Conversion percentages.


aikenair@...
 

Denny,

Wouldn't the reduction be 76 divided by 87.1 or 87.3% reduction?
But isn't S-scale 1:64?

Then 64 divided by 87 is 73.5 % reduction.

Don Barnes


Denny Anspach <danspach@...>
 

Off hand, does anyone know what percent rule of thumb reduction (e.g. as would be set on a copying machine) to accurately reduce S-gauge plans to HO (1:76 ---->1/87.1)?

Thanks!

Denny
--
Denny S. Anspach, MD
Sacramento


Tim O'Connor
 

s is 1/64

-------------- Original message ----------------------
From: Denny Anspach <danspach@macnexus.org>
Off hand, does anyone know what percent rule of thumb reduction (e.g.
as would be set on a copying machine) to accurately reduce S-gauge
plans to HO (1:76 ---->1/87.1)?

Thanks!

Denny
--
Denny S. Anspach, MD
Sacramento



Yahoo! Groups Links






Andy Sperandeo <asperandeo@...>
 

Hi Deny,

From "Model Railroader" ­ To convert S scale drawings to your scale copy at
these percentages: N 40 percent, HO 73.5 percent, O 133.3 percent

So long,

Andy

Andy Sperandeo
Executive Editor
Model Railroader magazine
asperandeo@mrmag.com
262-796-8776, ext. 461
FAX 262-796-11142


Andy Sperandeo <asperandeo@...>
 

Of course, I was writing to "Denny," not "Deny." My typing gets worse as the
day wears on. - Andy


Rod Miller
 

Hi Denny,

The method Jerry White showed me was to draw/tape a line that was a
specific length in the scale of the image to be enlarged/reduced.
E.g., an O scale (1:48) drawing would have a line, say, 2.5 inches
long which represents e.g. 10 feet.

Start with an approximate enlargement/reduction setting and make a
copy. Measure the length of the line on the copy and determine its
scale length for the scale you want. When the line is 10 e.g. feet long
in the scale you want, you have the correct reduction/enlargement.

E.g., suppose you want to reduce an O scale (1/4 inch = 1 foot) drawing
to S scale (3/16 inch = one foot, or 1/64 inch = 1 inch).

A 10 foot long line in O scale is 10 1/4s or 2.5 inches long.

A 10 foot long line in S scale is 120 1/64s or 1 7/8 or 1.875.

When your line on the copy is 1.875 inches long the copy is accurate
for S scale.

IMHO that is more accurate than calculating a reduction/ enlargement
percentage.

Regards,

Rod Miller

Message: 18
Date: Wed, 18 Jan 2006 13:51:26 -0800
From: Denny Anspach <danspach@macnexus.org>
Subject: Re: Conversion percentages.

Off hand, does anyone know what percent rule of thumb reduction (e.g.
as would be set on a copying machine) to accurately reduce S-gauge
plans to HO (1:76 ---->1/87.1)?

Thanks!

Denny
--
Denny S. Anspach, MD
Sacramento


Schuyler Larrabee
 

Rod's point here is a good one. I just emailed Denny off-line that the factor is 0.7348, which is
64/87.1. Some copiers will do this level of precision, but even those are not COMPLETELY reliable.
Using the known length of line to get a reduced length so one can check the machine's capabilities
is a very good idea. One more thing, a machine I had in my office would be different reductions in
the two principal directions. 85% LtoR would be about 83% Top to bottom. That machine got
replaced. But putting lines in both directions will reveal this.

If it's critical, you should get this done photographically. It's increasingly hard to find shops
that can do this, but not impossible.

SGL

-----Original Message-----
From: STMFC@yahoogroups.com [mailto:STMFC@yahoogroups.com] On
Behalf Of Rod Miller
Sent: Wednesday, January 18, 2006 9:12 PM
To: STMFC@yahoogroups.com
Subject: [STMFC] Re: Conversion percentages.

Hi Denny,

The method Jerry White showed me was to draw/tape a line that
was a specific length in the scale of the image to be
enlarged/reduced.
E.g., an O scale (1:48) drawing would have a line, say, 2.5
inches long which represents e.g. 10 feet.

Start with an approximate enlargement/reduction setting and
make a copy. Measure the length of the line on the copy and
determine its scale length for the scale you want. When the
line is 10 e.g. feet long in the scale you want, you have the
correct reduction/enlargement.

E.g., suppose you want to reduce an O scale (1/4 inch = 1
foot) drawing to S scale (3/16 inch = one foot, or 1/64 inch
= 1 inch).

A 10 foot long line in O scale is 10 1/4s or 2.5 inches long.

A 10 foot long line in S scale is 120 1/64s or 1 7/8 or 1.875.

When your line on the copy is 1.875 inches long the copy is
accurate for S scale.

IMHO that is more accurate than calculating a reduction/
enlargement percentage.

Regards,

Rod Miller

Message: 18
Date: Wed, 18 Jan 2006 13:51:26 -0800
From: Denny Anspach <danspach@macnexus.org>
Subject: Re: Conversion percentages.

Off hand, does anyone know what percent rule of thumb
reduction (e.g.
as would be set on a copying machine) to accurately reduce S-gauge
plans to HO (1:76 ---->1/87.1)?

Thanks!

Denny
--
Denny S. Anspach, MD
Sacramento



Yahoo! Groups Links







David Smith <dsmith@...>
 

Most copiers have this sort of bias and anyone photocopying plans should
be aware that, even without reduction, there will commonly be a change
in length in the horizontal (scanning) direction. Repeatedly
photocopying photocopies magnifies the distortion. Photocopying once,
then rotating the copy 90 degrees and copying it again cancels the
distortion but does subtly change the overall scale. Scanners may show
similar effects.

Dave Smith, who knows this from having to reproduce perfect circles for
structural geology classes

David L. Smith, Ph.D.
Director of Professional Development
Da Vinci Discovery Center, Allentown, PA
http://www.davinci-center.org <http://www.davinci-center.org/>

"Who will pick up where Leonardo left off?"



One more thing, a machine I had in my office would be different
reductions in
the two principal directions. 85% LtoR would be about 83% Top to
bottom. That machine got
replaced. But putting lines in both directions will reveal this.