New to AutoCad and Confused

[Njprince94]

Hey there,

 

I am completely new to AutoCad and I barely know the basics. I am here trying to duplicate this design which seem's to be fairly simple. To my understanding you can draw a quarter of it and mirror the image for the rest of it. I am not sure where to start as I have very little experience with this program.

 

If anyone here can guide me through it and/or duplicate this design on autocad for me I would really appreciate it. It has to be on a 1:1 scale.

 

Edited September 23, 2012 by Njprince94

[ReMark]

Start with a circle that has a diameter of 154. Draw a second circle with a diameter of 122 using the center of the first circle as the center for the second. Draw the vertical and horizontal centerlines. Do you know how to create different layers and assign a linetype and color to the layer?

[Njprince94]

Thank you so much for the reply. Alright so like I said I am very new to AutoCad so please bare with me Am I supposed to change the dimension style or units to metric? The drawing is in metric so I have to make an exact replica of it. I tried to make a circle with a diameter of 154 but it goes off the screen? I also do not know how to create different layers or assign linetypes.

Edited September 23, 2012 by Njprince94

[ReMark]

Technically to do a metric drawing you should use a metric template but I'm guessing you did not do that right?

 

Want to see your circle? Do a Zoom > Extents. See it now?

[Njprince94]

Nope I did not, and yes!

[ReMark]

I asked about layers and linetypes because I like to put my centerlines on their own layer in a different color than my geometry.

 

You got all the circles drawn yet?

 

Do you know about Orthomode?

 

Have you used such commands as Mirror or Trim?

 

Have you used the Polar Tracking feature yet?

[ReMark]

Here is one way to approach the problem.

OOps...forgot that notch on the outer ring. That's what I get for doing CAD and drinking a beer at the time.

[ReMark]

Any better?

[Njprince94]

I have only done the first three simple circles, the rest seem's jibberish to me haha. I have used the commands mirror and trim and I do not know what orthomode or polar tracking is. I'm not sure how to create those horizontal and verticle lines or those inner/outer notches. So after the last picture you put up all that needs to be done is add the dimensions by putting in text right?

 

[ReMark]

Orthomode constrains lines to horizontal and vertical (no lines at an angle).

 

Mirror is just what it sounds like. You've heard the phrase "mirror image" right?

 

The Trim command allows the user to use one 2D entity and trim (cut) another that crosses it.

 

The last picture would still have to be dimensioned, yes.

[Njprince94]

Oh I see! Yes I have. Alright cool, thank you very much!

[ReMark]

Are you basically trying to teach yourself AutoCAD or is this for a class you are taking?

 

Have you viewed any of the tutorials here at CADTutor or any other place for that matter?

 

You should become acquainted with the basic drawing and modifying commands to create objects such as the one pictured.

 

Have you purchased a good after-market AutoCAD book? Did you know you can get explanations about how commands work using AutoCAD Help?

[ReMark]

Layers are created in the Layer Properties Manager.

You have to click on the icon for creating a New layer. You can accept the layer name that AutoCAD gives you (Layer1 for example) or assign your own like I did (Centerline). You can assign a color to the layer as well as a linetype you would like to use on that layer (like "Center"). My centerlines are on a layer called Centerline, color: green and created with the Center linetype. To get my centerlines to display properly I changed the linetype scale (LTSCALE) to a value of "10" in the Properties palette. I'm pretty sure you have no idea what that is now do you?

 

The lines were put in the drawing using the Line command and I had Orthomode enabled. I drew both lines based upon the quadrant points of the outermost circle. Are you familiar with OSnaps? This feature let's the user make accurate picks of geometry based on ednpoints, midpoints, quadrants, centers, intersections, etc. After I drew both lines I used the Scale command to scale them up 1.25X picking the center of the circles as my base point.

Edited September 24, 2012 by ReMark

[ReMark]

Next step is to create the two lines and smaller circles in the right upper quadrant.

 

I used direct distance entry to create each line. Goes something like this. Start the line command, pick the center of the circle (using your OSnaps) as the basepoint, then instead of picking a second point I typed @96>30. That produces a line 96 units long (an arbitrary distance by me) at an angle of 30 degrees. I repeated the procedure for the next line substituting an angle of 60 degrees. Followed this up by drawing a circle at the intersection of the first line and the circle with the 122 diameter. Made my "pick" using the Intersection OSnap. Copied this circle to the second intersection.

 

I used the Mirror command to make a mirror image of the first two circles to the upper left quadrant of the circle then repeated the command to mirror all the small circles in the upper half to the bottom half. Two circles become eight circles in a matter of seconds. I also mirrored the lines that pass through them too. No sense drawing them from scratch right?

[Njprince94]

This is for a class I am taking at a college. I am trying to go ahead a little bit to do well in that class because it is important for me. No I have not as I am new to this forum but I will get right on it! I have purchased a Technical Drawing book and yes I am aware of that.

 

Does the color have to be specific to what kind of lines you draw? I have read about the linetype scale and it mentions to use a value anywhere from 8"-10" to show the proper line in the scale when plotting.

 

I have followed every step and am currently at the last picture you drew. Now I am stuck on making the notches. Thank's again for making this easy for me, I really appreciate it and it is helping me out alot.

[ReMark]

No, the color does not have to be specific to the type of line or even the layer. As a student you are free to create your own "standard". However, if you go to work for ACME Consulting Engineers they may have a standard they want everyone to follow so all drawings produced by the company look the same.

 

You will find that at times it may be to your advantage to increase the linetype SCALE (never expressed as inches) while working in or plotting from model space. Move to a paper space layout and things are done differently. Look into the variables LTSCALE, MSLTSCALE and PSLTSCALE to see what I mean.

[ReMark]

The notches were constructed using a line at 15 degrees and mirrored. The outer circle was trimmed then I used the Array command (Polar option) to duplicate the geometry at the other quadrants. Trim was used to finish it up.

[Njprince94]

Hey mate,

 

So I got up until the part where you mentioned the Array command, I attempted to play around with it but I can't seem to get it right.

 

 

Any tips?

[Dadgad]

Hey mate,

 

So I got up until the part where you mentioned the Array command, I attempted to play around with it but I can't seem to get it right.

 

 

Any tips?

 

 

ReMark is in Connecticutt, so he's sawing some much needed logs about now.

You want to create a POLAR ARRAY, comprised of 4 units, filling 360 degrees,

with the center point of the array being the center of the piece.

[ReMark]

Maybe he missed the part where I said "Polar option"?

 

Njp: Arrays can be either Rectangular (think rows and columns) or Polar (circular). Follow Dadgad's advice and I'm sure you'll be fine.