CamCopyM4

UCamCopy for Mach4 — User Manual — Version 2.400

A video-camera based reverse-engineering and tracing program for Mach4
Manual revision: October 18, 2026
www.craftycnc.com

1. Introduction

CamCopyM4 is the Mach4 edition of UCamCopy, a vision-based probing and line-following program for CNC machines. It needs a webcam, preferably a “microscope” camera with fairly high magnification and adjustable focus. The camera image is processed with the EMGU/OpenCV libraries to find edges, lines, circles and enclosed shapes. Once an edge or target is found, CamCopyM4 drives the machine along it and records the path to a DXF file (and optionally a CSV file), so that you can reconstruct or copy existing geometry.

It runs as a separate program next to Mach4 and talks to the running Mach4 through Mach4’s own inter-process library, Mach4IPC.dll. No Mach4 plugin or screen-set change is needed. The windows, the image processing, the PID velocity control, the recorder and the 3D viewer are the same as in UCamCopy for UCCNC, so everything from section 6 on works the same way. Sections 1 to 5, and the notes marked Mach4, are specific to this edition.

• Edge tracing. Put the camera over an edge, press Run, and the machine follows the edge around the part, recording points as it goes.
• Target finding. Drive to the intersection of two lines, the center of a hole, or the center of an enclosed shape.
• Circles and arcs. Collect three or more points on a circle or arc that is too large for the camera view and let CamCopyM4 work out its center and size.
• Auto Tune. One click chooses the blur, edge-detection, color and line-detection settings for the part under the camera.
• 3D viewer and DXF editor. Shows the recorded geometry and the camera position live, and lets you pick, delete, move to another layer and draw lines.

There is no scaling or dimensional calibration between the camera image and the machine. The image is used in a unit-less way to calculate position errors, and those errors drive the machine’s velocity through a closed-loop PID (proportional / integral / differential) controller using gains that you enter. The PID only generates velocity commands. Every dimension recorded in the DXF comes from Mach4’s actual axis position in the active work coordinate system, so the recorded data is as accurate as your machine’s steps-per-unit calibration.

1.1 How this edition differs from UCamCopy for UCCNC

About the picturesThe screenshots in this manual were taken from the UCCNC edition. The windows are the same in CamCopyM4; only the title bar, the About tab’s License ID and a few messages differ.

2. Important: limitations and safety

2.1 Motion is on, with a read-only mode for set-up

Started normally, CamCopyM4 can jog and move the machine. A dialog at start says so, and asks you to confirm that the machine is clear and you can reach the E-Stop. Answer No and the program closes without touching the machine.

To work without any risk of motion, start it with the switch /read-only (the installer adds a read-only shortcut). It then only reads Mach4: positions, state and limits. It never jogs, moves, changes an offset or sends G-code; anything that would is refused with a message on Mach4’s status line, so you can set up the camera, the image detection and the viewer, and check the DROs, safely. Stopping is always allowed. The title bar shows [MOTION ENABLED] when motion is on.

2.2 What happens when something goes wrong

2.3 Warning and disclaimer

CamCopyM4 tries to be as reliable as possible, but it operates your machine through Mach4 and its settings. Setting up Mach4, your machine and the camera is your responsibility. You are responsible for checking and testing all signals, for the setup of your machine, and for becoming familiar with the software and its routines.

Machining is dangerous. Even though CamCopyM4 is only a video-probing utility and is not used while cutting, operate the machine as carefully as if you were machining. Keep your hand near the E-Stop whenever motion is enabled. Never place your hands in the machine’s working envelope while video probing. Always turn off or disconnect the spindle motor power when a camera is mounted. Do not video probe at excessive feed rates, and use common sense. By using CamCopyM4 you accept all liability for damage or harm that could be caused by its use, to you and to your equipment. If you do not agree, do not use this software.

CamCopyM4 is still in development. It has been tested to make it as bug-free as possible, but it is not guaranteed to work with every setup. CraftyCNC is not liable for any damage or lost time resulting from its use. UCamCopy, CamCopyM3, CamCopyM4 and CraftyCNC are in no way affiliated with Newfangled Solutions (Mach3, Mach4) or CNCDrive (UCCNC).

3. Requirements and installation

3.1 Mach4

CamCopyM4 talks to Mach4 through Mach4IPC.dll, which is part of every Mach4 installation. It has been checked against Mach4 4.2.0.4612 and 4.2.0.5036 (Mach4 Hobby). Other 4.2.x builds are likely to work but have not been tried. The program is a 32-bit (x86) program, which is what Mach4IPC.dll needs; it runs on 32-bit and 64-bit Windows. You need the .NET Framework 4.0 or later, which every current Windows has. Mach4 must be running, with your profile loaded, before you start CamCopyM4.

It was developed and checked on a router profile in inches (Mach4Router). Other profiles and controllers should work the same, because the program uses Mach4’s own jog and motion functions.

3.2 Equipment

You need a video camera connected and configured on the PC that runs CamCopyM4. Notes on the camera:

• Resolution is not very important. CamCopyM4 opens most cameras at 640 × 480 pixels, which is enough; higher resolutions only slow down the image processing and the frame rate.
• A frame rate of 30 frames per second is desirable. Frame rate matters more than resolution.
• Cameras with built-in lighting that can be dimmed work best.

