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CNC Guide

A guide to using the Shopbot CNC machine in MAKE ll

First Things

You must attend a badging class before using this machine.

This guide is a supplement to - not a replacement for - the badging class.

When you come in to use the CNC, first check in with the staff member on duty. They will verify that you are badged, give you a kit with the tools and bits, and log you into the computer.

Once you are ready, turn on the machine using the red switch on the front side.

The machine may take a moment to start up (it's ready once you see numbers on the control box on the side). When it is ready, open the ShopBot control software. If you open the software before turning the machine on, it will give an error message and offer to startup in Preview mode. If this happens, turn the machine on and then choose "Retry Control Box".

Before running the machine, it is important to understand how to manually move the spindle and how to set the spindle speed.

Basic Operations

There are two pieces of software needed to use the CNC 

  • VCarve Pro - Layout and design software used to convert vector files into toolpaths.
  • ShopBot 3 - This controls the machine itself and runs the toolpaths created in VCarve Pro.

While most of the work is done in VCarve Pro, you will first use ShopBot 3 for the initial setup. In order to mount your material and access the spindle control box, you may need to move the spindle out of the way.

Spindle Control Box

This is where you set the actual rotation speed of the spindle (measured in rotations per second and displayed as hertz). Simply turn the dial until the display shows the desired speed. You to not need to be completely accurate - within 5hz is acceptable. (Ex: if the desired spindle speed is 150hz, anywhere from 145hz to 155hz will work)

Moving the Spindle Manually

Click on the yellow icon on the red control panel to open up the Move Tool. Among other things, this panel lets you manually move the spindle unit. You will often need to move the spindle out of the way or forward to be able to reach the Spindle Control Box.

Use the 4-directional arrows on the left side to move the spindle left/right and forward/back and the up/down arrows on the right side to move the spindle vertically.

When moving the spindle, make sure that the bit does not drag against the material by raising it before moving.

At this point, the machine needs to be warmed up, so move the spindle forward enough that you can adjust the spindle speed.

Initial Machine Setup

At this point there should not be a bit in the machine. From the ShotBot software, go into the "Cuts" menu and choose "Spindle Warmup Routine". Set the spindle speed to 150 (see above for how to adjust the spindle speed), click okay and allow the machine run through the routine, which takes approximately 10 minutes.

While the machine warms up, you can create your toolpaths in VCarve.

VCarve Setup

Open VCarve Pro and set up your workspace (if you have previously created a project in VCarve, you can open that file here). It is very important to precisely describe your material as that is how it will determine where the router bits move.


  • Width - The width of the material relative to how it will be placed in the machine.
  • Height - The length of the material along the y-axis. Not to be confused with the thickness of the material.
  • Z Zero - Whether the top or bottom of the material should be considered the zero-value for the material. For almost all projects, the top is preferable.
  • Thickness - How thick the material is - for uneven material, use the highest point from how the material will be placed in the machine.
  • XY Datum Position - Which corner or center should be used as the origin (x=0 and y=0). This will determine where For rectangular objects, the lower right corner is often easiest to work with as it will let you reach the material while using the computer. For irregularly shaped objects, the center may be best as the object may not line up to an edge very easily.
  • Units - You can work in inches or millimeters. This does not have any impact on the ShopBot software, which works in inches.
  • Modeling Resolution - The level of detail for the previews - this has no impact on the quality of the actual cuts. Higher resolutions have more detail but take longer to render.
  • Appearance - The texture/color of the preview. This is purely visual and the material selected is factored in when determining toolpath default settings.

Once you have entered the necessary information, click OK and you will be ready to start adding vectors to the VCarve workspace.

Adding Vectors

There are three ways to adding vector lines and shapes to the workspace:

  • Create them using the tools in VCarve
  • Import a vector file
  • Converting a raster image to vector lines

See the individual tabs in this section for more information on each process. The panel on the left contains options for (among other things) manipulating vectors that have been created or imported.

File Options

The first three icons are for creating a new VCarve project, opening an existing one, and saving. Next to that are the buttons for importing vector files and bitmaps. On the second row, the first icon will let you edit your material information (size, thickness, origin point, etc), and the rest are the standard Windows functions of cut, copy, paste, undo, and redo.

