Advice on Dapol light signal, please

ohlavache · July 21, 2015, 08:52:23 PM

Hello.
I am about to install a Dapol light signal on my existing layout and your advice would be welcome.
This layout is built upon expanded polystyrene placed on a wood plank.

To make the 14mm hole, I will use a heavy power drill.
I fear the unexpected damages on my layout (which is almost completed). I'm not used to power drills: I just bought it for this purpose.

So, I would welcome any advice to prevent any damage and ensure that the light signal is well installed.
Thanks by advance for your help.

Steve Brassett · July 21, 2015, 10:30:03 PM

I've never drilled through expanded polystyrene, but standard practice with a power drill is to drill a pilot hole first, with a drill around 4mm. This gives a guide for the larger drills. Personally, I would not go straight to the 14mm, but use a drill around 8-9mm first. The exception to this is if you are using a flat wood borer - then go straight from the pilot to the borer.

Malc · July 21, 2015, 10:52:27 PM

Get some masking tape and cover the area you are going to drill through. Then proceed as Steve says.

A.Carter (BiG-T) · July 21, 2015, 10:57:52 PM

It might be better to use something like an apple corer through the expanding foam then drill the baseboard with a pilot drill before opening the hole up to 14mm.

Tony

ohlavache · July 22, 2015, 07:53:24 PM

Thanks a lot for your answers.
I will apply them.
I hope I'll be able to tell you what will have happened when I come back from vacation.

Ancient Hermit · July 23, 2015, 10:12:01 AM

If at all possible, use the drill from the wood side first, just so as to establish a nice firm and true pilot hole or even the main hole. Then you'd have something firmer to work with in removing the styrene. Personally I'd give my 12mm forstner bit a go for removing that and then try test threading the mounting tube into the hole in the foam to see if it would play ball. Then, if it looked like it would behave, I might remove it again and finish off the hole in the wood with a 14mm spade bit (assuming they don't make a 14mm hole saw) in the wood first, then finally thread the tube into the foam.

It's got the potential to be a tricky one this one, for sure. Good luck, it might be just fine.

MikeDunn · July 23, 2015, 10:42:33 AM

Why not ... make the 12mm hole in the wood (as above) then a pilot through the foam followed by hot wire to cut a cylinder ?

ohlavache · August 17, 2015, 06:41:59 PM

I'm back from vacation... :'(
But I had some time to work on my layout ! I managed to renew almost all the rail tracks (I had huge problems) and I managed to install the Dapol light signal thanks to your advice !!!

First, I've done a test on a spare piece of wood with some styrene glued on it. It appeared that the power drill would damage the styrene around the hole and thus the layout.
Then, as suggested, I have manually removed the styrene without the power drill, but thanks to the 14mm drill rotating in the counterclockwise direction. It perfectly cut the styrene.

Afterwards, I've drilled the wood plank step by step starting with 4mm, then 8mm, then 14mm. It seems that it may be better to do 4mm, then 10mm and then 14mm.
The result is ok anyway.

Unfortunalety, I was not able to connect the light signal. I didn't have any push-to-make switch with me (I should have read the instructions more carrefully before.)

Here is my new question: where can I find a push-to-make switch that I could easily fix below the wood plank of the layout ?
Thanks by advance for your help.
Have a nice week.