See the appendix for the camera I use and what I do not recommend.

3.3 Installing

Run CamCopyM4-2.400-Setup.exe (it needs administrator rights). It asks for the folder for the program (default C:\CamCopyM4; use a folder you can write to, because your settings and recordings are kept below it) and adds Start Menu shortcuts: CamCopyM4, CamCopyM4 (read-only) and the manual. Nothing is installed into Mach4, and no Mach4 setting is changed.

Silent install: CamCopyM4-2.400-Setup.exe /S /D=C:\CamCopyM4 (/D must be last, without quotes). The installer never touches your settings and recordings, and the uninstaller keeps them too.

Before the first real use, run CamCopyM4.exe /probe with Mach4 running. It writes Mach4Probe.txt next to the program, a read-only report of what Mach4 answers (positions, velocities, signals). Nothing moves. The report is also what to send if something does not behave.

4. Trial and licensing

CamCopyM4 installs in a demonstration mode. In Demo Mode all features are fully functional for a trial period, so that you can try it before buying. The window title bar and the About tab show the current status.

To get a license, send an email asking to purchase one, and include the License ID shown on the About tab. It looks like 1a2b3c4d5e6f7a8b9c0d_Mach4: a 20-character code followed by the fixed word Mach4. The code is made from the computer ID that Mach4 reports for this PC (the same ID as the MAC: line in Mach4’s Licenses\Mach4Lic.dat). A Mach4 license holds no name, so the ID has none either. After payment, a passkey for that ID is emailed to you. Enter it in the Passkey box on the About tab and click Validate License Key. The status then shows Licensed.

• Mach4 must be running when you open the About tab, because the ID comes from Mach4.
• The license is tied to the License ID, so it follows the PC (the Mach4 computer ID), not the Mach4 profile or the CNC controller. If the computer ID changes, a new passkey is needed.
• The license never expires, does not need an internet connection, and updates never require a new license.
• The trial lasts 20 days. A license for CamCopyM4 is separate from the one for UCamCopy for UCCNC and for CamCopyM3.

The Check Online for New Version button on the About tab compares your version with the latest one on the CraftyCNC website.

5. Starting CamCopyM4 and the machine controls

5.1 Starting

1. Start Mach4 and load your profile. Wait until it has finished loading.
2. Start CamCopyM4 (or its read-only shortcut for set-up and viewing, section 2.1).
3. If Mach4 cannot be reached, a dialog explains why (for example that Mach4 has not finished loading, or that the Mach4IPC.dll does not match your Mach4, section 3.1) and offers Retry.
4. A dialog asks you to confirm. Make sure the machine is clear and you can reach the E-Stop, then answer Yes.
5. The main window and the 3D viewer open, and the status line says which Mach4 and which Mach4IPC.dll are in use.

Nothing moves while Mach4 is in E-Stop or while its control is not enabled (the same state as Mach4’s Enable button being off). Enable Mach4 first, then jog or run.

5.2 What the buttons do in Mach4

5.3 Jogging

Each axis is jogged by Mach4’s own velocity jog at a rate that is a percentage of the axis’s maximum velocity, so X and Y can run at different speeds together. The jog panel on the right of the main window has Continuous (hold the button) and Step (a fixed distance; it runs to its target and does not stop on release). Moving by hand with the jog panel works the same as with Mach4’s own keys; CamCopyM4 does not take over Mach4’s jog keys, so do not touch them or a pendant while Run is on.

5.4 Speed limits and very slow moves

The top speed per axis is read from Mach4: the slowest motor driving the axis, converted from counts per second using the motor’s counts per unit. If Mach4 does not report one, the switch /maxvel=NNN (units per minute) supplies it; it is also the number the feed rate is turned into a percentage with, so it should be the real maximum.

Mach4 refuses to start or stop a jog while the jog rate is below about 0.05% of the axis maximum, and an idle axis does not move at all below roughly 0.15 units per minute. The PID asks for such tiny speeds when it settles on a target, so CamCopyM4 starts a jog at no less than 0.1% and stops at no less than 0.5%, lowers the rate after the start, checks every call, and retries a refused stop. The practical effect: very slow corrections at the very end of a move may be ignored, which is harmless. Mach4 remembers the jog rates, so CamCopyM4 puts your original jog rates back when it closes.

5.5 The E-Stop button

The E-Stop button in the main window is a toggle. Not in E-Stop, it stops all jogs and puts Mach4 into the not-enabled state, which is the same as pressing Mach4’s Enable button off. In E-Stop (or not enabled), it asks you to confirm and then enables the control again and waits up to 1.5 seconds for Mach4 to follow. If a hardware E-Stop input keeps Mach4 in E-Stop, it says so. The button flashes while Mach4 is in E-Stop or not enabled.

5.6 Closing

Close CamCopyM4 with its window close button. Any jog is stopped first, and Mach4’s jog rates are put back. Settings are saved if Auto Save is on (section 18).

