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[peteski]

I've heard this before, but don't understand. If I'm drawing something that is N scale, then N scale is 100%. I usually have to draw at x48 N scale and then I use Netfabb to shrink it x48 down. Still a pain because I have to convert every single measurement from N scale to x48 N scale.

If I took all of my scale drawings and sized them up to 1:1 scale that would be a large file.

Large file when drawn in 1:1 (prototype size)? Not at all.

Unlike bitmap files (JPG, TIFF, PNG, etc.), as I understand, vector based file size is not dependent on the size of the drawing stored in it.  The file stores the numerical values used to draw the vectors.  A line that is 0.1" long takes the same amount of storage space in the file as a line that is 200" long.

Can't you do the scaling within SketchUp?

If you draw something in N scale then blow it up 16000% (to get it to prototype size), and save the file, it should not be appreciably larger in size than the original N scale drawing file.

[rodsup9000]

  Chris
 When I'm copying a object (like your loco cylinders), I take the measurement and multiply it by the scale that it is. If it's HO, i multiply all measurements by 87 (N scale would be 160), and that will give you a the prototype (1 to 1 scale) dimensions. Once it all drawn up, scale it down in Sketchup by .01145% for HO and .00625% for N.
 
  This is where my old computer would take up to 20 minutes to reduce a very large file and the new one will do it in seconds. From what I understand, the video card does most of the processing for this kind of work.
  Looking at your tool bar, I see you don't have the "solid inspector" tool on it. Have you used it??? I use it just to make sure I don't have any holes in the mesh. If it doesn't pass, I let it try to fix it, but only about halve the time it works and the other times, it reverses some faces or closes holes and/or some other weird things happen.

[rodsup9000]

Large file when drawn in 1:1 (prototype size)? Not at all.

Can't you do the scaling within SketchUp?

If you draw something in N scale then blow it up 16000% (to get it to prototype size), and save the file, it should not be appreciably larger in size than the original N scale drawing file.

Yes the files are the same size, no matter how big it's drawn.
 Yes you can scale with Sketchup
 For N scale it's 160%, not 16,000%

[Chris333]

Yes I scale in Sketchup. That chassis once I got all the hard dimensions in N scale set I scaled it up x48 just so I could do simple things like round off an edge. Things I shouldn't need to scale up to do. The thing is now once it's scaled up if I want to make a hole for .015" wire to fit in I need to draw the hole 0.720" because it is x48. I need to use a calculator for just about every measurement to re-scale it. I just started using x48 so I would remember it and it seems to be a big enough jump that Sketchup will work. A lot of times I will draw a 1" long line off to the side just so I can know what scale I'm at in the drawing process. If I measure that line and it is 48" well now I know.

I think .018" radius is the smallest Sketchup will do. So just a hair big for a #90 screw hole, but that will work because 3D printing grows the parts slightly.

Again AutoCAD don't care how small a circle I draw. 

[Chris333]

I don't have "solid inspector", but I never have a problem with making it water tight model. I use Netfabb to check for any problems and keep Sketchup open while doing it so I can fix anything Netfabb finds. Usually my problems are Sketchup giving a surface 2 surfaces. And usually when that happens I go into Sketchup and "unhide" all. This will show a bunch of crap lines that I never put there. I delete them all and now there is only one surface. I never "hide" anything when I draw so they aren't my lines and they are so random.

Also thinking of solid inspector just makes me think of all the plugins I need just to use Sketchup 

[peteski]

Yes the files are the same size, no matter how big it's drawn.
 Yes you can scale with Sketchup
 For N scale it's 160%, not 16,000%

If you want to take N scale drawing you need to scale it up to 16000% to make it prototype (1:1)  scale.  Scale is not the same as percentage.

Example: if you have 1" long line in your drawing, to  make it 5" long you enlarge it by 500%
To make that 1" line 10" long, you enlarge it by 1000%
To make it 100" long you enlarge it by 10000%


I still don't understand why Chris stated that a file drawn in prototype size (1:1)  would be large.  Well yes, the drawing will be large, but couldn't you  zoom the view out until it is comfortable to work with?

[Chris333]

No what I mean about drawing 1:1 is I'm not drawing something that is 1:1. I'm drawing scale model trains.

What is a 1:1 scale 7x16mm motor?  It is 7x16mm that is it's full size.

The coupler pocket I showed. This is a 1:1 coupler pocket:
https://ogrforum.ogaugerr.com/fileSendAction/fcType/0/fcOid/151773314460105556/filePointer/151914096249609962/fodoid/151914096249609948/imageType/MEDIUM/inlineImage/true/Quincy%2520Mine%25202019-1732.jpg
How is that of any use to me when I need to fit a Microtrains 1015 coupler that is 0.280" above my scale railhead?

[peteski]

No what I mean about drawing 1:1 is I'm not drawing something that is 1:1. I'm drawing scale model trains.

What is a 1:1 scale 7x16mm motor?  It is 7x16mm that is it's full size.

I understand that you draw things in 1:1 scale (or 100%).  I suspect that when model company designers design N scale model of a locomotive, they either get the original CAD drawings or draw their own in prototype dimensions, then they scale them down to N scale.

