Tangent lines permissable on a 2-D drawings?
Tangent lines permissable on a 2-D drawings?
(OP)
My question is, If you are detailing a drawing, in the standard 2-D views is it acceptable to leave the tanget lines visable on the drawing. With the Iso view this is common practice but I believe it is becoming more of an accepted practice. Can anyone confirm what I'm saying or am I incorrectly detailing 2-D drawings?





RE: Tangent lines permissable on a 2-D drawings?
I'm not real thrilled with having tangent lines or nothing as the only options, but the tangent lines add clarity. ... sometimes.
I don't know what the various standards have to say about it.
Mike Halloran
Pembroke Pines, FL, USA
RE: Tangent lines permissable on a 2-D drawings?
I don't like tangent lines but I will sometimes turn on one or two in an orthographic view that looks like an unintelligible blob without them. Some times I'll draw in the imaginary lines but that kind of defeats the purpose of parametric solid modeling. I don't even show all tangent lines in an iso view as there tend to be way too many and our iso views are usually small.
RE: Tangent lines permissable on a 2-D drawings?
My thoughts exactly, but I have a co-worker that is 2 decades earlier than myself, and I do believe that this type of drafting was frowned upon at that time. With that being said and having to work with other countries, the more information that you can put on a drawing the better. It closes that door for interpretation, which in our case could be in the tens of thousands of bad parts.
RE: Tangent lines permissable on a 2-D drawings?
I do remember during my manual drafting days that you are correct and it was a way of not blurring the views and making them hard to visualize. We use Solidworks here for our CADD package and I think that the program does a real good job of making the drawing views very clear.
RE: Tangent lines permissable on a 2-D drawings?
If it may lead to confusion, or a messy/busy/crowded... drawing, leave it off.
Put the minimal information required to explicitly define things - less is sometimes more.
Before I bother looking, what drawing standards, if any, do you work to?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Tangent lines permissable on a 2-D drawings?
Chris
SolidWorks 10 SP4.0
ctopher's home
SolidWorks Legion
RE: Tangent lines permissable on a 2-D drawings?
Here are the main ones that we try to always conform too.
ASME Y14.100-2004 Drafting Standards
ASME Y14.5-2009 Dimensioning and Tolerancing
Tom - automotive
Virginia
RE: Tangent lines permissable on a 2-D drawings?
I'd look in Genium or Global but don't really have the time right now.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Tangent lines permissable on a 2-D drawings?
Adding clarity requires dealing with SW's drawing editor, which I _really_ hate, mostly because it actively fights doing anything in a way other than whatever the hell way Dassault thinks things should be done. There must be some Gallic logic to its schizophrenic behavior, but so far it eludes me.
Mike Halloran
Pembroke Pines, FL, USA
RE: Tangent lines permissable on a 2-D drawings?
Tom - automotive
Virginia
RE: Tangent lines permissable on a 2-D drawings?
"Imaginary intersection lines (such as fillets or rounded corners) may be indicated in a view by means of continuous thin lines, not touching the outlines."
I don't know of a single solid modeling system that can automatically produce those lines. I can manage to fake it sometimes & keep associativity with the model if I have dimension lines to sharp corners that were subsequently rounded. I can drag & break the dimension leader line so it can also make an imaginary line.
We really should beat up on the CAD companies to get them to implement this functionality. I'm sure they could if there was enough demand. They implement tangent lines just because it is easy for them to do so but they really have no place in proper drawings.
RE: Tangent lines permissable on a 2-D drawings?
RE: Tangent lines permissable on a 2-D drawings?
I agree that SolidWork's 2D drafting is adequate, rather than excellent. My 2007 version has the option of adding tangent lines has heavy, solid line, or as thin phantom lines. I add the thin, phantom lines when I think it will make make drawing clearer.
I mess with line thicknesses when I think it makes the drawing clearer. This includes side views of chamfers and other oblique angles, and it includes foreshortening of parts with messy front and rear features. Back in the old days, on a drafting board, I would break the distant lines as they approached the lines of the front features. There is no convenient way to do this in SolidWorks.
RE: Tangent lines permissable on a 2-D drawings?
*Some time Intersection also used :)
NX 6.0.2.8 MP4
Teamcenter 2007
WINDOWS XP (64 Bit)
RE: Tangent lines permissable on a 2-D drawings?
SolidWorks does. Check "Hide Ends" in "Tangent Edge" settings. Unfortunately only works for straight edges, revolved features are not supported yet.
And Mike, about "schizophrenic Gallic logic".
Solidworks is located in Concord, Massachusetts.
RE: Tangent lines permissable on a 2-D drawings?
Re "schizophrenic Gallic logic" Salidworks is owned by Dassault, a French company.
RE: Tangent lines permissable on a 2-D drawings?
Some shapes may be better off dimensioned to tangent line, but if "sharp corners that were subsequently rounded" are your game, SolidWorks calls them "virtual sharps"
htt
No need to fake anything.
RE: Tangent lines permissable on a 2-D drawings?
RE: Tangent lines permissable on a 2-D drawings?
I understand what imaginary lines are, I just feel uncomfortable with using the word "fake" next to "dimension", and I was trying to point out that until software companies start do things your way, there is an alternative that allows you to dimension with precision.
RE: Tangent lines permissable on a 2-D drawings?
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net
RE: Tangent lines permissable on a 2-D drawings?
RE: Tangent lines permissable on a 2-D drawings?
The traveler carries all the information that is needed to make the part("says here"). The problem occurs when the paper drawing is used on the shop floor to clarify something and it becomes the final word.
Some companies make the 3D model then use it to create a paper drawing. I always ask, "What has the final word in a released part?" It comes down to "Paper or plastic (silcon)?"
Certainly, we all miss the paper drawing days. I've seen some mfg engineers add things on the face of a paper drawing, attach it to the traveler and then write the change order back to engineering which references the hand-modified drawing. They don't know that the engineering CAD program can't do it.
Some CAD programs like CATIA have first-rate 2D drawing tools built in to make the paper drawing exactly as wanted. In my opinion, this is why Autocad continues to be so popular -- 3D modeling plus a robust 2D drawing ability.
Frank
Frank Reid
Reid Engineering Services of Utah
-
You'll never know what you are worth until you learn to say NO.
RE: Tangent lines permissable on a 2-D drawings?
It all depends on where you work, what you need fabricated and who you send it to.
We send out drawings. I suspect that a lot of our SolidWorks stuff goes out exclusively as DXFs. Whenever I have control over the process, I include PDFs, ensuring that my lines, my tolerances and FCFs are shown as I intended. I don't think we send out much paper anymore.
Clear tolerances are absolutely necessary, and are hard to specify on 3D models. Telling the CAM programmer what you want is easy. Telling your machinist and any inspectors what you want is more challenging.