Monday, November 20, 2006

The Odd Thing About CAD...

I use DeltaCAD, a simple, inexpensive 2D replacement for the traditional T-square and triangles, to make patterns for parts, from a 56" rib to itty-bitty things for home-made clocks, tiny steam engines and similar stuff. And I talk about it, too. If you hope to share information at a distance you need good drawings and a simple CAD program is miles ahead of old-fashioned drafting and snail-mail.

That produces a lot of mail, almost all of it from guys telling me why they don't use CAD, or at least, not DeltaCAD. Such as the message I received last night in which the feller explained that the reason he didn't like DeltaCAD -- and only had it so he could print out my drawings of VW conversion parts -- was because he was accustomed to working in fractional inches.

"In the time it takes me to convert 27/64ths to decimal and get it typed in," he wrote, "I could have drawn it a dozen times with a drafting scale."

I had to think about that for a while. A private answer would have been more polite but if one person thinks DeltaCAD can't handle fractional inputs then others might, too. And the truth is, it handles them just fine. Want a line 27/32nds in length? Then select the LINE function, indicate the point of oirgin with your pointer and type in 27/32.

One and nine-sixteenths? Then type in 1 (space) 9/16. Two feet, three and three-sixteenths would be entered as 2'3 3/16.

I can appreciate the feelings some guys have when they're faced with converting a 1920's drawing into a digital format. Back then, everything was in fractions of an inch and American Wire Gauge, neither of which is in common usage today. But DeltaCAD, with which I have no relationship other than as a satisfied customer, really is handier than your T-square, triangles and drafting scale. The odd thing is that so few guys my age think so and I really can't understand why. The complete manual is only 218 pages long and most of that is white-space. In fact, compared to other CAD software DeltaCAD is so simple most guys start turning out usable drawings without ever reading the manual.

-R.S.Hoover

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