Beacon3D mount for Qidi Plus4

A design for mounting a Beacon3D H Normal probe onto the tool-head of the Qidi Plus4

Update: 10th April 2025

I have uploaded an M3 screw variant of the mount for later model versions of the Plus 3 that use M3 bolts instead of 2.5mm self-tapper screws to hold the fan in place.  This model requires 2 of M3 nuts, and 2 of M3x16mm bolts to attach the heatsink fan to the mount.  The Beacon mounting holes in the model are sized to accept 2 x M3 HeatSet Inserts for attaching the Beacon to the model. 

Introduction
 

I make no apologies for the focus of this design.  It is not compatible with the stock front cover, but there is a printable model for one (see below).  It also does not allow the hotend to be changed without first removing the probe mounting frame. Mounting the Beacon3D eddy-current scanner introduced some unique challenges regarding the stock Qidi Plus4's toolhead design.  See Design Goals section below.

This mount should be compatible with all models of the Beacon3D eddy current scanners, as well as the Cartographer eddy current scanners, but I am using the Beacon3D H-Normal variant myself.
 

This mount provides for an x_offset of 0.0mm, and a y_offset of -18.8mm

There is a compatible replacement front-cover model for this mount available here: https://www.printables.com/model/1216779-qidi-plus-4-basic-toolhead-cover-for-beacon-with-s

Plus 4 Configuration Guide

I have written up a guide for configuring a Beacon H in Contact mode on the Qidi Plus4 using this printable mount, which is available here: https://github.com/qidi-community/Plus4-Wiki/blob/main/content/bed-scanning-probes/Beacon3D/RevH-Normal/README.md

Design Goals

This model's design goals were as follows:

• To have no probe x_offset so as to not limit the X bed-meshing range
• To have as minimal Y-offset as practicable to minimise impact on the Y meshing range
• To be as rigid as practical to minimise any negative impact on input shaping performance that can be caused by having the probe wobble on a (semi)-flexible arm
• To remain light.  Despite its somewhat bulky appearance, it only adds 4g of weight when the stock inductive probe and stock heatsink fan mount are (necessarily) removed.
• To fit well into the various key points on the stock Qidi tool-head carrier
• To double as an integrated fan duct to provide for better cooling of the hotend heatsink.
• To fit within the established keep-out zones on the Plus4, resulting in no loss of tool-head movement range

Printing Tips

Be sure that you've calibrated your filament and flow rates carefully.  This mount has some rather tight tolerances with respect to how it mates against the stock tool-head carrier.

Suggested Filaments

• Avoid PLA or any other low temperature filaments.
• Avoid any metal filled filaments to minimise the chance of eddy current interference
• There is a theoretical chance that a CF filament may also interfere, but it's never been observed in practise
• Choose Glass or Carbon Fiber filaments for greater rigidity
• PC, PA, PPA (aka PAHT), or PET with CF or GF filling are usually all good choices.
• It is recommended to only use PC or PPA if you regularly print with high temperature filaments, as the elevated temperatures may cause some deformation for certain manufacturer's blends of PA or PET

Printing Settings

• 0.2mm initial layer height
• 0.1mm layer height for all other layers
• 0.4mm nozzle
• 4 walls, 20% honeycomb infill
• 14 bottom layers, 15 top layers (we're aiming for rigidity here)
• Print in the upright orientation (as shown in the image where it is mounted)
• Use NORMAL supports.  Tree supports won't work as well for the larger flat supported areas of this model

Installation

• Remove the stock probe and hotend heatsink fan brackets.  We will not be needing either any more
• Unplug the hotend wiring (but leave the hotend in place)
• Install Beacon/Cartographer probe onto the bottom of the mount (see photo)
• Install hotend heatsink fan into the fan mount portion.  Secure with the same screws taken from the stock fan mount.  Note that the top-right screw nearest to the fan's cable doesn't have enough clearance to re-use the stock screws.  See photo for a fan installation example.
• Pass the hotend cables through the arched opening on the mount (see photo)
• Press the mounting frame into place.  It is designed to be a very snug/tight fit onto the tool-head carrier.  The carrier's built-in guiding pins can be used to properly locate the mounting frame against the tool-head.
• While a firm amount of pressure should be sufficient to push the mounting frame into place, it is not necessary to brute force it.  If it feels like it is too tight and won't go on, then you are likely over-extruding in your filament settings.  Lower your filament extrusion multiplier and re-print.
• Re-use the stock screws to secure the frame to the tool-head carrier
• Remember to plug the hotend back in again :)

Updated notes for M3 Model Variant: It's come to my attention that later shipping models of the Plus 4 now use hex screws for mounting the heatsink fan, as opposed to the 2.5mm self-tapping screws used in earlier Plus 4 models.  An M3 nut and bolt variant is now supplied in the model list.

It should be noted that the M3 variant also requires the use of M3 Heatset Inserts inserted into the holes to attach the Beacon unit to the mount.

It is very strongly recommended to use a thread-locking agent to secure the M3 beacon mounting bolts into the M3 heat sets, as if the bolts work their way loose then this can lead to damage to the beacon unit itself if it hangs loose as the print head moves about.
 

Post-Installation

Follow your probe manufacturer's guidelines for configuring the probe

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