2D View Control

These options change the view of the workspace, but do not change the vectors. The first icon lets you move the camera around (you can get the same results from holding down the mouse wheel and moving). The three magnifying glasses change the zoom level to fit a box you drawn, all objects, or all selected objects. The next two let you tile windows, and the last one switches to the toolpaths panel.

Layers: You can have multiple "layers" in your workspace, which function as if they were a transparent stack of plates containing vectors. These are used to help you organize your project and want to group vectors.

Create Vectors

This is where you manually create vectors. See the "Creating Vectors" tab for more information.

Transform Objects

With the first five options (Move, Scale, Rotate, Mirror, and Skew), you can manipulate the vectors either with the mouse or by putting in exact measurements. Select the vector(s) you want to alter and then one of the options. A new panel will pop up with options to put in the measurements for dimensions and position. Additionally, anchor points will appear around the selected vectors to control them with the mouse.

Edit Objects

Align Objects

Offset and Layout

Once you have the vectors in the workspace, you can begin to turn them into toolpaths.

VCarve has several options for creating vectors, however they all fall into one of three categories - shapes (closed vectors), lines (open vectors), and text. A shape is considered closed when the start and end points are the same, which gives it a defined inside and outside. Closed vectors can work with all types of toolpaths (see the next section for more), while open vectors can only work with profile and similar type toolpaths. Text boxes are a special type of closed vector that uses fonts installed on the computer to create the vector shapes.

Closed Vectors

There are five types of shapes available in VCarve - circles, ellipses, rectangles, polygons, and stars. These are all available on the top row of the "Create Vectors" section of the left panel. When you click on one you will have a variety of options based on what the shape is such as position, length, width, and radius. You can set exact measurements in the panel on the left, or you can draw it using the mouse by clicking and dragging in the workspace. You can also click and drag to set the basic size and position and then use the panel to change other settings such as rounding the edges of a rectangle.

Once you have everything set, click the Apply button to create the shape, and then Close to return to the main panel. You can create multiple shapes by clicking Apply repeatedly. If you have a shape selected in the workspace and click the appropriate drawing button, you will edit the selected shape instead of creating a new one.


Open Vectors

Open vectors give you a lot more flexibility than closed shapes because you can put the nodes (corners) wherever you want and the lines can go at any angle. Open vectors come in polylines, arcs, curves, and patterns. The polyline is the most basic format and the most commonly used because all you have to do is draw line segments. Arcs create half-circles between two or three points, and curves are similar to polylines except with non-straight lines. Patterns create a repeating waveform either across the entire workspace or within a closed vector.

Polylines and curves can be closed off by clicking on the original node when you are drawing it (the icon will change to show the polyline or curve icon when it is close enough to the origin node). Once you do this, the shape has all of the abilities for being turned into toolpaths as the basic shapes.

If you would like to close off an open vector after it has been created, you can do so with several of the options under the Edit Objects section of the main panel. These options will close off an open vector by joining the start and end nodes with a straight or curved line, or by moving the two nodes to the midpoint.

Important! An open vector that has been closed is not the same as a basic shape, as the basic shapes contain additional information that tells VCarve how to treat them. For example, the rectangle shape has data on the shape of the corners, and - most importantly - that it is a rectangle and should always be treated as such and given the options for editing a rectangle. On the other hand, a closed-off vector with four lines at 90 degree angles is just four points connected by lines - the software does not "see" it as a rectangle.



Text blocks are specialized closed vectors where the shapes are created through fonts installed on the computer. Simply select the Text Within a Vector Box icon (there's another text option to the left of that icon, but it has been know to cause issues). There are several different options for styling the text, however the two that matter the most are the top box where you put in the text and the font selector.

When selecting a font, it is important to use one that works well with the router bits. Since router bits are relatively thick compared to a pen, it is important to use a font that and be carved properly. Thin serifs and other stylistic lines often cannot be carved properly because even a small bit is too wide to fit in a narrow space. The larger the text, the more room a bit has to move, however you will need to check the previews after creating a toolpath to ensure that it will cut enough out to be legitble. Thicker, sans-serif fonts generally work better as there are fewer thin areas to work around.

You can set a bounding box to fit the text into, but it is easy to resize and move later on. As with the basic shapes, if you select and existing text box and then the icon, it will edit the text instead of creating a new one.

