HI!

I am planning my 3rd layout (first two built and taken apart due to poor wiring) and would like to use a wye so the main line becomes a double... which track pieces do I need to use with the wye to make two paralell tracks from it? I thought I saw something online about it but can't find it this morning...

Cheers!

Check this out!

http://www.bradfordexchange.ca/products/103509004_track-train-accessory.html

What are the two 4 1/2" curved track pieces and will it make paralell tracks from the wye?

A wye turnout is probably not your best choice since both legs of the wye diverge.  I'd use a #6.  I'd use flex track to bring the diverging route back parallel with the straight leg.  Parallel straight tracks are normally about two inches apart, measured from center line to center line.

With regard to the remark you made about your wiring of previous layouts, good practice is to check the operation of each connection as you make it.  That way, when something suddenly doesn't work the way it should, you  know that the last connection you made is at fault.  Wiring an entire layout, even a small one, offers LOTS of opportunities for making mistakes and checking as you go can save you a lot of grief.
Old Timer

Dear TTL,

Anyrail.com shows a 6 degree divergence angle on each side of the #5 wye turnout.  You would need a 6 degree curve on each side to get them both back to parallel.  

The only 6 degree curve that Bachmann makes has a 33-1/4" radius.  Item # 44508,  four per card.

Hope this helps.

Sincerely,

Joe Satnik

Edit: Added "of the #5 wye turnout."

One additional note on wiring especially for DCC is you almost always need to run a main heavy gauge wire that follows the track and then take off lots of feeders. This way the voltage drop does not cause any problems. 

I recently converted my DC layout to DCC and followed this method. No problems.  When it was DC at the far side the engines always slowed down.  I suspect it was because I did not utilize the heavy gauge wire all the way around the layout. Just a few feeders on one side.

This might explain the problems you have experienced before.

Micromark has some feeder connectors that make the connection by clamping through the insulation when they are closed.  I believe they call them suitcase connectors.  Very easy to use.

Hope this helps!

Thanks, everyone! Your advice is greatly appreciated )