BigInch : I'm not surprised that "somebody" didn't know the meaning of "renumeration" - it's not in our big office dictionary. I suppose it could mean "The process of renumbering" (grin).
Now we might be getting somewhere .... which one of you is correct ? What exactly does the standard say ? I think conceptually and logically it ought to work the way drawoh seems to think, but the impression I get is that the standard is actually written the way ringman says. I also think...
ringman: The point is that I am assuming that it is specifically desired to orient the pattern of holes so that one reference plane is parallel to C - at least, that is apparently the design intent of person #2's drawing. This part (which is actually quite large) is being checked on a CMM -...
drawoh:
Well - I guess I am still not really getting my point across. I don't have a problem with anything you have said - I am not the person saying it should be A,C,B. The issue is not whether a particular interpretation makes sense, but what the wording of the ANSI Y14.5M - 1994 standard...
drawoh:
I am not disagreeing with you - I am in conflict with person #1, but I don't know enough about the standard to know if it is being interpreted correctly or if there is something wrong with it. The issues boil down to this:
1. If you make B the secondary datum and C the tertiary, is...
ringman: I don't think you quite follow me - the slot does not go through the B axis - you cannot determine its orientation with a point on B and a point on the slot. And when you do determine it, as I understand it, you are supposed to be able to do it with points only, according to the...
ringman - C is derived from an off-center feature (the slot)- so as far as I can see, you cannot angularly orient the two axes through B using C, with only one point on C - you would have to use two points - both of them on C. Drawoh seems to be in agreement with this, unless I misunderstand...
ringman:
I don't see how you can angularly orient the two planes through B, using the orientation of C, with only one point, regardless of whether C is defined as only one side of the slot or the slot feature itself. With the A,B,C designation, the third plane does not necessarily pass through...
Thanks Drawoh.
This question came up because of an argument between two people, and one of them casually asked my opinion. Person #1 is the best expert we have in the plant and is GD & T certified at technician level (he operates our large CMM and consequently gets heavily into the subject on a...
Actually, I've just noticed on this recent thread1103-169440 that the ANSI standard section 4.4.2 seems to indicate that it should be A,B,C in this case. But still interested in any comments.
Suppose we have a cylinder, with an off-center slot extending right across one end face. Suppose the surface of that end face is defined as Datum A, and that the axis of the cylinder is defined as Datum B by using a datum callout on the diameter. Also, suppose one side of the off-center slot is...
I did not notice the two posts after my last one until now. Even today, friction is a controversial subject, but the following quotes are taken from a relatively old book I possess entitled : "The Friction and Lubrication of Elastomers". I think they basically support the comments I have made in...
MintJulep - Just out of interest, why did lockwashers ever become prevalent in the first place ? They used to be all over the place on cars and electrical equipment, and in some cases still are. Were no tests ever done ? When was it discovered that they are in fact useless ? Wouldn't the kind...
