Re: Scale factors for drawing and printing with English units

[planned.obsolescence]

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.

Cadintosh is based entirely on the metric system. Remember that 30.48
cm 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 scale
factor (which is the standard 8-1/2" by 11" page). This converts your
page size from metric to English units. You can set up more pages of
any size, just use the 1/30.48 scale factor.

3) Now select your drawing scale size. Cadintosh develops all English
scale ratios off 30.48 cm. The 1/4" scale factor is really 1/48 of
30.48 cm (0.634) and not 1/48 of one foot (0.0208) as you would
expect. Don't use any of the 1:1, 1:2, etc. scale factors for English
units. 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 case
it 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 of
drawing elements twice. Create the group of items to be changed.
Select "Group->Change Scale" and for the scale factor use the inverse
of your original scale factor. This gets you back to full scale. Do
the proceedure again using your new scale factor.

If you export a DXF file, it will not be the correct size for other
applications unless you scale it up. For example, a 1/4" drawing
should be scaled 48/30.48 (inverse of the original scale factor) and
then by 30.48 to convert it from metric to inches.

None of this is explained anywhere and, unfortunately, is not
intuitively realized.

John

[Richard Ellam]

Dear All
Alternatively, 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 412 797
richard@lminteractive.eclipse.co.uk


On 21 May 2007, at 20:24, 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.

Cadintosh is based entirely on the metric system. Remember that 30.48
cm 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 scale
factor (which is the standard 8-1/2" by 11" page). This converts your
page size from metric to English units. You can set up more pages of
any size, just use the 1/30.48 scale factor.

3) Now select your drawing scale size. Cadintosh develops all English
scale ratios off 30.48 cm. The 1/4" scale factor is really 1/48 of
30.48 cm (0.634) and not 1/48 of one foot (0.0208) as you would
expect. Don't use any of the 1:1, 1:2, etc. scale factors for English
units. 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 case
it 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 of
drawing elements twice. Create the group of items to be changed.
Select "Group->Change Scale" and for the scale factor use the inverse
of your original scale factor. This gets you back to full scale. Do
the proceedure again using your new scale factor.

If you export a DXF file, it will not be the correct size for other
applications unless you scale it up. For example, a 1/4" drawing
should be scaled 48/30.48 (inverse of the original scale factor) and
then by 30.48 to convert it from metric to inches.

None of this is explained anywhere and, unfortunately, is not
intuitively realized.

John

[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.

regards

Rowland
--
| Wilma & Rowland Carson http://home.clara.net/rowil/
| ... that's Rowland with a 'w' ...

[planned.obsolescence]

--- In cadintoshmac@yahoogroups.com, Rowland & Wilma Carson
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 foot
as 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 0,10
inputs to draw a series of lines with each of the English scale factors.

You will notice that the sequence of lines all scale proportionally
through the 2" scale factor. Everything below that is not proportional
to the above lines.

To print the 1/4" through 2" scale factors correctly on whatever
printer or plotter you have (A4, 8-1/2"x11", D size, etc.), you must
scale the output by 1/30.48.

Only Thorsten can explain why the program's output is inconsistent and
hopefully fix it for the 5% of us who have not caught up with the
world. My original intent was just to provide a series of steps to
deal with the inconsistencies.

Regards,

John

[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]

I'm about 24 hours into trying to figure out the non-metric scaling
issues for cadintosh, having just downloaded and licensed it. I was
going 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 the
people I have to deal with are in the other 5%, making that suggestion
useless to me.

[stodieck]

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.
>

[tkat@tkat.com]

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 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






Oh?  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]

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" 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.
> >
>