Jump to content

Best Fits of Multiple Curves


---
 Share

Recommended Posts

I am measuring four 3d curves (patterned 68 times) on a turbine blade with 68 blades. I did a Best Fit of Multiple Curves of all of the curves, allowing all degrees of freedom, and finding a portion of the blade to be out of spec. Odd thing happens when I turn off either the Z translation or rotation, all best fit values went to 0.0000. When I turn off both Z rotation and translation, the other values re-appear with their adjustments.

Anyway, to my question. Is there a way to adjust the Z location of the alignment so I can look at the results at different locations?
Link to comment
Share on other sites

I have difficulties to imagine your axis and model.
It should work if you are measuring part similar ar cog wheel where is Z axis same as rotational axis of cog.

If you are measuring it as Y or X axis is rotational, then you may have problems with that.

If you have model you can use FF bestfit. You can combine alignments - so one can translate XYZ and then you will continue with next alignment, where you use previous alignment.
Link to comment
Share on other sites

Do not have full model. I want to move the best fit of multiple curves alignment up or down along z axis and re-evaluate the line profile. I am thinking of creating standard alignment, reference the best fit of multiple curves alignment and use special button to translate along Z. I've tried this before but I recall it not working but I am going to try it again.

Blade_sm.jpg

Link to comment
Share on other sites

Well i think you should enable only rotation for Z and translation for Z - translation for XY should not be allowed, but maybe i am wrong here.

You can try to select for bestfit only few of curves from one blade to make it simpler for fitting.

Perhaps actual blade is far from nominal and then it can force you to use both Z settings.

Special in alignment won't help you - only if you change nominal from used plane to make move a part
Link to comment
Share on other sites

Just a thought, but why not take a single space point at the same XYZ
location on each blade as a "Sanity check". Wouldn't that show a Z (±)
deviation to confirm what the curves show?
Link to comment
Share on other sites

 Share

×
×
  • Create New...