This week we will take a simple look at rotating objects. This one is not as long and thought provoking as last weeks episode………..

The Basics to AutoCAD
Part 5

By now you should be fairly confident in drawing lines, circles and ellipses. You should be able to move them around your model space at will and you should be able to set up your AutoCAD Interface for your ease of finding the icons we need to use. If you are not quite there yet don’t panic, just go back through the tutorials and move to the next one only when you are ready. There is no rush to complete, unless you have a target!

Time To Turn Around……………..

So we have learnt how to draw some objects in constrained positions, i.e. a circle with its centre at 0,0. What we are going to discuss today is rotation, or as AutoCAD likes to call it ROTATE. Below is a diagram that maybe familiar to you from our “co-ordinates” lesson. We will be using this diagram to show how Rotate works.

I will try and keep this as simple as possible, if I can.
Right then, I have drawn four lines, the blue ones, labelled A, B, C and D.
LINE A; from its end point, where the X and Y axis cross, is at an angle of 36˚ from the X-axis in

the positive direction. It is rotated about its end point. AutoCAD by default sets the X-axis as 0˚,

this can be changed but I would suggest it is left well alone.
The red lines indicate the positive directions that all four lines have been rotated around their end
points.

LINE B; from its end point is rotated about that point 160˚.

LINE C; from its end point it is rotated 180˚ + 68˚ = 248˚. The 180˚ comes from LINE C being below the X-axis. The 68˚ comes from the angle, in a positive direction, from that axis. These two values are then added together to give us the 248˚.

LINE D; this is rotated about its end point 180˚ + 145˚ = 325˚. Well we know where the 180˚ comes from, see LINE C. the 145˚ comes from the angle the line is away from the 180˚ point of the X-axis, i.e. 180˚ -35˚ = 145˚.

Ok so we have determined the angles, in the positive direction, at which the four lines have been drawn, by simple math. Now let’s look at the negative direction!

This is basically worked as an opposite of the positive direction because the lines are below the X-axis; look at LINE C and LINE D.

LINE C; is rotated about its end point -35˚.

LINE D; is rotated about its end point -112˚. (180˚ - 68˚ = 112˚).

Read through these two or three times to get a better idea of how the angles work. When we start rotating objects it will become a lot easier to understand, but we must go through the theory part to help you understand.

Let’s rotate it then………

Right then here we go, let’s do it…………

OK open AutoCAD as normal. Hopefully you have set up your interface as instructed in the last tutorial. If you haven’t, then go back and do that now.

First things first, make sure the ORTHO and OSNAP buttons are turned ON.

Now draw a line from left to right across your screen, the length and position is not a concern just yet. Select the ROTATE icon button from your toolbar menu on the left; MODIFY toolbar, 7^th icon down, a circle with an arrow on it.

Your cursor turns into a small square. With the cursor, select the line by left clicking on it. If it is selected it should be shown as dotted. Now right click your mouse. Your cursor crosshairs return. By moving the crosshairs close to the left hand end of the line we can select its end point when the little orange box appears. When it does, left click your mouse. We have now told AutoCAD the point about where we want to rotate our line.

If you move your mouse in a circle around the left hand end of the line you will see a representation of the line being rotated into three positions as you go. As we have our ORTHO button on, we are constraining AutoCAD to the X and Y axis directions. So, go down and turn off the ORTHO button by left clicking on it. Now go back and if you still have the line selected move in a circle again around the left hand end we selected. Now the line should be permanently attached to your crosshairs and you should be able to move it round and round and round and round and rou…. I’m getting dizzy now.

OK, left click where ever you want. There is your line rotated about its left hand end point.

To rotate the line from its other end just go through the same procedure but select the right hand end of the line. As a little test, see if you can rotate your line about its centre!

How good was that?

Now let’s do some rotating using some values.

First make sure your ORTHO button is turned off and your OSNAP button is turned on.

Draw a triangle with these line values, (0,0) enter, (45,0) enter, (45,45) enter, (0,0) enter and press enter again. You should have an equilateral triangle on screen. What we are going to do is change one of the existing angles from 45˚ to 30˚.

Select the ROTATE icon from the toolbar and then select the diagonal line with your mouse, right click once selected. Then select the end of the line at the bottom left, when the little orange square appears. The line is now attached to your crosshairs as before.

What we want to do is decrease the angle we have at the moment, which is 45˚, to 30˚. So to do this we just type into the command line -15 and press enter. The software does the rest.

