circle sketch over an existing hole

[fdefilippi]

I can't figure out how to place a circle sketch over an existing hole, why can't it snap to the centers of the existing circles. 

[StephenW]

Select the reference icon and then select the hole or the axis as a reference and it will constrain to the hole.

[fdefilippi]

not sure I follow you.  I new to this program

[StephenW]

The reference icon is here. It allows you to select geometry or datums to reference in your sketch.

When you use a hole as a reference, if you move the hole, your sketch will move with it (depending on how you dimension it).

[StephenW]

eferences video on youtube

Choosing appropriate sketch.references : PTC Creo - YouTube

[cprice]

This is from PTC's Tips and Tricks document - Please find the document attached to view their Tips and Tricks

A Faster Way to Select References

As you create geometry using the Sketcher tool, you

may want your cursor to automatically snap to existing

geometry (e.g., a reference) to more easily align

components within your drawing.

However, if you’re in the middle of using the Sketcher command, it’s

too late to select a reference. You have to create your

references before you start sketching. Alternatively,

you can cancel the Sketcher tool, go to the upper left

hand corner of your screen, use the Reference tool to

specify the references, and then go back to using the

Sketcher tool.

With Creo 3 -

The Alt key suspends the Sketcher tool, allowing

you select your references as you work. As you

sketch, simply hold down the Alt key and select your

references. Releasing the Alt key instantly returns you

to the Sketcher tool. You can now snap your cursor to

the references you just selected. This tip applies to any

version of PTC Creo Parametric.