Arc Creation Guide

Back to App

Creating Arcs in the Template Designer

Introduction to Arcs

Arcs are curved segments in a contour that can be used to create rounded corners, circles, and other curved shapes. In the MDF Door App, arcs are defined using the following parameters:

  • End Point (X, Y, Z): The destination point where the arc will end.
  • Center Point (I, J): The center of the circle that defines the arc.
  • Radius (R): The distance from the center point to any point on the arc.
  • Direction (DS): Defines how the arc should be drawn (clockwise or counterclockwise).

Direction (DS) Parameter Explained

The Direction parameter controls how the arc is drawn between the start and end points:

0: ≤180° CW

A clockwise arc that is less than or equal to 180 degrees.

Center Start End

1: ≤180° CCW

A counterclockwise arc that is less than or equal to 180 degrees.

Center Start End

2: >180° CW

A clockwise arc that is greater than 180 degrees.

Center Start End

3: >180° CCW

A counterclockwise arc that is greater than 180 degrees.

Center Start End

Step-by-Step Guide to Creating an Arc

  1. Start a contour or continue from an existing segment

    Before adding an arc, you need to have a contour started with at least one point.

  2. Switch to arc mode

    Click the "Arc" button in the drawing mode section to switch from line to arc mode.

  3. Define the end point

    Enter the X, Y, and Z coordinates for where you want the arc to end.

  4. Specify the center point

    Enter the I and J values for the center of the circle that defines your arc. The center point determines how the arc curves.

  5. Set the radius

    Enter the radius value. Note that this should match the distance from the center to both the start and end points.

  6. Choose the direction

    Select one of the four direction options as described above.

  7. Add the arc

    Click the "Add Arc" button to add the arc segment to your contour.

Tips for Working with Arcs

  • For a perfect quarter circle, set the end point at (center.x + radius, center.y) or similar positions.
  • You can use variables in arc parameters, such as setting the radius to a variable value.
  • The start point of your arc is automatically set to the end point of the previous segment.
  • When editing an existing arc, click on it in the canvas to modify its properties.
  • Make sure the radius matches the distance from the center to both the start and end points to avoid errors.

Creating a Full Circle Using Two Arcs

Since the template designer doesn't have a dedicated circle tool, you can create a perfect circle by combining two 180° arcs. This technique is commonly used in CNC programming and CAD systems.

Step-by-Step Instructions

Step 1: Define Your Circle Parameters

First, determine:

  • Center Point: The center of your circle (e.g., X=50, Y=50)
  • Radius: The radius of your circle (e.g., R=25)
  • Starting Position: Where you want the circle to begin (e.g., rightmost point)
Step 2: Create the Starting Point
  1. Click "Add Start Point" button
  2. Set coordinates to: X = centerX + radius, Y = centerY
  3. For our example: X = 75, Y = 50, Z = 0
Step 3: Create the First Semicircle (Right to Left)
  1. Switch to Arc mode
  2. Set End Point: X = centerX - radius, Y = centerY
  3. For our example: X = 25, Y = 50, Z = 0
  4. Set Center Point: I = centerX, J = centerY
  5. For our example: I = 50, J = 50
  6. Set Radius: R = 25
  7. Set Direction: 1 (≤180° CCW)
  8. Click "Add Arc"
Step 4: Create the Second Semicircle (Left to Right)
  1. The starting point is automatically set to the end of the first arc
  2. Set End Point: X = centerX + radius, Y = centerY
  3. For our example: X = 75, Y = 50, Z = 0
  4. Set Center Point: I = centerX, J = centerY
  5. For our example: I = 50, J = 50
  6. Set Radius: R = 25
  7. Set Direction: 1 (≤180° CCW)
  8. Click "Add Arc"
Step 5: Close the Contour (Optional)

If you want a closed circle contour:

  1. Click the "Close Contour" button
  2. This will complete the circle and mark it as a closed shape

Alternative Circle Configurations

Clockwise Circle

For a clockwise circle, use:

  • First arc: Direction 0 (≤180° CW)
  • Second arc: Direction 0 (≤180° CW)
Top-to-Bottom Circle

Start from the top of the circle:

  • Start Point: X = centerX, Y = centerY + radius
  • First arc end: X = centerX, Y = centerY - radius
  • Second arc end: X = centerX, Y = centerY + radius

Using Variables for Parametric Circles

You can create parametric circles using variables:

  1. Define variables: CX (center X), CY (center Y), R (radius)
  2. Start Point: X = CX + R, Y = CY
  3. First Arc End: X = CX - R, Y = CY
  4. Center Points: I = CX, J = CY
  5. Radius: R = R
  6. Second Arc End: X = CX + R, Y = CY

This allows you to easily modify the circle size and position by changing the variable values.

💡 Pro Tips

  • Both arcs must have the same center point and radius for a perfect circle
  • Use the same direction (both CW or both CCW) for both arcs
  • The end point of the first arc becomes the start point of the second arc automatically
  • You can create circles of any size by adjusting the radius value
  • For very large circles, consider using the ">180°" direction options instead

MPR File Format for Arcs

When exported to an MPR file, arcs are defined using the KA descriptor with the following parameters:

$E2
KA
X=1400
Y=0
DS=0
R=B/2

Where:

  • X, Y, Z: End point coordinates
  • I, J: Circle midpoint coordinates
  • DS: Rotary direction (0=≤180° CW, 1=≤180° CCW, 2=>180° CW, 3=>180° CCW)
  • R: Radius

Advanced Arc Examples

Here are some common arc patterns you might want to use in door designs:

Rounded Corner (90° Arc)

To create a rounded corner with a 20mm radius:

  • End Point: (X+20, Y)
  • Center Point: (X, Y)
  • Radius: 20
  • Direction: 0 (≤180° CW)

Semi-Circle

To create a semi-circle with a 50mm radius:

  • End Point: (X+100, Y)
  • Center Point: (X+50, Y)
  • Radius: 50
  • Direction: 1 (≤180° CCW)
Return to Template Designer