Mirror Parts

[GunT]

Hello,

What is the proper way to Dimension and Tolerance "Mirror" parts? Should Mirror Parts need to be completed D&T as any other part or is it sufficient to show only D&T that is different from the Original Part or is it somewhere in between.

Thanks in advance

 

[ctopher]

We treat all parts as a separate dwg with D&T. In some cases, we have had tooling dwgs with the main part and mirrored part on the same dwg, the main detailed and the mirrored part with a note stating it is mirrored.

Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP3.1 / PDMWorks 05
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716

 

[GunT]

Thanks Chris. But is there any ASME/ANSI/ISO standard that deals with this issue?

 

[ctopher]

Not that I'm aware of. I just did a quick search and can't find anything about mirrored parts on dwgs.

Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP3.1 / PDMWorks 05
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716

 

[ewh]

While it is not the current standard, MIL-STD-100G states that it is acceptable to detail only one of the parts and note which part no. is shown and which is opposite.
If there are differences between the parts, they are not true mirrors. In this case, I have seen it done in a similar way, with the different details noted as XXXX-1 only or XXXX-2 only (-1 and -2 being the preferred method for numbering opposite parts). I don't know how closely this follows the latest standard.

 

[ctopher]

ewh, I have seen it drawn that way also. I think that is how I would do it.

Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP3.1 / PDMWorks 05
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716

 

[wes616]

Ewh,

That method is classic aerospace. I have a copy of a LMAO design standards that lists this (suffix indentifier) method, or mirrored componets.

It is also common to our companies drawing practices. Based on Mil-std-100 (now ASME Y14.100-2000.)

Wes C.

 

[ctopher]

wes616,
Do you know what section in Y14.1? I must have overlooked it.
thanks

Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP3.1 / PDMWorks 05
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716

 

[GunT]

I have two parts(-001 and -002) which are same except that they have Counter Bored Holes on opposite faces. They mount onto to a third part(two sides of the base plate). Its important for me to control the parallelism between the two mirrored parts (They are not mated to each other, but rather mated to the base plate)

In this case, can I just specify three datums for the first one and put a note on the mirrored one?

Or do I need to exculsively define my 6 datums (3 for each). And dimesions everything of that.

Thank you all

 

[wes616]

Chris - I apologize. That is from mil-std-100, which was s/s by Y14. but I don't have a copy of y.14, so i couldn't tell you where it is, and I said that because y.14 is supposed to have all the govt. approved practices included. But i think they are in special indices or something.

GunT - If you are drawing the mirrored part, then specify the datums directly, if you are only calling out (-2 OPP) Then obviously there would be no need to define the datums for the second part.

If the part is a true mirror, there is no need to draw again. This comes from the "don't duplicate work" idea behind these drawing practices. I say, feel free to call it out as:

-1 PART / -2 PART (OPP)

Wes C.

 

[GunT]

Thanks Wes. The part is a true mirror.CB holes for Right Part(-001) are on the right face and for the Left part(-002) are on the left face. But is there no need to specify the "Mirroring Plane" explicitly? Is there any standard procedure to do it?

 

[wes616]

GunT,

It would be redundant to do so, from what I can tell of the situation. Unless your symetry is very unusual, the mechanic making the part would be just fine with the callout.

Wes C.