Scale factors for drawing and printing with English units

This area contains the messages from the old Yahoo cadintoshmac group after the port.
planned.obsolescence
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Joined: Wed May 21, 2008 7:39 pm

Scale factors for drawing and printing with English units

Post by planned.obsolescence »

There appears to be confusion about setting up and printing drawingswhen using English units. This is what I have realized while usingthis program.Cadintosh is based entirely on the metric system. Remember that 30.48cm equals 1 ft. Here is how to use English units.1) Select "Options ->Drawing" from the menu and chose "feet" and"fractions" for your drawing units.2) Next, set up your print page. Select from the menu"File->Area->options...". Enter 1/30.48 for the default page scalefactor (which is the standard 8-1/2" by 11" page). This converts yourpage size from metric to English units. You can set up more pages ofany size, just use the 1/30.48 scale factor.3) Now select your drawing scale size. Cadintosh develops all Englishscale ratios off 30.48 cm. The 1/4" scale factor is really 1/48 of30.48 cm (0.634) and not 1/48 of one foot (0.0208) as you wouldexpect. Don't use any of the 1:1, 1:2, etc. scale factors for Englishunits. If you need an unlisted scale factor such as 1"= 20', go to"user define" at the bottom and calculate your own ratio. In this caseit would be 30.48 cm divided by 20 ft times 12 in per ft or 30.48/(20 x 12) = 0.127.4) To change the scale factor, the safest way is to scale a group ofdrawing elements twice. Create the group of items to be changed.Select "Group->Change Scale" and for the scale factor use the inverseof your original scale factor. This gets you back to full scale. Dothe proceedure again using your new scale factor.If you export a DXF file, it will not be the correct size for otherapplications unless you scale it up. For example, a 1/4" drawingshould be scaled 48/30.48 (inverse of the original scale factor) andthen by 30.48 to convert it from metric to inches.None of this is explained anywhere and, unfortunately, is notintuitively realized.John
Richard Ellam
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Joined: Sat Jan 21, 2006 1:10 am

Re: Scale factors for drawing and printing with English units

Post by Richard Ellam »

Dear AllAlternatively, you could do what 95% of the world does, and use the ISO metric system!So much easier.Cheers Richard EllamL M InteractiveScience Shows and Hands-On Stufftel/fax 01761 412 797richard@lminteractive.eclipse.co.uk On 21 May 2007, at 20:24, planned.obsolescence wrote: There appears to be confusion about setting up and printing drawingswhen using English units. This is what I have realized while usingthis program.Cadintosh is based entirely on the metric system. Remember that 30.48cm equals 1 ft. Here is how to use English units.1) Select "Options ->Drawing" from the menu and chose "feet" and"fractions" for your drawing units.2) Next, set up your print page. Select from the menu"File->Area->options...". Enter 1/30.48 for the default page scalefactor (which is the standard 8-1/2" by 11" page). This converts yourpage size from metric to English units. You can set up more pages ofany size, just use the 1/30.48 scale factor.3) Now select your drawing scale size. Cadintosh develops all Englishscale ratios off 30.48 cm. The 1/4" scale factor is really 1/48 of30.48 cm (0.634) and not 1/48 of one foot (0.0208) as you wouldexpect. Don't use any of the 1:1, 1:2, etc. scale factors for Englishunits. If you need an unlisted scale factor such as 1"= 20', go to"user define" at the bottom and calculate your own ratio. In this caseit would be 30.48 cm divided by 20 ft times 12 in per ft or 30.48/(20 x 12) = 0.127.4) To change the scale factor, the safest way is to scale a group ofdrawing elements twice. Create the group of items to be changed.Select "Group->Change Scale" and for the scale factor use the inverseof your original scale factor. This gets you back to full scale. Dothe proceedure again using your new scale factor.If you export a DXF file, it will not be the correct size for otherapplications unless you scale it up. For example, a 1/4" drawingshould be scaled 48/30.48 (inverse of the original scale factor) andthen by 30.48 to convert it from metric to inches.None of this is explained anywhere and, unfortunately, is notintuitively realized.John
RowlandCarson
Posts: 1
Joined: Fri Dec 30, 2016 10:56 am

