4X4 1/4 inch thick plywood

If you are going to move the plywood with the track attached, I'd go with either 3/4 or 1" plywood.  Why scrimp?  You can't build a skyscraper on sand, why have your base so flimsy?  When moving the board, it will flex.  What do you think will happen to the track when the board flexes? Whatever ply you choose, you might consider painting the upper surface before attaching the track.  Any color, so you won't have any wood surface showing through the scenery.   John in Lansing, ILL

It's not a matter of cost, it's a matter of practicality. The layout will be put away after Christmas.  I am 70 years old. Just moving the 1/4 inch plywood is a major effort. 

I'd think about screws from the back side through the plywood and into the screw holes in the Fastrack pieces. Viewing a Fastrack piece from the backside this is what you see:

The screwdriver tip points to the mounting hole.

I would first attach the track to the plywood in the conventional manner, driving screws through the Fastrack mounting holes and through the ¼" plywood. I would then stand the whole thing vertically to provide access to both sides. Next I would remove one screw at a time from the track side and drive a slightly larger screw through the hole on the back side of the plywood and into the Fastrack mounting hole.

Oh, and I find ¼" plywood to be just fine for decking. In my case I simply drive screws through the plywood because the underside is open, unlike your situation wherein the floor will be immediately adjacent, thus the need for no protruding screws.

I don't see anything wrong with using 1/4" plywood for your purpose. It's not like you are going to walk on it.  You might need to nail a few stiffeners made from 2x2 to the back.

One way to attach the track would be to use tiny machine screws/nuts/washers. You can get most anything you need from eBay in bulk for very little money.

Another possibility is to simply glue the track to the plywood. RTV would probably be strong enough while still being removable from the plastic. Hot glue would also work, but would be messier.

If possible, glue it down with good construction adhesive. Besides holding with less effort than screwing down, it will help isolate some of the sound. That said, you may want to add some foam subroadbed like Vinyl Bed which deadens the sound even more. My entire railroad is held with construction adhesive and it's seven years old and still holds perfectly.

geysergazer posted:

I'd think about screws from the back side through the plywood and into the screw holes in the Fastrack pieces. Viewing a Fastrack piece from the backside this is what you see:

                                          

The screwdriver tip points to the mounting hole.

I would first attach the track to the plywood in the conventional manner, driving screws through the Fastrack mounting holes and through the ¼" plywood. I would then stand the whole thing vertically to provide access to both sides. Next I would remove one screw at a time from the track side and drive a slightly larger screw through the hole on the back side of the plywood and into the Fastrack mounting hole.

 

Oh, and I find ¼" plywood to be just fine for decking. In my case I simply drive screws through the plywood because the underside is open, unlike your situation wherein the floor will be immediately adjacent, thus the need for no protruding screws.

I was thinking of this same solution -  the screws from the top are a #4 -3/4" flathead Philips sheet metal screw - you will have to test a screw from the bottom possibly a #6 of the same type and determine if it splits the plastic screw bung. 

Screwing from the bottom will be secure. 8 pieces of O36-45° will make the circle with 2 screws in each piece.

Another though is to router or chisel a channel on the bottom for the power feed. 

Rounding off the sharp corners may also be a good idea.

"Another though is to router or chisel a channel on the bottom for the power feed."

Carl, you can see in the pic there is such a channel provided on the underside of Fastrack pieces. It looks suitable for #18 wires but would be really difficult to use because the wires wouldn't stay in place while laying the track. With a layout this small if I wanted feed wires I'd probably drill holes through the ends and cross-braces and feed wires through the holes before flipping the whole assembled thing over onto the plywood base.

I would use 3/4 inch, then cut out sections on the plywood not needed to reduce the weight. You could even make 2 half circles and allow of exansion.

Actually, you can use lighter half-inch birch multi-ply, and I can assure you that it'll be more than rigid enough for the task!  There is even quarter-inch multi-ply, but I've never used it.

If you have a Dremel tool use a cut off disc . and cut the end of screws .

If it's going on a wood floor. Get some indoor outdoor carpet glue it on.  It will also cover the end of screws if you can't cut flat.

But you should be able to cut them flat. I guess you could use tape too.to cover screws  If carpet would make it to heavy.

Fort Pitt Highrailer modules are done with luan board, may be 3/16", (1/4").  Design and support important. 

