quotation of a base to be soldered

[floppyes]

Hello, everyone!

I have a question regarding the quotation of a base, more precisely how to quota the profiles regarding one of departure. carrying a design of a base made up of four profiles welded each other, the prof told me that the quotation was wrong as there was a reference surface from which to start to place the rest of the components with the various tolerances.

I did not understand if I have to finish a profile surface with a high surface finish, then starting to quote the rest of the elements from that surface, or if the surface finish I only need to set the geometric tolerances on the components that will have to be mounted later on the base.

for example in the case of this base (I made it on the right flight to understand) how would you have quoted it? as in the case of left or right, or in any other way?
View attachment base1.PDFThis reference surface only serves me to set the geometric tolerances on the components that I will go up later, so as to have a precise reference for the measurements, or should it also be used for the welding of the profiles? (taking into account that all the base has an iso tolerance indicated in the cartilage)

thanks in advance
Hi.

 

[MassiVonWeizen]

o,8 finishing on a carpentry? hope that a nn miller will never see such a thing. but do you have a manual in which it is explained in which fields are used various tolerances?
carpenters do not need special tolerances during welding; only for the forces at stake of the weld you will never get them, then you should check out every single profile that is not crooked or snagged and other things that in a carpentry workshop can explain to you.
a reference plan can be used, based on precision and needs, only to make machining of particle removals. in this case weld plates in some points of the structure and cut them the way that the stirring in the machine make from support and feedback; such processing will be done by milling and a 12.5 is more than enough.

for quotation it is used to quote from axis to axis because then they will refer to other positions; but if quoti indicating the light of the profiles usually build the stess.
always the profil, the welder has neither time nor desire to look for the prontuary to see how wide an ipe 180 is and to make calculations.

probably on those beams you will have to make holes to fix something, here are those to be tolerated and therefore a refectory plan (the above plate) you need because the profile could be not perfectly parallel/perpendicular; if the profile below is at 392 nothing changes.

summing up:
your professor has to take a ride in the workshop and see how you work
you don't know what they need and how roughness is

the surface finish I only need to set the geometric tolerances on the components that will have to be mounted later on the base.

Geometric and dimensional tolerances serve to make machining, then often serve to make couplings with other components, but also not. not all processing require tolerances

 

[meccanicamg]

always there: incompetent teachers and students without experience. the carpenters normally follow only design where there are indicated quotas and tolerances of positioning plate and tubular and removal quotas of truciole post the various processes. everything must be indicated with a logical sense.
actually it would be possible to make two distinct designs: one for carpentry and one for mechanical processing even if often avoids uncomplicated post things to the carpenter unless the designer has skills on it.
Of course, the profile or pipe type is indicated with notes but they certainly put the measurements to place and therefore also the outer dimensions of the tubular or profile that it is.
if you have to put geometric tolerances on crude carpenters you will be sufficiently wide and will indicate it only if it has a well defined functional purpose