S3D_Adam
Plastic
- Joined
- Nov 6, 2015
- Location
- Woodinville, WA
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When I have something like that I use a linear scan on the profile of the draft so I have a "linear" pointcloud. Then I use PCDMIS to give me some geometry with a least square method. Then you can pop it in AutoCad and play with it to your heart's content.
So something like this?View attachment 176631
Does anyone have any tips for measuring dimensions on drafted and rounded edges? I can never seem to find a consistent edge with an OMM, and with a CMM, it is difficult to measure points at the correct z-height. See the picture below for the type of dimension I'm talking about.
View attachment 174802
We inspect a lot of small plastic injection molded parts. Many times there will be a small screw boss protruding from the "solid" part. The drawing will have a width dimension to the tangent of either the top fillet tangents or the bottom fillet tangents that will state a dimension and then either +draft or -draft.
We inspect a lot of small plastic injection molded parts. Many times there will be a small screw boss protruding from the "solid" part. The drawing will have a width dimension to the tangent of either the top fillet tangents or the bottom fillet tangents that will state a dimension and then either +draft or -draft.
Gordon's sketch shows a width that I may need if I use the roll pin method. I've never use the roll pin method, I've never seen anyone use the roll pin method, and I haven't been able to find a visualization on the internet anywhere, so I'm not even sure if I need that dimension.
Perhaps I just need to purchase a copy of ASME Y14.8. I'm not even sure if the engineers are dimensioning these types of features properly.
I work in a metrology lab that was built to do short runs and one-off parts. My primary function is to help engineers solve issues quickly. Our parts are manufactured overseas, so I never know very much about the parts I'm inspecting. I am usually just given 2 or 3 to find out why something isn't fitting or if the engineer doesn't believe a measurement that the vendor made.
Guesswork and speculation is exactly what I'm after. I'm not looking for one solution to perfectly match one problem. Instead, I want to know what options are available so that I can be better prepared the next time someone brings me a molded plastic part to inspect.
I'm afraid that the only question I can really answer is regarding size and tolerance. Parts typically range anywhere from about 5 to 300 mm in length, but the typical size and tolerance on a dimension like the one in the image in my original post would be 3+/-0.15 mm.
Sorry I can't give more information than that. As it stands, I think the only option I have to go on is Rewt's suggestion (post #3).
I work in a metrology lab that was built to do short runs and one-off parts. My primary function is to help engineers solve issues quickly. Our parts are manufactured overseas, so I never know very much about the parts I'm inspecting. I am usually just given 2 or 3 to find out why something isn't fitting or if the engineer doesn't believe a measurement that the vendor made.
Guesswork and speculation is exactly what I'm after. I'm not looking for one solution to perfectly match one problem. Instead, I want to know what options are available so that I can be better prepared the next time someone brings me a molded plastic part to inspect.
I'm afraid that the only question I can really answer is regarding size and tolerance. Parts typically range anywhere from about 5 to 300 mm in length, but the typical size and tolerance on a dimension like the one in the image in my original post would be 3+/-0.15 mm.
Sorry I can't give more information than that. As it stands, I think the only option I have to go on is Rewt's suggestion (post #3).
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