OK, I want you to save this drawing with the file name TRIANGLE1. We will use it again in the next lesson. See those two long lines on the top point of the triangle………..we are going to remove the long bits past where they intersect next time.

Back to today.

So what if I want to draw a line 100 units long at an angle of 57˚?

Well this is what you do. For a start let’s begin with a new drawing. Select the LINE icon and draw a line, with your ORTHO on, left to right, 100 units long. Now select your rotate button, select the line and rotate it from the left hand end 57˚ by typing that value into the command line. That’s the easy way………..

Now the more complicated way, but you will need to learn this as you will, at some stage, find the need to draw a line like this.

This is all done on the command line. First though select your line button, type in (0,0) and press enter. Right now it gets a bit more technical. I will explain each command when we have finished, it won’t hurt I promise…….. Now type in @100<57 and press enter, and enter again. There is your 100 unit line at 57˚.

Now the explanation………. See diagram below………….

Ok so now try drawing some lines with different start points, you don’t always need to use (0,0), select the start points at random. Then enter values of your choosing but one thing you must

know, the angle value can only be to a maximum of 360, as there are only 360˚ in a circle. If you do use a value larger than 360 for the angle AutoCAD will start at 0 and keep going round in a circle until it reaches the value you give it. But between you and me, you will never see a value over 360. Remember you need to always use the @ and < symbols and when you want to finish your line either press enter again or right click your mouse.

How did you get on? Here’s one for you…… now that you have tried with positive numbers, try inputting some negative values for both the distance and angle. Try mixing negative and positive values on the same command.

Well that’s all for this time…… next time we will get back to our drawing that we started a couple of weeks ago.

As usual here is the download that goes with the tutorial;

the-basics-to-autocad-pt-5

This week we will be looking at your computer screen……. the interface!

The Basics to AutoCAD

Part 4

 

Before we get too involved with more drawing there is a bit of AutoCAD housekeeping that we need to do. We are going to have a look at the AutoCAD interface that we are working with today. Hopefully by the end of this lesson you will have the basics behind setting your software up for your own comfort. Sorry but this one is a bit long winded.

OK then, open AutoCAD as normal. There are six main areas that we are concerned with,

Model Space (Drawing Space)

Main Menu Ribbon

AutoCAD Toolbars

Paper Space Tabs

Command Line

AutoCAD Tray Settings                  See diagram below……….

 

Model Space (Drawing Space).

The model space is the real world. What you draw in this space is actual size depending on what units have been set up in the default drawing when AutoCAD opens. We will go into building our own template to open when AutoCAD opens at a later date.

Main Menu Ribbon.

Like any other windows based software AutoCAD has its own drop down menus. From here almost all operations can be accessed and used. I rarely use this method as it can be time consuming and confusing sometimes.

AutoCAD Toolbars.

AutoCAD has its own toolbars which you can use and customise to your heart’s content. We will be looking at these later in this lesson.

Paper Space Tabs.

These tabs take you to your paper space. Don’t worry too much about them just yet as we will be using them later in these tutorials. For now if you click one of the tabs you will see a representation of a sheet of paper, this will become your drawing.

Command Line.

This is where AutoCAD does its business. If you are struggling with something you are drawing, typing a word in this line may help. Try typing circle and see what happens…….don’t forget to press enter. Numerical values are typed into this line to constrict lengths of lines, radii of circles and even directions, which will be covered soon.

AutoCAD Tray Settings.

For the basic user there are only three buttons that we are seriously concerned with here, ORTHO, OSNAP and MODEL. I will deal with these buttons a little later in this tutorial.

 

Toolbars………….

Around the edge of your Model Space there are some AutoCAD Toolbars. For me they are the easiest way to instruct AutoCAD in how you want to proceed with your drawing. AutoCAD has numerous default toolbars in its system and after years of using the software I have found my four most useful toolbars and made one custom toolbar with a couple of AutoCAD operations on it.

So where do we find these toolbars? Quite simple really………..drag your mouse over to one of the toolbars and click your right button. A drop down menu appears with a list of all the default toolbars that AutoCAD has its system. What we are going to do is open, delete, move and lock some toolbars.

OK then, in this drop down list some toolbars are already ticked. They are the ones we have already been using, DRAW and MODIFY being the two main ones, and then LAYERS, PROPERTIES, STANDARD and STYLES being the other ticked. So in all you should only have these six toolbars ticked. If you have more than these ticked, don’t be scared untick (deselect) them now. If AutoCAD asks is this what you want to do, just say yes.

