Replies

1. 
   sjrcabs | Nov 23, 2002 02:26pm | #1

   Jeff,

   Don't feel like the Lone Ranger! I have the same problem. I can't for the life of me begin to figure out how to even get started. To me even the help screens and tutorials are difficult to understand. The only suggestion I have is this. The community collage near me offers a two day seminar for about $300. That is what I am going to do to try and get up and running as soon as possible. You can find classes new you by going to the Auto Cad website and they will give you a list of instructors and/or classes near you. That is how I found out about the community collage seminar.

   Good luck 

1. 
   JeffKurtz | Nov 23, 2002 05:55pm | #2

   Thanks.  Guess that's the route I'll have to go.

   Jeff

1. 
   corners | Nov 23, 2002 07:47pm | #3

   Get "DeltaCad" from Midnight Software and make life easy. A simple 2D CAD program that can be learned in about 2 weeks at an hour each night and will do all you need for woodworking. And it's less than 50 bucks!

   Edited 11/23/2002 11:48:42 AM ET by Corners

1. 
   JeffKurtz | Nov 25, 2002 07:34pm | #8

   Thanks for the tip!  Autocad has a free trial period of 45 days, and a tutorial as well.  For someone who has never used CAD before, it's a great program to start with.  Doesn't assume you know anyything, so the instructions are simple and specific.

   Jeff

2. 
   Paul_Snyder | Nov 24, 2002 11:40pm | #4

   In response to this thread I downloaded CadLite thinking I might be able to try some real simple drawings for now - but I can't even find the tutorials you mention. Do they come with the "pay" version or are they somewhere were anyone can look at them? Thanks for your help.

   Paul

   F'burg, VA

1. 
   sjrcabs | Nov 25, 2002 02:44pm | #7

   I guess I ment to say the "Help" screens. I saw a version that had a tutorial with it, but I don't think Auto Cad LT comes with one. Sorry

   Scott

   Edited 11/25/2002 6:46:34 AM ET by SJRCABS

2. 
   DennisS | Nov 25, 2002 07:54am | #5

   Jeff -

   What is it that you 'can't figure out'? That's not a specious question as there are many aspects of computer drafting that differ from hand drafting.

   For beginners, you're drawing full scale. That is, if you're used to sketching or drafting at some scale, like 1:50 or 1/4" = 1'-0", forget everything you know about drafting! (grin). You're drawing in actual feet-inches or mm. Or cm. Or light years or angstrom units.

   Now that you're totally confused on the point of scale, just remember that when you draw a line x units (I'll use inches and feet from here on since that's what I use), that's how long the line is as far as the computer is concerned. We don't even -consider- scale until we decide to print something out. That's when we have to be concerned with how big the drawing is and make it fit on the piece of paper we use for printing.

   OK - I'm assuming since you used the term CAD 'lite' you mean AutoCAD LT. (the LT, by the way, implies Lap Top rather than 'Lite' since it was Autodesk's way of marketing a product designed to be run on a laptop machine). That being the case, you draw a line by entering "line" at the Command: line -without the quotes, of course. Note that I cut my teeth on AutoCAD years before Windows and the Iconographic interfaces that have overtaken the market. Rest assured that if you learn the commands at the Command: line level, you'll be far more efficient at using the program than you will be hunting for little pictures to make the program respond to your needs and wants.

   So you enter Line and AutoCAD responds with "From point: " - whereupon you merely pick a point on the screen. Doesn't reall matter where at this juncture, we're merely learning to draw a line.

   So you move the mouse to a point on the screen and click at the start point of the line. Then AutoCAD responds "To point: " and there's a 'rubber band' between this first point and your cursor or crosshair.

   Sidebar note - if you have what's called Orthomode active, you'll only be able to drag this rubber band at 90 degree increments from your start point - or with the latest versions of Acad LT, you can also set orthomode to certain multiple angles as well. But that's another issue. The point is, if your cursor only "snaps" to 90 degree angles or some set angle from the start point, orthomode is turned on. You can hit the F8 key or toggle ortho on and off with the little button at the bottom of the screen.

