About making point at max distance.

Forum|Forum|11 years ago
June 4, 2014
4 replies
4240 views

You can make points when you measured the two curves.

But you can't make points when you measured max distance of two curves.

Do you know way of making point at max distance?

N

neomechanikos

1-Visitor

I don't think you can do it directly. Here is another workaround:

Create a datum to the left of the two curves and another datum to the right of the two curves.
Measure from the left most datum to the left most curve to measure for the minimum distance and create the point features as you show above.
Do the same for the minimum distance between the right curve and the right datum.

The distance between the points on the curves should be the maximum distance as long as you've set up the datums properly. You should create a new product idea.

D

dschenken

1-Visitor

It seems like that would work - but not for the general case.

Picture a hex in a slot. The maximum distance is across corners, but there isn't a guarantee the point on each flat found to be closest to the slot is at the opposite corner. It could be anywhere on each face giving an infinite set of 'farthest' points.

I think this is equivalent to asking for the diameter of the smallest circle that is tangent to the two curves and that completely surrounds them, with the definition of tangent including passing through an endpoint.

This is equivalent to finding the shared radius of two circles such that the center of each circle lies on a curve and is tangent to the other curve, where, for finite curves, passing through the endpoint is considered tangent; and the circle envelopes the finite curve.

This can be used to check a suspected solution by drawing a circle on each end of the suspected maximum distance line with a radius of the suspected maximum distance. If any part of either curve is outside either respective circle, the distance is not the maximum distance.

As a method, one would start by fixing one end of one curve as a start point and find the radius to each end of the other curve, then repeating the operation for the other end of the first curve. This will give four radii, of which one is the largest. WIth that radius, and the points it relates to, draw the two circles. Only the portions of the curves outside the respective circles need be investigated to see if they are candidates that could provide larger distances.

For mutually convex (each curves away from the other) curves and pairs of straight curves, the endpoints will be the only candidates. Only for straight and concave and mutually concave curves will the maximum distance points not be the endpoints of both curves.

Y

YuichiKashima

Author

1-Visitor

Thanks for your message.

...uploard creo parametric 2.0 data.

This is very simple.

1_curve_distance-prt.zip