Atlas track screws, or 3/4" black #4 flat head screws used with Gargraves track.   Group members complained about the screw points sticking through the luan board.  We remove the screw tips with  a dremel tool, and abrasive grinder. 

Note where the screws have been dremeled.  (Four) curved track corner.   

Modules require two people to transport.  

Dremel cut-off wheel. 

Avanti posted:

I don't see anything wrong with using 1/4" plywood for your purpose. It's not like you are going to walk on it.  You might need to nail a few stiffeners made from 2x2 to the back.

One way to attach the track would be to use tiny machine screws/nuts/washers. You can get most anything you need from eBay in bulk for very little money.

Another possibility is to simply glue the track to the plywood. RTV would probably be strong enough while still being removable from the plastic. Hot glue would also work, but would be messier.

Thanks for all the suggestions guys. I really appreciate them. Think I will go with this one. The board will lay on carpet, so anything sticking through won't be a problem. And sound transfer isn't a problem either. I'm more of a mechanic than a carpenter, so working with screws/nuts/washers appeals to me. And attaching some stiffeners sounds like a great idea. Will eliminate flex. Thanks again everyone! 

Dep

The 1/4" thick 4 X 4 is more than sufficient for your intended use.

Paint the top earth brown with a small can of latex paint and let dry or glue down a piece of I/O carpet.

Connect the track and lay it down on the board and screw down through the Fastrack holes with the screws mentioned above. You do not have to screw in every hole or piece of track in order to keep the track from moving around. I would start with a screw every other piece. Don't screw down too tight - just enough to seat the screw and keep the track from moving. If you are going to store it vertically, you may have to put a screw in every piece if it flexes when you tip it up.

If the screw heads protrude through to the other side, just cut them flush with a Dremel tool and cut off blade.

Dunskey.

Above are construction views of a 6mm  (1/4") 4 x 8 multi ply module which traveled to many shows then was installed on my RR.  Very durable without any deflection.  It is all in the support design and  construction.

A number (39 to be exact) of years ago I built a layout for my then 4 year old daughter that could roll under her bed. I simply framed it around the perimeter with 1X4 pine using #8 or #10 CS wood screws, stiffened it with 1x2 furring strips (same size wood screws) placed somewhere about 15"apart underneath. The surface was 1/4" ply fastened with #6 CS wood screws. Track was 027 fastened down with #4 RH woos crews. It lasted through two long distance moves; it now has been cut up and is part of a friends HO layout. While you have seen some good advice here among the many suggestions, there is absolutely NO reason to over engineer or over build what you are planning on. Good luck and have fun.

Richie C. posted:

The 1/4" thick 4 X 4 is more than sufficient for your intended use.

Paint the top earth brown with a small can of latex paint and let dry or glue down a piece of I/O carpet.

Connect the track and lay it down on the board and screw down through the Fastrack holes with the screws mentioned above. You do not have to screw in every hole or piece of track in order to keep the track from moving around. I would start with a screw every other piece. Don't screw down too tight - just enough to seat the screw and keep the track from moving. If you are going to store it vertically, you may have to put a screw in every piece if it flexes when you tip it up.

If the screw heads protrude through to the other side, just cut them flush with a Dremel tool and cut off blade.

Dunskey.

  

Excellent! Pretty much EXACTLY what I plan on doing. I will also be including some support strips on the underneath to keep the plywood from flexing. 

modeltrainsparts posted:

A number (39 to be exact) of years ago I built a layout for my then 4 year old daughter that could roll under her bed. I simply framed it around the perimeter with 1X4 pine using #8 or #10 CS wood screws, stiffened it with 1x2 furring strips (same size wood screws) placed somewhere about 15"apart underneath. The surface was 1/4" ply fastened with #6 CS wood screws. Track was 027 fastened down with #4 RH woos crews. It lasted through two long distance moves; it now has been cut up and is part of a friends HO layout. While you have seen some good advice here among the many suggestions, there is absolutely NO reason to over engineer or over build what you are planning on. Good luck and have fun.

Thank you sir! I am actually looking forward to working on this. As I said, I'm more into mechanics than wood-working, but the advice I have received should get me through the project. Thanks again to everyone. 

Several years ago I built this 4X8 pike using ¼" plywood and 1X2 framing:

 Although not completely rigid corner-to-corner it worked fine with no sagging.

I did use Oak 1X2 for the two long chords.