   OK - that said, you stretch the 'rubber band' to another point and click. You've just drawn your first line!!

   Circles are a matter of entering "Circle" at the Command: line, picking a center point (the center of the where the circle will appear) and entering a value for the radius or diamter (pay attention to the prompts at the Command: line that Autocad responds with) or even dragging the circle to the size you want. Entering a value will get you a precise circle of the size you want, of course.

   Most drawings are simply an accumulation of lines and arcs or circles. To start a line at the end of an existing line, use what are called "osnaps" or 'object snaps' which enable you to attach the start point (or endpoint for that matter) of one line to the other. To draw a line from one end of that last line you just drew, start the line command with "Line", and when AutoCAD asks you for a "From point: " enter END, then AutoCAD requests "Endpoint of: " whereupon you put your cursor on or near the end of the line you want to continue and click - then Voila! your new line is started Exactly at the end of the last line.

   Experiment with all this and if it makes sense, and if you need additional advice, we can go to greater depth via email if this is beyond the scope of the forum.

   I spent 10 years as an architect doing hand drafting and detailing. It took me almost a year to understand the concept of working full scale using computer drafting. Don't feel bad!!!

   ...........

   Dennis in Bellevue WA

   [email protected]

1. 
   sjrcabs | Nov 25, 2002 02:38pm | #6

   Thank you very much for your help. I now think I have enough info to get started. I did not understand the command line until now. I am currently using Auto Cad 8. It is very inexpensive and very user friendly but it does not work the same way as Auto Cad LT. I will learn alot more by trial and error, the same way I learn everything else on the computer. My next problem is to conquer this full scale thing. My mind will not allow me to visualize that yet. I have to see a page to work on, but I will unsterstand it once I start working with it a little bit.

   Thanks again for your help.

   Scott

2. 
   JeffKurtz | Nov 25, 2002 07:37pm | #9

   Dennis,

   Thanks for the instructions.  I've never used any CAD program before, and CAD Lite contains no instructions or tutorial, so nothing about it made sense to me.  I'm getting started using Delta CAD now, since it provides good instructional material.

   Jeff

1. 
   DennisS | Nov 25, 2002 07:56pm | #10

   Most, if not all CAD programs work in similar fashion - that is, you design/draw in real life scale. For the most part, a line is a line and a circle is a circle, all initiated with the same command in one way or the other.

   For any object type, the computer and the program need to know certain parameters for their creation: a line has a start and end point, a circle a center and radius or diameter. Arcs have several methods of definition which may or may not be entered in similar ways depending on the program - center of the arc along with start and end points, center of the arc along with start point and included angle, using any three points that would lie on the arc, so on and so forth.

   A little further up the food chain you'll be faced with drawing a line (or arc or circle) with pre-determined length or other parameters. Then you need to learn about the coordinate system which is the same as we learned in highschool geometry, relative and absolute coordinate point entry and polar vector input. Sounds daunting but it's a rather easy concept once you envision it and understand how the program needs to receive the input.

   Let me know if you have any questions and don't be shy about email direct if you prefer.

   ...........

   Dennis in Bellevue WA

   [email protected]

3. 
   UncleDunc | Nov 25, 2002 10:26pm | #11

   >> ... you're drawing full scale.

   The way I read this, you're saying you can't use a CAD program to design anything larger than your screen. I know that's not right, so what am I misunderstanding?

   >> ... that's how long the line is as far as the computer is concerned.

   Same question, basically. If I tell the computer a line is 24 feet long, and it believes me, how can it draw the line six inches long on my screen?

   Edited 11/25/2002 3:06:34 PM ET by Uncle Dunc

1. 
   charlesm | Nov 26, 2002 12:16am | #13

   The screen just shows a representation of the line/object/whatever. You can change the level of zoom to see the whole object or just parts of it but that doesn't change the actual size, just your view of it (just like standing back really far or moving in close). It's when you need to print it out that you become concerned with the scaling.

