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True Position with Cylinders
Good Morning,
Question : I was measuring critical features off a fixture that a customer wanted data on and came across something pcdmis did that I'm not quite sure of when I analyzed the true position results. There were some tight toleranced hole locations with mmc that when measured as circles printed out perfectly allowing the bonus tolerance amply for the deviation of the hole's diameter from the low diameter limit. However, I did another feature as a cylinder (there was a perpendicularity callout of the bores' axis of .0005 to the datum plane) and something odd happened that my customer is frowning on as he observed the printout. The cylinder was created by two circles at the top and bottom of the bore and when expressed as a true position callout pcdmis gave me bonus tolerance even though the displayed diameter size of the cylinder was at the low limit. Now, from what I see this may be a result of the way that pcdmis analyzed the cylinder's diameter. On the T.P. printout it specifically calls out the cylinder using the "axis=average" and specifies the diameter at the low limit of tolerance (.1877 + .001) measures .1877. The T.P. is .002 mmc and below it suppiles the deviation from basic and gives me .0004 bonus tolerance that I can't explain to the customer based on the readout of the bare low limit of the diameter. Yet the circular T.P. measurements of other features calculates out to the letter. Is pcdmis doing something here that I should be aware of based on the usege of a constructed cylinder? Could it have something to do with the possibilty of a slight variance of size of the 2 circles used to form it? I need some inputs on this one............
One more thing please.......
In an unrelated matter, does anyone have knowledge of a quick inexpensive software to convert TIFF files to something vector related like DXF or DWG. I have a customer who doesn't have a clue that his complex TIFF files contain no geometry that pcdmis can just whip out like a solid model. Thanx everyone!
Question : I was measuring critical features off a fixture that a customer wanted data on and came across something pcdmis did that I'm not quite sure of when I analyzed the true position results. There were some tight toleranced hole locations with mmc that when measured as circles printed out perfectly allowing the bonus tolerance amply for the deviation of the hole's diameter from the low diameter limit. However, I did another feature as a cylinder (there was a perpendicularity callout of the bores' axis of .0005 to the datum plane) and something odd happened that my customer is frowning on as he observed the printout. The cylinder was created by two circles at the top and bottom of the bore and when expressed as a true position callout pcdmis gave me bonus tolerance even though the displayed diameter size of the cylinder was at the low limit. Now, from what I see this may be a result of the way that pcdmis analyzed the cylinder's diameter. On the T.P. printout it specifically calls out the cylinder using the "axis=average" and specifies the diameter at the low limit of tolerance (.1877 + .001) measures .1877. The T.P. is .002 mmc and below it suppiles the deviation from basic and gives me .0004 bonus tolerance that I can't explain to the customer based on the readout of the bare low limit of the diameter. Yet the circular T.P. measurements of other features calculates out to the letter. Is pcdmis doing something here that I should be aware of based on the usege of a constructed cylinder? Could it have something to do with the possibilty of a slight variance of size of the 2 circles used to form it? I need some inputs on this one............
One more thing please.......
In an unrelated matter, does anyone have knowledge of a quick inexpensive software to convert TIFF files to something vector related like DXF or DWG. I have a customer who doesn't have a clue that his complex TIFF files contain no geometry that pcdmis can just whip out like a solid model. Thanx everyone!
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