Applying Feature Control Frame on a part 1

[tmackay]

Hello,

My Boss is trying to mark up a drawing to have the Perpedicularity Feature Control Frame on the center line of the Rod (Rod being welded to a plate. I can't find anything in ASME Y14.5M 2009 that says you can or you can't (my gut tells me no). The only backing I have is that nowhere in the standard does it show the Feature Control Frame coming off of the center line. I would prefer it coming off the edge of the Rod or off a size dimension.

Should I let it go ... or challenge him? Am I wrong?

Thanks - Todd

 

[KENAT]

forum1103 might have got you more expert answers but here goes.

You mention -2009 standard that I don't have, but in -94 version at section 3.5 it talks about FCF placement. It doesn't mention attaching it to a center line as being valid.

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[SamPorter]

I have attached what I would do. This method does control the centerline as perpendicular within a cylindrical zone, and allows you to define the size, alse you could use this axis as another datum (but not needed).

Hope this helps. I am no expert but there is a very similar example in our training material!

Sam

 

[tmackay]

That's is man - Thank you so much ... pretty much the same in 2009. They added 3.5 (e) placing in a note, chart, or general tolerance block

 

[KENAT]

Something like Sams would be my preference on a cylindrical feature too.

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[SamPorter]

I would use the maximum material modifier (as shown), so that if the pin is on the small side you get some bonus tolerance on the perpendicularity.

Enjoy!

 

[drawoh]

tmackay,

The feature control frame goes on the feature, or on the feature specification as per SamPorter's post.

Your model is simple enough that the centre line is unambiguous, but lots of models are not. If your pin was stepped, the FCF would apply to one diameter. I could be really stupid and pedantic and ask if your centre line applied to the diameter, or the chamfer.

JHG