I decided to proceed with what I previously attached after removing the redundant coincident constraints and examining the sketch for other possible problems of my own making. I mirrored the sketch, added equality and symmetry constraints (very cool when you figure out how they work) and added the connecting line and arc to complete the outline. Validating the sketch produced "20 missing coincidences", one at each location that didn't have a Coincident constraint (the location had either a tangent or a perpendicular constraint applied by the Polyline tool). I didn't bother to have the validation tool fix them. I now see from a post from NormandC that this is a known problem and I should not be concerned about it - even better, he has reported a bug so it will hopefully get fixed.chrisb wrote:You found an error in the "Validate Sketch" tool. Since my first analysis was based on that tool you may want to revisit your first model and neglect all hints mentioning these special tangent constraints. I don't have the time now, if you don't succeed write back and I will have a look tonight.
I next tried both the Pad and the Extrude tools to create BasicCylinderBlock. Both worked and created a solid that passed the Check Geometry tool.
You will note in the attached model four "slabs" called "LeftFrontCutout", RightFrontCutout", "LeftRearCutout" and "RightRearCutout". LeftFrontCutout was modelled from sketches to represent the material to be removed and the sketches are independent of the cylinder block itself (they were not based off any face on the cylinder block). The other three were created using the Draft->Mirror tool. Only the LeftFrontCutout is currently displayed.
When I attempt to Cut the LeftFrontCutout from the BasicCylinderBlock, FreeCAD crashes. I'm kind of stumped at this point as this doesn't seem like it should be that difficult of a thing to accomplish, but I'm currently at an impasse.
Any help would be greatly appreciated.
Bill Lugg