Fillets in the draft

[Mans]

This time I created an irregular shape with some curvature elements to transfer it to the drafting and also made it more complex with applying some fillets and also created a dint on one of the elements with a hole that neither has the shape of a circle nor an ellipse.

Well, this shape was changed into an approximate complicated shape for measurement in drafting.

The curves of the shape themselves make not problem, but the dint (No.1), its unknown hole plus to the various fillets makes the measurement difficult and messy.

Also specifying the dimensions between two filleted elements makes me confused that whether I should base the larger boundary of the fillets or smaller.

What I have to do with this problem? do I ignore fillets and specify the dimensions based on the main shape (without fillets) or I have to do measurement with the troublesome fillets?

Thank you

 

[MrCATIA]

First of all, I think you mean "dimension" when you say "measurement"

How you dimension this part depends of the accuracy you need when the part is made. This looks like a formed sheetmetal part, so most features do not have to be made that accurate. If this is the case, drawing of this type will usually have a note that describes all the fillet dimensions. Something like "1. ALL RADII 2.5mm UNLESS OTHERWISE NOTED" Or maybe something like "2. MAX INSIDE BEND RADII 0.5mm UNLESS OTHERWISE NOTED.

The round hole in the dint (No. 1) may be dimensioned several ways. Assuming the roundness in not important, a Ø10±2 dimension might be used with a large tolerance to specify the irregular shape. (If the curves will not permit a diameter dimension, a Text With Leader might have to be used instead). Or, a drawing note might be used such as "3. DRILL Ø10 HOLE BEFORE FORMING DINT NO.1"

Fillets or other features that need to be more accurately specified might have section views or detail views that contain all the necessary dimensions to make and inspect the part.

 

[Mans]

Thank you very much

First, I used measurement in some places of my comment because I saw in a dictionary that one of the meanings of measurement is:

noun 1. a quantity or size, found by measuring - He took the measurements of the room. - The piano wont go through the door are you sure you took the right measurements? - The measurements of the box are 25cm x 20cm x 5cm.

Is it a wrong usage of the word in drafting? If it is so I apologize you.


second, another question raised in my mind:

Is one plan of the shape with the same three views (supposing with perfect dimensions) enough to be offered to an engineering or manufacturing environment such as a company or factory, or it needs some other supplementary plans to light the details of the object more? (for example some additional sectioned views plus to the main plan)

Usually, what is done by engineers, planners or draftsmen as a routine; offering just one plan or a few separate plans of the design?

 

[MrCATIA]

….. Is it a wrong usage of the word in drafting? …..

Yes, this is wrong usage.

Measures are, as the definition above, "found by measuring." In CATIA, the use of the Measure and Measure Between and Inertia tools would be considered "measures."

Dimensions are specific to engineering drawings and they indicate the size or position of a feature. Dimensions often include a tolerance, and may include other annotations.

Also, I think you are using the term "plan" wrong (at least in terms of engineering drawings). A drawing consists of one or more views that describe the size and shape of a part (or assembly of parts). Simple parts can be described with two or three views. More complex parts may require many views, that are often placed on multiple sheets. With the advent of 3D CAD systems (such as CATIA), currently many drawings include a 3D pictorial view as an aid to describe the shape of the part.

 

[MrCATIA]

…. another question raised in my mind:

Is one plan of the shape with the same three views (supposing with perfect dimensions) enough to be offered to an engineering or manufacturing environment such as a company or factory, or it needs some other supplementary plans to light the details of the object more? (for example some additional sectioned views plus to the main plan)

Usually, what is done by engineers, planners or draftsmen as a routine; offering just one plan or a few separate plans of the design?

To avoid confusion, only one drawing should be made to fully describe a part, so that the part can be made without any discrepancies. Depending on the complexity of the part, the drawing may require multiple views to specify the shape of the part, with each view containing multiple dimensions to specify the size of the part. The drawing should also include: Part Number, Name, the material, surface finishes, and coatings, tolerances (such as GD&T), and other information necessary to manufacture the part.

The part shown in the pictures above, would probably require 3 or 4 views, plus 2 or 3 section views.

 

[Mans]

Thank you very much


Your comments enlighten me a lot. From the beginning of working with the two engineering software, AutoCad and Catia I mostly was interested to work in 3D and didn't pay attention to drafting except a little for taking the patent of one of my innovation that was a wrench (about 5 years ago). At the time I was not familiar with Catia and I sketched its 2D draws with AutoCad, though its dimensions was not standard.

Last week I saw a calling for a job in a factory as a draftsman. I contacted the manager and claimed that I'm a capable designer and send some of the pictures of my works for him. He called me for an interview and in the session asked some questions. He was an old and experienced engineer and his first question was this: " Have you worked in an industrial place yet, and are you familiar with production techniques?"

I replied honestly, no I have not worked in such the places and was not in a production environment yet."

As well as, he asked some other questions (among about drafting) to realize my abilities and talent. He finally said to me, sorry I can't accept you because despite you have a potential thought in designing but you are a person that worked for yourself and haven't any experience working in the manufacturing stage. I hope you get not bothering of me but you are not capable for this job. and finally a bitter goodbye for me!

I left the office thinking, sad and unsatisfied. I was angry at myself that why I didn't work during the years based on the standards according to realities of industry.

As I was going back to home uneasy I was thinking, what my greatest defect in designing is, with regards to conditions of working in a company or factory? I analyzed myself and found out some failures, but the greatest one was my shortcoming in drafting. I realized, my ability in innovation and designing in 3D is not the only qualification that is expected for working in a company or factory as a draftsman. Although I haven't an engineering degree but my free studies in the industries and technical matters plus to my talent and experiences in designing have made an engineer of me approximately, during the years. I said to the factory manager, I haven't the degree but he called me engineer frequently due to visiting my works.

From the time of leaving the factory and recognizing my failures about working for a company I decided to compensate my shortage and work on the techniques that are necessary for working in a corporation or industrial factory.

The failure mostly limited to two things; removing my shortcoming in drafting, and memorizing the standards (numbers, symbols, scientific terms and so on) that are used vastly in the industries and manufacturing.

Now, I start up! The first step is that to complete my drafting along with memorizing the terms. I think, it take not long.

The trouble of learning is more tolerable than tribulation of feeling shortage and weakness.

 

[MrCATIA]

Sorry the job interview didn't go as you planned, but it sounds like you have gained some great insight into what's required to work in the manufacturing world. Use this as a valuable lesson and I wish you the best with the next job opportunity.

 

[Mans]

Thank you sir

As you pointed, it was a great lesson for me that demonstrated what I need to do in this serious and absolute technical world to be acceptable. Sometimes, realizing our defects and shortcoming seems bitter (I example myself), while the realization can be the start point of our movement toward perfection by removing the failures with study and learning techniques more and more.

Yes, the bitter unsuccess and embarrassment taught me to achieve the knowledge and skills that I need for entering the industry world practically.