Could someone do this for me (easy)

[es12]

Here is machine drawing I need to draw in Inventor, but I'm not sure if I fully understand the drawing. If someone could draw it properly I could check if my own drawing is exatcly right. Thanks!

http://i.imgur.com/NilgN.jpg

To me there's few measurements missing in the drawing and few unnecessary measurements included, which just tells my I can't figure out how to properly sketch it from the drawing 😛

[JDMather]

Is this a school assignment?
You state it is easy - attach what you have attempted so far.

I don't think someone is going to do your homework for you - but I'm sure you will get help if you show what you have done so that others can see why you are having difficulty with this easy part.

[es12]

No it's not school assignment. This is standard "Nato rail" used in guns etc (picture taken from wikipedia).

My attemp attached.

[Anonymous]

As far as I can tell, the only dimension missing is the height of the lower rectangle.

Edit: Height and width

[JDMather]

You haven't made a very good effort.
There are NO dimensions on your sketch?

Your origin is not in a logical location.
You are not modeling correctly for a revolved part.

You might want to read this document

http://home.pct.edu/~jmather/skillsusa%20university.pdf\

and sign up for a class.

Inventor is a professional program and deserves (requires?)  a professional level of preparation.

After you  have read the linked document above and made an attempt with constraints and dimensions - attach your file here again and I'll then walk you through the solution step-by-step if you can't figure out this easy part on your own.

[es12]

"The requested URL /~jmather/skillsusa university.pdf\" target= was not found on this server."

I have done very complicated parts with Inventor. I just don't know how to read the machining drawings properly. Is there classes that teach how to read machining drawings?

For example, I don't understand what is the purpose of dimensions 19mm, 2,74mm and 4,17mm on the drawing.

The part is not round. It's rail, like I said: http://en.wikipedia.org/wiki/NATO_Accessory_Rail

I don't need to add measurements. I just need to make the shape.

[JDMather]

Oops, maybe I need to sign up for that class to learn to read engineering drawings!  My mistake.
You should be able to dimension and extrude though.

Somehow I got an extra character on the end of the link - try this one http://home.pct.edu/~jmather/skillsusa%20university.pdf

[JDMather]

---

@es12 wrote:

For example, I don't understand what is the purpose of dimensions 19mm, 2,74mm and 4,17mm on the drawing.

I don't need to add measurements. I just need to make the shape.

---

Uhmmm, yes you do.
When you add those dimensions they fully constrain (define) the part profile.

[es12]

Your link gives now blank page.

I made another try with the drawing. Does it have proper dimensions now?

[JDMather]

---

@es12 wrote:

Your link gives now blank page.

 Does it have proper dimensions now?

---

I just tried the link and it worked for me?

No - you are missing the most important dimensions - the Datum dimesions.

Inventor indicates in lower left corner missing 15 dimensions (this is a little misleading since if you add geometry constraints for symmetry you need add only the dimensions shown in your original post.

You state you have created more complex parts - I'll wager that every one of them is wrong in some way if you aren't using dimensions and constraints.

This is good reason why Inventor Fusion should have never become a released product. (not your problem - but your part is a good illustration)

[es12]

I meant is the shape correct...

Most of my parts are my own so they are correct shaped when the measure tool says so 🙂 I will learn how to make the dimensions to be visible before I send the parts to machinists so they can read the drawings more easily. For now I just need to make the shape correct.

oh I see one measurement is off in my part...

[es12]

ok here's the part and to me it has identical measurements.

(btw I have no idea what fusion is)

[JDMather]

You are doing wayyyyy too much work.
Simply dimension.

How are you getting dimensions without dimensioning?
If you simpy dimension - Inventor will tell you when it is right.

You don't need someone else to tell you.

You have double lines over short lines?
Why?

[JDMather]

While in active sketch - right click and select Show all Degrees of Freedom.

You should have zero red arrows (degrees of freedom).

[es12]

Of fourse I measure things I sketch, but I don't add the measurements on the drawings so that they can be seen.

Yes I might have few lines over other shorter lines because of the way I sketch it.

[Anonymous]

But why? Dimensioning in a drawing is far from being a sign of weakness or inexperience.

[coreyparks]

     Everything you draw should have dimensions and contraints on the sketch to hold it together and so that the part will act correctly when dimensions are changed.  The dimensions are absolutely required at this level so that you can size the part properly.  Notice how the lines change color when fully constrained.  How would you change this in the future if you didn't have dimensions?  One otehr thing you woul never want to do is draw lines over the top of one another.  It has the potential to confuse invetor whn you try to extrude the solid later not to mention that you will have no idea just how the sketch constraints get applied.  It is very hard to debug sketches with overlapping lines.  This is a very easy part to sketch, as you have originally stated.  I picked the middle of the bottom surface as my datum but you may want somewhere else.  I am assuming though that the rail is mounted on that bottom surface with bolts possibly down the center?  One last question, was this drawn in Inventor or imported from AutoCAD?  If drawn in Inventor make sure you have the constraint inferance and persistence turned on.

    Not to be rude, that is not my intent, but have you ever used a 3D modeler before?  Things need to be done drastically different from 2D AutoCAD to make sure they work smoothly and you don't seem to have even the basics of running a 3D modeler down.  You say you have created very complex parts with Inventor and maybe you have but I have a hard time beliving that when you are having such a difficult time with something so simple.  Like I said I am not trying to cut you down here but the part you posted is one of the worst attempe at sketching I have seen.  Take a look at the part I have attached to get an idea of how things should be done.  Also the construction lines in that sketch were placed only as a ref and really do nothing other than show vertical and horizontal relationships. 

     Hope this might help out in some way.

[Anonymous]

Well, a bit harsh, but true. It is very important that you get to know how a 3D design application is used. It is not something most people could learn by themselves because there are many concepts that are not that easy to grasp. I really recommend you to get a course or some kind of prestigious preparation to uncover your drawing potential in Autodesk Inventor. Watching the video tutorials is a very good start - in fact, many things you will be able to learn from the videos are not taught by courses alone.

[es12]

I'm sure this is true if modeling is your profession, but I don't understand what does it matter in this case what the sketches look like if the 3d solid model has correct measurements. If you take the measurement tool and measure all distances and they are all correct, what does it matter if there's two lines over each other in the sketch? I've sent few of my files already to the machinist and he didn't mention anything and those parts were a lot more complicated.

I didn't have hard time modeling that part, I had hard time reading the drawing (where the 45 degree lines started and ended). When you model your own parts you don't read drawings.

[JDMather]

You continue to try to argue rather than listen to those with more experience.
For one thing, you are doing too much work and doing it the hard way.

I worked out on the shop floor for 8 years as a machinist.
I often has to make up for the shortcomings of poor design or information.
As a machinist I had to use the sort of disciplin in how I went about making real parts that you are resisting in you digital prototypes.

Read the document I linked earlier.
Start cleaning up your sketches - even if you measure (why would you waste time doing that) everything as correct.
Even if the parts have already been made.

A year from now you will come back and acknowledge that everything you did - was not well done.
We all look back a year, a month, a week and shudder at how we did something then.

Those who don't - aren't learning.