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Introduction to Digitizing

The controlled motion capabilities of a CNC tool make it possible to use the tool to digitally sample or scan an object in order to record the shape of the object. The data from the sampling can be used to cut a new version of the part, or can be imported into a design program for further work. An object can be scanned in many ways, and the digital sampling can involve contact with a probe, or may be a non-contact process based on optical or imaging technology. In all cases, the final data are coordinate points representing either the outline of the object (2D) or its shape (3D).

One of the most straightforward and least expensive approaches to digitizing is to use a contact probe, which signals each contact with an object so that the location of the probe at that point can be recorded to define a point on the surface or edge of the object. The mechanism can be as simple as a sensitive switch that is triggered by slight motion of the probe.

ShopBot Digitizing Probe
ShopBot Digitizing Probe
The ShopBot Digitizing Probe allows you to use your ShopBot to map the 3D shape of an object or to record the object’s outline. The probe is chucked up in the collet of your router or spindle. The probe is simply a switch that is triggered when the tip of the probe contacts the surface of your sample object. When digitizing a 3D object by probing, your ShopBot will methodically move the probe tip, in a raster pattern, carefully contacting and recording the position of each contact in order to reconstruct the shape of the part for cutting. The internal switch in the probe is optical and highly reliable.

The Copy Machine probing functions of the ShopBot Control software allow you to save two types of file. You can save a Part File of native ShopBot CNC instructions that is ready to cut at the end of the probing process. If you need to do some modifications to the shape before creating your final file, you can instead save a file of 3D points or a polyline that you can use directly as primitive entities within 3D modeling software. Alternatively, you can process the 3D points into a 3D surface file using the 'Probe to Surface' Virtual Tool in the ShopBot software. The shape can then be brought into 3D modeling software such as Rhino for further editing, manipulation, or processing, or directly into a CAM program such as Cut3D for specifying and generating high quality a 3D roughing and finishing toolpaths.

Image:sb_probe03.jpg Image:probe_path1.jpg

Hooking Up Your ShopBot Digitizing Probe

Probe Operation

The Copy Machine

  • Other software

Doing "3D" with the Probe

Doing "Outlines" with the Probe

Probing without a Probe

  • Other pattern copying options

Ted, Martin2Reid
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