Re: Scale factors for drawing and printing with English units

Post by RowlandCarson »

At 2007-05-21 19:24 +0000 planned.obsolescence wrote: >There appears to be confusion about setting up and printing drawings>when using English units. This is what I have realized while using>this program. [snip] >Enter 1/30.48 for the default page scale>factor (which is the standard 8-1/2" by 11" page) John - I was a bit confused by this statement. I don't think the scaling of the printout is changed by choosing a different page size. For a given page scaling, the parts of your drawing will be the same absolute size on the paper whether printed on US letter or the more widely-used A4 (210mm x 297mm) standard.[snip] >None of this is explained anywhere and, unfortunately, is not>intuitively realized It's certainly not intuitive! However I have not found it necessary to go through all that complicated stuff on the very few occasions a long time ago when I wanted a drawing constructed (or dimensioned) in Imperial units. I do seem to recall something unexpected about scales other than 1:1, but the built-in imperial units seemed to work OK for me. However, I wasn't doing anything very complex (like drawing on one scale and exporting in another).Perhaps Thorsten will have some reactions to your proposed method of working.Incidentally, I have never been able to retain in my head the number of centimetres in a foot, but can always recall that 25.4mm = 1 inch.regardsRowland-- : Wilma & Rowland Carson http://home.clara.net/rowil/: <rowil@clara.net> ... that's Rowland with a 'w' ...
planned.obsolescence
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Joined: Wed May 21, 2008 7:39 pm

Re: Scale factors for drawing and printing with English units

Post by planned.obsolescence »

--- In cadintoshmac@yahoogroups.com, Rowland & Wilma Carson<rowil@...> wrote: > Perhaps Thorsten will have some reactions to your proposed method of working. > > Incidentally, I have never been able to retain in my head the number > of centimetres in a foot, but can always recall that 25.4mm = 1 inch. Thorsten appears to have used the cm as a basic ISO unit and the footas the basic English unit. 1 inch = 2.54cm and the foot is 12 of these(30.48cm).Try this little exercise. After selecting feet and inches with"Options->Drawing", use the "line at an angle" command with 0,10inputs to draw a series of lines with each of the English scale factors.You will notice that the sequence of lines all scale proportionallythrough the 2" scale factor. Everything below that is not proportionalto the above lines.To print the 1/4" through 2" scale factors correctly on whateverprinter or plotter you have (A4, 8-1/2"x11", D size, etc.), you mustscale the output by 1/30.48.Only Thorsten can explain why the program's output is inconsistent andhopefully fix it for the 5% of us who have not caught up with theworld. My original intent was just to provide a series of steps todeal with the inconsistencies.Regards,John
Eric Eccleston
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Joined: Sat Dec 01, 2007 1:24 am

Re: Scale factors for drawing and printing with English units

Post by Eric Eccleston »

On CADintosh, what I do is sort of what people did in the olden days when drafting by hand (and for $30 to register the program, this was worth my time):I set up a template file for each scale I typically work in (mostly 1/4" = 1'-0" and 1/2" = 1'-0"). I hand calculated what the scale borders, text heights, line thicknesses, etc. should be with various page sizes at those various scales. This is basically my making a few virtual mylars to draw on at full scale. Then I don't mess around with CADintosh doing the scaling.If I worked in metric units, I would have been tempted to use the scaling features of CADintosh. As to the comment about 95% of the world using metric... I can only say, maybe 95% of the countries may have adopted metric systems, but the US does way more than 5% of the world's work, and we do it just fine in feet and inches, thank you very much.Oh, and let me introduce myself. I'm new to this forum. My name's Eric and I'm an engineer.
mwr1026
Posts: 0
Joined: Wed May 21, 2008 7:39 pm