6. The windows

CamCopyM4 is made of two main windows, plus a few settings windows:

• The main window, with the camera view, the controls and the DROs.
• The 3D viewer, which shows the recorded geometry and the camera position, and is also a basic DXF editor.
• The settings windows: Image Detection, Offset & Velocity and General Settings for the main window, and a settings window for the viewer.

Windows snap to one another when you drag them close together. When the viewer is stuck to the main window the pair moves as a group if you drag the main window; grab the viewer and pull to unstick it. CamCopyM4 works best at a screen resolution of 1280 × 1024 or higher.

6.1 Settings windows

The settings are not in tabs under the video any more. They are in separate windows that you open from the Settings menu, the first item of the menu strip above the camera view:

The windows have a blue frame, can be dragged anywhere (also onto a second monitor), and remember where you left them. They snap to the other CamCopyM4 windows too. Closing a window only hides it. The viewer has its own settings window, opened from its toolbar.

6.2 Hiding panels

The side panels can be tucked away to give the video more room. The small arrow buttons on their edges (labelled Hide / Show) slide a panel away and bring it back. The viewer has the same strips for its two right-hand panels (Hide DRO / Info and Hide Layers / File Info). Which panels are shown, and how wide they are, is remembered.

The E-Stop button flashes while Mach4 is in E-Stop, so it is hard to miss (section 5.5).

7. The main window

The main window gives access to all of CamCopyM4’s features, laid out like a CNC control screen:

• Top panel: DXF and CSV recording controls (section 15).
• Left panel: camera selection and controls, the image view selection, and the mask settings.
• Right panel: axis DROs, work-coordinate selection, and the jog and Move To controls.
• Bottom panel: detector selection, velocity (feed rate) and the Run/Stop button, and the E-Stop button.
• Central area: the video view.
• Menu strip: Settings, Special Operations and Configuration Help.

7.1 Special Operations and Configuration Help

The Special Operations menu holds the arc/circle collection dialog (section 12.3) and the G68 rotation setup. The Configuration Help menu opens two guides that walk you through the first setup: camera alignment, and calibrating axis velocity (section 13).

8. Quick start

This is the shortest path from an unconfigured install to a traced part. Each step is described in detail in the later sections.

1. Start Mach4, then start CamCopyM4 (section 5).
2. Select your camera in the left panel and start it. Check focus and lighting in the Camera Capture view.
3. Align the camera so that image-up is Y+ and image-right is X+, using the Configuration Help → camera alignment guide (section 13).
4. Set the PID gains with a dot on a piece of paper (section 13.3). Do this once per machine and camera zoom.
5. Put the part under the camera so the edge to trace is in view, open Settings → Image Detection and click Auto Tune (section 10).
6. Select Lines / Edges, check that the mask shows a single clean line with a target dot at each end (section 11).
7. Click the DXF button on the top panel so it shows DXF ON (section 15).
8. Press Run (or the space bar) to start tracing, and press it again to stop.
9. Click Save DXF.

9. The camera and the image views

The left panel controls the camera and selects which stage of the image processing is displayed.

• The pull-down at the top selects your camera. CamCopyM4 remembers the last camera you used and selects it again next time; the camera starts automatically when it is found.
• If you plugged the camera in after starting CamCopyM4, click the refresh button to add it to the list.
• The start button starts the camera and the stop button stops it.
• Flip Vert and Flip Horiz are only needed in rare cases where the camera produces a reversed image.

The Use HSV color for edges and detections checkbox (in the Image Detection window, next to Auto Tune) makes CamCopyM4 use color information instead of grayscale to find edges. This helps when your part looks similar to its background in grayscale. It is always better to create a color or shade difference yourself, for example by placing the part on light or dark paper.

9.1 Zoom and field of view

I usually zoom in so that about 1 cm (0.5 inch) spans the width of the camera view. Even with 640 × 480 pixels that gives less than 0.001 inch (0.015 mm) per pixel, which makes CamCopyM4 accurate without any calibration.

9.2 How the image is processed

EMGU/OpenCV captures the video and runs several steps to find lines, edges and circles:

Grayscale flow (HSV off): Capture → Grayscale → Blur → Mask (narrow region of the image) → Canny filter (edge detection) → Detections → output to drive the machine.

HSV color flow (HSV on): Capture → HSV conversion → Blur → Mask → Canny filter → Detections → output to drive the machine.

The Select View options let you look at each stage, so you can set thresholds more easily. During normal operation you will leave Composite Output selected.

9.3 The image views

The pictures below all use the same example part so you can compare the stages.

Camera Capture

The original, unmodified camera image. Use it to check lighting and focus.

Mask Only

A black and white picture of the mask. Image processing is limited to what falls in the white area.

Edges (Canny)

The most important view. It shows the edges the program finds after processing the image inside the masked region (yellow outline). Use the Edge (Canny) Threshold values and Thicken Edge (Canny) Lines to filter the edges until you get a strong, clean result like this one.

Gray / Blurred

The grayscale image with blur applied. Available only when HSV is not checked. Adjust the Blur Amount in the Image Detection window to remove noise: too much blur makes edge detection difficult, too little leaves a lot of noise.