To the right of the Text Box icons, there are two more icons with important functions. The first will adjust the spacing between characters and the second will put the text along a vector line (open or closed). For instance, if you want the text to go in a circle, you simply create the text and then a circle shape. Select the two vectors and click the button to automatically move the text, which will then be linked to the circle. If the circle is then moved or resized, the text will move with it.

Node editing

 You can edit the individual nodes of any vector by clicking on the second icon in of the top row under "Edit Objects". By doing this you can move each node around freely, and the two connected lines will move and resize automatically to stay connected. You can also grab the faint square in the center of any line to split it with a new node created at that point. You can select multiple nodes by holding shift, and then they will move in sync.

If a node is select, you can right click to get options for removing nodes, turning them into smooth curves, splitting the vector (turning it into an open vector), or closing the vector. If you right click on a line segment you can create either new nodes or a midpoint at the spot where you clicked.

When you are done, click anywhere in the workspace or press Esc to return to normal editing.

Important! Once you edit the node on any basic shape or text it losing any special properties and becomes just an undefined shape. This is especially important when it comes to text - you will never be able to edit the text by choosing new fonts, changing the actual text, and so on. Therefore this should only be done if you are completely done making those types of changes.

VCarve Pro can import a variety of vector files including SVG, DXF, PDF, and AI, as well as other VCarve files. To import a file, simply click on the "Import Vectors From a File" button (the fourth from the left on the top row) or drag the files into the workspace. Once imported, the vectors can be manipulated as with any vector that was created in VCarve.

Important! While VCarve is very good at importing files, it is not perfect (especially with Adobe Illustrtor's *.ai files). The most common issue with  importing are vectors being group together, however these can almost always be ungrouped within VCarve. In order to help ensure that files are imported correctly, in the design program, remove anything that is not part of your project, including hidden objects. Additionally, combine all layers into a single one.

An important note about text

If you are importing text, be aware that if the font you used in your design program is not installed on the computer with VCarve Pro, it will not import correctly. Because of how programs store text, it must be able to find the font in order to display it. If it cannot find the font, it will use a generic font (e.g. Arial or Times New Roman) in its place. 

If you are using a special font, you must convert the text objects into basic shapes. Almost all programs that work with both vectors and text have an option to do this, though the terminology varies. For example, in Inkscape, you select "Object to Path", while in Illustrator it is called "Create Outlines". By converting the text, it turns the characters into vector shapes that no longer need the font file for reference. However, once text is converted it cannot be edited. Therefore, this should only be done as the final step of your design, and preferably to a second copy of the file. That way, if you need to change anything, you can go back to the original version.

PPLD will not install extra fonts on the computers and the Adobe suite is not installed on the computer connected to the CNC.

Tracing bitmaps is a way of converting a standard image file (e.g. JPGs, PNGs) into vector files by drawing a line along the border of any two pixels of different colors. In order to do this, select the "Import Bitmap for Tracing" button from the File Operations group or simply drag and drop the images into the workspace.

Next, select the "Trace Bitmap" icon in the "Create Vectors" group. You can trace either black & white images or full color ones. Black & white images are the easiest, as all the software has to do is draw lines around the black shapes. If you need to work with full color images, the software will first have to simplify the image by reducing it to no more than 16 different colors. There are other options to account for color gradients and feathered edges - if the trace is not working properly, try adjusting the slider bars to see if you get better results. Be aware that not every image can be traced well, and the more complex it is the more difficult it will be to get a satisfactory tracing. If you are unable to get a proper trace in VCarve, you may be able to get better results by taking the bitmap into a graphics design program such as Inkscape or GIMP and simplifying it before trying to trace it in VCarve.

After selecting the options, click on the Preview button and it will show you where the vector lines will be placed. If you are satisfied with it, click Apply to actually generate the vector lines, otherwise change the options and click Preview again. You can create multiple traces from the same bitmap, which you will often need to do with multi-color images.Once you've created the vector lines, click Close and then delete the original bitmaps.


Creating Toolpaths

Hover your mouse cursor over "toolpaths" in the upper right corner of VCarve and the toolpaths menu will slide out. If you click the small pin icon it will prevent the menu from retracting when you move the cursor away.

Select the vector(s) that you want to cut - if you select multiple vectors they will all have the same toolpath settings. Select the type of toolpath you want to create; there are several different types, however the most commonly used ones are Profile, Pocket, and V-Carve.

