We just purchased a Romer arm and I am having some issue with Cones and Cylinders. The parts we are working on are basically a bullet so to speak. I scan the part, create mesh, save as STL and start a new program importing the created mesh. I create an alignment on the STL/CAD and scan the part. (we put coatings on the parts so they are larger O.D.) . If my "bullet" is sitting on the granite table, I do a point cloud alignment and the Z value or vertical value slides down the part, thus doing the best fit and not showing any coating on the sides of the part. I am new to programming and any help would be appreciated.
Do your scans and STL include points all around the part or just on the O/D of the cylinder / cone? Ideally for a best fit you need data that constrains movement in all directions. In your case you need points on the top and bottom end faces of the cylinder as well as the sides. You may also have more luck picking point pairs for the alignment rather than using the auto function. If you only just purchased the arm then you will have a support contract. Call your local Hexagon office and explain what you need to do and they should be able to talk you through it.
Thanks Neil
Sorry I have not responded earlier, I have been on a project and not had a chance to get on site. I have started using point pairs on the part and creating circles, then a best fit line for the level feature. I have found a small area on the part I can use as a plane. this seems to work. Before I was using the table as a plane but when creating the STL I could not "touch" the feature on the part so it would not orient, the part would slide up and down trying to fit on the part. I had a fellow here from Hexagon and he was a lot of help, but he even said the parts I am doing look simple, but they are very had to get repeatable alignment. I greatly appreciate your recommendations and advise, it is very helpful. Some on this sight do not like to assist you without making you feel inferior, and that has not been the case with you.
