[StuBeeDoo]

I'm thinking about doubling the length of my SCX/Scalextric classic/Sport rally loop. If I do, it's going to end-up in excess of 60mtrs lane length. On my current 30-ish mtr track, I think I have a power drop for roughly 1mtr at around 25mtrs.

I'm using a standard SCX mains-14v PSU. Is there some kind of rule-of-thumb regarding boost cables? Roughly, at what sort of lane lengths do boost cables become necessary? I'm guessing that the tap (or taps) should be taken from as close to the Rally Chrono start ramp as possible - but I'm not good with electrical theory.

What sort of cable should I be using? I've got a pair of Scalextric classic cables. Are these OK? They look like glorified bell-wire to me.

TIA
Stuart.

 

[300SLR]

You might as well make use of the cables you already have and see how much they improve things. It cannot do any harm, although from your description they might not do all that much good.
Is there much difficulty in adding more boost cables when the track is complete?
On many tracks it's easy enough to add cables afterwards. For those the easy thing to do is try it and see if you notice a power drop. If you do find a problem then add boost cables - if not you haven't wasted money on cable you don't need.
The wire size for boost cables depends on their length. With a track that turns back on itself a lot you can often get quite short runs of boost cable to half way round the lap length. The sizes can all be calculated, but it might be easier try those cable you already have and ask for more advice if there is still a problem.

 

[Mr Modifier]

Hi StuBeeDoo,

Any chance of a track plan for your new layout? Even if it is hand drawn fairly close to scale we might be able to suggest the best places to power tap. If you can do a plan - show where the power is fed into the layout.

If your layout is permanent you should also consider track piece connectivity - on Scalectric Sport there's a trick with pinching in the tabs under the rails - not sure if there is a similar trick for SCX track. If the track is permanent and you notice drop-off at certain points you could solder bridging wires under the offending track pieces to guarantee better connection.

Finally - if your track is two lane track pieces configured as one large single lane track (either using a single crossover or a rally loop at each end) then power tapping will be as easy as soldering wires between lanes (making sure left goes to left where left refers to the direction of travel of the car in that slot).

 

[PJF]

Hi Stu.

I don't think that there is any hard & fast rules on booster cables as the condition of your track will have a lot to do with volt drop.

For any large track the easiest method of checking your power is to put a multimeter on your track rails at the power source, record the result then do the same at the furthest point of you track. If you see any drop in voltage then you need booster cables. Make sure that your throttle is fully pulled in for this test.

Cheers
Paul.

 

[StuBeeDoo]

QUOTE (PJF @ 19 Feb 2012, 09:02) <{POST_SNAPBACK}>For any large track the easiest method of checking your power is to put a multimeter on your track rails at the power source, record the result then do the same at the furthest point of you track.
D'OH! Why didn't I think of that??

Thanks Paul. .....And thanks everyone for your input. Greatly appreciated, as ever.

Cheers,
Stuart.

 

[356speedster]

Actually the voltage meter can fool you if you don't add some load on the track while testing.

The easy method is simply to drive a car slowly around and mark the track where it drops and gain speed, or use a volt meter while stalling a car on the piece you test, just don't stall the car more than a couple seconds at a time to avoid burning out the motor.

Tore