SW API help - inside or outside??

[DesignModeler]

Hey Forum,

I'm designing a macro that automatically creates and adds a custom length o-ring to an assembly based on the cylindrical groove surface diameter. My problem is if its an inside groove, the OD of the oring must be the diameter, or if its an outside groove, the ID of the oring must be the diameter. I am having trouble determining a simple way to check if its an inside or outside groove.

Mathematically, if its an inside groove, if you have a point on the surface, its normal is directed towards the origin of the surface, otherwise, its normal is directed away (negative of) from the origin... anyone else have any simpler ideas?

 

[CorBlimeyLimey]

Seating-face diameter at the bottom of the groove is < or > the open edge?

 

[DesignModeler]

@CBL

Yes, its possible to do it that way, but I'd rather not try to reference adjacent faces and edges due to fillets or chamfers that may exist on seating face and open edge... if I can't come up with anything easier I may have to resort to that, thanks.

 

[CorBlimeyLimey]

OK ... Seating-face diameter at the bottom of the groove is < or > the diameter into which the groove is cut?

 

[CorBlimeyLimey]

Ohh! By "cylindrical groove", do you mean the groove is cut into a cylinder (round shaft or round hole), or the groove itself is cylindrical (semi-circular) in cross-section?

 

[DesignModeler]

The groove is cut into a cylinder for the oring (male or female side) or for simplification, any cylindrical surface should work.
don't know how to recognize if inside or outside

 

[SnowCrash]

IIR, the groove design is related to the sealing requirements, not the nominal size of the oring or the shaft. I have used this site as a reference in oring design:

http://www.allorings.com/gland_static_axial.htm

The site is a technical asset.

--
Hardie "Crashj" Johnson
SW 2011 SP 2.0
HP Pavillion Elite HPE
W7 Pro, Nvidia Quaddro FX580

 

[DesignModeler]

@ Snowcrash,

That has nothing to do with the thread topic or my original question. I didn't mention my lack of knowledge in sealing solutions or O-ring groove design because it is entirely irrelevant. If you are unfamiliar with SW API, don't bother. Please read the entire thread before you post.

@CBL,

"...A positive curvature by convention implies a centre of curvature on the side pointed away from by the surface normal (convex)..." - what does that mean in terms of this method:

http://help.solidworks.com/2011/eng...nterop.sldworks.isurface~evaluateatpoint.html