In this tutorial we will understand how we can sketch the arcs and Ellipse. Let’s start with Ellipse.
The Ellipse Tool
In Creo Parametric there are two ways to make an ellipse and they are as follow:
- Ends and axis
- Center and Axis
Axis and Ends Ellipse
First select axis and ends ellipse option then make a click in sketching plane. This will be the starting point of your axis. Now make a suitable length of axis and click again to make the end point of axis. The method of sketching axis is just like sketching a line. Now move the mouse cursor about the axis, you have just made, and you will see an ellipse is going generated in this cad software.
Center and Axis
After selecting this tool option, You need to point a center of an ellipse and then you need to make a suitable length of axis. Make a first click this will be the center of ellipse and then move the cursor along any direction, with in suitable length, to draw the axis and make second click. Now move the cursor about the axis and you will see the ellipse. Make it suitable in size and then make third click to complete the tutorial. In the following fig (left) the cross sign “x” is pointed to the center of ellipse.
The Arc tool
Arcs can be sketched in different ways in Creo elements. First let me listed all ways and then we will start understanding each one by one.
- 3-point / tangent End
- Center and End
- 3 Tangents
- Concentric
- Conic
3-point / tangent End
As name suggest you need to draw three points at different locations to make this type of Arc. After selecting the tool you will need to make start point by clicking in sketching window then you will have to make the end point. The third point will specify the size of Arc. So after making start and end points move the cursor away from points and you will see a dynamic arc generated.
Center and Ends
This is can also be a 3 point arc but the difference comes in third point. Here third point ( that will be actually first) will lie at the center while in 3-point options it lies on to the Arc. To draw center ends arc first you will have to specify the center by making a click at desired location, then move the cursor suitable away or at specific radius and draw the start point by clicking at desired location. After this click for the end point at specified arc length to complete your arc. See the following fig ( left to right in sequence )
3 Tangents
To use this option we need three curves so we can have their tangents. I create a triangle for this purpose (don’t worry about the dimensions you can create it of any size. After this select the 3-tangents option under arc menu and then select one side of triangle by clicking on it. Then select the second line as you see in the fig (left) below. As soon as you select the second side, an arc will appear. Now you need to select the third side to complete the Arc see the fig (right) below.
Concentric
To draw this arc you need to have a curve, with some center point, already sketched. I use the circle for this purpose. Now select the Concentric arc option under arc menu and then select the center of the circle or the curve that you have sketched for this purpose. Now you will see a doted circle will appear see in fig (left) below and you need to make start and End points for your arc. Just as you did in 3-point-arc option. You can create as many concentric arcs as you want. This is the same procedure that we have already used in circle sketching tutorial 
Conic Arc
You can frankly define it a loosely constrained arc. Because first it is con like shape second it will not have any proper radius. To create it you need two points, with some distance apart, first select the conic arc option under arc tool menu and then make a first click. Now make the second point and your arc will appear in sketching window. To place this arc in sketch first make it reasonable in size by moving the mouse cursor away and then make third click to place it.
