I need some advise. I used a sheet of 4 x 8 x 3/4 inch plywood for my layout. I also used 2 x 4's around the perimeter and across 2 feet on centers. The problem I am having is my plywood and 2 X's were straight when i picked it out at the lumber yard, but now my top has a bow in it. I really don't want to start over but if I need to OK. Is there anything I can do? I thought of using bridge piers that would give the appearance of a bridge but in fact my track would be level.
Thanks,
Wes
Wes, if you got a straight 2x4 at one of the 'box stores' (or probably any other supplier0 you were extremely lucky! I spend most of my time, shopping for lumber, by looking the the most straight boards.
OK, more to the problem: Get rid of the 2x4s and use 1x4 lumber. I have found the L-girder construction (ala Model Railroader and Lynn Westcott) to be the best all-around type of benchwork support. There are numerous articles on this type of construction. Check out the Info Station on Model Railroader's website. You can purchase downloadable articles on many subjects at this location...one of which is benchwork construction.
Regards,
Ray
Thanks for the info. I want my first layout to be right.
Wes
Dear Friends,
Is not a 5' x 9' to be recommend to allow 22 inch curves ? Seems to me that was much discussed on this forum several years ago. Too, I believe a ping pong table is 5 x 9, is it not ? That is for one who wishes a portable item.
Best Wishes,
Jack
For those of us who like to live dangerously, 22" radius curves fit quite nicely on a 4' wide sheet, leaving about an inch between the edge of the road bed and oblivion. For those a little less venturesome, it is possible to install a guard rail between the roadbed and the big cliff in places with a high risk of derailment, both at the ends and along the front. To guard against "spillage" at the back of the layout, a backdrop is the perfect answer.
Another solution is to use 1x1 trim around your table, adding 1-1/2 extra inches to its width and giving a nice, splinter free edge to the layout. For a little more insurance, use 1x2 as trim, applied flat ways using glue and 3" screws in drilled and counter sunk holes.Your 4' sheet has miraculously become 51 inches wide, a full 5" wider than the roadbed. This allows room for trees/hedges/bushes between the rear track and backdrop and enough room on the front to lay a train over on its side without it falling to the floor.
While I really like Jack's ping pong table idea, sometimes we are forced to use tighter dimensions. I am presently working on a 4' x 10' 0n30 portable show layout that has to fit in the back of a mini van. So it is a loop with 22" radius curves with a single track folded dogbone inside the loop. This works out to 18" curves and 4% grade in the helix, which in turn means running multiple small locomotives and/or geared locomotives to get the tonnage up the hill. But hey, that is part of the fun of model railroading - overcoming obstacles by building railroads suited to our self imposed terrain.
Jim
Jim-
I like your idea of edging a 4x8 with 1x2s on their sides to widen the train table. Could one then perhaps use 2x2s or 2x3s to frame the table with half of the 2" under the plywood and half under the 1x2s to further reinforce the side piece joints? I mention this because I think that two-by material under the joints would be good reinforcement but I wouldn't want to see something get as heavy as 2x4s would make it.
-- D
what i've done is similar to what jim described, but using 1x4 or 1x6 extensions along the side. rather than using 2x lumber for the frame to support these extensions, i used blocks made of 1x4 sawed diagonally to make a triangular bracket, which was screwed into the layout from the inside of the main frame.
The 2x4's are the problem. Boards can also give you a similar warping problem.
Use 3/4" plywood. Buy a sheet of AC 3/4 (about $25) and rip it into 4" strips. Use these instead of boards to build with. They won't twist and warp like the new growth boards you get from the big box. And the plywood won't change over time with humidity differences like boards.
Quote from: Jim Banner on January 31, 2011, 08:59:04 PM
While I really like Jack's ping pong table idea, sometimes we are forced to use tighter dimensions. I am presently working on a 4' x 10' 0n30 portable show layout that has to fit in the back of a mini van. So it is a loop with 22" radius curves with a single track folded dogbone inside the loop. This works out to 18" curves and 4% grade in the helix, which in turn means running multiple small locomotives and/or geared locomotives to get the tonnage up the hill. But hey, that is part of the fun of model railroading - overcoming obstacles by building railroads suited to our self imposed terrain.
Jim
Indeed. I once built a platform designed to fit under a twin bed; it was only 39 inches wide. I adapted a track plan from Kalmbach's
Small Railroads You Can Build, using 15-inch radius curves on one end of the layout--I wasn't planning to run anything larger than a 4-4-0. For various reasons that railroad never got built. I ended up laying one loop of 18-inch radius curves with an inner loop of 15-inch radius curves, just so I could keep my locomotives in running order.
Thanks for all the feed back. This is a great forum for new members who are just getting started in the hobby. I went by my local hobby shop today and picked up a bargain on two hopper cars that fit my theme.
