Is it legal, advised, to use defined surfaces and multiple surface profiles as one datum as shown in

[EvoSteve]

A circuit board, shown below, needs to fit into a plastic housing. There are no datum holes in the PCB and the outside of the PCB will be used to register it inside a plastic housing.
The PCB sits on shelves in the plastic housing, as indicated in the pictures. The plastic part has small ribs that will hold the PCB in the proper place.
My desire is to select outside edges on the PCB as datums, which is straight forward. Since the location of the PCB is restricted by 5 ribs inside the plastic part, can I specify the location of each rib with a profile tolerance AND use all the ribs as one datum? I’ve made my attempt to define the ribs in the drawing below.

 

[Belanger]

Can't see the pic. Does it need an extension such as PDF, JPG, etc.?

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

http://www.gdtseminars.com

 

[CheckerHater]

I think file has "&" symbol in the name. That's the problem.

 

[EvoSteve]

Thanks for your quick response!
The file is a Word document, but as suggested having the "&" symbol may be a show stopper.

The new document is a PDF file, and of course there is no "&" symbol.
Again, thanks

 

[MechNorth]

Quick answer: No. You can't call out 5 separate features as datum feature-D, at least not the way you have.
Better Solution:
Leader & Label the 5 surfaces 'K' or such. Put a single profile control with 5 leaders pointing to the five surfaces. With the profile control, include the annotation '5 SURFACES MARKED K'. Attach the datum feature identifier symbol for datum-D to the surface profile control frame. Then, you need to ask youself whether you want datum-D simulated at MMB, LMB or RMB, and modify the datum-D references accordingly.


Jim Sykes, P.Eng, GDTP-S
Profile Services

http://www.profileservices.ca

TecEase, Inc.

http://www.tec-ease.com