  • Profile: The bit follows the line exactly, which can be used to cut all the way through the material.
  • Pocket: The bit clears out the entire area inside of a closed vector shape.
  • V-Carve: A special type of profile cut using V-bits to create engraved text.

Once you select a type, you will be able to put in specific settings for that toolpath, including cutting depth and speeds. See the PDF linked below this section for information on specific types.

After you have setup the toolpath, the last thing to do is to name it. Complex projects can have a dozen or more toolpaths, so it helps to have names that describe the toolpath with information such as the order in which you are going to run the cut, the number of the bit being used, what type of cut, etc.

After putting in a name, click Calculate to actually generate the toolpath. It will add it to the list of toolpaths on the right and automatically take you to the preview screen.

Preview Mode

The preview window will give you a very accurate simulation of what the cut is going to look like - if you see any problems in the preview, you will have problems with the actual cut. Specific things to look for:

  • Are the tabs visible? If not, you probably either forgot to add them or the width/depth are so small that it ends up having nothing to add.
  • Do the profile cuts go all the way through the material? If they don't, then check the cut depth of the toolpaths. If those are accurate, check to make sure you defined the material thickness correctly.
  • Are sections of a pocket cut or text omitted? VCarve will not remove more material than is defined by the vector, so if the selected bit is too big to fit into an area, that area will be ignored. You will need to use a smaller bit or redo your design.

There are several options on the right panel for controlling the preview. "Preview Selected Toolpath" will only run the currently hightlighted toolpath, "Preview All Toolpaths" will run them all, and "Preview Visible Toolpaths" will run any ones with the boxes checked.

You should click "Reset Preview" before running any because it will not automatically remove old toolpaths. Additionally, you can manipulate the camera view by holding the left mouse button and moving the mouse, or by using the scroll wheel to zoom in and out. In the upper right corner you can click one of the icons to show a direct view along any axis, move the camera to an angled view, or reset the camera.

Once you are done in the preview tab, click on the tab to the left of "3D View" in the upper left corner to return to the design area.

You should always run a preview with all toolpaths to look for errors. Once you are satisfied with the design, you can export your toolpaths.

Exporting Toolpaths

Since VCarve cannot connect directly to the CNC, you will need to export the toolpaths into files that can be loaded by the ShopBot 3 software. From the main toolpaths menu, select the Export icon from the bottom row. For each toolpath, select it and then select Save As - the toolpath that gets saved is the one clicked on, not ones with the boxes checked.

Important! While you technically can save multiple toolpaths as a single file, doing so often makes the ShopBot 3 software unstable and prone to crashes. It is almost always best to save each toolpath as a separate file.

Profile toolpaths can be used either to cut completely through the material or to carve lines into the material.

There are several options for how the toolpath will function, and it is important to set everything properly.

Cutting Depths: This is the starting and stopping points of the cuts. In almost all situations, the start depth should be zero - generally speaking, the start depth only needs to be changed if you are working with multiple layers. The cut depth is how far down to cut from the start depth. This means that if your start depth is 0.25" and your cut depth is 0.5", the CNC will remove material from the top 0.75" of the material. If the start depth is left at 0", then the cut depth is simply how far down from the surface to cut.

Tool: This is the bit that will be used. Click "Select..." to open up the tool library and choose one of the bits to use. Generally speaking, the larger the bit, the faster it can work. However, the larger the bit, the more material is lost during the cut. In the tool library, there are several settings that can be changed, however the only ones that may need to be adjusted are the Feed Rate (how fast the bit moves through the vector) and Spindle Speed (how fast the bit is rotating). Lowering the Feed Rate can significantly reduce the chances of the material being damaged during the cut.

After selecting a tool, you can adjust the settings by clicking on Edit. Passes refer to the number of times the CNC will have to go over the vector in order to complete the toolpath. Each bit has a maximum depth that it can go through at once so if, for example, the bit has a maximum pass depth of 0.125" and the cut depth is 0.5", it will take four passes to complete. Individual passes should not be edited as it can result in the bit being broken.

Machine Vectors: This is how the software accounts for the thickness of the bit on a closed vector.

  • On: The center of the bit moves directly down the vector line. This is usually for when you are cutting lines that do not go all the way through the material.
  • Outside: The bit will be offset so that only the edge of the bit touches the vector line, with the rest on the outside of the shape. This is ideal if you are carving out a shape as it will ensure that the shape retains it's proper size.
  • Inside: As with Outside, only the edge of the bit will touch the vector line, however the bit will stay inside the vector shape. This is for situation such as cutting a frame.

