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Is showing hidden lines a good practice..

SRINIVASANIYER1

New member
This thread has been started to get your views as Mechanical Engineers and not as Pro/E users.There was a thread by puppet on what you would like to see on a drawing? There was also a view expressed by me in a thread that Hidden lines should never be shown in a drawing as a good practice though "Technically Correct". Instead one must add as many Sectional views REQUIRED for complete definition of geometry. This does not mean superflous data, but just the required data.


There was also a view expressed by Scubadude which I reproduce:


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I beg to differ on NEVER showing hidden lines. Having cut my teeth as a hand drafter for 5 years while getting my engineering degree, I feel that this is one of the most overlooked issues with engineers in general, especially new engineers. I believe it's BAD FORM to NOT show hidden lines. A drawing should have the least amount of views possible to completely convey design intent. To add views, simply because its easy, is not a good practice. I always add an orthogonal view to help clarify the part. I wouldn
 

burnsp

New member
My $.02...I also spent a lot of time 'on the board'and now spend some of it on CAD. In the old days it was much moretime consumingtodraw a new view so hidden lines were used to helpclariyspecific views. Now it's much easier to add a view and the need for hidden lines is perhaps less. Today, I think the use of hidden linesshould be determined by the simplicity of the part, size of the drawing sheet and perhaps whose making the part. Maybe these aren't the technically correct reasons but they are reality. I do agree that the ortho view is really helpful and try touse at least one, sometimes two if it's necessary. I'll even put hidden lines on some views and not others. One thing I don't do is dimension to a hidden line. IfI feel the need to do this, I'll add another view or create a cross-section.


In my opinion, use hidden lines if you want and add views if you want. Do whatever is necessary (within reasonable standard practices) to clarify what your intent is. The shop making the partusually doesn't care if the drawing has hidden lines or not - they just want a clear, conciseand dimensionally correct drawing.
 

twincam88

New member
.02 cents more


I have 25 years experience in the toolmaker trade with the last 10 as a
cad/cam programmer for 3 to 5 axis machines. I am also selfteaching
myself pro-e now because of customer demand. any machine shop out there
that is not driving there cnc's with solid model cad/cam is not going
to last. in reality who needs a print ? I program all our cnc's with
solids. I do make prints when needed but I like to stay away from
hidden lines because of clarity. so



+1 for the no-hidden
 

dr_gallup

Moderator
There is nothing incorrect about hidden lines but I avoid them whenever possible. We have our templates and drawing configs all set to default to no_hidden and no_display_tangents. When I need to use hidden lines I will selectively display only the ones necessary. I hate drawings with hidden lines in every view, they just add clutter when over used.

I think there is some art to cleanly displaying everything needed with as few views as necessary. I like to keep drawings small when possible because most people are going to print them out on A or B size paper. Small drawings can not have a dozen part views.
 

burnsp

New member
Like it or not, the reality is drawings are still used and still needed, especially for inspection. Computers didn't create paperless offices and CAD/CAM won't create paperless shops for production work, at least in the near future. Believe me, I'd love to not have to create drawings but for now, it's a necessity.
 

jrobi

New member
twincam said "driving thier cnc's with 3D"- and hes right on- shops that still have guys typing in g-code are packing thier own caskets. .02
 

burnsp

New member
I think they'll be packing for another 20 years at the current adoption rate - too many issues with tolerances,reference surfaces and inspection.
 

twincam88

New member
like it or not guys. we have grown big because we are able to produce
from cad data. the turn around times of today do not allow time for
making prints. we have dedicated customers designing rapid prototype
that need parts next day. they design it, I program, it cut, and we
ship it. Tolerancing is fairly easy to handle. set up a standard for
holes based on the dia's extruded use colors for surface tolerance
changes. CMM inspection was mentioned. We do it the same way. Inspect
to the same model that we program the CNC to.



Im not trying to be harsh, Just explaining how we have gotten to where we are at this shop
 

burnsp

New member
"the turnaround times of today do not allow for making prints" That's a pretty bold andonly partially truestatement - it completely depends on what your market and competition is.


Somehow ourseveral billion dollarworldwide company with consistent 15% annual sales growth struggles along with prints. Yes, we are changing, but it'snothappening overnight.
 

cjdolle

New member
If you're going to go paperless you better make sure the purchasing, and quality departments know how to use Pro/E not to mention your final assembly department if you have one.
 

daiosama

New member
There are many tools out there that allow one to view parts without
requiring a pro-E license. The simplest of course is
acrobat. But there are a number of 3-d viewing programs that
allow a user to take dimensions, cut sections, etc.
 

SRINIVASANIYER1

New member
Thank you all for the replies and inputs.


Personaly I am very much against showing hidden lines in a drawing because of certain costly misinterpretationof the drawing on the shop floor during my "drawing board" years and"AutoCAD" years. Hence I make it a point to standardardize the practice of not showing Hidden lines in a drawing because it not only adds to the clutter but also leads to mis-communication (may be for simple drawings it may not make a difference).


This certainly does not mean showing multiple views just for the hect of it, but to have all the information in the drawing clearly and unambiguesly defined, with minimum number of views and without hidden lines ofcourse. There are many ways of doing it e.g taking scrap section, Half section etc.


As dr_gallup said, "it is an art", which needs to he honed over the years.


Thanks once again.
 

cjdolle

New member
I didn't know acrobat could import a Pro/E file and allow you to view the model and iterrogate it. Is that in version 7.0???


Do the 3D viewers allow you to see 3D notes, geom tolerances and parameters???That would be great and save a heck of alot of money.
 

hrj0

New member
daiosama said:
There are many tools out there that allow one to view parts without requiring a pro-E license. The simplest of course is acrobat. But there are a number of 3-d viewing programs that allow a user to take dimensions, cut sections, etc.

Please namea few ofthe 3D viewers, which allow you to see dimensions, 3D notes, geom tolerances...
 

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