uses of Best Fit

[Mranaskw]

Hello once again,

i have been searching for a week and for the first i feel unable to fulfill my greedy curiosity , i did understand several aligning methods , but this , this misterious best fit i have no clue what the heck is it about ,
it follows iterative aligning , found this on a old post and also in of our programs (there were more than 30 hits ) , if best fit was alignment why it used (i guess) in measuring and dimensioning , till now it feels to me like a method of measuring more than an alignment (alignment concept for me is to tell the machine where part is and move from machine to part cord)

the prg that i have seen is for a reflector (curvy) why not just measure after the iterative only , whats so special about best fit , how can it serve and how does it operate (it displays deviations why why !!)

gonna get a beer to cool me down

cheers

[RandomJerk]

|TP|.005|A|B|C| is a constrained alignment
|TP|.005|A|B| is not fully constrained and allowed to... best fit.

[NinjaBadger]

RJ provides an excellent example.

Feature control frames define a tolerance zone shape & size. The datums specified in the control frame dictate how this tolerance zone is located relative to the datum(s).

If the tolerance zone isn't fully constrained to the datums then the tolerance zone can shift (in the unconstrained directions) to minimise the deviation of the considered feature(s).

Several years back (I forget which version) but the Profile dimension (form only) wasn't best fitting correctly. The solution was to use a best fit alignment on the features and report as Form & Location.

There are many valid uses of best-fitting.