We make a lot of display elements out of 6mm EPVC sheet using dados and V-grooving. I have figured out a pretty good way to accurately create these parts and get usable flat patterns. I have started running into an issue that happens only on occasion and for the life of me i cannot figure out. I unfold my part, add necessary features, and when i fold my part again it completely changes the orientation despite having the same surface selected as i did in the unfold feature.
- I start out with .050 sheet metal and a bend radius of .001 because we cut our V-grooves down to a remaining thickness of .05 and heat bend the parts.
- unfold part, and make a sketch with lines offset .001 from the bend radius and extrude all surfaces .186 to get a 6mm part
- add a .186 @ 45 degree chamfer to the edges around the bend lines to create a "V-groove"
- add Dados, corner relief for router bits, cut outs etc.
- Fold part.
In all cases this works great. i get a 6mm "sheet metal" part with v-grooves and accurately fitting dados that i can generate flat patterns off of, but 10-15% of the time the part changes orientation. which is only detrimental in that is a hassle in making an assembly and that it is perplexing me.
If anyone has any thoughts or insight it would be much appreciated.