So now your AutoCAD interface should look something like the diagram below……….

If it’s not quite looking like that then we will not worry about that right now as we are about to open some new toolbars.

Now then, with your mouse on one of your toolbars, right click to open the drop down menu.

There are two toolbars which we will start to use in the next tutorial so we need them. Find the DIMENSION toolbar and left click to select it. It should appear in the model space window. Now go and select the OBJECT SNAP toolbar and that will appear in the window as well. As in the diagram below……………………

As you can tell these toolbars are now directly in your drawing area. So we need to move them. With your mouse click and hold on the coloured bar across the top of a toolbar and drag it. You can now place the toolbar where you wish on your AutoCAD interface. If you drag them to the sides they will attach themselves to the frame of the interface when you release the mouse button. Try it. Once they are attached, two bars appear at the top of the attached tool bar. If you pick these with your left mouse and drag it back into your work area it will bring the toolbar with it.

These two new toolbars, DIMENSION and OBJECT SNAP, will be the ones we will leave on the interface, so we need to dock them.

First we need to move the MODIFY bar. This is the one to the right; drag it onto the work area. Now set up your interface as I have mine. It will be easier for us to go through the rest of the tutorials if we are all working from the same page. See the diagram below…….

All we need to do now is lock them in place. Right click on any toolbar and select LOCK LOCATION and then DOCKED TOOLBARS from the drop down menu. This will lock your toolbars in place and you won’t move them accidentally.

We will go into customisation in greater detail later in the series.

So basically that is toolbars covered, we have the main ones on our interface now and we will have them there all the time. Everytime you open AutoCAD they will be there now.

AutoCAD Tray Settings……….

Finally we are going to have a quick look at the tray settings tabs at the very bottom of your interface.

The two main ones that we will be using are ORTHO and OSNAP. If you want to know more about the other tabs they are comprehensively covered in the help section of your AutoCAD software.

In Ortho mode, when the tab is selected, your cursor movement is constrained to the horizontal or vertical direction (relative to the UCS). Try drawing two diagonal lines with and without the ortho button selected. As you will see when the ortho button is on your direction is constrained. This is, as you will discover, really useful when drawing almost anything.

Osnap is a way of picking points on various objects. Take your cursor to the OSNAP button and right click, then select SETTINGS. The illustration below show what appears………

As you can see there are a few choices to make……….. I usually have the following checked…….

If you select the same boxes then click OK we will be up and running.

Ok let’s see how this all works. With your ORTHO and OSNAP buttons on we will draw a line in the centre of your scene going from left to right. OK, now we will draw another line from the centre of the first line in a northerly direction. Click the line icon and run your mouse over the line you have already drawn. Three things happen, as you move your mouse over the length of the line, a box appears at each end and a triangle appears in the centre. These are the SNAP POINTS that we have constrained AutoCAD to select for us in the OSNAP settings box we had on scene just a minute ago.

Well we want the centre, so when the triangle appears again left click your mouse. You do not need to be directly above the triangle to select it as AutoCAD is constrained to make the selection. Now move your mouse above the line as far as you want and finish the line.

Now what we want to do is draw a circle with a radius the distance between the two ends of the two lines.

Select your circle icon. Your circle centre is going to be one of the ends of the horizontal line. So when you move your mouse near to the one of the horizontal line ends left click when the box appears. This is the centre of your circle. Now move your cursor towards the most northerly point of the vertical line. When the box appears, indicating the end point of the line, left click to accept. Your circle will be drawn automatically with the centre on the end of the horizontal line and the circle itself touching the top of the vertical line at some point.

Again if the circle does not fit on the scene, type z and press enter, then e and press enter.

If you right click on your OSNAP button again you will notice that we have selected more the just end points and mid points. We will be using a lot of them, if not all in the weeks to come.

As you have the basic idea about lines, circles and ellipses, have a go at drawing them using the ORTHO and OSNAP buttons both on and off.

Well that’s it for now. I know there is a lot to take in with this tutorial but these are important items to look at and learn how to use. They will be second nature once you set them up to your own liking. I rarely work without ortho and osnap. And trust me you will find the same thing happening to you soon as well………

Happy drawing for now…………………….

 

Here are the downloadable bits……..

interface          the-basics-to-autocad-pt-4