Since you already work in 48 times larger than N scale drawings, why not just draw in prototype scale?  I understand that some things (like rivet sizes of handrail diameters) would be too small if scaled from prototype size to N scale, but the amount of manual calculations you have to to with 48 times size drawing would not be any different than with prototype size drawing.  Just the numbers would change.

[rodsup9000]

I think .018" radius is the smallest Sketchup will do. So just a hair big for a #90 screw hole, but that will work because 3D printing grows the parts slightly.

This is why I like to draw everything in 1 to 1 scale. The round part of your cylinders on your loco looks to be done with only 24 segments in the circle.
If you would of increase the size you were drawing it in, you could of made them with 192 segments and it would print much more rounder.

If you want to take N scale drawing you need to scale it up to 16000% to make it prototype (1:1)  scale.  Scale is not the same as percentage.

Example: if you have 1" long line in your drawing, to  make it 5" long you enlarge it by 500%
To make that 1" line 10" long, you enlarge it by 1000%
To make it 100" long you enlarge it by 10000%

 Pete I just scaled some N scale structure parts I'm working on for the laser. I drew them 1 to 1 and then scaled it by .00625 for N scale (I measure doorways to make sure they are .500" which is 80 scale inches) and then scaled it up by 160% and they came back out the size I drew them. So maybe it's not "%" that I'm using, but every other program (slicer for 3D printers) I use for scaling uses "%" and it comes out to 1 to 1 when enlarged by 160%.

[Chris333]

Or Sketchup could just work no mater what numbers I type into it.     Like CAD does.

Things are oversized in N scale. I know that. I know what will print. So I draw what will print and not what is perfectly scaled down from the real thing. Like the N scale bricks.

If I was trying to make a 1:160 perfectly scaled model then I could just draw 1:1 and scale it. But when I need to incorporate actual items like couplers, motors, gears, wheels. 1:1 just does not compute. A 1:1 steam locomotive does not have a tiny DC motor in it or screws that are 160 times larger than a #90 screw holding it together. I am not drawing a 1:1 item. If I measure something sitting here at my desk and it is 1"long I should be able to draw that item 1" long.

I bet Kato uses a program that work in N (or any) scale.

Not trying to argue with anyone, but Sketchup sucks.

[Chris333]

I think the cylinders are just stepped from printing flat. Looking at the drawing I have no idea how to tell how many segments they are, but when calculated down to scale they are .005" long segments in the circle.

The curved ends to the pilot beam have far less segments and look smooth in the print.


Edit: the cylinder tubes have 56 segments and the outer caps have 77 segments. I drew them about a year ago and would do it differently today.

[Chris333]

Just about everything starts with a scale drawing. I had one on my desktop that was to HO scale. I just tried to resize it to 1:1 (x87) scale and the program (XnView) shut down. it took a 2011x1357 jpg and turned it into a 174722x117900 jpg.  So just that alone...

[peteski]

 Pete I just scaled some N scale structure parts I'm working on for the laser. I drew them 1 to 1 and then scaled it by .00625 for N scale (I measure doorways to make sure they are .500" which is 80 scale inches) and then scaled it up by 160% and they came back out the size I drew them. So maybe it's not "%" that I'm using, but every other program (slicer for 3D printers) I use for scaling uses "%" and it comes out to 1 to 1 when enlarged by 160%.

Well, then you are  multiplying the dimensions, not doing it by the percentages.  A scale of 160:1 is not the same as 160% of the original size.  A scale of 1:160 is not  the same as 160% than the original.  It just doesn't compute.  Percentage is a ratio, not a multiplier.  https://en.wikipedia.org/wiki/Percentage

Sounds like the CAD program uses multipliers for  resizing (not percent values).  It is multiplying the dimensions by 160 to enlarge, or multiplying  by 0.00625 to reduce down to N scale.  0.00625 is a reciprocal  of 160. It is not a percentage.

[peteski]

Just about everything starts with a scale drawing. I had one on my desktop that was to HO scale. I just tried to resize it to 1:1 (x87) scale and the program (XnView) shut down. it took a 2011x1357 jpg and turned it into a 174722x117900 jpg.  So just that alone...

But you are manipulating a jpeg (bitmap), not a vector-based drawing.  So yes, it will get huge in size.  But if it was a vector based H0 drawing, enlarging it would not  have resulted in dramatic file size increase.   I know, we are starting to go in circles.

I understand your need to make some things (like that coupler box) out-of-scale.  But as I mentioned, since you are already working in a drawing 48 times  the N sclae size, I'm wondering why not work in 1:1 dimensions (160 times the size)?  You will still have to recalculate things.

[Chris333]

What I mean about 1:1 being too large is the scale plans (jpg) I start with. If I'm drawing 1:1 I need to trace a 1:1 drawing. Just about everything I do starts with importing a scale drawing into CAD and tracing over it.

This is an old image, but the locomotive drawing in the photo is scaled so it is Z scale. I traced the feedwater pump (in red) and now I have a Z scale feedwater pump etched in brass.


I do basically the same thing still. After I do an outline in CAD I import that into Sketchup. The whole process is much easier when everything stays the same size. All of this re-sizing is just because of Sketchup.