CAD program - Where to begin

[Nova]

No! ;-(

-- Jack Novak Buffalo, NY - USA (Remove "SPAM" from email address to reply)

[B a r r y B u r k e J r .]

Don't laugh, I recently bought some NEW drawing tools, as I prefer them to CAD for many projects.

Barry

[CW]

Turbocad works the same way. Draw 1:1 in model space, insert in paper space and scale to suite. There are different methods (in detail only) and there is even a setting that will let you think that you are scaling the model space drawing but you are still drawing 1:1

[Mark]

Not to mention a few missing body parts.

[Mark]

My cad instructor said if there is one thing to take with us when we leave his class, that is to draw to full scale. 1:1

I took drafting at the 'university' in the late 70's. Went back to school a couple years ago, figured I should do a refresher so I took drawing 101 (paper and pencil). I got an A. If I had turned that work in back in the 70's I would have probably had to have taken the class again.

How things have changed.

[j]

Why a CAD program? If you are drawing cabinets how abaout a cabinet program?

[Swingman]

There you go ... I took drafting in HS and engineering drawing in college, but having never taken a CAD course, that _is_ valuable information to me, and something I've never heard before.

With regard to 1:1, what about "grids" for alignment of your drawing ... do you use them?

I don't have my program on this computer (QuickCAD) so I can't bring it up to check, but at 1:1, what effect does that have on the size of each grid square?

Before I figured out how to enter things like length of a line with the keyboard using my current program, I used the grid squares like graph paper to do that, and it could be a battle to get the scale right in order to work in 1/32nd increments, etc.

It's those little, non-intuitive things, with no quick answers to be found in the Help files without some lucky searching, that makes the hill steeper.

I've been around software for a long time, beta tested programs and operating systems long before they hit the street, wrote a commercial program (accounting) back in the 70's, co-authored pre-Internet modem to modem communications software, and find most GUI software intuitive ... but find CAD both intuitive as to concept, but often non-intuitive as to methodology.

[Upscale]

Many of us aren't doing this professionally, so why is a Cad program even necessary? I use Fireworks for all my designs. Agreed, it's not 3D, but it's a vector drive program, (points are mathematically calculated), I can design in exact dimensions (eg 8 or 16 points to the inch) and it's reasonably easy to learn the basics. You can save the files to .png which leaves all the behind the scenes mathematical constructs in place for easy editing afterwards. Agreed it's not a cabinet program and but it seems to me that this great push towards cad for most woodworkers is only driven by the desire to use the latest and the greatest just because they're out there.

And yeah, I have and do occasionally use the french curve shapes that my father left me.

[Scott Brownell]

As Mark said, always draw at full size (1:1). I never use a grid when I'm doing a drawing because I find it to be something of a distraction. I find that a blank screen and working in ortho mode are all I need 99% of the time. As you've discovered, keyboard entry of the distances is the easiest & most accurate way to go. Does QuickCad have a users group that you could get help from?

It's really a damn shame that programs today have such poor manuals. When I began with Generic Cadd 15 years ago it came with a terrific ring binder manual that I still reference to today. I've never had a reason to go looking for 3rd party info so have no clue as to what to recommend to others.

Scott

[Mark]

I have AutoCad-LT (ACad), a 2d educational version. I have access to the full blown 3d at school. I'm unfamiliar with QuickCad and it's terminology.

In ACad the grid is a series of evenly spaced dots. Do I use the grid? yes and no. The grid is only useful for a visual reference.

ACad has 'snap' which one type of snap 'zeros in' on intersecting lines of imaginary graph paper. Do I use it? Rarely after the first two lines are created.

If rule 1 is always draw 1:1 rule 2 is always start your drawing at a snap point that's a whole number. If you don't snap to a whole number the start point could be a number to (I think) the 13th decimal.

Snap and grid can be set to different spacing. I always set snap to a even multiple of grid, 2 or 4 snaps per grid. I don't think I have ever used 8 snaps per grid. When I drew the deck (16' x 20') I had the grid set for one foot and snap set to six inches.

