Datum and Datum Feature Simulator
Datum and Datum Feature Simulator
(OP)
Hello,
The answer to these questions may be obvious. I am new to many details regarding GD&T.
I provide a section drawing from a part to illustrate my questions. The hole is through the part and of fixed size.
1. I believe the datum feature is a cylinder. Is this correct?
2. I believe the datum feature simulator is a "v-block". Is this correct?
2. I believe the datum is an axis. The axis is where the two sides/surfaces of the v-block intersect. The axis is offset from the center bore axis through the part. Is this correct?
The answer to these questions may be obvious. I am new to many details regarding GD&T.
I provide a section drawing from a part to illustrate my questions. The hole is through the part and of fixed size.
1. I believe the datum feature is a cylinder. Is this correct?
2. I believe the datum feature simulator is a "v-block". Is this correct?
2. I believe the datum is an axis. The axis is where the two sides/surfaces of the v-block intersect. The axis is offset from the center bore axis through the part. Is this correct?





RE: Datum and Datum Feature Simulator
2) datum simulator is a v-block at 90-degrees basic
3) datum is actually two planes (the intersection of which is an axis), established by the v-block. Vertical through the intersection of the v-block sides, and horizontal thru the basic center of the radius
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Datum and Datum Feature Simulator
Are you sure that horizontal plane passes thru the basic center of radius and not thru the intersection point of v-block sides?
RE: Datum and Datum Feature Simulator
RE: Datum and Datum Feature Simulator
The radius is givens as basic = 1.220.
RE: Datum and Datum Feature Simulator
If so, that brings up another question: If they didn't show those x y z origins, would say that the true datum passes through the intersection of the V ?
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
http://www.gdtseminars.com
RE: Datum and Datum Feature Simulator
Yes, if x y z origins were not shown on that figure, I would say that datum planes passed through the intersection of the V.
RE: Datum and Datum Feature Simulator
RE: Datum and Datum Feature Simulator
Dean
www.d3w-engineering.com
RE: Datum and Datum Feature Simulator
The datum feature is the radius, not the 'V', so the center of the basic radius would be the origin; the simulator helps you establish that origin, though in this case inconveniently. Of course, this is based on datum E being the primary.
Dean, I agree that alternate datum selection would be preferable.
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com