Need help trying to finish this.

[fishwater71]

This is my first CAD class I feel freaking lost and increasingly frustrated. Need help trying to finish this slotted ellipse. It's out of a book so I cant post the pic. Here is the file of what I have already. Hopefully somebody recognizes this and can help. Thanks.

slotted ellipse pg190.dwg

[gazza_au]

Post a picture and we can then help, your rectangle isn't a rectangle for a start..

[ReMark]

What is the name of the book? What is the figure number for the exercise?

 

Or....take a good digital photo of the page of the book and post the image.

[fishwater71]

The book is Tutorial Guide to AutoCad 2014

exercise 4.11 slotted ellipse on pg 190.

Thank You.

[ReMark]

Oh, THAT exercise 4.11!

 

I think this is it.

Looks easy enough. Draw one side then mirror the result.

[fishwater71]

That is the one. If you open the file I posted you can see that I am lost on how to make and place the L-shapes. Also lost on how to use mirror. Just so confused. Any help is appreciated. Thanks for your time.

 

After this one I have exercise 4.6 interchange.

[ReMark]

Take a close look at the offsets for the slots that are given, namely the 1.00 and 0.75 dimensions then note the setback of 0.25 which will tell you where the center of each semi-circle is located.

 

What is your problem with the Mirror command? Pick the geometry you want to mirror, select your basepoint (hint: intersection of your vertical and horizontal construction lines that pass through center of ellipse), then move your mouse while watching where your new mirrored geometry appears on screen. Make your final pick based on what you see.

[resullins]

Where I would start with the L shapes is finding the center of the main arcs. If you look, you have a radius of 0.75, with a center point that's @0.75,-0.75 off the center of your main ellipse. Place that circle, then offset it by 0.5 to create the outside of your L shape.

 

After that, you can try to place you end caps. You'll need to take you two circles and trim them at the quadrants (unless of course you made arcs), and draw two 0.25 lines up or out from the ends. That will give you a place from which to find your center point for the end caps.

[Dana W]

It would help if you specifically referred to just one single part of the drawing you are having trouble with, one part at a time.

 

Here, I'll start. I can't open the drawing with my program, and I can't convert it with Trueview since it is an EDU version, but I can look at it on trueview, and measure the drawing.

 

Erase everything but the ellipse. That is the only thing you have on there that is accurate. Everything else is off by at least .20 and that is not good enough. I meant 0.020. This is mechanical drafting, and in the real world your dwg data will be used in a machine that will make this part. You have to be spot on.

 

The rectangle is one way to construct the placement of the circles but it has to be accurate, which it is not. The lines aren't even horizontal, or vertical so they have to go.

 

 

We'll do a little bit first. Turn Ortho on. If you don't know how to do that with the button at the bottom of the screen, type ORTHO in the command line and type ON if it is OFF.

 

Do you know how to change the linetype to Centerline? If you put the center lines in on the ellipse first, you can use them and their intersections for a guide to place the other circles and arcs.

 

We'll work on just one quadrant, since mirror will handle the other three quadrants.

[ReMark]

One possible way is depicted in the progression above.

Commands used were Rectangle, Ellipse, Line Offset, Circle, Mirror, Trim and Polygon. The Polygon has to be Inscribed within the circle shown in red not Circumscribed about it.

[ReMark]

A close up of the lower right hand quadrant of the ellipse showing the creation of one of the slots. I used a different color for each circle just for affect.

[fishwater71]

I erased all except the ellipse, put a rectangle around it. Turned Ortho on, even though I am not sure what that does. I do not know how to change linetype to centerline.

Thanks all of you for your time.

 

I need to make sure the lines going thru the center of ellipse are correct......I am sure there is an easy way.

[ReMark]

To make sure the centerlines were correct in relation to the ellipse I thought you might find it easier to draw a rectangle first and then place the ellipse inside it. I did not expect you to do the opposite.

 

Orthomode keeps lines straight whether drawn vertically or horizontally.

 

Re: linetype. Did you load one of the Center linetypes yet? If so I would create a separate layer called Centerlines, assign it a color other than white, and assign one of the center linetypes to the layer. Do you know how to do this?

[Dana W]

I erased all except the ellipse, put a rectangle around it. Turned Ortho on, even though I am not sure what that does. I do not know how to change linetype to centerline.

Thanks all of you for your time.

Ortho helps hold your cursor on 90 deg or 180 deg. you will see how it works as you go.

Since all of this drawing can depend on ortho (orthographic) we can use it.

 

Never mind the cengterline thing for now. We can change the line type later.

 

Do you have object snaps enabled? If not, look at my attachment. To get that dialog to appear, type OSNAP in the command line and hit enter. check all the boxes, that I have checked. then click OK. Once we're there, we'll draw some lines and circles.

snaps.docx

[fishwater71]

Thank you both. I am on Spring Break and visiting family in Texas. We are about to head out for lunch. Be back in a little bit. I appreciate the help of everyone here, trust me I WILL be back.

[MSasu]

I do not know how to change linetype to centerline.

This tutorial will help you understand the work with linetypes in AutoCAD.

[Dana W]

Thank you both. I am on Spring Break and visiting family in Texas. We are about to head out for lunch. Be back in a little bit. I appreciate the help of everyone here, trust me I WILL be back.

Yes you will, or I will hunt you down. You seem a little overwhelmed with some of the examples posted so we will go one thing at a time, one step at a time. I am not saying the examples are not good, quite the contrary, there are just a lot of them all at once. I just want you to understand each command and each step. Almost everything you draw in the future, can be drawn with the simple commands you will use in this one example.

 

You will notice that the object is symmetrical about two axis, right. It has 4 quadrants. That means we only have to draw one circle and one curved slot. AutoCad can MIRROR the other three quadrants with just two mirror commands.

[Dana W]

Are you back from lunch yet?

 

Here is some more stuff that you should check on before you get started drawing. There are three SYSTEM variables that should be set to a value of 1 (one). The way you do that is to type their names into the command line, one at a time. Then, if they are not already set to 1, give them the new value of 1. The three of them amount to a sort of Golden Rule of AutoCad.

 

Here are their names and what they do.

 

Filedia - when set to 1, and you click the OPEN icon, or type OPEN, it displays a Windows type file explorer window, so you can browse for a drawing to open. No biggie, this one probably defaults to 1, but check it anyway. If it is set to 0 (zero) you have to type the whole file name and folder path to the drawing in the command line.

 

Pickfirst - This one, when set to 1 allows you to select one or more objects BEFORE executing a command. It can be handy, and it's the way I usually do things. If set to 0 (zero) commands will only work on objects you select after starting a command.

 

An aside to this one; To de-select one thing out of a bunch of things, hold down the shift key and click on it.

 

Pickadd - This one allows you to select MORE objects or add to an already selected group of objects without having too hold down the shift key to do it.

 

I'll be back in a bit. I have to go walk Daisy.:lol:

[fishwater71]

The only one not set to (1) was the Pickadd. I changed it to 1.

[fishwater71]

Ortho helps hold your cursor on 90 deg or 180 deg. you will see how it works as you go.

Since all of this drawing can depend on ortho (orthographic) we can use it.

 

Never mind the cengterline thing for now. We can change the line type later.

 

Do you have object snaps enabled? If not, look at my attachment. To get that dialog to appear, type OSNAP in the command line and hit enter. check all the boxes, that I have checked. then click OK. Once we're there, we'll draw some lines and circles.

 

Did all this, now ready.