GD&T Question 3

[bluepgt]

I got a drawing today from a car manufacturer and the coordinate system is shown as H, BR, and T. Has anyone seen this before? I'm having trouble visualizing it.

Thank you

 

[Belanger]

It's doesn't really have to do with GD&T, but I've dabbled with prints like this (probably from the same car company) and those are simply different names for the X, Y, Z coordinates. H is the up/down direction, B is the cross-car direction, and T is the fore/aft direction. (I've seen it as "B" not "BR.")

I don't know how they came up with these letters, but it's no different than a large-scale X-Y-Z system: it allows any point on the vehicle to be described with an (H, B, T) location. The trick is to be sure of where they are defining the (0,0,0) point on the car.

See the attached sketch -- it's very crude, but gives the basic idea.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[TED7]

H for Height, B(BR) for Breadth?

No idea on T though, Thickness doesnt quite make sense.

Will Walters
Sheffield UK
Designer of machine tools - user of modified screws

 

[bluepgt]

Alright thank you guys for your help. I figured it would be just different nomenclature but I had problems visualizing the coordinate system simply because I was confused.

Thank you for the clarification and have a great weekend.

 

[dtmbiz]

Traverse works for "T"

 

[TED7]

That 'T' had me puzzled all weekend.

Will Walters
Sheffield UK
Designer of machine tools - user of modified screws

 

[pmarc]

'Traverse' or 'Transverse'?

 

[dtmbiz]

Even though I would agree transverse is more technically suited;
either works.

Chevy picked "Traverse" as the sporty version