HSV Original

The original image converted to HSV color space and blurred. This can separate the image much better than grayscale, but needs extra thresholds to isolate the area of interest.

HSV Threshold

The HSV image needs the Color Detection Thresholding sliders adjusted. On the left below there are no thresholds and the areas are not separated well enough to detect an edge; on the right the thresholds give a clear edge.

Composite

The final image, with overlays of the DROs and cross-hairs (if turned on) and the detections that drive the machine. The dark blue arrow is the direction the machine moves when Run is on. Red points and light-blue lines are the detected edges and the endpoints used to calculate the movement.

Multiple View

Shows the four most useful views at once, so you can adjust thresholds without switching back and forth. With HSV on you see the HSV image, HSV threshold, masked Canny edges and composite output; with HSV off you see the gray image, gray threshold, masked Canny edges and composite output.

10. Image detection and Auto Tune

Open Settings → Image Detection. The window opens in a Simple view that shows only what most people need: Auto Tune and its Undo button, the Use HSV color checkbox, the blur value, the Canny low/high thresholds and, when HSV is on, the HSV color range sliders. Tick Advanced settings to show every detection setting.

10.1 Settings

The line-detection values (Advanced view) control the line detectors and the line-merging algorithm:

• LineThresh: the “quality” a line needs to be accepted. Raise or lower it.
• LineMin: the minimum length of a line that can be found.
• LineGap: the maximum gap in a line before the detector treats it as two lines.
• DistThresh: the maximum gap between two similar lines before CamCopyM4 tries to merge them (lines that overlap have a gap of zero).
• AngThresh: the maximum angle between similar lines before they are merged. Direction does not matter; a line and its reverse count as the same angle.
• CoLinThresh: the maximum sideways offset (“colinearity”) between lines before they are merged. Parallel edges farther apart than this are not merged.
• Rho: leave near 1; it sets the minimum line width, in pixels, for the line detector.
• 1/Theta: leave near 180; it is how many angles the line detector samples. Lower numbers filter out more lines.

10.2 Auto Tune

Finding good blur, Canny and line-detection values by hand can take a while. Auto Tune sets them for you with one click.

1. Start the camera and put the part under it so that the edge you want is in view. If you use HSV color detection, put the target color at the center of the image first.
2. Click Auto Tune. It samples a few live frames and tries different blur sizes (and, in HSV mode, different color-range widths). It scores each one by how continuous the resulting edge is and how strong the real image contrast under it is, then fills in the blur, Canny low/high, HSV range and line-detection values with the best result.
3. A message reports the edge score before and after, and asks whether to keep the new values. Choose Yes to keep them or No to leave your settings as they were.
4. The Undo button beside Auto Tune puts the previous settings back after you have kept a tune. It is greyed out until a tune has been kept.

Auto Tune needs the camera running (it asks you to start it first). You can still adjust any value by hand afterwards.

11. Masking

The mask limits the part of the image that is used for detection. It has two shapes (round and rectangular) and an adjustable size. When you edge-trace, the size and shape of the mask are important: they reject noise and keep the tracing on course. The mask follows the angle of the edge it finds, which helps with steering. Items inside the white area of the mask are “seen”; items in the black area are rejected.

• The round mask usually gives better results around sharp corners because it can see to the sides and a little to the rear.
• The rectangular mask is better for gradually curving shapes because it looks mostly straight ahead.
• Mask Max Angle Delta sets how quickly the mask can rotate from one video frame to the next. A value of 1 lets the mask swing only 1 degree per frame (lots of damping); 30 lets it swing 30 degrees (little damping). Lower values calm things down when the image is noisy.

When edge tracing, your goal is to adjust the image and the mask until you have essentially a single line with a target dot at each end inside the mask. That is the line that will be followed.

12. The detectors

The detector buttons in the bottom panel choose what CamCopyM4 looks for:

12.1 Lines / Edges

The detector you will use most, for auto-tracing the outside edges of objects. It needs a clear edge in the image and a mask that limits detection to the area of interest.

You choose the direction the machine travels around the perimeter by double-clicking the image to re-orient the mask in the opposite direction:

You may have to help by positioning the part so the edge is initially centered, and by orienting the mask. In the next picture the edge is in the right place but is not detected, because the mask is not oriented over the edge:

Edge tracing

When you are calibrated and ready to trace: switch to line mode, jog until the cross-hair is over an edge, and adjust the image and the mask until you have a clean line with target dots at both ends. The mask aligns itself with the edge and can go either way around the part (clockwise or counter-clockwise makes no difference). Double-clicking near the center of the image re-orients the mask direction.

You can start and stop the velocity and move around as needed to cover all the edges. If the line is lost or the machine gets off track, stop the velocity, jog back into place, adjust the video and mask, and enable velocity control again.

• Auto stop after loop: after a full loop around a profile, velocity stops by itself and waits for you to move to a new edge and start again. It also breaks the line when it triggers.
• Auto Close Shape: tries to close the shape with a line between the start and end points after a lap that auto-stops where it started.
• Point Sample Distance: how far apart recorded points are along the edge (see section 15).

