Implied Centerline
Implied Centerline
(OP)
(see attached figure)
The only requirement on the print for the keyway is the width and length (from opposite side of ID to flat of keyway).
here are the questions:
Is this keyway "implied to be on center"?
If so, what would be the tolerance?
If engineering does NOT need the keyway to be on the centerline, how would this be shown on the print?
The only requirement on the print for the keyway is the width and length (from opposite side of ID to flat of keyway).
here are the questions:
Is this keyway "implied to be on center"?
If so, what would be the tolerance?
If engineering does NOT need the keyway to be on the centerline, how would this be shown on the print?





RE: Implied Centerline
There is no implied tolerance for that, however, and this is where position (GD&T) would be used.
If the keyway were to be designed to be off-center, a dimension would have to be shown indicated the offset between the keyway's centerline and the hole's centerline. (Again, position should probably be used, so that dimension would be basic.)
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Implied Centerline
In this case, the location of the keyway does not matter. It can been at any location in relationship to the 8 holes or "notch".
So how would engineering show this?
RE: Implied Centerline
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Implied Centerline
"orientation optional"
RE: Implied Centerline
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Implied Centerline
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Implied Centerline
My initial response was the same as MechNorth but as the sketch isn't completely dimensioned it's difficult to say for sure.
The concept of 'implied centerline' has been discussed a few times, if you don't get a full answer in this thread you might try finding one of the old threads.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Implied Centerline
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Implied Centerline
RE: Implied Centerline
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Implied Centerline
Al
RE: Implied Centerline
The intended location of the slot relative to datum A would be by way of the centerlines of each. If the slot is to be centered on the block, then the location can be implied as zero by showing a common centerline through both. If there is an intended offset, then a basic dimension is given between the two centerlines.
Remember, even though you said that the width is datum A, it's really the center plane of that width that is the true datum.
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Implied Centerline
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Implied Centerline
Could you post a sketch?. If I read it correctly you have an assembly. Not totally clear as to what you have.
RE: Implied Centerline
Regards
RE: Implied Centerline
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Implied Centerline
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Implied Centerline