spherical radius dimensioning 1

[jerry1423]

I have a spherical radius on the end of a cylinder.
The center point of the spherical radius is on the centerline of the cylinder.

A basic picture of it is attached, with some dimensions missing.

Can I use "true position" to locate the center point of the spherical radius in relation to the centerline of the cylinder?

Is there a better way to dimension the spherical rad in relation to the centerline of the cylinder?

 

[ewh]

1) Yes
2) If your CAD system permits, you could use a folded radius dimension, which would show the dimension originating from the centerline. This will however make your view wider.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[dingy2]

Centres are not confirmed but the feature is confirmed following ASME Y14.5 - 94 or 2009. In your case, you have a spherical radius.

Positional tolerances only apply to features of size which, arguably, is at least a semi-circle so that one can measure the diameter. Positional tolerances would not apply in your example.

We have a spherical radius and I would suggest that the centre of this radius should be shown using basic dimensions (theoretical) from the primary, secondary and tertiary datums. The feature should then be reflected as a profile of a surface with the value being a range of a bi-lateral tolerance.



Dave D.

http://www.qmsi.ca

 

[pmarc]

Provided that you are following ASME Y14.5 std., I agree with Dave. Profile of surface looks much better in this case as your spherical surface can't be considered as a feature of size.
However if your drawing is going to be according to ISO standards you could use either profile or position tolerance. In both cases SR dimension should be basic.
As ewh suggested, because the center of the radius can be located far away of the view or even a drawing frame, you should try to use folded radius dimension to save some space on the drawing.

 

[jerry1423]

Thank you very much for the excellent answers, they helped a ge=reat deal.