The direction sets whether the bit should follow the vector in a clockwise or counter-clockwise direction. Which one works best depends on the material, the grain direction of wood, and the type of bit. If you are unsure, use climb, but you may want to test the cut on scrape material. Allowance Offset and Last Pass can be used to fine tune the cut for parts that need to be perfectly sized. See the VCarve documentation page for more information.

Tabs: These are thin pieces of the material that are not cut away, allow the cutout pieces to remain anchored to the the main piece (and, by extension, the screws/clamps). After cutting, the tabs can be removed by hand or using a saw/Dremel. Tabs are always recommended when cutting all of the way through mateiral because otherwise the cutout pieces will get knocked around by the bit.

Generally speaking, Tab Length should be equal to the thickness of the material and Tab Thickness should be half the thickness of the material. Selecting 3D Tabs will make the tabs triangular instead of rectangular, which are easier to remove by may not be as stable. Once setting up the size of the tabs, you must click Edit Tabs to put them in. You can have a specified number of tabs added, have tabs added every so many inches, or you can manually add tabs. In most cases, putting one tab near the center of each edge will be enough, but larger pieces may require multiple tabs on an edge.

Note that tabs are rendered in the preview, so if you have added them but they do not show up in the preview, they will not be included in the cut. The most likely problem is that either the size was set, but the tabs were not added or they are too small.

After everything is complete, name the toolpath and click Calculate to create the toolpath.



Pocket toolpaths are used to carve out the entire interior area of a vector shape.

undefinedDue to the nature of pocket cuts, this toolpath will only work on closed vectors - open vectors do not have a defined inside or outside. For more information on open and closed vectors, see the Adding Vectors section of this page.

Cutting Depths: This is the starting and stopping points of the cuts. Unless you are working with complex, multi-layered designs, the start depth will almost always need to be zero. The cut depth is how far down to cut from the start depth. If the start depth is left at 0", then the cut depth is simply how far down from the surface to cut.

While you can use pocket toolpaths to carve through the entire piece of material by making the cut depth greater than the thickness of the material, it is better to use a profile toolpath if you want holes. Profile toolpaths will get the same results faster, with less debris, less wear on the bits, and less damage to the spoil board.

Tool & Use Large Area Clearance Tool: This is the bit that will be used. Click "Select..." to open up the tool library and choose one of the bits to use. In most cases, the larger the bit, the faster it can carve out the area - the bit has a larger surface area, can move faster, and has a greater cutting depth. However, larger bits cannot fit into narrow spaces, limiting what can be carved. Note that if the chosen bit cannot reach an area, the machine will simply ignore it.

The Large Area Clearance option can help find a balance between the run time and the need to carve small areas. By using this you can select two bits - a large one and a small one. The software will automatically determine which areas can be reached by the larger bit and what can only be reached by the smaller one. While you can choose any bits, it is often best to have the large area clearance tool be a bit with twice the diameter of the smaller one (e.g. use a 1/8" and a 1/4" bit). While a much larger bit can be used, it is often less efficient. It will carve the wider areas faster, but there will be significantly more areas that have to be left to the smaller bit.

Beside the specific bit to use, there are several settings that can be changed. The two most important ones are the Spindle Speed, which is how fast the bit is rotating, and the Feed Rate, which is how fast the bit moves along the path. The higher these values, the more material that the bit removes at once and the less time the job can take, however high speeds increase the risk of damage to the material and bits.

Another important value is Cut Depth, which is the maximum depth that a bit can go down at once. If you are cutting deeper than the cut depth, it will take multiple passes to complete the job. For example, if you are cutting 0.5" inches down and the bit has a cut depth of 0.25", it will take two passes to complete. The number of passes is important as it will greatly affect how long the job takes. If the number of passes is very high, see if you can get the same results with a different bit.

Clear Pocket: This determines the pattern for how the pocket is carved out - Offset moves in a circular path, while Raster moves left-to-right. If Raster is selected, there is also the option of setting the Raster Angle. This determines the angle of the left/right movement relative to the axis of the machine - zero degrees will have it move parallel to the X-axis and 90 degrees will have it move parallel to the Y-axis. Cut Direction will switch the movement from clockwise to counter-clockwise. In most situation, the difference in quality and cutting time is trivial, however, if scrap material is available, it is often useful to cut small samples with different settings.

