Get a stiff wire like a straightened out coat hanger. Put a crook in one end and feed it through the hole. Hook the power wires into the crook and pull them through.
The other way I did it recently through foam was to get a screw driver with a long shank. I made the initial hole "drilling" with the screw driver. Took the screw driver out, I then just folded the end of the wire over the blade of the screw driver and punched it back through. Of course this was just foam, no plywood hole involved.
Get a box of drinking straws. You may need a slightly larger hole, but you should be able to push the straw all the way through, which will give you a smooth conduit through which you can easliy slip the wires. You may be able to find plastic coffee stirrers which are a bit thinner, but most of these are under 6 inches. Once you've run the wires, you can remove the straw over the loose end of the wires and re-use it.
It takes an iron man to play with a toy iron horse.
That's why when I did the foam thing before, I didn;t use any plywood, it's easy to push through just the foam. This time I put plywood under it. With plywood, a coat hanger won't cut it. Home Depot and Lowes have extra long drill bits, smallest I saw there was 3/16" which is a little large for single feeder wires, but that's how you get through foam plus plywood with a clean hole in the right spot. I have the smallest plus a larger one I used for the switch throwbars.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Another option would be Plastistruct or Evergreen Plastic tubing as long as you can find an interior diameter that will take the wire. May be a little sturdier than a drinking straw.
Bear "It's all about having fun."
I would suggest that you do it the same way seamstresses have been doing it with thread for centuries. A long needle with a hole in it. I made one with a scrap piece of rail. Just drill a small hole in one end.
Dave
Lackawanna Route of the Phoebe Snow
I use a piece of 1/8" brass tubing 12" long that I fit the wires inside then push through the hole in the foam.
Mike
Taping the wires to a wooden skewer, avaialable in every super market, should work just fine.
The skewers can also be used in various scenicing ways.
Bob
Don't Ever Give Up
I often use a straw as a conduit
model in O. the Western NY and Ontario Railroad
Here's another thought on getting wires through the foam.
The first wires I had to get throught foam were from turnout switch motors mounted directly under the turnouts. I solder spade connectors to the wires at the work bench so as to attach them to terminal strips. I then drill the smallest hole that the spade connectors would fit through. After struggleing at times to get them through the light bulb in my brain finally lite. Why was I making the hole so small when a larger one would make the job so much easier and no one would see it??
So now I make a generous size hole based on it being covered up by whatever is above it and have no trouble getting wires to the under side of the layout.
When a small hole is needed I use a wood skewer as decsribed earlier
If you have a plywood base it makes it much easier to drill from the bottom throught the plywood and then insert a tool to make the inital hole.
So obvioius, after you have tried to drill from the top.
I made a tool that's basically a long sewing needle from a wire hanger.
To use, thread wire through "eye" and twist. Push through foam. This only works if you don't have a plywood base under the foam. I found that out the hard way, and had to drill large holes in the plywood with a hole saw.
Marlon
See pictures of the Clinton-Golden Valley RR
I tape one end of the wires and feed them though the foam carefully since I have 2 or 3 wires going through the same hole. I use a hook for feeding only when really needed.
The Lehigh Valley Railroad, the Route of the Black Diamond Express, John Wilkes and Maple Leaf.
-Jake, modeling the Barclay, Towanda & Susquehanna.
Hey Willy,
I use straws also, like that's been said before, drill a slightly bigger hole, so your straw will fit, and make sure the straw is long enough to make it under the plywood and foam. Good Luck,
Trainsrme1