Dimensioning to hidden lines

[Michael Reynolds]

Is it against ANSI standards to dimension to hidden lines??

Thanks in advance!

Mike R.

[mcrae_andrew]

Dimensioning to hidden lines is just plain lazy - the elegant solution (as taught by most schools, what about yours Mike?) is to generated a section view for the hidden features. Most CAD packages make quick work of this.

[Michael Reynolds]

Andrew,

I'm sure our engineering graphics professors do teach that. I'm NOT one of them. I'm more into manufacturing than drawing. That's why I ASK QUESTIONS.

Thanks anyway,

Mike R.

[Colin G]

It's not an ANSI standard, but if it gets you the finished part more quickly, then go for it. Remember, the print is just instructions for the guy who actually has to make the part.

Just my 2 cents from having been a production machinist.

Colin Gilchrist

Gilchrist Consulting Services

[email protected]

[Will Slota]

I believe its lazy and unacceptable. It shows that the designer/engineer 1) either doesn't care enough about their own work to make their drawings clear, 2)doesn't have a comprehensive grasp of drafting "STANDARDS", 3)they're also generally the kind of designers/engineers who don't even bother to check if their tolerances stack-up and when you try to explain their mistake to them they get an attitude and tell you "make the part like I designed it. I know what I'm doing. I'm the degreed engineer." and then can't understand why assembly can't press fit the parts together. Or better yet why two differrent types of plastic bonded together and baked don't have the same thermal co-efficiency and one side shrinks more than the other and fractures the laminate.

I don't really mean to rant but nothing frustrates me more than crappy designs both under and over-engineered. Unnecessarily tight tolerances and in adequate or unclear dimensioning TWEAK me off.

On the other hand theres nothing like a KISS design with clear drafting and dimensioning to make a job pleasant to cad/cam.

[Scott Bond]

Hi

"Is it against ANSI standards to dimension to hidden lines??"

We must make "SOLID STANDARD",and put the ansii standard in a museum.

I have been making "The chassis from hell" for about 90 days.This is a part made to ansii standards,but the 2-d approach to the work allows the cad operator to make mistakes that he could not make with solids.

Friday and yesterday we had 8 man meetings with people that had big titles. I tried to pursued them to create solids for there simple 2-d type wire chassis company wide.The unanimous reply after two days of meetings was it was to hard to bring all of the engineers up to speed. Instead It was agreed to start a report every day for 90 days what will be wrong with the jobs.This will cause the team to prepare the excuses instead of the parts. I am disappointed with their approach.

[Michael Reynolds]

Since this was my question, I'll ring in again. First, thanks for the replies. I appreciate all of them.

I am NOT a "degreed engineer". I am a Journeyman Toolmaker who has a BS degree in technical education. That's why I post questions like this, I'm trying to get better at doin' drawings that are technically correct. And thanks to your replies, I am. I DO NOT TEACH drafting, so the parts I design are for the purpose of manufacture. I just don't want anyone to think I teach drafting without knowing the standards.

I have since "redone" the dimension to include a cut away view, replacing the hidden lines with solid lines.

Thanks again for your input!

Mike R.

[Scott Bond]

Hi

Michael Reynolds

 

I have been fixing prints and cad files all week.

My post on solids was more of a statement on

were I would like to see the industry go .(SOLID)

I didn't and I don't mean any offence to anyone.

[Michael Reynolds]

Hi Scott!

None taken!

Mike R.

[Will Slota]

Quote"I have been fixing prints and cad files all week."

Precisely why a clear concise intent and a standardization for "prints" is still necessary today.

[kathy]

It is a big draftig no-no (look at Ansi Y14.5M) to dimension to hidden lines!

It is permissiable to add a 'cutout' around the hidden area making it a 'sectioned view' and exposing the hidden features on the plan view, This will give you real features to dimension too if you don't want to create an actual section. It's hard to explain in words - maybe I'll get a picture to Jay tommorow.

It's worth wile for anyone making drawing to draft per Ansi Y14.M (imho) - you can be assured that everyone will understand what you want if you follow that standard!

Kathy

[johns]

I've worked om CNCs since '83. All my Mastercam work here since '90 has been in full 3D no matter how the design was generated. I spent time re-creating 3D from 2D up until '98 when I moved into design. I use Mastercam Design and our other design seats have always been Cadkey so I have no idea why all our mold design wasn't 3D anyway. If you have a design team that isn't 3D capable, replace them or train them. There is no reason to be afraid or hesitant of 3D. You wouldn't believe the number of serious errors I find building a 3D model from 2D. At present, at my insistance, all our designs in house and outsourced are done in 3D. If the design source won't do it, we don't give them the business. If designers aren't 3D capable, how will they make the transition to solids? I see a definite move to solids based design and in another two years or so, that's where we should all be for design. About half of our customers already are 100% solids and if we aren't compatible and knowledgeable, they would go elsewhere.