Profile question

[BANDY]

I have a couple of different profile call outs on my B/P. On the same print there is a profile of a surface .010 to BAC then on an other surface .010 BCA. I have not started programing it yet and I just wonder if dmis calculate the profile any different if I just dimensioned as .010 ABC for both cases. Should I stick with the B/P or I can use .010 to ABC?

[Paul Sarrach]

I would think you need to use the correct Datum scheme. If we could see a pic it would be easier to explain. But they may want to know what the profile is from each feature. What type of features are -a- -b- -c-? Are holes or are the other planes?

[Sinned]

I would say stick to the print. Is there a basic dimension from the surface to the B datum? You B is primary so I'm thinking that they're more concerned about the distance betwen the surface and B datum than the A.

[cmmguy]

The datum schemes also define which features level and align - changing those can really change the meaning of the measurements.

[Paul Sarrach]

The datum schemes also define which features level and align - changing those can really change the meaning of the measurements.

What I said, only maybe better.

[BANDY]

The part is a hinge by definition, datum -A- is a flat surface, B and C are close tolerance holes. I guess those holes are the once that they want to check the part to, because of the functionality of the hinge. Thank you for the reply. Learning something new everyday.

[Paul Sarrach]

The part is a hinge by definition, datum -A- is a flat surface, B and C are close tolerance holes. I guess those holes are the once that they want to check the part to, because of the functionality of the hinge. Thank you for the reply. Learning something new everyday.

Thats what I thought, they wanted to know what something was to two different areas

[Jan d.]

I have a couple of different profile call outs on my B/P. On the same print there is a profile of a surface .010 to BAC then on an other surface .010 BCA. I have not started programing it yet and I just wonder if dmis calculate the profile any different if I just dimensioned as .010 ABC for both cases. Should I stick with the B/P or I can use .010 to ABC?

BAC can give you vastly different results from BCA. And the demons evaluate this correctly.

HOWEVER, in my humble opinion, PC-DMIS incorrectly reports profile, so be VERY careful.

Hexagon is unwilling to correct this issue because in their opinion they do it right. I totally disagree and before you report any results, make sure you study the attached post from some time ago. On top of that, you are using 4.0. There are several reporting issues with profile in 4.0 that have now been resolved in 4.2.

STOP USING 4.0!!!!!! It is not very good.

http://www.pcdmisforum.com/showthrea...hlight=profile



Jan.

[BANDY]

I am currently using 4.1, I am getting 4.2 next week. I noticed that some cases when I see a profile out of tolerance, I do analyze each point location and they are all within tolerance. Is that what you mean by dmis calculating profile wrong?

[BANDY]

Ohh...ok I just read the link you put there...I do the same just print out the location for each point then calculated myself.

[Wingman]

If you have profile report MIN MAX from the Dimension Menu you can get the numbers you want without calculation.

[Paul Sarrach]

All I ever use as to report a profile is the "T Value" of points. We are Sheet Metal. I make a note on the report for each call out and show the axis or axis's and the T Value

[Matthew D. Hoedeman]

All I ever use as to report a profile is the "T Value" of points. We are Sheet Metal. I make a note on the report for each call out and show the axis or axis's and the T Value

Works great, don't it, Paul?

I have been doing that since the DOS days of Pcdmis.

[Paul Sarrach]

Works great, don't it, Paul?

I have been doing that since the DOS days of Pcdmis.

Me too. Not only does it give you the profile,it shows you the curve of the profile and how good or bad it really is. Most engineers want it that way.

[Wingman]

T Value?