particular quotation, do you think it's okay?

[costalola]

Hi, I'd like to confront you.

is it correct to quote the piece as I indicated in the attached drawing? ?
I refer only to the quota in red, corresponding to the vertical distance of the 2 holes.
otherwise how should I do it? I am interested that the quota refers to between the 2 holes and not to the walls of the piece, that I can also be rather unprecise.

thanks and hello

 

[PierArg]

Hi.
I've never seen a quote like that. to make it clear that the holes are on the same axis you should use a slight horizontal (tract-point) that passes for the two holes centers. in particular would be the one you have quoted with 20

 

[c._mauro]

I think it's actually wrong, in my short experience I've never seen anything like that.
I would put the tolerance on the 20 which represents the distance from the base, despite what you say you do not care that the holes are at height/2.
But wait for someone more experienced than me, I can be wrong. . .

 

[gerod]

I would say that 0h7 is at least abnormal.
it is not correct because it assumes that there are two lines (the quotas are made of 2 lines of reference + that of quota) but in reality do not exist.
follow what pierarg says.
Hi.

 

[PierArg]

Excuse me, but why do you use 40 h7?
I remind you that letters are used for mating. in case of simple linear quota you have to put only the shocks.

 

[cacciatorino]

According to me you have to put a 3.2 or 1.6 working sign in the lower surface, and then put a 20 +/- 0.01 on both holes. Consider that the alignment you want to achieve makes sense only if you define even in relation to which plane the two holes must be aligned, and this you can achieve in the way I told you, that among other things I think it is the only one to allow those who make the acceptance to verify the conformity of the piece with the project.

 

[costalola]

the initial piece could be an extruded trade that I do not want to spy on, is an unjustified additional cost.

put a horizontal line, not from an indication of tolerance to the operator who has to do mechanical processing, I have to circumscribe it somehow.
the question is how do we indicate tolerance on the vertical? ?
If for example it was 0.5 h7 on the vertical (lightly shifted hole) nobody would have anything to say, but if you wanted them aligned?? How can I say how much I want them aligned? ?
is not such a trivial problem as you might think

ps: This comes to me new that you cannot put the letter on a quota, why do you say so? What rule do you mean?

Hello everyone

 

[cacciatorino]

the initial piece could be an extruded trade that I do not want to spy on, is an unjustified additional cost.

I'm so sorry, but then that 0/+0.01 over what plan do you mean? If the reference supericie is rough (and therefore it will not be flat) how do you say that the two holes must be at the same distance with tolerance 0.01 mm?
I think if you don't spy on the surface that tolerance you indicate doesn't make any sense.
when you send the piece to test, you have to put the operator can make the measure: The first hole is at a certain distance from a plan that you do not know well what it is, the second hole must be at a distance equal to less than the tolerance indicated, but always with reference to a plan that surely so much plan will not be because it is a rough... You know, things aren't going.
In practice, before you define a quota system, you have to implicitly define a x-y reference system, which in your design is missing because the axis you want to identify the x axis is actually a more or less irregular primitive, result of an extrusion made as. Your reasoning would be fine if the tolerance was a few tenths, but if you're looking for the penny it can't work anymore.

I sincerely would have to say even if those holes were disapproved of 1 mm or 10.

 

[PierArg]

ps: This comes to me new that you cannot put the letter on a quota, why do you say so? What rule do you mean?

I always used the letters on the matings of the type hole-shaft. capital letters should be indicated on the holes while the lower ones on the pins/albers.
I have never seen, nor used, letters to indicate tolerance on linear quotas (such as a distance between two holes, a thickness, a length of a plate and anything else).

I hope someone corrects me

Thank you.

 

[MBT]

I'm so sorry, but then that 0/+0.01 over what plan do you mean? If the reference supericie is rough (and therefore it will not be flat) how do you say that the two holes must be at the same distance with tolerance 0.01 mm? I think if you don't spy on the surface that tolerance you indicate doesn't make any sense.