12.2 Intersections

When enabled, the detector looks for the two most prominent lines in the image and uses their intersection as the target. Turn the mask off.

12.3 Circles and arcs

There are two ways to deal with holes and circles.

Circle detector

If the hole is small and fits completely in the camera view, select the circle detector and the machine drives to its center point. It only finds a location; the size of the circle cannot be determined from the camera image alone. Adjust the Circle Threshold until you get a reasonable detection (it may bounce around quite a bit). In the picture, the red dot is the center target and the dark blue arrow is where the machine will drive.

Arc or Circle From Points dialog

For geometry that is too big for the camera view, open Special Operations → Arc or Circle From Points. The dialog helps you collect circles and arcs into the DXF or find sizes and center points.

Follow the prompts: jog to at least three locations on the arc or circle and click Sample Point at each. With three points the center and the diameter/radius are calculated and shown. You can collect more points for a least-squares fit, and then use the result to:

• move to the center only,
• move to the center and zero X/Y there, or
• save the arc or circle to the DXF data.

For an arc you can only use three points: sample one end, a point along the arc, and then the opposite end.

12.4 Contours (enclosed shapes)

Similar to the circle detector, but it finds shapes that are not perfect circles more easily. It is the detector I recommend when calibrating, because it is more reliable and stable than the circle detector and has no threshold to adjust.

13. Velocity control and PID tuning

Before going far with CamCopyM4, set up the PID controllers (proportional / integral / differential) that drive the axes together with the velocity you choose. They are on the Offset & Velocity settings window (Settings → Offset & Velocity).

13.1 Setup helpers

Under the Configuration Help menu, camera alignment and Calibrate Axis Velocity open guides that walk you through the initial setup.

Key points:

• You must set up and orient the camera so that image-up is Y+ and image-right is X+ (the normal coordinate system, matching your machine).
• Align it squarely so that when you move in X only or Y only, the cross-hairs follow the axis as closely as possible. Use a reference mark such as an existing cut in your spoil board to check.
• To run the calibration you need to set up the camera and a detector that can find a dot on a page to use as a target (see section 12).

13.2 Velocity control mode

13.3 PID values

PID is a classic negative-feedback control (servos, thermostats and so on). In CamCopyM4 it looks at the error in the camera image — how far the center of the picture is from a defined target — and sends velocity commands to Mach4 to drive that error to zero. kP, kI and kD are gain coefficients. They must be set before you let CamCopyM4 control your machine.

• Set them so the machine runs to a target and settles without overshoot or oscillation.
• kP (proportional): set this first, to a value that just stops oscillating when the target is reached.
• kI (integral): I recommend leaving this at zero.
• kD (differential): add a small amount after setting kP, to help stabilize the control.
• If you use centering, set the same kP, kI and kD for the centering part, and reduce its Output Limit % (I suggest 10–20%).

The total gain fed to the machine is the combination of the maximum velocity you enter and the PID gains for the normal and center PIDs. If gains are too high the machine oscillates; if too low, it is slow and the following error grows, which turns into measurement error.

Tuning procedure

Place a small dot on a piece of paper as a target, then:

1. Turn off Lines / Edges and turn on Contours. When the dot is detected, a target dot appears at the center of the outlined dot. Make sure the mask is off.
2. Enable only the X PID first (leave the Y PID off with its enable checkbox). The kP, kI and kD values apply to both axes equally, but it is easier to watch one axis at a time.
3. Jog to one side of the contour (left or right).
4. Enter a starting value for kP, and leave kI and kD at zero.
5. Click the Run button. The machine should move the center of the dot to the center of the screen and stop. Turn Run off.
6. If the machine goes in the wrong direction, stop and check the camera orientation and your axis definitions.
7. If it goes to the center and stops without oscillating, try a larger kP. If it overshoots and swings back and forth, reduce kP and try again.
8. When kP is just starting to cause a small overshoot, cut it in half.
9. Enable the Y PID as well and check that it settles similarly. Reduce the gain if Y oscillates.
10. Run X and Y together and check that the machine centers on the dot while both axes move.
11. Leave kP alone and repeat the process for kD only.
12. Until you are tracing real profiles and watching the line-following behavior, leave kI at zero. It is used to eliminate overall following-error offsets.

When it works, the target dot is brought to the center of the view and stops without oscillating. You can then change the values, jog off center and run again to test them. You want the machine to snap quickly to the dot without oscillating or overshooting.

13.4 Update rate

The PID Update Rate (in ms) is how often the PID loops are calculated and velocity commands are sent to Mach4. I suggest about 100 ms (10 times per second). It should be slower than the camera’s frame rate by about 50%. For example, a camera running at 15 fps delivers a frame every 67 ms (1/15 = 0.067), so set the update time larger than that; 100 ms gives 10 updates per second. If your camera has a consistently high frame rate you can decrease the value: 50 ms (20 Hz) works with a 30 fps camera.

You can see the real frame rate in the status messages at the bottom of the window:

• Act FPS is the frame rate the camera is running at. Use it to choose the update rate.
• Process FPS is the rate at which the image processing runs. If it is lower than Act FPS, the bottleneck is the computer, not the camera, and a faster camera will not help.

