Designing in CAD vs Laying Out Track on the Floor

I designed mine all in AnyRail, then went to town on the layout.  I did do some adjustments on the fly during track laying, and I back-filled them to AnyRail.  Since I used mostly Gargraves flex track, some of the curves aren't exactly representative of the end product, but it's very close.  There comes a time when the CAD layout isn't as instrumental in changes, but I did still try to keep my CAD copy current.

Things can look great in a drawing program but actually operating the trains can reveal a number of flaws in the design.  I was using Anyrail since it had templates for both Lionel Fastrak and Kato Unitrack.  I have a pretty good room (19x14)  to play with and no human extra human traffic so I tried out various designs on the floor.   I started with 048 curves and quickly went to 060 with 072 or 096 transitions with one large 096 curve.    The biggest problem running on the carpet identified was the need for straight sections leading into turnouts that were part of a curve.  Many larger locomotives would split the switch and adding that extra bit of straight took away from the loop, sidings, yards, etc,..   I kept things on the carpet for almost a year, adjusted the CAD to match reality and then boxed up the big stuff.   Next came the "N" scale and basically the same process and some of the same problems except this time I was dealing with grades to create an upper level.  Those were fine in the CAD but in reality the transition had to be extended in the curves.   Lots of fun, but now I'm going to sell this house and will basically repeat the process in the new house, oh well,

-Mike in NC,

I sometimes caution folks that software is exact while tracks are not, especially tubular tracks and those with plastic roadbed. I also caution that things should be test fit before tracks are tacked in place.  Unless you draw center rails on the decking, it doesn’t take much for things to get out of kilter, especially curves, but straight sections aren’t immune. Just because the 3 rails of a track line up with the rails on a preceding track doesn’t mean they’re “straight”.

My train room has two doors in one corner, one to the family room and one to an outside patio. I did not want a duck under to enter the train room. My layout was made using the following steps

1. Laid out using tubular track on the floor.
2. Made measurements and copied the plan into a CAD program.
3. Created the table outline 6 inches outside of the track.
4. Divided the table into sections that could be cut out of 4 X 8 sheets of MDF.
5. Made table drawings and fabricated the 20 tables.
6. Bolted the tables together into two dog bone shapes.
7. The two dog bones are connected by a bridge.

Wow David.  Interesting process you went through with a good result.  Big layout.

I have a 5x9 layout that was first built in SCARM. I had no issue assembling the layout with Fastrack. As it was my first layout, I adjusted more by first modeling in SCARM before buying any additional track and switches. It worked very well for me.

Still running trains on the basement floor.

I learned AutoCAD while an RA in the 1980s. AutoCAD Lite around Y2K. Used Draftsight 2D but it went to subscription, then NanoCAD free version, but if you didn't use it for a month, would time out the license. Found out about the IntelliCAD alliance, a group of companies that support a library that is mostly AutoCAD compatible, then put their own GUI over it. I bought CADHobby when it was on sale, ~50$

CADHobby calls itself 3D, but its more like 2.5D.

I've messed around with Fusion360, FreeCAD, TinkerCAD, but since I already now the UI for AutoCAD, I use one that is compatible.

I have found is O72 is not O72, K-Line O72 switches are about 1/8" off from 360/16 * radius, whomever makes the curves for Menards goes cheap on the rail bender so the last 1/2" is straight, it just goes on and on. What I do is put together a circle of the track, try to get it as circular as possible, then take 3 readings of the distance center to center and average. I draw a straight section as a rectangle with a line down the middle, and then a box that has its length (5.5,10,20,36,40,custom, etc). Takes a while to get the individual track sections.

@illinoiscentral posted:

I have found is O72 is not O72, K-Line O72 switches are about 1/8" off from 360/16 * radius,whomever makes the curves for Menards goes cheap on the rail bender so the last 1/2" is straight, it just goes on and on. What I do is put together a circle of the track, try to get it as circular as possible, then take 3 readings of the distance center to center and average. I draw a straight section as a rectangle with a line down the middle, and then a box that has its length (5.5,10,20,36,40,custom, etc). Takes a while to get the individual track sections.

That's where flex track comes in, you just bent it to suit.

One observation for the original poster... SCARM has an optional add-on module that allows you to place trains on the layout and run them, even in 3D view.  IMO it's a worthwhile investment, and you can quickly check the capacity of a yard, siding, etc.  The locomotives and cars in the program are six-axle modern diesels and rolling stock.  If you're planning to run small stuff from the transition era, or traditional-sized trains, you could expect to squeeze a bit more in.

I determined the width of my aisles by observing other narrow spaces around my house (such as the gap between my dining room chairs and a china cabinet.)  If you're planning for a lot of visitors obviously, you would leave more room than what's needed for one person to retrieve a derailed car or loco.  One other thing about planning on the floor: some of us are wider at the waist or shoulders, than we are at the ankles!

@David Nissen nice layout!  A few questions...

1. Ultimately, which software program did you use?

2. What are the overall dimensions of your train room?

3. What curve diameter(s) did you use on your layout?

Thanks for sharing!

CAD lets you iterate many design ideas before doing the final layout and testing.  I used Scarm for 2 layouts.   I like the bill of materials.   I know the amount of track and when needed, length of cut sections.  Measurement on the layout gives me length of wiring.  I built the wiring harness at the table and then put it in the layout. 

CAD knows no variation.  There is "flex" in most tracks, especially with a long straight area.   Even when Scarm shows a mismatch of a bend and straight, you can tell if it will work.   

Been working in CAD since the beginning.   Learning "size" in your mind takes practice and patience.    On my overhead layout I drew in the boards and bracket mount points.  It all worked.  Cut the boards to the design measurements.    The only real variance was some of the boards did not lay against the wall flat.  Boards were straight but the walls were wavy.   It still looks good.   Better than the house I grew up in,  the living room was out of square by 9" corner to corner.   Late 1800's Adobe construction.

For a room layout, build it on the carpet before building the rest is still a good idea.  The full scale perspective may give you ideas for improvement.

FWIW, my current layout is the only one I did with a CAD layout package, and I'd never go back to doing them "on the fly" just sticking track together again.  I was able to try out lots of combinations and see how they'd work much easier sitting at my computer rather than crawling around on the floor!

Being a designer for an engineering company by trade, Autocad is my main design tool. I designed everything for my current/basement/layout using CAD, including room lighting, track layout, bench work framing, sub-roadbed and wiring.

@Ted S

A few questions with answers.

1. Ultimately, which software program did you use?

    I used the software that I was using at work at the time
    which was Mastercam.

2. What are the overall dimensions of your train room?

    The room is 20 by 45 feet.

3. What curve diameter(s) did you use on your layout?

    The curve diameters of the track are O72, O96,
    and O110.

    The large loop by the doors is alternate O72
    and O96. This makes a curve that will go outside
    of an O72 track.

    This was the starting point 15 years ago. Since
    then 3 elevated tracks, a trolley line, a circus
    train line and a turntable have been added.

The wide aisles have been filled with a bench, two rocking chairs (for us old people), two control panels, a wood stove, a 3D printer, a small work bench that rolls under the table when cleared, and a small table and chair with my computer.