True position with angle basic

[MJBolster]

I have a cylinder like a hub of a wheel with spokes coming out all around at 30 degree intervals- like a wagon wheel- easy to visualize I hope. Okay- I've pulled out all the spokes- so I now have the cylindrical hub with "empty" spoke holes all around. The holes are different sizes (.159 and 200").
Anyway one .159 hole is flanked by two .200 holes 30 degrees away on either side of the .159.
The question- the only basic dimension is the 30 degrees- What relationship
between the (two) holes is addressed by the feature control frame- the angle only? I'm having brain lock trying to figure it out so I can get Pc-dmis to
verify it. To frustrate things further, The hollow cylindrical "Hub" is relatively thin and the holes are shallow blind holes apx .16 deep- not much to measure.
I can construct lines between each hole and the center of the cyl. and get angle numbers that way- but Pc-dmis TP menu doesn't address angles- or does it??

Time to retire- for the long weekend anyway-
Any help guys
thanks
MJB

[Matthew D. Hoedeman]

I don't think you can TP an angle, you can dimension one, but I am not sure if an angle is a 'legal' TP function. How do you put a 'round' tolerance zone around an angle?

I would say the angle only is what is addressed, no location at all.

[cmmguy]

I think you will need to rotate to the angle... but without a drawing it is difficult to say exactly.

[slesholdofthreep]

In any feature there is a toggle field for polar or rectilinear coord system. Choose polar. This assumes of course that the datum is at the center of the wheel and that you know the radial disatnce from center for all features.

At second glance I'm not sure I'm getting it. Can you post a snippet of the print?

[MJBolster]

The datum is the center hole- .159

MJB

[John Riggins]

The datum is the center hole- .159

MJB

[MJBolster]

You got it!

MJB

Hey y'all They're shutting this place down till Tuesday-
shutting the lights off now.
Thanks all-
I'll check back in from home!

Have a good long one- did I say that out loud?
I mean long weekend-

[Kluong]

You should have bolt circle basic dimension and the angle, that way will take care the true position.

[cmmguy]

Welcome Kluong!! Thanks for your first post.

I think they are holes around the perimeter of the part and not on the face.

[QC Rick]

If the holes are on the circumference pointing outward or inward (as in a spoked wheel) then the Basic angle is the control. The holes diameter must lie within the basic angle by the given modifier of the feature. A polar radius won't suffice because the holes axis is in the same linear space. Each hole will have an intersection to the circumference at the basic angle, that is the target along with perpendicularity to the center line. A height from a surface may also apply.

If the holes are on a Bolt circle and parallel to the center line then a polar radius can be calculated and then the holes diameter must lie within the Polar Radius by the given modifier of the feature. (can also be done with XY coordinates) Perpendicularity may be involved.

[John Riggins]

TP with PA as the only variable will give you what you need.

[Barry Dawson]

Gday,
Agreed use Polar!
Man_Of_The_Year_1.jpg
Cheers

[cmmguy]

Me still thinks polar would make measuring the holes a pain also. Without rotating the CS to the basic angle, what will the IJK axis of each hole look like?

[inspector212]

Are you looking for angularity? Orientation without location.

[Barry Dawson]

Me still thinks polar would make measuring the holes a pain also. Without rotating the CS to the basic angle, what will the IJK axis of each hole look like?

Gday,
When you bring up "auto circle box"prior to measuring holes on perimeter select "polar" before measuring, vectors etc will be correct without rotating alignment. As long as your tip is rotated to the right angle for each respective hole you should be away. Also ask for polar when reporting if that is how it is drawn. Cheers Paul