table tolerances, interpretation.

[stevio]

Good evening to all,
cause change of work I am approaching the field of sheet metal molds, I am a mechanical designer and for a long time we always discuss with regard to the table masses of the various plates of a mold, platelets, door matrices, hat, base, etc. etc.
The annexed table for general tolerances is shown on the cartilages of our designs. I press that I never see it, on the vademecum is absolutely not mentioned.

Is there someone who uses it and who can give me an interpretation?

Thank you.

 

[PierArg]

Hi, I've never seen her.
I think it's not even normal.

general tolerances (dimensional and geometric) follow the standard iso 2768

 

[Mocca]

Bye.
also in thermoplastic moulds, in some workshops, this system is adopted.
I make some premises:
1st the "zero mold" is located at the center of the mold and normally the x=0 and y=0 are located at the center of the steel block.
2nd the x, y and z axes of the mould design-design are oriented in the same way as the mold itself would be placed on the milling machine (e.g. the x axis is horizontal right direction; the axis of y is vertical high direction; the axis z is the axis of decommissioning of the tool- milling machine).
said this, when you go to plant the machining centers you will have to adopt the symbolism indicated in your table by imposing the digit with or without the decimal zeros according to their importance; i.e. if you have to quote the center of a seat for a plug (precise), and this is 35 mm from the mold center, its share will have to be 35,00.
another example: if you have to quote the center of a threaded hole, and this is 68 mm from the center, its share will have to be 68.0.
another example: if you have to quote the center of a "scaric" hole, and this is 123 mm from the mold center, its share will have to be 123.
in a few words you have to impose the decimal zeros according to the precision that the miller will have to follow in the processing otherwise on a "short" quota the operator can adopt the tolerance that believes why not indicated.
I hope I helped you.
we waved

 

[marcofor]

is a table that reminds me of the details that sent me a moldist time ago, according to him when the tolerances varied according to the decimal figures present after the quota es 5,00 ±0.01 the first series are the linear measures, the second the holes the third are scaffoldings for trees, however the system I never liked considering it a misleading thing I always prefer the sitema with general tolerances indicated in the cartiglio application and tolerances

 

[linch]

...... However I never liked the system I consider it a misleading thing I always prefer the sitema with general tolerances indicated in the cartiglio and specified tolerances of the point of application to simplify the life to those who realize the work and the system thus set on a hole of 180,00 would allow me 0.01 of tolerance practically a h4

I share in toto, I believe it is the right path to create great "casini" and various misunderstandings.

 

[SHIREN]

Hi.
there are companies using certain tables
that are part of an internal capitulation to the company
and when you rely on external work
must be delivered as well the corporate capitulate
on moulds of any technologgia
giving tolerances on the equipment is not really important
because the molder sure knows his job
vice versa the tolerances that count are those of form
in practice the relationship between who commissions the mold and who executes it
and this
make me the mold as you want
but the piece you need or must print must have these tolerances of form
or intera and similar things
Thank you very much

 

[zeffiro62]

the table is not in accordance with qmq is interpreted with its field of tolerance and quotation of decimals, if you have in the drawing a quota 100 tolerance will be 99.5 100.5
if on the drawing the quota is 100+ its tolerance will be 100 101
if on the diegno the indicated quota is 100.0 tolerance is reduced to 99.9 100.1
if on the design the quota indicates is 100.00 òa toleranza is reduced to 99.99 100.01
if she has 100.00- her tolerated size will be 99.98 100
I hope I've been clear

 

[stevio]

OK, thank you 1000, so far I was there, but the table creates a lot of disagreements and misunderstandings......
I don't like it.. .
the director likes so much and according to him it takes absolutely, denying the evidence, despite having pointed out many times that there is the big risk of wrong.... at this point sometimes you also have to "go behind the wave". .