changing relative accuracy

[MichaelDouglas]

I have a rather large model that fails regen when I put in a 0.25-20 bolt. If I change the relative accuracy Creo shuts down. Any ideas??

Mike

[Patriot_1776]

For a large model with small features, go to absolute accuracy, and set it to about .0001. For large assemblies with small components compared to the overall sizze, do the same. I've never seen it shut down because of that, but have seen features fail.

[MichaelDouglas]

I can take it 0.0006 but items fail. If I go any lower than that Creo shuts down. It happens on any computer I try it on.

[BrentDrysdale]

Hi Michael,

I am getting the idea that you are changing the accuracy of the assembly. If so then maybe look at the accuracies of the large parts first. The setting depends (I think) on whether you are working in furlongs per fortnight or metric (guess which one I use). I think Frank's suggestion should be OK for Imperial. Once all parts are at the same accuracy then the assembly should work.

Regards, Brent

Oh yes. You say Creo but what version and cut just in case that is relevant.

[gkrishna]

Relative accuracy is relative to biggest dimension of the part.if relative accuracy 0.001 and biggest dimenion is 3m,then relative accuracy is 3mm.if biggest dimension is 2mm then relative accuracy is 0.002 mm.

[BrentDrysdale]

Ah yes the point is well made. I was assuming that Michael meant changing from Relative to Absolute accuracy so if it was trying a much tighter figure in Relative that could be a cause of problems. As stated above Relative is exactly that and mostly it works OK but when you have a mix of large and small parts you can have issues and this is where using Absolute accuracy where all parts have the same value is an advantage. You do pay a penalty in regen times for large parts though.