   Charles M

   Freud, Inc.

2. 
   DennisS | Nov 26, 2002 01:09am | #14

   Unc'....

   Imagine the frame around your computer screen as a frame around a window. The closer you move to the window, the more you can see. Or better put, the closer you bring the window frame to your eye, the more you can see. The further away it is, the less you can see. Just imagine that the stuff you 'draw' on the screen stays put and you move the frame in and out.

   As an example, scribble some stuff on a large piece of paper. The cut out a smallish, say 4" square in a piece of cardboard. Now take the paper up to the wall and put your little 4x4 window up and look through it. As you move the window closer or further away from your eyes, you'll see more or less of the drawing on the wall, right?

   That's what the "zoom" command does in a CAD program. Let's say you draw a line 6" long and another, parallel to it 24' long. If you see the 6" line across probably 2/3, more or less, of your screen, the 24' long line is way out there somewhere.

   Now zoom "out" so to speak by (metaphorically speaking) moving the screen frame closer to your eye. The 6" line will become more or less a dot while you see the entire 24' line.

   I've drawn 100,000sf buildings on a computer so believe me, it's very much a real thing! (grin).

   Now that that's explained - imagine you're drawing on the surface of the earth. OK, so the earth's surface is curved but let's not get into too much philosophy here! grin - Now presume that your window frame and eye position are fixed relative to each other. Perhaps a cearer way of understanding the zoom "in" and "out" is that given the fixed relationship of your eye/window situation. the further you move away from the earth's surface, the more you'll see out of your window. Try taking your little 4x4 cardboard window outside, hold it about 20" from your face and 12" off the ground. You'll see just a little bit of the ground. Now go up on your roof or climb a ladder or otherwise elevate you and your window. Now look down at the earth with the same window to eye relationship. You should see quite a bit more of the ground below you.

   Presuming you snapped a line 24' long on the ground, and presuming you had a platform high enough, you should be able to get up there and see the entire line through your little 4x4 window.

   The way a vector CAD program works, Unc', is by defining various 'primitives', that is lines, arcs and circles using coordinate points. A line consists merely of two sets of coordinate points (assuming 2 dimensional drafting here - we'll cover 3D in the next chapter -hehehe-. So, say you want to draw a 24' long line from point a to point b. Point a is defined as x=0,y=0, in other words, the origin of your coordinate system. So when the program asks for a start point, you enter 0,0. Note that no units are required at this point. 0 is, simply zero whether it's metric or otherwise.

   The next point, since we're dealing with imperial units (you said 24') would be entered 0,24'. But let's make it less that a round figure to illustrate units further. Say 24'-6 1/4".

   Note first of all, that in AutoCAD you need to specify the type of units you're using. For imperial (feet & inches) you need to set your units display to architectural. There are two versions of architectural units in the newer versions of the program, using either stacked or unstacked fractions. Choose either will be OK. Enter DDUNITS to access the dialog box for setting the units.

   Now for the second point, after entering 0,0 (note the format! - value/comma/value - that's the format you must use), you enter 0,24'6-1/4". Not the placement of the hyphen!!! It comes after the even inch value between it and the inch fraction. *Not* between the feet and inch values we're used to seeing.

   Thus we have a line from 0,0 (the origin of our coordinate system) to 0,24'6-1/4". It will be way off to the right of the screen (by default, AutoCAD uses the lower left corner of the screen as the 0,0 origin, not the center of the screen. Some CAD programs default to the center of the screen). You won't be able to see the right hand end. S0....

   Use the "zoom' command.

   There are several sub commands to the zoom command. For our purposes, simply enter E for "extents" which will result in zooming the display to show everything that's been drawn thus far.

   And there you should have a line displayed on your 12" or whatever monitor which is, mathematically speaking, 24' 6 1/4" long!!

   Are we having fun yet?

   ...........