The last option is Pocket Allowance, which leaves the edge of the pocket uncut. This allows you to create a separate profile to cut the edge if desired. Similarly, Profile Pass can set the edge carving to be done at the beginning or end. The default of having the edge carved out at the end of the pocket cut works in the majority of situations.

Ramp Plunge Moves: This has the bit start carving into the material at an angle instead of straight down. Using these will not alter what material is removed, however it can reduce the amount of heat generated during the job and lessen the wear on the bit and help preserve the material.

Use Vector Selection Order: If this is checked, the vectors will be cleared in the order they were selected at the beginning. If it is left unchecked, the software will determine the optimal order of clearing the vectors. If only one vector is selected, this has no impact on the job.

Once you are done, name the toolpath and click Calculate to create the toolpath. Note that if you used a Large Area Clearance Tool, two toolpaths will be created - the large area clearance tool will have "[clear]" appended to the name.

VCarve toolpaths create specialized pocket cuts with slanted edges, and are generally used for engraving text.

undefinedUnlike pocket and profile cuts, the software will determine the depth of the cut based on the shape and size of the vector. Familiarity with pocket toolpaths will make it easier to understand VCarve toolpaths.

Start Depth: How far down into the material the cut should start. Unless you are working with a multi-layered design or material that is not flat, this should almost always be set to zero.

Flat Depth: This sets the maximum depth of the carving. If unchecked, the cut will create a v-shaped trench in the material. If checked, the cut will go down until the specified depth and then stop. This results in angled sides with a flat bottom. This is often ideal for very wide vectors as it keeps the cut from going nearly through the material, and limits the number of passes necessary.

Flat Area Clearance Tool: This is functionally identical to the Large Area Clearance Tool used by Pocket toolpath. Two bits will be used - a V-Bit for the edges and an End Mill for the flat (interior) areas. Unless the vector is extremely wide, a 1/4" or 1/8" bit will generally work best for the flat area.

Flat Area Clearance: This determines the pattern for clearing out the area. Offset moves in a circular pattern while Raster moves left-to-right, and the direction can be changed under Cut Direction. Generally speaking, the difference between the two methods is trivial both in terms of cut quality and run time.

Ramp Plunge Moves: This has the bit start carving into the material at an angle instead of straight down. Using these will not alter what material is removed, however it can reduce the amount of heat generated during the job and lessen the wear on the bit and help preserve the material.

Use Vector Selection Order: If this is checked, the vectors will be cleared in the order they were selected at the beginning. If it is left unchecked, the software will determine the optimal order of clearing the vectors. If only one vector is selected, this has no impact on the job.

There are several other toolpaths available and, while useful, they are not as commonly used as pocket, profile, and VCarve toolpaths.

  • undefinedDrilling - Allows for drilling into the center of closed vectors, with options to creating cleaner holes than with other toolpaths.
  • Quick Engraving - Creates engraving patterns with stylized patterns.
  • Inlay - Multiple cuts are generated for creating cut out pieces that will sit inside pocket cuts.
  • Fluting - Creates profile-style cuts along vector lines with varying depth.
  • Texture - Creates 3D textures into pocket cuts without needing a 3D model.
  • Prism Carving - Uses VBits to create raised, beveled shapes (essentially inverted VCarve toolpaths)
  • Moulding - Creates pseudo-three dimensional rounded shapes without a 3D model.
  • 3D Rough and 3D Finish - Used for carving 3D models. See Advanced Techniques for more information.

More Machine Setup

Changing the Collet

There are three different sized collets - 1/4", 1/2", and 1/8", and you will need to use the one that is diameter of the shank (the top part of the bit, which is not necessarily the same as the cutting diameter). Most bits provided by PPLD use the 1/4" collet, however there are a few exceptions.

To change the collet, loosen the collet nut (the black ring) until it comes off the spindle. Push the collet out with your thumb and put the new one in, then screw the nut back into the spindle until it stays. Do not tighten it, as you still have to put a bit in.

Changing the Bit

Important! When changing a bit, do not have the spindle too close to the edge of the spoil board, as the bit may roll under the machine. Move the spindle head at least 4 inches from any edge before changing bits. Raising the spindle to around 2 inches will give you enough room to insert the next bit.

