi flybarless stabilization system for remote-control helicopters. These parameter sets define how the control electronics manage stabilization, response to stick inputs, gyroscope gains, PID loops, and other behavior of the helicopter in flight. Files with this extension are created and used by the official 3Digi setup software, which lets users load, save, and switch among multiple tuning sets appropriate for different flight styles or conditions.

The 3Digi hardware writes these files when the user saves a configuration or selects a parameter bank. They do not contain full hardware configuration (such as sensor orientation or servo mappings) or entire setups, only the tuning parameters in each of three flight-parameter banks. The setup software can load a .3dp file to apply or compare those tuning parameter values without affecting non-tuning configuration data. Users fly with one of the parameter banks active via a switch on their transmitter.

Files of this format usually start with an ASCII header "[ParSet0]" at offset zero. They include identifiable labels such as "PIDHECKDREHMOAUSGLEICHPITCH", "PIDROLLPFACTOR", "SPISENSORNOISEFILTERSETTING(0)", and "RCINDYNAMICLIMITROLL" among many others, which correspond to specific PID gain terms, noise filters, coupling settings, and dynamic limits. These internal keywords help distinguish .3dp parameter-set files from other file types.

How to open 3DP files

Important: Different programs may use files with the 3DP file extension for different purposes, so unless you are sure which format your 3DP file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested ten different 3DP openers which you will find listed below.

Last updated: August 16, 2026

All known file formats using extension .3DP

While 3Digi Parameters is a popular type of 3DP-file, we know of 3 different uses of the .3DP file extension. Different software may use files with the same extension for different types of data.

ArtCAM Project

ArtCAM Project (.3DP) files are used by ArtCAM Pro and its derivatives for storing complete design projects that may include multiple parts, models and assemblies. A .3DP file bundles together all components of a work-in-progress project - such as ArtCAM Model files (.art), assemblies (.3da), reliefs, bitmaps and vector artwork - into a single project structure for editing and layout. It lets the user organise and manipulate various elements in three-dimensional space within one unified workspace.

The .3DP format is written by ArtCAM when the user saves a project (via File → Save or Save As). Once saved, the project can be reopened to continue editing: you can add or modify individual models, import 3D mesh or surface data (e.g. STL, OBJ, IGES), combine assemblies, apply material settings or set up toolpaths. The project retains references to its component files and maintains their relationships inside the project tree.

A .3DP file is identified by an OLE file header starting with the byte sequence D0 CF 11 E0 A1 B1 1A E1 at offset 0. Additional internal identifiers include the ASCII text strings Root Entry, Assembly Info, Material, Workplane, ShadingSets, Rendering, etc., embedded at various offsets.

Spin 3D Model

Spin 3D Model (.3DP) is a proprietary 3-dimensional mesh file used by Spin 3D, a model conversion tool made by NCH Software. It saves 3D model geometry in NCH's own format so that Spin 3D can both read and write files with the .3DP extension. Users working in Spin 3D can convert between .3DP and formats like STL, OBJ, 3DS, PLY, and 3MF.

Spin 3D Model files are typically produced when you save or export a mesh from a model loaded into Spin 3D without converting it into another format. These .3DP files retain internal mesh data (vertices, faces) using the format's native structure, allowing editability or reconversion in Spin 3D later. The workflow is: you import or create a 3D model in Spin 3D, save it as .3DP to keep the Spin-native version, then optionally convert it to another supported mesh format when needed.

Files of this format start with a fixed binary signature at byte offset zero: the ASCII characters "lsdf" followed by some control bytes (in one example: 6C 73 64 66 01 00 20 00).

Various apps that use files with this extension

These apps are known to open certain types of 3DP files. Remember, different programs may use 3DP files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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