Best Fit Using CAD Model

[mattfurtaw]

I have been strugling with a forging that uses target datums to estabish the starting point. Problem is I can't seem to get all the points lined up with the model perfectly. When I say perfectly I mean better than .020".
I measured all of my points and then best fit using 3 Dimensional, rotate and translate.

Isn't it supposed to fit the acutal points with the CAD model ?

[John Riggins]

Can you attach the code thru your alignment?

[JamesMannes]

Seeing as you are using CAD, why not an iterative alignment manually, then an iterative alignment DCC, and then start using your datum targets andthen if you want/need to do a best fit to them.

[mattfurtaw]

Here is a PDF file of the code

[John Riggins]

Seeing as you are using CAD, why not an iterative alignment manually, then an iterative alignment DCC, and then start using your datum targets andthen if you want/need to do a best fit to them.

The Mannes is correct. You need to do an iterative alignment.
Unless the datum planes are far from perpendicular, you should be able to get all of the points within .005" on nominal.

[mattfurtaw]

That is the problem the there are 6 target datums

The blue print doesn't specify enough information. The targets are not at the same plane. So I was tasked to fit up the part with the model and see what it looks like. I can start off by fitting up the machined features but I can get the part to line up with the model exactly.

The targets are on a diameterical surface and the targets are specified by an X Y corrdinate. I have tried to come in at the vector of the part and also the vector of the alignement. But I am still not able to line up the part.

[JamesMannes]

Can you make a digital photo(s) of this part and then place all 6 of the target datums on the photo(s)? As it stands I can't get an idea of what you are doing based off of your thumnails provided. In the first one the greatest number of targets you show is 5, and in the next thumbnail provided you only show three at any one time. A section of the print would help also.