On Oct 12 2015 12:38 PM, TJoseph Powderly wrote: > On 10/12/2015 12:11 PM, EBo wrote: >> On Oct 12 2015 10:01 AM, Stuart Stevenson wrote: >>> >>> I think we should be able to probe coordinate rotations >>> >>> Two points for a plane rotation and three for a complete coordinate >>> system >>> orientation >> >> If you only probe 2, there are special collinear cases which could >> still be two of the three standard planes. I think you have to >> choose >> three to definitively define even the the three standard ones >> (without >> having to worry about special cases. >> > yes people like to do this. > remember there is a loss of precision when you do this. > your stepper or sale cannot resolve the 1/2 or less units that > the translation incurs. thats why putting stuff on the table and > indicating it in is a _good_ idea. > tomp tjtr33
I'm actually a fan of taking statistically meaningful samples for such things. I would have to look at the error propagation, but given sufficient samples you can resolve the 1/2 step transition as long as the errors are normally distributed. That raises the question on how the bed/part/etc. would be sampled (to account for any swarf or deformations in the probed part, etc.). That said, there is very good reason to indicate it in as you suggest. EBo -- ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
