Does anyone has or know where to find the solution to FIG.4-7 drawing from ASME-Y14.5M-2009. 2

[JGarcas]

I am dealing with a part that is using an inclined datum feature, and I will like to use as a reference the solution of FIG.4-7 sample from ASME-Y14.5M-2009, does anyone know where could I get this?

 

[greenimi]

Search this forum first
One example: here

https://www.eng-tips.com/viewthread.cfm?qid=500899

But could be many more

 

[axym]

JGarcas,

I'm not sure what you mean by the "solution" of Fig. 4-7. What specific information are you looking for?

Evan Janeshewski

Axymetrix Quality Engineering Inc.

http://www.axymetrix.ca

 

[JGarcas]

@axym

I meant the calculation of that specific example for the inclined datum feature.

I would like to have that example as a reference.

 

[3DDave]

cal·cu·la·tion
/ˌkalkyəˈlāSHən/
noun
a mathematical determination of the size or number of something.
"finding ways of saving money involves complicated calculations"

There is no calculation in that figure.

 

[greenimi]

I meant the calculation of that specific example for the inclined datum feature.I would like to have that example as a reference.

I think we have a language barrier here.
I mean not only GD&T language.

 

[JGarcas]

OMG guys, I guess people have not had their coffee yet. XD

I am asking if there is any place where I can find the true position calculation for Fig. 4-7 drawing.

Its a simple question, no need to think too hard lol.

 

[3DDave]

There is no calculation in that figure.

 

[JGarcas]

Ok, let me try again 3DDave.

How would you calculate the true position from that Fig.4-7 given the datums and other dimensions?

 

[3DDave]

The True Position is given by the basic dimensions.

If you want to calculate the deviation of the actual as-produced feature, from the true position, then you double the square root of the sum of the delta-x squared and the delta-y squared, just like for any other variation calculation.

 

[greenimi]

How would you calculate the true position from that Fig.4-7 given the datums and other dimensions?

Do you mean where Ø0.5 is coming from?

 

[JGarcas]

I was asking if by any chance there is an example for Fig.4-7, obviously with given measured dimensions, I just would like to know how you calculate the true position when you have a datum in an angle.

Thanks 3DDave.

I have a very complex part and I am having a very difficult time defining GD&T to check the part properly.

See the drawing attached, please consider what is shown is not right, it's just for reference.

Is anyone able to advise what would be the best datum structure, and GD&T callout, considering the bracket is in the open position, and the function of the part is to hold 2 flexible tubes in those radiuses and then the bracket is fixed to the small and big hole on the side, the difficulty is that you have 2 angles affecting that surface (87.2 & 17.2 degrees).

I appreciate the help.

 

[JGarcas]

Part 1 of drawing.

 

[JGarcas]

Part 2 of drawing

 

[JGarcas]

Part 3 of drawing

 

[3DDave]

It would most likely use a profile of surface tolerance to control the angled/tab surface; the datum features are sufficient to to that.

If you mean about the holes in the tab, you can just use the same 3 datum features as are already defined and add basic dimensions relative to those features, which makes sense if those are what locates and orients the part in the next assembly.

Alternatively, define the face of the tab as a datum feature and use the intersection of datum A with that datum feature as a dimension origin to control distance down the face and pick an edge to use as a datum feature and add a basic dimension to control distance across the face. Then a true position tolerance can use those references.

 

[3DDave]

I find that it helps to choose datum features by imagining what surfaces I would use to index the part in a machine if I wanted related features to be made in a single setup. I would tend to chose those same features as I expect will be used to locate and orient the part in the next assembly.

If the related parts are fixed in location and orientation by the mounting surfaces and hardware and cannot easily adjust to the variations in the part in question, then look at how much they can move and leave that much clearance.

 

[JGarcas]

3DDave


To give you a better picture, we produce the part in open position, then out customer assembly to the tubes and that whole assembly tubes + bracket goes to OEM, where is assembled to the car. I find difficult to have a datum structure based on functionality of the part, that could help make a fixture since there two surfaces are affected by those 2 angles.

I was thinking more about using same datums A and B shown in the drawing, but datum C change it to the small hole(6.5)located in the angled tab in reference to Datum A. The issue for me using Datum C as it is shown in the drawing is that using an edge will conflict with datum B when making a fixture.

Does it make sense to you to have C as the small 6.5 hole?

 

[3DDave]

With out knowing what all the holes are for, I can't make a meaningful recommendation. Does the face the other hole goes through orient the part? If so I'd use the face as an orientation reference rather than the hole, changing the angle to a basic angle and using a profile of surface tolerance to locate and orient it.

 

[JGarcas]

See attach for reference a picture of the final assembly in the car, just consider it is a defective part, that is why it is open.