Wes
it would seem to me that unless you have access to a table saw (i don't) making side beams for your table from plywood would be much harder than using pine board. i also question how well screws would hold driven into the layers of laminate from the sides which you'd have to to to assemble a plywood frame. driving screws between the laminated layers might split the plywood. since the use of higher grade pine or spruce would eliminate warping, that in my opinion is the way to go. my dad and i have built tables this way for 35 years, and even under extreme conditions of humidity, warping has not been a problem. to be honest, i have seen alot more warping with plywood than with a properly constructed pine wood table.
which brings up a question for the original poster: is it the plywood or the 2x4 that has the warp in it? and is it objectionable to the point it affects the operation of your trains?
It is the plywood that has bowed. It does not affect the operation of the train it just don't look as flat as i want. I used 2x4's turned up edge ways to pull most of the bow out. I agree that any fastner ran into the edge of plywood will split.
you can often straighten out bowed plywood by sinking a couple of screws into the table frame in the area where it has bowed. the screws should pull the plywood down flat against the frame. and if you do this all around your layout, you can prevent further problems. i'd sink screws about every 12 inches over the whole layout, and 6 inches or less in the trouble area.
jward-
Properly-sized pilot holes will allow you to screw into the
edges of plywood without splitting the material. Other
possibilities for this constuction would be dowels or biscuits.
The biscuits, especially, would avoid splitting.
-- D
all in all it sounds like more trouble than it's worth.
Why is it you suppose that all quality kitchen cabinet boxes are built from plywood? Could it because it is the most stable material available?
Oh well, do what ever you want.
please don't get me started on "quality" kitchen cabinets. lord knows i have delivered enough of them. i have picked up at at least 3 different factories, and delivered cabinets from probably a half dozen others that were delivered to our warehouse. i have seen them made out of particle board, plywood and solid wood.....and lord knows i have returned enough of them due to damage incurred in transit. plywood chips just like particle board, and all of them were put together in ways i wouldn't recommend. why? they do it to keep the cost down and increase profits, not because the materials are better. if you want something built right you have to get the amish to do it. they don't take shortcuts......
that said, most of us out there are going to find it a royal pain to try to cut down a sheet of plywood into useable beams, then work around its various flaws to build a nice table. pine on the other hand, can be worked with tools most of us have around the house. and held together with common screws. i built my current layout using a power dril and a jigsaw. i could have built it with all hand tools, and have done so in the past. and if you read the original poster's description of the problem, it was the plywood that warped, not the table frame. so evidently the plywood wasn't as dimensionally stable as was claimed. in fact, the simple and workable solution is not to build a complicated table out of the same material that warped in the first place, but to retain the table frame which DIDN'T warp, and use it's sturdiness to take the warp out of the plywood by better securing the plywood to the table frame.....
this method has been proven over the years, it has stood the test of time under various conditions. and not only in my own experience, but in the experience of countless model railroaders over the years. it is the method most often referred to for model railroad benchwork in books..... it can be easily built in an afternoon, from common off the shelf materials by anybody without needing woodworking skills....
Quote from: Doneldon on February 01, 2011, 12:46:00 AM
Jim-
I like your idea of edging a 4x8 with 1x2s on their sides to widen the train table. Could one then perhaps use 2x2s or 2x3s to frame the table with half of the 2" under the plywood and half under the 1x2s to further reinforce the side piece joints? I mention this because I think that two-by material under the joints would be good reinforcement but I wouldn't want to see something get as heavy as 2x4s would make it.
-- D
That sounds like a good plan, especially if, like me, the builder wants to be able to crawl around on the table if need be.
The 0n30 layout I mentioned before had to be light weight for one old guy to move the sections but strong enough to stand up to the rigors of transportation. My solution was to frame it with 1-1/4" x 2-1/2" box beams made of 1/8" and 1/4" Baltic Birch plywood. To reduce their weight and increase their strength, the 1/4" sides were drilled with 1-3/4" holes every 3" which incidentally made the beams a great place to run the wiring. A five foot length of this box beam, supported at the ends, easily held 100 kilograms (220 pounds) at its center . I used these box beams on 12" centers both ways, in a grid, that supports the 1-1/2" Styrofoam top directly. Total weight of each 4' x 5' section, before adding track and scenery, was less than 15 pounds. Cutting and gluing all of the many little pieces was quite time consuming.
Our modelling group also uses light weight construction for our large scale portable layout. Each section of that layout is 2' x 4' and consists simply of a piece of 1-1/2" Styrofoam framed with 1-5/8" wide strips of 3/4" plywood, either hardwood or Canadian Fir. The bottom of each of these tables is covered with 1/8" hardboard which both protects the Styrofoam during shipping and provides an additional stress member to help support the table. The track is laid on top of an inverted U-channel made of 1/4" hardwood plywood and the inside of that channel contains all the wiring. At present, we have 51 of these tables and they stand up quite nicely to the heavy G-scale locomotives and trains we run on them. It sounds crazy, and when I designed it in 1994, even I thought I was nuts. But the numbers worked and so do the tables.
Jim
Howdy,
What do you all think of the video building technique shown in "The World's Greatest Hobby" included with the track pack ? Looks pretty complete to me.
Best Wishes,
Jack
I'd say you got some really low grade plywood if it bowed that much.
Try it again and splurge on the $30+ premium stuff and it wont go anywhere.