Re: Scale factors for drawing and printing with English units

Post by mwr1026 »

I'm about 24 hours into trying to figure out the non-metric scalingissues for cadintosh, having just downloaded and licensed it. I wasgoing crazy until I found this thread. Hopefully it will all work out. And yes, it would be nice to join the enlightened 95%, but 100% of thepeople I have to deal with are in the other 5%, making that suggestionuseless to me. :-)
stodieck
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Joined: Fri Dec 05, 2008 9:36 pm

Re: Scale factors for drawing and printing with English units

Post by stodieck »

Well my name is Robert, I'm also an engineer in the USA, and I knowthat 95% of the US's work is done in China. Our failed Mars missionshave something to do with Ronald Reagan's reversal of the legislationto put the US on the metric system, and I suspect that you think thatinterlace HDTV is also a good thing. - Cheers! > As to the comment about 95% of the > world using metric... I can only say, maybe 95% of the countries may > have adopted metric systems, but the US does way more than 5% of the > world's work, and we do it just fine in feet and inches, thank you > very much.> > Oh, and let me introduce myself. I'm new to this forum. My name's > Eric and I'm an engineer.>
Tkat
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Joined: Wed Feb 25, 2009 1:55 am

Re: Scale factors for drawing and printing with English units

Post by Tkat »

On Dec 5, 2008, at 12:10 PM, stodieck wrote:Well my name is Robert, I'm also an engineer in the USA, and I knowthat 95% of the US's work is done in China. Our failed Mars missionshave something to do with Ronald Reagan's reversal of the legislationto put the US on the metric system, and I suspect that you think thatOh?  I too, have an engr degree - mechanical design option - & a US born citizen.  Not only that, but I've been "crank'n handles" for over 1/2 a century.  I've quite a history of mechanical machine design w/ a fair number of patents to back it up.  Plus I own/run a CNC proto type machine shop.The metric system may work for most measurements but is a joke in machining where tolerances are concerned.  In general machining 3 decimals generally means ± 0.005" or ± 0.127mm.  Any metal whittler worth his salt typically gets to w/in 0.002", or 0.051mm - say .05mm.  That means 0.001" ≈ 0.025mm.  What an ugly number to kick around!Sure, my machines will convert to mms, but the numbers are still nasty.  I agree inches and fractions thereof are hideous units of general measurements. That's why we should consider completely converting to a base 12 system.    ;)   But keep the physical size of the smallest unit a whole easily achievable number. Ciao, Tkat"Remember, there's alway room at the top --- particularly after the investigation." 
jaelje
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Joined: Fri Aug 27, 2004 9:27 am

Re: Scale factors for drawing and printing with English units

Post by jaelje »

I did'nt think this battle was still going on. I'm french, I'm an engineer (now retired) and I did work both in France and the UK (back in the 70s):I did the mental adjustement from micron to thou(sands of an inch) and although one was "speaking" more to me than the other, after a little while of getting used to it, I got on with it.No need to claim that one was better than the other...but one common system makes life easier to everyone and number of minds to set (brains to massage) is probably more the deciding factor...First and last input to this forum....-- In cadintoshmac@yahoogroups.com, "stodieck" <stodieck@...> wrote: >> Well my name is Robert, I'm also an engineer in the USA, and I know> that 95% of the US's work is done in China. Our failed Mars missions> have something to do with Ronald Reagan's reversal of the legislation> to put the US on the metric system, and I suspect that you think that> interlace HDTV is also a good thing. - Cheers!> > > > As to the comment about 95% of the > > world using metric... I can only say, maybe 95% of the countries may > > have adopted metric systems, but the US does way more than 5% of the > > world's work, and we do it just fine in feet and inches, thank you > > very much.> > > > Oh, and let me introduce myself. I'm new to this forum. My name's > > Eric and I'm an engineer.> >>