geo tol question

[dtmtim]

Good morning,

The drawing calls out profile of a surface .010" (no datums specified). The surfaces to be inspected are 2D profiles of irregular shaped pockets.

I have previously inspected this by inspecting each feature (circle or line) that makes up the outside profile of the pocket then creating a feature set and reporting profile of a line (since thats what it really is) to the datums on the part. I have a CAD model for this part I am using to drive PC-DMIS.

I have also done this another way by creating vector points all along the inside surfaces of the pocket then creating a set feature of those points and reporting profile of a surface to the datums on the part.

In your opinion what is the correct way to inspect this?

Thanks!

t.

[cmmguy]

Best fit profile tolerance

[JamesMannes]

Best fit profile tolerance

What cmmguy said, but I would add, either measurement methods of your should yield correct results. But, let me also ask this, can you scan this as a linear open or closed scan? If so, then you would have everything in one measurement to start with that you would need.

[Matthew D. Hoedeman]

You could do a 2-D linear scan (open or closed, your choice) and reporting the profile of it.

[dtmtim]

I haven't done a 2d linear scan yet. My experience is limited to UV scans. Can you explain how it's done? I attempted to figure out patch scans a while ago from the help file but gave up.

[cmmguy]

What cmmguy said, but I would add, either measurement methods of your should yield correct results. But, let me also ask this, can you scan this as a linear open or closed scan? If so, then you would have everything in one measurement to start with that you would need.

Cant you combine the individual features, once measured, into a feature set and then tolerance them as a set?

[Matthew D. Hoedeman]

I haven't done a 2d linear scan yet. My experience is limited to UV scans. Can you explain how it's done? I attempted to figure out patch scans a while ago from the help file but gave up.

Patch scans SUCK. The liner closed (or open) are really quite simple, especially with CAD. Click on the cad where you want it to start, give it a direction and an end point (linear open only), then you can simply click on GENERATE and it will pull the nominals and IJK from the cad data. Of course, if it is truely a 2-D profile you are trying to get, you WILL want to alter the Z (or wahtever axis) for the start, direction, end points so that they are all the same BEFORE you click on generate. AND, below those, there will be VECTORS. Change the plane and cut vectors so that they are all either zero or one (should be obviuos which you will need for each axis), then click on generate. It will show you the scan it is going to make, if you like it, UNMARK MEASURE, then click on create. Execute the scan later. Also, since you are using CAD, you will want to make sure the scan is set to MASTER (one of the choices).

[dtmtim]

Thanks Matt - again! - great solution - works well.

t.

[JamesMannes]

Good morning,

The drawing calls out profile of a surface .010" (no datums specified). The surfaces to be inspected are 2D profiles of irregular shaped pockets.

I have previously inspected this by inspecting each feature (circle or line) that makes up the outside profile of the pocket then creating a feature set and reporting profile of a line (since thats what it really is) to the datums on the part. I have a CAD model for this part I am using to drive PC-DMIS.

I have also done this another way by creating vector points all along the inside surfaces of the pocket then creating a set feature of those points and reporting profile of a surface to the datums on the part.

In your opinion what is the correct way to inspect this?

Thanks!

t.

Cant you combine the individual features, once measured, into a feature set and then tolerance them as a set?

Yes, that is why I said either of his methods would work, or, using an open or closed scan.

[cmmguy]

Sorry, missed that....