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Discussion Starter · #1 ·
Hi everyone

I know this topic is been discussed to death but I still can't solve my problem. I have 2 large scalextric sets and 2 SCX sets and when I put them together as one big set I cannot figure out the power issues. In total I have 2 scalextric "wall warts" and 2 SCX warts as well. I've been trying to make a 2 lane track. Could someone please tell me a general rule for spacing of the power tracks and how to make sure that power does not cross both lanes.


Premium Member
1,165 Posts
Hi Mark,

At least with Scalextric Sport track, you cannot use two powered PowerBases in your layout simultaneously. Power from the wall warts goes to only one PowerBase, the one your controllers are attached to.

You can, of course, use PowerBases in your track as regular track sections without attaching a wall-wart to them. If you do this you may need to set the little blue switch on the PowerBase to the 16~ 16~ position - the position for powering the track with separate wall warts for each lane. The reason you might need to do this is because the circuitry in the PowerBase receives electricity from the track even though it is not being used as a PowerBase and can cause you to be able to control both lanes from a single controleer unless the little blue switch is set in the double 16~ position.

For large tracks - in my experience tracks larger than about 50 feet - it is usually necessary to use "power taps". A power tap is simply a length of wire that runs from each individuals lane on one track section to each lane on another track section at a more distant point on the layout. Scalextric sells booster cables for both their classic and sport track that have terminals that attach easily to small tabs on the underside of most straight track sections. Get the booster cables that are appropriate for the version of track you are using, either sport or classic. They come with insturctions. Alternatively, you can make your own power taps. Slot Car Illustrated as a how to at

You do not need to use your extra wall warts or PowerBases to install power taps. In this way, modern 1/32 scale racing is a little different from racing years ago when we used extra "terminal track" pieces to distribute power evenly around the layout.

But even then, we did not bring extra power from additional transformers or wall warts to the power taps!

A booster cable or power tap wire actually has two wires or conductors. One conductor attaches to one rail of a slot, the other conductor attaches to the other rail of the same slot. You then run the power tap wire over to another point in the layout that is farther away from your PowerBase. The wire makes a parallel path for current to flow besides flowing through the track and having to overcome the resistance at each track joint. The parallel path ensures that the voltage is constant all around the layout.

The general rule for installing power taps is that they should be located about every 25 track joints. I apply this rule in this way: I have a layout with 111 pieces of track that is 77.8 feet long. I locate one end of the first power tap at the straight section to the left of my PowerBase. The other end of this power tap is attached to the underside of a straight section that is 111/3 or 37 track pieces away from my PowerBase. This power tap consists of four wires total, one for each rail of each slot.

The second power tap is attached to the underside of the straight section to the right of my PowerBase. The other end of this power tap is attached to a straight section that is 2 * 37 = 74 pieces away from my PowerBase. This power tap also consists of four wires total, one for each rail of each slot.

In this way I have clean fresh power coming into my layout at three points - at the PowerBase, at a straight 37 track pieces away from the PowerBase, and at a straight 74 pieces away from my PowerBase.

The tricky thing in installing power taps is making sure you attach the wire from one rail on a given slot to the very same rail on the same slot. This is because each slot has a positive and a negative rail. If you attached the power tap wire from the positive rail to the negative rail you will short out power on that track and perhaps damage your PowerBase or wall wart.

The easiest way to keep the polarity straight on a two lane layout when you install power taps is to use four colors of tape or post its. Start at your PowerBase and label each rail of each slot with its own color. Then work your way around your layout marking each rail as necessary so when you get to the point where you want to attach the power tap wire you know for sure which rail is which.

You can use two PowerBases in your layout to race in either direction but you do not connect both PowerBases to a wall wart at the same time. See the article on using two PowerBases at my layout's website at

You might also want to read through this thread in the master class area here on slot forum:

Hope this helps, I do not have any experience with SCX track.


5,195 Posts
That's a great reply Paul - Welcome to the forum and thanks for taking the time to write it up. I was a little weary about replying to this as it looks like a tricky situation.

Of course if the "wall warts" are not powarfull enough for you large track than you should upgrade to a regulated power supply that has a significantly higher amperage. There are many threads on the forum discussing this. Search the forum (link at the top of page) using keywords: regulated / Power / Control / Amps / power tap
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