geometric tolerances in parts 1

[lejeanmi]

Is there a way to attach geometric tolerances to the dimensions of the 3D model? The goal is for my 3D models to have all the information necessary on them without looking at the 2D drawing. Then when the 3D part is pasted on a drawing, the tolerance would be attached to the corresponding dimension.
Thanks in advance.

 

[TateJ]

Yes. After you initially place the dimension, you can click it and add all the same toleranc information as in a drawing.
But - as I see it - you're going to have other issues.
Unless your part is an extreemly simple one - say, a widget, for example - the dimensions you pull in from the model are never going to be presented on the drawing page as you would like to see them. They just never drop in at the right place. You'll always have to drag them around - or delete and replace them. And if you want to see ordinate dimensions in your drawing - forget about it.
Believe me - I've tried, and tried - you're much better off building you model with the perfect dimensions and then dimensioning the drawing the hard way.
Now, my experience is with 2003 - haven't seen 2004 yet - maybe it'll be better.

We'll raise up our glases against evil forces.
Whiskey for my men, beer for my horses!
T.K.
tatejATusfilter.com​

 

[Regg]

While you can attach tolerances to dimensions as in drawings. Notes for datum planes, concentric, flatness, etc cannot. You can attach them to their respective surfaces. The only drawback is that if you turn on annotations in your assembly, all these notes will show up (can make for a very cluttered assembly). I do agree that the model should contain all information necessary to make the part. I worked on a project where that was done (we sent out the parts to be detailed). It took alot of time upfront but saved time later when you did not have to go back and try to remember what tolerance was needed where.

Regg

 

[StarrRider]

Hay Regg

Is that a normal practice with your company? I just finished detailing about 40 drawings for a company a couple of weeks ago. None of the models had any tolerances specified in them - so I added what I thought was reasonable. I got Fax mark-ups over the next few days. The thing is - I spent more time changing the drawings than it took to create them in the first place.

The customer was happy but I kept thinking that there has to be a better way of doing this. I know that they spent more time checking these drawings than they should have. Part of the problem was that they didn’t have (or make available) a cheat sheet and I had to improvise.

Lee

Consciousness: That annoying time between naps.

 

[Regg]

StarrRider,

What I described was a project done for one our companies overseas. Normal practice is to put dimension tolerances in models, especially on critical bores and shafts for bearings, etc. This "implies" finish surface and RMS value. Also dimensions put in at x number of decemial places follow standards in drawing title block (also can imply finished surface {some of our designers color-code finished surfaces}). Raw material is put in ( ). No geo-tolerencing notes, etc (although I have asked SW for an enhancement to be able to add these to sketches {I feel they are important}).

I have found it easier to put tolerances in when doing sketches first time around. Although I cannot say I always do this especially when I am concepting or modifing someones elses work for my design (and then find tolerances on drawing when I make new ones).

Best Practices....another subject for another time.

Regg

 

[TateJ]

Are you guys modeling parts that are going to be dumped into a CNC machine for production? That would be the only way I could justify putting the extra information in the model dimensions. In my experience, the machine shop will manually input the geometry anyway, so they're basically just reading the paper drawing. And the clean-up time I see with INSERT MODEL ITEMS is just about equal to the time I spend dimensioning the drawing anyway. So it's a wash. What am I not getting here? Maybe the difference is you guys have the CNC stuff in-house and we contract all that out to the lowest bidder of the week. Also we need one or two only and maybe you are mass-producing parts. Just what is the dang deal anyway?

We'll raise up our glases against evil forces.
Whiskey for my men, beer for my horses!
T.K.
tatejATusfilter.com​

 

[Regg]

Putting tolerances on the model upfront can save time if someone else does the detailing. The detailer does not have to guess what tolerance you want and the designer spends less time having to send the detail back to have it corrected when that guess is wrong. Showing design intent takes awhile to get use to.

Yes clean-up time can be a wash. We only make one or two parts also but those parts most times are used as reference for future designs.

In the end I think any system can work. Unfortuanately every individual has a preference. That is why I believe a company has to set up Best Practices so everyone at least trys to be on the same page.

Regg