Bilateral Profile

[jkb_mcg]

Could anyone tell me why when you check the profle of a surface it is doubling your actual readings? Ex. Max> .0076 / Min> .0049-----So my profile figures out to be .0152. My quality manager is asking me why the proflie of that surface is .0152 and not .0076. Anyone have an explanation?

Thanks in advance!

Josh

[bw_bob]

Could anyone tell me why when you check the profle of a surface it is doubling your actual readings? Ex. Max> .0076 / Min> .0049-----So my profile figures out to be .0152. My quality manager is asking me why the proflie of that surface is .0152 and not .0076. Anyone have an explanation?

Thanks in advance!

Josh

That is the size of the actual profile envelope. If it is .076 on one side then the profile would be.152....Basically +/-.076...Bilateral = both ways

[dccfreak]

See this: http://www.tec-ease.com/tips/november-01.htm

Pretty good explanation here. Thanks to Kev Botta for sharing this one. Hollah!!

[jkb_mcg]

Thanks for the reply and the link.

Josh

[Jan d.]

In order to correctly report the profile to the print FCF, you MUST double. That's the standard.

However, it is my opinion that that is a non-informative number: machinists have no clue as to what to do with those numbers. I can not use it for meaningful process control.

I have resorted to also reporting Min/Max. That results in very applicable information for the machinists. They can adjust their machine to what I find.

Warning: Be very careful with what PC-DMIS reports on profile! It is inconsistent, in my opinion. Using Min/Max is the only way to find the real profile and provide process relevant information.


Jan.

[Jeffrey Lovely]

Where is that standard written.

[joe.sha]

When I measure a profile pc-dmis adds the min and the max, in this example I would get .0125" not .0152". If my profile has two positive values it dimensions the profile as the greater value. What am I doing wrong??

[Matthew D. Hoedeman]

When I measure a profile pc-dmis adds the min and the max, in this example I would get .0125" not .0152". If my profile has two positive values it dimensions the profile as the greater value. What am I doing wrong??

That sounds like you are NOT using FORM AND LOCATION but FORM ONLY.

[joe.sha]

Hi Matt, I'm using form and location, it gives me the same result using pc-dmis cad++3.5mr2 & 3.73060347-3-6_vane_final_insp_071006_121825_685_1.PDF