Insert the bit into the hole in the center of the collet - most bits will have a cutting diameter equal or less than the shank diameter, so you should push the bit in right to the edge of the cutting blades. If the cutting diameter is greater than the shank diameter, simply push the bit in as far as possible. While holding the bit in place, turn the collet nut to tighten it as much as possible.

Next, use the two wrenches to further tighten the collet. Slide the silver wrench up from the bottom, ensuring that all of the teeth are in the grooves of the collet nut. The blue-handled wrench goes around the spindle shaft above the collet nut. Once in place, pull them together to tighten the collet nut. Do not over tighten it - simply pull them together slightly.

Once the bit and collet are loaded, you are ready to mount the material.


Because there is no vaccum table, the material must be mounted to the spoil board. While not required, it is often easiest if material (especially rectangular boards) are placed against one or two edges. There are two ways to do this - clamps and screws.

  • Clamps are stored in the blue bin on the table by the CNC. Slide the silver part into the groves of the CNC plate below the spoil board and then tighten the nut to secure it.
  • Screws are in the bins on the table, and come in a variety of sizes. Use the smallest size possible with your material. There are two drills available - a 12 volt and a 20 volt. Use the 20 volt to drill pilot holes through your material and slightly into the spoil board, and then use the 12 volt to screw the material down.

Which method works best depends on your specific project. Screws generally hold material more securely, but require putting holds in the material. Additionally, because clamps have to be anchored around the edges of the spoil board, materials usually need to be about the width of the board to be clamped down on both sides.

Where you should put the screws and/or clamps also depends on the nature of the project. The more you use, the more secure the material is, however the harder it is to ensure the spindle will not run into them. For screws, the most common points are the four corners, however extremely long pieces may require more screws on the long sides.

A combination of clamps and screws will work in many situations. In any case, place the clamps and screws in places where the spindle bit will not pass through them either during a cut or while moving into position.

Once the material is secure, you will need to zero the X and Y.

Zeroing the X & Y

To set the zero-point for the X and Y axises, you will have to manually move the spindle into position. Using the control panel in the Shop Bot 3 software (see Basic Operations above), move the spindle so that the center of the bit is directly over whichever spot you selected as the XY Datum Position during the initial setup in VCarve.

Once in position, click on "Zero Axes" on the yellow control panel. Check the boxes next to X and Y axis, and then click Zero. Do not check the box for the Z-axis as that has to be done separately. Once you do this the current position of the bit will become the new "home" position, with an X and Y coordinate of zero. You can now close the white "Select Axes to Zero" dialog box.

Important! If you change your material, close the software, or turn the power off, you will need to re-zero the X and Y. You do not need to re-zero them between cuts or when changing the bit.

Running a Cut file

Zeroing the Z-Axis

The z-axis can be zeroed automatically using the metal plate and alligator clip located on the front, left side of the CNC. The alligator clip can be placed on the spindle shaft, the collet nut, or the bit - generally speaking, it is easiest to place it on the spindle shaft with the clip on the flat parts. The metal plate needs to be placed underneath the bit and held flat.

Once the plate and clip are in position, click on the Z-Zeroing button on the red control panel. A message will pop up telling you to move the plate into position, and when you click Ok it will move the bit down until it makes contact with the plate. It will touch it twice, and if it work properly, a mess will pop up telling you it is zeroed and you can put the plate away. If it did not work properly - which is almost always because the plate was moved - you simply need to repeat the process.

When you are done zeroing, place both the plate and clip back in the holders.

Selecting the File

After everything is set up and calibrated, you are ready to run the cut. Click on the Cut Part button on the red control panel and the Windows file selector will pop up. Choose the file that you want to run and a new panel will pop up with summary information. Click the Start button on the red control panel and it will begin the process.

Adjusting Spindle Speed

When you click start, it will prompt you for three confirmations:

  • Do you have the right bit in the spindle? Unfortunately, the only reference that the ShopBot 3 software has is the tool number that VCarve uses to index their bits, not the name or product ID of the bit. It is important that you use the bit selected in VCarve because the machine does not know if the bit the right size or shape. If you are using the same bit as the previous cut, it will not prompt you for this.
  • Is the z-axis zeroed? You have to zero the z-axis every time you change the bit, even if you are going back to a bit you previously used. Even if it is the same bit, you will almost certainly not have it exactly as far into the spindle as you did the last time.
  • Set the spindle speed and confirm that you want to start. The machine cannot automatically adjust the spindle speed - the speed put into VCarve is simply a reference. Use the spindle control box to adjust the speed to the frequency (Hz) displayed on the third prompt. If you are having trouble reaching the spindle control box, move the spindle closer to the front.