And here is all my approval!

at the limit of the theorist you may use a localization tolerance, but regardless of the indication you can put is the wrong concept.

as rightly says hunter, you can't accurately tolerate centesimal a processing that refers to a rough surface, or however of which the condition is not certain.

would be like to tolerate +/- 5 mm the height of a pole planted in the gravel

 

[zeigs]

Consider that if the surface of support is rough, it does not make much sense to talk about alignment of the two holes. also because ok, you want them aligned, but how is the assembly of the detail? on the lower floor? because if it is not so it makes no sense to define the alignment of the two holes, they are anyway.
otherwise on which surface rests? that of the tool machine is good, so a reference plan "is created" itself by leaning on it, is it equally in operation? because if it is not you can not replicate the same placement and the horizontal alignment goes to copper.

I would use the allego symbolism (l-23 of baldassini)

last known purely personal: I prefer to put scaffolding in linear dimensions, rather than quality, those I use only for holes and trees.

p.s. I have seen now that things have already been said, but when I started writing those answers there were not yet

 

[costalola]

you are right, in a hurry I made an incorrect example.
the question, is understand how I can quote the 2 hole compared to the first, without referring to the side planes of the piece.
I do not see why the possession of the second hole cannot be related to the first hole (which is usually done if the holes are not aligned), the question is as if they are aligned.

hello, and thank you all for this pleasant exchange of views.

ps: in my opinion there is no normative reference that prevents using letters to indicate the quotas any quota it is, it is only a more compact notation.

 

[costalola]

I answer to zeigs.

That's what I thought.
But then I thought about this:
Your choice requires you to perform both holes with great precision, as you undelete each other by referring to the side walls.
This is uneconomic, to me only the 2 is well aligned with the first; That's why I wanted to get out of the side walls.

 

[cacciatorino]

I answer to zeigs.

That's what I thought.
But then I thought about this:
Your choice requires you to perform both holes with great precision, as you undelete each other by referring to the side walls.
This is uneconomic, to me only the 2 is well aligned with the first; That's why I wanted to get out of the side walls.

Therefore, to define an alignment, there must be a long line to align.

if you only need the holes to be very precise at a distance, and then the two holes are on a large parallel line to the lower side of your extruded, just put only the interasset in tolerance.

 

[MBT]

the question, is understand how I can quote the 2 hole compared to the first, without referring to the side planes of the piece.
I do not see why the possession of the second hole cannot be related to the first hole (which is usually done if the holes are not aligned), the question is as if they are aligned.

You can't do anything about the side of the piece!
in which direction misuse the distance between the two holes? What do you say is correct or not?
physically, I mean, how do you check that share? or mix both holes with a plane or, measured a hole, check the other one on the same line. but also in the second case to track the line you have to use a plan as a reference!

as rightly written to you, you must see what the "function" of the piece is. if you have to lean on a face, that will be your reference for quotation and for relative tolerances. If it stays suspended in half air, everything loses meaning!

 

[Alberto.E]

cost it, you can't say that you just have the holes aligned, because then wherever you piss two holes are always aligned (for two points passes a straight) don't you think?
all lies in defining a reference to which the straight that unites the two holes should be placed. You must have a reference point.
the design that you did at the beginning is fine (excluding that awful and wrong 0 h7 and 40 h7), then to the axis that joins the two holes you can apply a geometric tolerance of parallelism compared to the base of the piece and add a tolerance to the quota 20 and then it is enough, otherwise it becomes an overquoted design that only creates confusion. Also remember that all odds that are not tolerated are regulated by general tolerances, do a research and apply a general tolerance that respects your needs.

 

[costalola]

I can only add that I thank you all.

Hello again

 

[SHIREN]

Hi.
I draw my mind
can be critical
But it still works
Thank you very much

 

[maxopus]

I would do it like 20 for the 2 holes... and good night.
I also do not understand how to interpret the indication 0/+0,01 ... is not unique.

 

[sampom]

..I would take a tour of the workshops with the drawing of his beautiful plate in his hand.:biggrin::tongue:

do not want me, you joke. but certain things cannot be seen (no hear).

greetings
Marco:smile: