Can a CMM do a point cloud?

[vmipacman]

We have an older manual cmm running Power Inspect. I want to simply take points of a part so i can put it in Solidworks and draw the part features around it.
PowerInspect appears to suck for this purpose. It wants to measure features from a solid model, not free hand a part from nothing. But also, when I do get it to make a point cloud and import into SW, it seams to only be the center of the probe tip. If i account for the probe tip diameter, The point cloud makes sense.
Is this because the CMM does not have enough data from a point touch to know where on the point tip to place the actual contact point?

 

[lobust]

Is this because the CMM does not have enough data from a point touch to know where on the point tip to place the actual contact point?

Yes, when working from a model or touch trigger probing a simple geometric form like a circle, there is always some form of vector reference to infer the contact point from, either a surface normal vector or an approach vector or a combination of the two.

If you are doing a raster scan then you have neither of these references - there is no surface normal, no known form, and the approach vector is unifrom across all points.

 

[Barbter]

I had a CMM from a UK company with their own software (QCT).
I used this process only 3 or 4 times but was always annoyed with the result. This was straight XY 2D shapes and saved as a dxf file.
Import into CAD and square up the longest face but the others were obviously always just a bit out.
Drove my OCD mad....!