   Dennis in Bellevue WA

   [email protected]

1. 
   UncleDunc | Nov 26, 2002 03:19am | #15

   OK, that's reasonably clear, given that I don't have AutoCAD and couldn't actually do all the steps. But my question was, if I have a line that's 24 feet 6-1/4 inches long in the real world but only 12 inches long on my screen, in what sense am I working at full scale? I would describe that as working at 1:24.52083 scale.

1. 
   DonaldCBrown | Nov 26, 2002 03:44am | #16

   Let me take a whack.

   You are absolutely right, but strangely that only confuses matters.

   As you draw and scroll and zoom in and zoom out, you will work at a lot of different scales in the sense you have described. But the line, whether it occupies an inch or a furlong on your monitor, will always show up as 24'-6-1/4" if you ask the program to put a dimension on it. And any line that is supposed to be 12'-3-1/8" will half as long on your screen.

   The important point is not that the screen drawing has no scale--it does--but that the scale is not something you have to worry about. In old-timey drafting, confusing the 1/8" to a foot scale with the 1/4" one on your (peculiar name coming up) scale could be disastrous. But a CAD program keeps track of the viewing scale for you. Tell it to draw a circle with a 6' radius, and it will do so such that the diameter is almost as large as your original line.

   If you are not worried about taking measurements directly off your drawing, then you'll probably print so that the drawing fills your whole page. The print scale then may be something zany such as 1:24.52..., but who cares. If you are worried about measuring from the drawing, then you can arrange to have the print be any conventional scale: 1/4" = 1' (1:48) that suits your fancy.

2. 
   UncleDunc | Nov 26, 2002 05:29am | #17

   Well, it's not the first time my literal-mindedness has led me astray.

   Your explanation and Dennis's were both good, it's just that if I were trying to make the point that the user doesn't have to worry about the scale on the screen, 'always working at full scale' is not the phrase I would pick. I'm not sure I can offer a better alternative. Maybe something like 'always working with actual dimensions.'

3. 
   DennisS | Nov 26, 2002 06:24am | #18

   Don pretty much got it right - the image on the screen is, indeed a scaled down (or up depending on the item you're drawing) version of the real thing. But mathematically, in the computer's "mind" the model (we call drawings 'models' rather than drawings) is actual size.

   Now in order to lend chaos to the confusion - when you go to print something out, say you want it to appear at 1/4"=1'-0" scale, you need to specify that the printed output be 1/48 actual size. That's because in the printed output, 1" will equal 48 inches in the model. Likewise, to get something printed at 1/2" = 1'-0", you'd specify the print to be scaled at 1/24 actual size. Depending on the program interface and how it wants to accept the plotting/printing parameters, you would, in the first case, specify that 1" in the output is to represent 48" in the model/drawing. Or in the second case, 1" is to equal 24" in the model.

   Keep in mind, Unc', that the computer file that represents your CAD drawing contains nothing that would resemble a line. Or an arc or a circle. All it contains is a bunch of numbers. These numbers tell the graphics system on the computer to light up all the pixels on the screen between point a and point b. Or to light up all the pixels at are an equal distance from point a for circle.

   That's why the emphasis on coordinate geometry and understanding it is so important. Once that hurdle is over, the sky's the limit, quite literally. Working in 3D, which is all I do any more, is merely the addition of a third vector point to represent the third coordinate axis, Z.

   But .... when All's said & done, I can still sketch out freehand most of what I need to do for shop projects faster than firing up the CAD machine, doing the drawing, saving it, then printing or plotting it out .... etc. It's not all that much different from the analogy of setting up a woodworking machine to do a single proceedure as opposed to grabbing a backsaw and cutting off the piece by hand. More complex drawings where the design may go through a number of iterations ... that's another story, to be sure.

   ...........

   Dennis in Bellevue WA

   [email protected]

3. 
   ScottInMadtown | Nov 25, 2002 10:39pm | #12

   I second the guy who suggested DeltaCad.  It's great and easy to use.