Starting the Cut

At this point the safety hood must be closed and remain closed while the machine is running!

When you click Ok on the final confirmation part, the machine will begin running the cut. Keep an eye on the machine to ensure that it is cutting in the proper area. The mouse cursor will be locked over the stop button on the software. If you have to leave the machine for any reason or want to stop it, click the mouse button or press the space bar. Wait until the spindle comes to a complete stop before opening the hood.

When paused, the following menu pops up with several options:

  • Quit: Ends the job. If you reload the file, it will start again from the beginning.
  • Resume: Continues where it left off.
  • Insert Command: Allows you to insert lines of gCode. Not recommended unless you know exactly what you are doing.
  • Close & Exit: Closes the software. If you restart it, you will have to re-zero all three axises.

The emergency stop is the power switch - simply press down on the red cover to immediately stop everything.

If you want to check the quality of the cut, or the debris is piling up to the point where it is nearing the spindle, pause the machine and use the ShopVac to clear out the table.

The Next Cut

After each cut, you should vacuum off the material as it will keep debris from building up and getting into the spindle, as well as make it easier to check the quality of the cuts.

Do not open the safety hood until the spindle stops moving.

The spindle will return to the home position after each cut, however you should not change bits while it is near the edge of the board as the bit could drop down and roll under the machine. Move the spindle at least four inches from any edge and approximately 2 inches up. Using the same wrenches used to tighten the collet, loosen it until the bit drops out. If you need to change collets, continue loosening and then unscrew it with your hands.

Place the next bit/collet in, tighten them, and then re-zero the Z-axis. From here, simply repeat the process for each cut.

Finishing Your Project

Once you are finished running all of the cuts on the board, you can safely remove it. Vacuum off the board, machine, and table as best you can, and then move the spindle out of the way using the control box. If you used screws and they are still in good condition, return them to the tray. If they are broken, bent, or stripped, simply throw them away.

If you have more material to work on, simply repeat the setup process. After mounting the next board, you will need to re-zero the X and Y axises.


When you are done using the machine for the day:

  • Remove all of your material. PPLD does not have the capacity to dispose of large amounts of waste, so you will need to dispose of any material yourself.
  • Return screws and clamps to their proper place.
  • Lock the drills, but keep the standard drill bit and screwdriver bit in.
  • Thoroughly vacuum the area - on the spoil board and tray, the sides of the machine, the table, and the floormat. Do not vacuum under the machine bed or behind it - the staff will take care of it.
  • Save any files you wish to keep to a USB drive or cloud storage.
  • Exit VCarve, ShopBot 3, and any other applications.
  • Turn off the machine.
  • Return all bits and collets to the box, except for the 1/4" collet which stays attatched to the spindle.
  • Put the box, wrenches, and papers back in the plastic tub
  • Take your USB drive with you.
  • Return the tub to the staff member and let them know you are done.



  • Save your work often, preferably to a USB drive - any files left on the computer will be lost once it is restarted.
  • If you make toolpaths (included exported files) in a copy of VCarve other than what is available at PPLD, be aware of version differences. PPLD computers use version 8.5 and files made in a newer version may not be compatible.
  • VCarve is installed on one computer outside of the Makerspace (the CAD comptuer at Library 21c), which can be used to set up all of your designs even when the Makerspace is closed.


  • If you change any settings in an existing toolpath, you must click Calculate to save the changes.
  • Changing a vector (including position) does not automatically update the toolpath - you can either open each affected toolpath individually and click Calculate, or select Recalculate All from the Toolpaths side panel.
  • If you make any changes to a toolpath that has already been exported, you will need to re-export it.

ShopBot 3

  • Any time you change bits, you will have to re-zero the Z axis, but not the X or Y.
  • Any time you change or move the material, you will have to re-zero the X and Y axises, but not the Z.
  • Generally speaking, you will want to do pocket and shallow profile cuts first, and do all cut-through profiles at the end.
  • If possible, group cuts based on the bit they are using as it will reduce the number of times you have to change hardware and re-zero the Z axis.