14. Running: Run/Stop and recording

CamCopyM4 does not run routines step by step like a touch probe. Instead you use the Run/Stop button to give CamCopyM4 control of the axes or to take it away.

• When the button is green, CamCopyM4 is in control of jogging the machine and will try to jog toward a target found in the camera image. When red, CamCopyM4 is stopped and has no control. The space bar also toggles it.
• Feed rate is the velocity value next to the button. You can change it on the fly: type a new value or use the arrows while Run is on, and the new feed rate is used straight away. You do not need to press Run/Stop to stop and restart first.
• Moves happen only when a target is found. Even with Run on, nothing moves until a target is detected, as shown by overlays of a target point and a move vector:

If there are no targets, jog the machine by hand to bring one into view. If the target is in view but not detected, adjust the image and the detections until it is.

Machine moves can be aborted, and fail safe: if Mach4 is in E-Stop or refuses a move, CamCopyM4 stops rather than guessing.

14.1 Working on one file

Once you have opened a file to record to, you can start and stop recording as often as you like. For example, you can record some perimeter feature (click Abort to stop), record a bore or edge feature elsewhere, set a new Z location, go back and record another perimeter, all to the same file. When you are done, save it all with Save DXF.

15. DXF and CSV recording

The top panel controls recording of DXF or CSV data, opening, saving and closing files, choosing the DXF layer to record on, and so on.

You can also record points manually and choose whether each point is joined to the previous one by a line (line join / break).

The Point Sample Distance is used during auto edge tracing and sets how far apart the recorded points are, which controls the resolution of the edge: a smaller number means finer resolution. Edges are recorded as points joined by straight lines. You can fit this data to polyline curves in your CAD or CAM software afterwards.

CamCopyM4 records to a CSV (comma-separated values) file that Excel can import, to a DXF file, or to both at once. Files are stored in the output folder inside the program folder, next to CamCopyM4.exe (section 18.4).

15.1 Starting a recording

Turn on the CSV checkbox, the DXF checkbox, or both. You are prompted for a file name; if you select both, the name is used for both formats. Once the DXF or CSV button shows ON and a name has been entered, you only have to trace the part: all data is recorded until you close the file. Starting a DXF recording creates (or selects) the DXF layer for you; use the Active Layer selector to record to a different layer.

15.2 Open

If no DXF data has been recorded, Open opens an existing DXF file. You can open several files, which are appended together; new data you collect is merged into them. When you save, you can overwrite or save under a new name. As soon as a file is opened or data is recorded, the button works for saving until you clear the DXF buffer or save the file.

15.3 Empty and Close

While a recording option is on, data keeps being collected and appended internally. After you finish probing a part, click Close DXF to close the file (you are asked to save if you have not). To throw away data you do not want, click Empty DXF, which clears it without saving.

15.4 Save DXF

You can click Save DXF at any time to make sure the results are on disk. If there is no file name yet you are prompted for one; if CSV and perimeter files are selected, they are saved with the same name as the DXF. Once the file has a name it is displayed, so you can confirm where the data is going.

15.5 Save As

To save the DXF data under a different name, use Save As on the viewer toolbar (or Save As… in the viewer’s right-click menu). Unlike Save DXF it writes the file whether or not the DXF button shows ON, and the new file becomes the current file, so a later Save DXF goes there (section 16.9).

16. The 3D viewer and DXF editing

The viewer shows the point cloud and DXF data measured and recorded while you probe, and the camera position in real time. It also shows information about the DXF, lets you control the layers and colors and choose the active layer to record on, and is a basic DXF editor: you can pick, delete, move to another layer and draw lines. Colors and visibility are set by you.

16.1 Window layout and panels

• Toolbar along the top: Open (a DXF, an STL for viewing only, or clear the view), Save As, Display Options, View (Top, Front, Right, Isometric, Isometric2), a pin button that keeps the viewer on top, Fit, Settings (opens the viewer settings window), and the DXF tools: Delete, Undo, Redo, Select, Zoom Box and Draw Line.
• DRO / Info panel: the axis DROs, with the E-Stop button and the velocity Run/Stop button. E-Stop flashes while active.
• Layers / File Info panel: the layer list for the DXF with the active layer, and below it a text summary of the loaded DXF: how many entities of each type, and the layers with their entity counts.
• Status bar along the bottom: what you picked, what Draw Line is snapping to, and what an edit just did.

Each of the two right-hand panels has a vertical Hide / Show strip beside it. Click it and the panel slides away to give the 3D view more room; click again to bring it back. Drag the left edge of a panel to make it wider or narrower. Which panels are shown, and how wide, is remembered the next time the viewer opens.

16.2 Moving around the view

• Pan: hold the left mouse button and drag.
• Rotate: hold the right mouse button and drag. The view turns around the point that was under the cursor when you started, and a dot marks that pivot while you rotate.
• Zoom: turn the mouse wheel.
• Reset the view: press R with the pointer over the 3D view.
• View menu and Fit: jump to the Top, Front, Right, Isometric or Isometric2 view, or fit everything in the window.

