Shifted datum at angle with vertical dimensions for TP

[sfin710]

We're working on the dimensioning convention of this drawing and one of my engineers gave me something like this, it makes sense to me but I'm not sure if it's technically "legal" anyone have any input? the important mating features are the two holes, but it's easier to dimension from a vertical axis, in my opinion it just will be guaranteed that the hole will be rotated exactly at 60 and then everything is dimensioned from that line. Or other opinions on dimensioning schemes?

 

[chez311]

I'm having a hard time deciphering your drawing. Is A one of the planar faces, B the large hole (no dimension shown) and C the smallter 3.5dia hole shown at 60deg to the large hole below it?

Theres no need for an angular dimension (which needs to be basic if its going to be utilized)*, and actually you're missing a linear dimension defining the *distance between the two holes shown as datum features B and C if I'm reading it right. All the holes can be dimensioned with linear cartesian dimensions/coordinates relative to each other. Realistically it doesn't matter as long as the true position of each feature is fully defined with basic dimensions, but certainly some schemes are easier to decipher than others.

*Edited

 

[sfin710]

Yeah I was trying to do it quick just to show the mixed coordinate types and the fact that the axis is based off the small hole and big hole alignment but dimensioned off the larger. Here's perhaps a better defined quick mock up.

 

[chez311]

If the 60deg dimension is changed to basic you have a valid dimensioning scheme. Linear dimensions in the x and y directions might be more common, but this is valid. Like I said, as long as the true position of each feature is properly defined from the referenced datum features with basic dimensions, these can be in just about any combination imaginable.

 

[chez311]

For future reference - you might want to insert the image html/hyperlink on a new line, possibly with a blank line or two, after your text so its more easily readable and you don't break up your text so that instead of breaking up your sentence like this

You can have your statement and the image following it like this: