Thoughts on optimizing cookie cutter roadbed?

[randgust]

OK, at the risk of setting the wayback machine to about 1984...

Did my entire layout cookie-cutter, with plywood.   With an 8' x 5'6" six-module design, and a VERY unforgiving, multi-level track plan, glued and taped up craft paper on the floor and drew the track plan out full size, using real switches as templates.    Cut the craft paper up for roadbed templates on the plywood.

I used thin quarter-inch plywood, on risers on a 1x2  grid system.   Still not stiff enough so I put a 3/4 x 1 1/2 riser on edge underneath all main line trackage, between the risers.   Then paint everything, and I mean everything, to slow down warpage.  Glue and screws too.

Live in northwest PA so we run between 10 below and 100 above, with zero to full humidity, basement room layout with a dehumidifier and heat.  But, it still expands and contracts.  And the WORST is the painted masonite backdrop material.   I'd never, ever, ever use that stuff again for anything.  No matter what you do, it's going to expand and contract more than wood does.   There's no economy in sprung track.

Very much of my consideration on this method was that I'd just lost a layout due to a move and this one was going to be movable and semi-portable (I can move it but it's not easy), so I wanted benchwork that would hold up to being moved and relocated.  No 'chunk' was bigger than 27x48, bolted together.   Plywood and wood grid, say what you want, but it's held up now to be moved to three different houses since, put in trucks, carried on edge, you name it.   Now that I'm doing T-trak it's just a smaller version of the same methods, I make my own.

If you'd rather mess with a computer screen than juggling around pieces of paper template on a real sheet of plywood, hey, good for you.  My father had a wood shop he left me, every woodworking tool you can imagine, and while it's not my hobby, you work with what you have.   My router is very capable of reducing nice material to scrap in short order.

[PiperguyUMD]

FWIW, I had the frames for several Freemo-N modules CNC cut at a local sign shop so that I could set up a round-round in my garage. It was pricey, but really easy. There was only one shop in town that was willing to do it for me so they may have gouged me a little. Now that they're done, I can use them as a templates to make more at the router table with a top bearing flush cut bit. Anyways - I think I used inkscape to draw up the plans, which I had no experience with. That was remarkably tedious, but if you need multiples of similar shapes, it's hard to beat. Otherwise, I'd fire up the jig saw

[NtheBasement]

Back in the day I worked at a company that made software for manufacturing.  Laying out parts on a sheet with minimum waste is called nesting.  Example: https://deepnest.io/

[Mark5]

I used thin quarter-inch plywood, on risers on a 1x2  grid system.   

In my opinion, that's way too thin. I always used 1/2".

[randgust]

Yes, it is too thin, but on a multi-level layout where you're minimizing grades, that buys you a tad of clearance, including for hands between levels.

If you look at the post - I turned a stiffener on edge between risers wherever I could.   Just scrap lumber, but it sure helps to have an overhead radial saw (which I do) to rip up almost anything to a consistent dimension shape.

The other advantage to 1/4" is that it makes it a heck of a lot easier for under-table switch mounts, makes it lighter, and does some of the vertical curve easements rather naturally.

This is a VERY old shot, but it does show the method nicely.   All the track in these shots is hidden now but the methodology for cookie-cutter is still pretty much the same.    I didn't really use L-girder, cut my own and narrowed the spacing, but it's still the same approach.

http://www.randgust.com/Layout_view_1983.jpg
http://www.randgust.com/Phoenix_loop_1983.jpg

And while it's old school, it's proven to be rock-solid and taken three moves.   

The portable layout I made with these methods in 1976 that everybody has seen in Altoona has held up the same way, including being dropped down a flight of stairs and being ferried all over the state at train shows.   

Maximizing the efficiency of plywood due to a cost issue is a different equation if you reduce the thickness, substitute scrap lumber for reinforcement (particularly free lumber) and use paper full-size templates for design using real track components instead of computer planning templates that can't be trimmed and tweaked.   I'm just not a big fan of Complexity Bias here.   

[wazzou]

I'll just say this. 
1/4" plywood purchased today, outside of the price, just isn't the same as 1/4" plywood purchased in 1983.

[Mark5]

I see. (insert missing thumbs up emoji) That would definitely call for (as mentioned) smaller support intervals or reinforcement if I were to use it (1/4") 

Those pics resemble the module I toted around with me for about 25 years in this wonderfully humid Maryland climate. 

Weight has never been an issue for me, though I always look to building a "permanent" layout (now kicked to the next house  ). If portability was a concern, this would be a serious factor then.

For me, this (1/2" plywood) caused no clearance issues the way I design my (mountain road) layouts, but then again I don't incorporate the helix concept in any of my designs. If I were to used a helix, I would certainly have to look at something thinner (but personally I don't care for the helix concept <-- my personal preference). The one thing I do like about thicker is that it forces smoother vertical easements (sorta).

substitute scrap lumber for reinforcement (particularly free lumber) and use paper full-size templates for design using real track components instead of computer planning templates that can't be trimmed and tweaked.   I'm just not a big fan of Complexity Bias here.   

That's pretty much my philosophy too. 

Mark

[CRL]

Based on the photos you’ve provided, that’s not what is traditionally thought of as a cookie cutter layout. You’re simply using sections of plywood on elevated risers as a roadbed. Using 1/4” plywood in your manner doesn’t really gain you any worthwhile clearance over 3/8” or 1/2” ply which are much more stable. Using stiffeners is just more wood, labor & expense incurred when you could have just used marginally thicker plywood... but hey... your project so whatever works for you.

Here’s a more traditional approach to cookie cutter:

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[Dksw]

I made my helix from CNC milled MDF quarter sections.  What really helped speed up construction and made the cost if the cutting worth it was having a 1 mm deep channel milled along the curved centerline to the exact width of Atlas Code 55 flex.  Once I had all the pieces ready, curves, spacer blocks & all rail joiners prewired with feeders I was able to build up the whole thing over the weekend with screws and construction adhesive to bond the track into the groove  No waiting for anything to dry to keep centreline.
At the same time I had the same vendor cut a few sheets of MDF into perfect splines for subroadbed.
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[randgust]

I made my helix from CNC milled MDF quarter sections.  What really helped speed up construction and made the cost if the cutting worth it was having a 1 mm deep channel milled along the curved centerline to the exact width of Atlas Code 55 flex.  Once I had all the pieces ready, curves, spacer blocks & all rail joiners prewired with feeders I was able to build up the whole thing over the weekend with screws and construction adhesive to bond the track into the groove  No waiting for anything to dry to keep centerline.

I'm easily impressed by some nice touches like the design of the spacer blocks with the vertical angled countersinking.   And, the track-laying channel.... 

On mine, if you'd see the visible level above all that hidden level, it's a lot more conventional cookie-cutter, except where I went below grade with scenery.  And my vertical clearances are squeaky-tight to hold to 2.5% max grade.   Most of the layout has 3 levels, the lower level staging yard, the intermediate reverse loop, and the grades climbing out in both directions to the visible track to the 'top level', which is all visible.   There's a four-inch difference between the visible level and the staging yard.   But even on the visible level, 1/4" with stiffeners under the main.   The stiffeners really only matter where the roadbed is narrow enough to not function as a stiff bridge between risers.

And to get to those levels, every scrap of lower and intermediate roadbed that wasn't necessary was removed to reach in from the sides and bottom.   Amazingly enough, it's still running, and more importantly, maintainable.   The current term is a "Nolix", invented after I finished it.

If you'd look at my wood shop, you'd conclude I never throw anything out, and leftovers eventually make it to kindling.   My wife's nickname for me is "Mr. Efficiency", sometimes a compliment, most times not.

[mmagliaro]

Ed,
How much surface are you thinking you need?   1/2" 5-ply, sanded, hardwood (maple or birch) plywood is about $55 for a 4'x8' sheet (I took a gander at Lowe's and a few other places online).  That stuff, as you probably know, is super strong, flat, and stable.  I know it's not "cheap", but if you only need 1 or 2 sheets, $50 - $100 for something that will be supporting an entire section of your layout doesn't seem like a bad investment.

[Steveruger45]

^^^^^^^^
What I’m thinking too. Plus if you get a Lowe’s credit card in store you get 20% off the first purchase and 5% off after that.
Then your 100 bucks works out to 80.
https://www.lowes.com/l/Credit/new-account-promo-tandc.html

[peteski]

My friend's layout is built using L-girder and 1/4" Lauan plywood with standard cork roadbed.  Build close to 30 years ago and still operational and stable.  1/2" plywood for N scale seems like a huge overkill.  Insulation foam? Sure, he used for scenery, but not for supporting track.

He hosts hosted many operating sessions (attended by modelers in all scales (from Z to G), and a lot of them are surprised just how well the "little" N scale trains run.

[Ed Kapuscinski]

Ed,
How much surface are you thinking you need?   1/2" 5-ply, sanded, hardwood (maple or birch) plywood is about $55 for a 4'x8' sheet (I took a gander at Lowe's and a few other places online).  That stuff, as you probably know, is super strong, flat, and stable.  I know it's not "cheap", but if you only need 1 or 2 sheets, $50 - $100 for something that will be supporting an entire section of your layout doesn't seem like a bad investment.

^^^^^^^^
What I’m thinking too. Plus if you get a Lowe’s credit card in store you get 20% off the first purchase and 5% off after that.
Then your 100 bucks works out to 80.
https://www.lowes.com/l/Credit/new-account-promo-tandc.html

Yep. That's pretty much what I was thinking about doing. I'm sure I'll find uses for whatever scrap I come away with. I really do love the idea of getting stuff CNC'ed, but I also feel like I like the process of doing it all myself with a jig saw. I think I'm going to measure the cargo space in the Shark and have them cut the sheets down to that size for ultimate portability. It can carry a surprisingly large load, but 4x8 sheets aren't gonna fit.

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Of course I've gotta get this f***ing floor project done first though 

[Point353]

I think I'm going to measure the cargo space in the Shark and have them cut the sheets down to that size for ultimate portability. It can carry a surprisingly large load, but 4x8 sheets aren't gonna fit.

Are you within a 75-minute round-trip from a Home Depot?
If so, then rent one of their trucks for $19.