A short right-click that does not drag opens the right-click menu instead of rotating.

16.3 Selecting entities

Click a line, circle, arc or polyline to select it. It is drawn in the Selection Color (cyan by default) and its layer and coordinates are shown in the status bar. Before you click, the entity under the pointer is drawn in the Hover Color (orange by default). Open shapes (lines, arcs, open polylines) show a green Start dot and a red End dot, and an arc also shows a blue Center dot. Closed shapes such as circles have none of these.

• Add to the selection: Ctrl-click or Shift-click an entity to add it, or to remove it if it is already selected.
• Select tool: click Select on the toolbar, then drag a box in the view to select every entity that touches the box. Hold Ctrl or Shift to add to the selection, or Alt to remove from it. Click Select again to turn the tool off.
• Zoom Box tool: click Zoom Box, then drag a box. The view zooms to it and the tool turns itself off.
• Clear the selection: press Esc.

While Select or Zoom Box is on, dragging draws the box instead of panning the view.

16.4 Delete, Undo and Redo

With entities selected, click Delete (or press Delete) to remove them from the DXF data. Undo (Ctrl+Z) takes back the last change and Redo (Ctrl+Y or Ctrl+Shift+Z) puts back what you just undid. The history covers deleting entities, drawing lines and moving entities to another layer, one change at a time. A new change clears the Redo history, and opening or clearing a DXF clears both.

Any edit marks the DXF as having unsaved changes, so the Save button on the main window becomes available.

16.5 Draw Line

Draw Line adds new lines to the DXF by clicking in the view. Click Draw Line on the toolbar (the button stays highlighted while the tool is on), then:

1. Click the start point. A green dot marks it.
2. Click the end point. A line is added, and its end point becomes the start of the next line, so you can keep clicking to draw a connected series. A rubber-band line follows the pointer from the start dot.
3. Press Esc once to end the series (then click a new start point), and Esc again to leave the tool. Clicking the Draw Line button again also turns it off.

Snapping: when the pointer is within about 12 pixels of the start or end of an existing line, an orange dot appears on that endpoint and the status bar names it. The point you click is then exactly that endpoint, so lines join cleanly. Away from an endpoint the point is where you click, at Z = 0. Only the endpoints of lines are snap targets; arcs, circles and polylines are not.

New lines go on the active layer (shown in the Layers panel; one is created if there is none). Each line is one Undo step. Pan, rotate and zoom still work while the tool is on. Use the Top view for drawing: in an edge-on view such as Front or Right a click cannot be placed on the Z = 0 plane.

16.6 Layers and Move to Layer

The layer list has these columns: Vis (click to show or hide the layer), Col (double-click to change its color), Del (delete the layer and its entities, after a confirmation), Layer Name (edit it to rename the layer) and Cnt (the number of entities on it). Add Layer creates a new layer and Refresh Layer List rebuilds the list. The Active Layer is the one that newly recorded data and newly drawn lines are put on. Layer names must be unique (upper and lower case count as the same): a name that is already in use is refused, both for a new layer and when renaming.

To move entities to another layer, select them, right-click one of them, choose Move to layer and pick the destination layer. The entities keep their positions; only their layer changes. They stay selected so you can see the result, and Undo moves them back. If the layer you want does not exist yet, create it first with Add Layer or New Layer… in the right-click menu.

To make a new layer, click Add Layer (or choose New Layer… in the right-click menu). CamCopyM4 asks for a name, then for a color. If you cancel the color dialog the layer is still created.

Moving entities, step by step: first select them (here part of the red Tri layer is selected, shown in cyan), then right-click one of them and open Move to layer, which lists every layer. Pick the destination.

16.7 Right-click menu

Right-click (without dragging) in the 3D view to open a menu. If you right-click an entity that is not selected, it becomes the selection; if it is already part of the selection the whole selection is kept, so you can act on a group. The menu has:

• Delete (n): deletes the selected entities (n is how many are selected).
• Move to layer: a list of the layers in the DXF; the selection moves to the one you pick.
• Draw Line: turns the Draw Line tool on or off (checked while on).
• New Layer…: the same as the Add Layer button.
• Undo and Redo: step back and forward through your changes.
• Clear selection: the same as pressing Esc.
• Zoom to fit: the same as the Fit button.
• Save As…: see section 16.9.
• Settings…: opens the viewer settings window (section 16.8).

Entries that do not apply, such as Delete with nothing selected, are greyed out.

16.8 Viewer settings

The Display Options menu turns the Axis / WCS indicator, the grid and the current-position marker (Show Cur. Position) on and off. The colors and sizes are in the viewer’s settings window, opened from the toolbar. Its groups are collapsible; Viewer Colors and Sizes are open by default.

• Viewer colors and sizes: WCS Size, Probe Cone Size, Probe Tip Color, Selection Color, Hover Color and Background Color.
• Grid: Grid Span, Increment, Line Width, and the X and Y Gridline Colors.
• Point Markers: Dot Size (in pixels) for the round Start, End, Arc center and snap dots, and the color of each. The markers keep the same size on screen at any zoom. The same group sets the color and size of the dot shown at the pivot while you rotate.
• DXF Colors & Display: Point Size, Show Line End Points?, Point Color and Line Thickness for the DXF data.