Snap is mostly shut off as lines and intersections rarely fall on snap points.

You and I and others know what a scale is. It's that funny three sided 'ruler' with 6 scales, and if you want to draw a line 1' long at half scale you would draw a 6 inch line. We draw to scale because of the limitations of the medium, the size of the paper.

Throw that thinking out. Forget it.

With cad programs the 'paper' in infinite (to the limits of the program and processor). There is no reason to scale anything (at least not while drawing).

I believe Dr. Boyl gave the example of why to never draw to scale: You draw one part 2:1 and its mating part at 4:1, now put them in the same drawing. They won't match. They can be made to match, but why hurt yourself?

Direct keyboard entry is imperative. This is why I don't worry about and generally don't use snap/ grid spacing for drawing. Fact snap is a hindrance as the machine wants to go to a snap point which may have nothing to do with the drawing.

But then like I said, my spacing are whole numbers.

How do I get fractional points? Geometric construction. Same as with pencil and paper.

Except with CAD it's lots easier to erase construction lines.

Let's not go there. ACad is infamous for having functions that don't appear in pull downs, tool bars, can be accessed only by keyboard, and some aren't documented.

Generally help files are frigging useless. I think companies went to on line help files so you would have to buy their book(s). That backfired because it created a market for third party instruction.

Hope this helped, like I said I'm familiar with AutoCad. I don't know what QuickCADs capabilities are, what they call their features and functions.

BTW, I've also had instruction in parametric drawing.

[Rico]

The advantage to learning a CAD program is that it's less specialized. What you learn in a CAD program is applicable to a boat load of other completely unrelated design uses.

[Frank Shute]

Can you draw a line from the centre of a line that's 15 points long? Have you got an object snap that will draw a circle centred on the mid-point of any line? Dimensioning? Scaling? Rotating? Mirroring? Arraying? Parts?....

CAD's hardly the `latest & the greatest' ;)

I suppose if I didn't have CAD (AutoCAD LT) & didn't have an engineering background I might not use it and just sketch out designs on paper.

But since I've got it and can use it, I find it invaluable.

If I'd used 3D CAD more when I was engineering then I'd probably use a

3D CAD program, but I didn't so I don't.

It's what you're used to I guess.

I've still got my french curves, adjustable set square etc. but they've stayed boxed up for ~10 years.

Studies where done when CAD came into drawing offices & they showed something like an 8 fold increase in productivity. That's the reason I use it. Even though I'm hardly a professional, I'm getting old & my time is valuable to me; much more valuable than the cost of my software which I've had for many years.

I'd agree with other posters who say that a book on technical drawing is worthwhile whether you use CAD or draw by hand. I'm sure there must be resources on the web too.

First step is to be able to draw to scale using a specific projection eg. 3rd or 1st. (Do they still use 1st in the US?)

BTW, I don't bother with isometric or oblique projections and beginners shouldn't either.

With CAD the things you have to get familiar with first are setting a grid and using object snaps. I think that the more you play around with it, the better you'll get; although it might seem confusing at first.

[WebsterSteve]

Who ever taught you to run your pencil on a scale? A scale is for mearsuing. A Mayline( or T-square) and triangle are for drafting. You NEVER draw on your scale.

[Swingman]

Damn ... learned more about the basic, conceptual side, of using CAD from your post than I have in a year of trying the various programs ... every little bit helps.

Thanks!

[PM6564]

Ahhh, must be the difference between Architectural and Mechanical drafting. All we ever used were Maylines. Those wackjobs in Mechanical had those things that didn't draw horizontal.

[Lawrence A. Ramsey]

Surely brings back good memories although I didn't see them as such at that time.

[Mark]

Welcome.

[CW]

Congratulations. You have just made the stupidest statement I have read today.

[Upscale]

[Mark]

Being from the Cleveland area I found it slightly humorous.