Just following on from the previous thread, I can understand why you would use an Intersect Dimension for a feature such as the upper radius in the figure, as this is where there will be material before the radius has been machined. I don't understand why you would use an intersect for the lower dimension as this material, which the intersecting lines would theoretically remove is used, rather than perhaps showing and dimensioning the Centre mark of that radius.
I just want to clear up that this is a standard way to dimension this "Internal" radius or if it would be clearer using the centre point.
Thanks
RE: Internal Curved Corners in BS 8888 - (Revisited)
If the radius changes then the center will move; the intersection will not. Suppose that radius had a large variation - say between half what is pictured and double what is pictured. Place the center point for each case. There will be a horizontal distance between them.
RE: Internal Curved Corners in BS 8888 - (Revisited)
wow 3 ddave good answer sir. also to stay consistent with dimension is is good practice. how ever i have done both. in this case it is done by the specification. so a process engineer must clarify this on the planning for the floor and inspection. so it is drawn, machined and inspected in the same method.
RE: Internal Curved Corners in BS 8888 - (Revisited)
Mr Burunduk some of my customers require these dimension to be inspected and recorded. either with a CMM or with a optical comparator.
during machining it has to be inspected as first article. this has been done before my time.
RE: Internal Curved Corners in BS 8888 - (Revisited)
It is true, if there is a direct tolerance applied to the dimension.
The question is in the context of the British standard, which is based on ISO. If it is anything like in ASME, I would not recommend applying a directly toleranced dimension. Considering a form error of the planar surfaces such as convex/concave, the intersection points on an actual part may be ambiguous.
RE: Internal Curved Corners in BS 8888 - (Revisited)
yes they can be a pita, and especially in internal diameters. and can be very difficult to inspect. and should be not used unless really necessary. standard shoulder with a corner radius is
so much preferred. and is much easier for every ones sake. easier to machine, inspect and to record.
RE: Internal Curved Corners in BS 8888 - (Revisited)
mfgenggear,
It gets worse, when you consider that a dimension like 22.4 shown above and its directly applied tolerance is supposed to apply in 3D. Not just as a 2D projection measurement of some local elements.
Red Flag Submitted
Thank you for helping keep Eng-Tips Forums free from inappropriate posts. The Eng-Tips staff will check this out and take appropriate action.
Reply To This Thread
Posting in the Eng-Tips forums is a member-only feature.
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Metal 3D printing has rapidly emerged as a key technology in modern design and manufacturing, so it’s critical educational institutions include it in their curricula to avoid leaving students at a disadvantage as they enter the workforce. Download Now
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
thread1103-485002: Internal Curved Corners in BS 8888
Talk To Other Members
RE: Internal Curved Corners in BS 8888 - (Revisited)
RE: Internal Curved Corners in BS 8888 - (Revisited)
RE: Internal Curved Corners in BS 8888 - (Revisited)
The inspector will not have to measure and report the dimension value.
RE: Internal Curved Corners in BS 8888 - (Revisited)
during machining it has to be inspected as first article. this has been done before my time.
RE: Internal Curved Corners in BS 8888 - (Revisited)
The question is in the context of the British standard, which is based on ISO. If it is anything like in ASME, I would not recommend applying a directly toleranced dimension. Considering a form error of the planar surfaces such as convex/concave, the intersection points on an actual part may be ambiguous.
RE: Internal Curved Corners in BS 8888 - (Revisited)
so much preferred. and is much easier for every ones sake. easier to machine, inspect and to record.
RE: Internal Curved Corners in BS 8888 - (Revisited)
It gets worse, when you consider that a dimension like 22.4 shown above and its directly applied tolerance is supposed to apply in 3D. Not just as a 2D projection measurement of some local elements.