Click a color swatch to change that color. The settings are saved with the viewer settings when you click Save Settings on the main window.

16.9 Saving a copy of the DXF (Save As)

Click Save As on the viewer toolbar, or Save As… in the right-click menu, to save the DXF data to a new file. The save dialog opens in the folder of the current file with its name filled in, ready to change. The data is written whether or not the DXF button on the main window shows ON, and the new file becomes the current file: the name shown on the main window changes to it, and a later Save DXF goes there. The original file is not changed. Save As writes only the DXF; the CSV and perimeter files are written by Save DXF.

17. Camera / spindle offset

You will most likely have the camera side-mounted to your spindle. The offset controls (in Settings → Offset & Velocity) let you set the offset between the spindle and the camera and then toggle the machine from one position to the other.

This is a good setup tool: use the camera and cross-hairs (or the detectors, or the arc/circle routines) to locate the origin you want, then move the spindle to that location and zero the DROs.

Each session, the first time you zero an axis or use a button to move between the spindle and the camera, you are asked which position you are currently using (camera or spindle). From then on the buttons only toggle between the two.

18. General settings, settings files and backups

18.1 General Settings window

Settings → General Settings holds the options that are not about image detection. They are in collapsible groups in two columns; whether each group is open is saved with your other settings.

18.2 Saving settings

Click Save Settings on the main window to save your settings (the controls of the main window and the settings windows, and the viewer settings). Settings are only saved when you click the button, plus an automatic save when CamCopyM4 closes if Auto Save is on and the settings loaded properly. If the settings could not be read when CamCopyM4 started, nothing is auto-saved over them.

18.3 Defaults

The first time CamCopyM4 runs with no saved settings, it asks whether you work in inch or metric and loads matching starting values. You can also choose a settings file instead. The starting values are sensible first-pass settings for both the main window and the viewer; the metric set has the feedrates and lengths converted (for example the probing velocity is 102 mm/min instead of 4 in/min, and the viewer’s grid is 127 mm across instead of 5 in). Please check the values against your machine, camera and zoom, especially the PID gains (section 13).

• Set Defaults – INCH and Set Defaults – MM (General Settings, Defaults & Backup) load those starting values again at any time. They also reset the viewer’s grid, marker and color settings, so use them with care.
• Save current as defaults… keeps your current settings (main window and viewer) as the starting values for inch or metric, whichever you choose in the dialog. Your own defaults are used before the built-in ones.
• After loading defaults, click Save Settings to keep them.

18.4 Where the files are, and backups

Everything is in Settings\, a folder that CamCopyM4 creates next to CamCopyM4.exe:

Settings are written safely (a new file is written and checked before it replaces the old one), and a settings file that cannot be read is never overwritten by the defaults.

Restore from backup… (General Settings, Defaults & Backup) lists the backups and puts the one you choose back.

19. Troubleshooting

Appendix: reference, switches, versions and cameras

A. Viewer shortcuts

B. Files and folders

Next to CamCopyM4.exe (the folder you installed it in):

C. Command-line switches

D. Version history

V2.400 — CamCopyM4 first release

The Mach4 edition of UCamCopy, built on the same code as UCamCopy for UCCNC: the main window, image detection and Auto Tune, the PID velocity control, DXF and CSV recording, the 3D viewer and DXF editor, and the safer settings files. Mach4 is driven through Mach4IPC.dll with no Mach4 plugin: per-axis velocity jog, step moves, G-code, work-coordinate selection, DRO setting through G10 L2, safe Z, and G68/G69. Motion is on by default, with a /read-only switch for set-up. The E-Stop button asserts (disables the control) and clears.

The history of the shared program before this release is in the manual for UCamCopy for UCCNC.

E. Cameras and FAQ

Cameras. I cannot make a direct recommendation on brand or model since I have only tried a few. In general, look for one that advertises 30 fps and has adjustable focus done with a knob at the back end.

What camera do I use? The one below, bought on Amazon. It is also sold by Oasis Scientific as model V1-PS.

Things I like:

• The focus knob is tight and holds its adjustment.
• Built-in LED lights with adjustable brightness.
• A solid 30 fps when the lighting is good. If lighting is bad, the frame rate drops to about 10 fps.
• Good image quality and color.
• 1600 × 1200 images are available for other tasks (such as using it as a real microscope); CamCopyM4 only works at 640 × 480.

Things I do not like: some background noise in the image, but I think that is common with all cameras of this type (CMOS sensors).

Any camera I absolutely do not recommend? Yes: the type with a focus wheel near the lens instead of at the back. The lens has play, so the image moves around and the focus does not stay adjusted. It is fine as a real microscope but does not work well mounted on a CNC. This type also had a lower frame rate and a noisier image, and a maximum resolution of only 1920 × 1080.

CamCopyM4! Copyright 2023–2026 by Crafty CNC / Eric Brust. www.craftycnc.com