SlotForum banner


2891 Views 29 Replies 11 Participants Last post by  Stubacca03
My new layout uses the SCX Rally Chrono, SCX Chicane and Scaley Sport Track for the rest. I've noticed a reduction in power on certain bits of track.
Whats the best option to create a consistent voltage throught the whole track?

I've looked at the SCX and Sport Boost cables, would they work with SCX sport combination, if so how? Or are ther better options?

Please be aware I'm a total noob when it comes to electrics so keep it simple!

Thanks in advance.

See less See more
1 - 7 of 30 Posts
If I had your situation I would get copper tape and run it all the way around, on each of your 4 rails. It will immediately cure that problem.
If you search the site for copper tape you'll find more than you ever wanted to know about it *grin* Be sure to get the tape with the
black conductive paste/adhesive. "Burnish" the tape with the edge of a plastic pen cap (like a "sharpie") once it's applied.

Other people have had good success with might research that as well.

best regards,
So here's what I'm thinking as we wrap this issue what way is copper tape, run full circle around the track, with conductive what way is that not simply a semi-infinite series of
power taps? *grin*

re: "The resistance of a track is made up of the resistance at the joints plus the resistance of the rails."

See, the thing is, you have to start by imagining the copper tape on top of the rails all the around to get my point. If any small section along the rail...the effective resistance in that section is the least of the following actually: the copper itself, the rail (and/or joint) itself or the combination of copper and rail and/or joint. That's one. The second point comes from extending this idea. Suppose you have amazingly good conductivity (low resistance) along the rail for 40% of the way and then suddenly have a bad joint...and of course the copper tape is on top of the rail all the very point where the rail voltage would drop dramatically, the copper tape "kicks in" and delivers higher voltage, effectively becoming a power tap. And because it is right there, all along the rail, just waiting until it becomes the path of least resistance at any effectively a semi-infinite power tap. That's the point I was trying to make.

One other point...I'm not sure what copper tape you guys are using, or how amazing your rail steel is, amazing joints, huge cross-section etc...but in my experience (and i prefer thick and wide copper tape personally), the copper tape alone is superior to the steel and/or joints anywhere and everywhere. I used to run it on my Carrera track (which admittedly has more nickel and chromium content and less conductivity than Scalex steel) and now run it on a wood track with no parallel run of steel at all (and no power taps)...and I get no noticeable voltage drop, and actually run at significantly lower voltages than I used to (partly because of so much less mechanical resistance from eliminating the joints, and less hysteresis at the tire/track interface).

I know some people have very strong feelings about this...steel vs copper etc. For me it's just a practical problem/practical solution strong feelings either way. But I do have the sense that it's worth reminding people once in a while that copper is actually a superior conductor to steel (like 10:1 better). Your rails aren't steel because it's a superior conductor, but rather because it's less likely to deform with use, more resistant to abrasion over time, and cheaper to obtain. To my mind, the ideal combination...the more robust to let the steel do it's "rigid" thing and then clad it with copper for superior conductivity and even for the decreased mechanical resistance (negative impulse) at each joint.

Anyway, those are my thoughts sitting here with my afternoon smoothie *grin* No big deal...

with best regards,

PS I'm tempted to pose another question...why do you think your power taps help? Is it (more) because they are shorter runs, or because you are using continuous, copper wire? *grin*
See less See more
I agree with Rich. For a steel-braided track, I think that is the wisest course of action. And if one feels that jumpers on plastic track are less
aggravation than copper tape, than clearly it is preferential there as well. Horses for courses...

QUOTE (300SLR @ 4 Apr 2012, 09:18) <{POST_SNAPBACK}>So you are saying the copper tape bridges a bad joint in the rails, pretty much eliminating the resistance at the joints problem.
Yes that's true assuming the tape is in good contact with the rails.

No, I'm saying the copper tape is not just a bridge, but effectively a power tap at each bad joint.
I could address your other comments, but I'd simply be repeating myself. I yield to superior endurance.

hi, Al
I appreciate your comment...I think we are all using the term "power taps" the same way, but yes, speaking past each other. I'm trying to explain why the copper works so well...and it's not only that the material itself is 10x more conductive but that it has no joints. As far as I can tell, noone (else) is quantifying the effect of the "choke" points of minimal contact area and/or air losses/arcing at each joint. This is a huge effect (well, huge percentage of overall power drop in a plastic slot track). I get the sense that most think that "transmission loss" is the larger culprit. It's not in most cases. About the "semi-infinite power tap", to have to imagine the copper tape on top the rail as not just a part of the rail (which it is with that conductive paste), but also as a true power tap, made of copper just like a normal wire power tap, and simply running the path of the track instead of the usuall path in a straight line from the power source to power tap location. This is a model of part of it's behavior. It's not literally true, but effectively behaves that way as well as creating a jumper over any bad joint. The cumulative effect of these three regimes (jumper, power tap basically whereever it's needed, as well as acting as a bi-metal rail of increased conductivity) is why it works so well.

Meanwhile, the "4th regime" is that the copper tape acts as a ramp to minimize "negative impulse" as the car literally collides with each new section of (slightly raised) track. I mean "negative impulse" in the sense of "force multiplied
times time, acting in the direction against travel." And just to be clear, in a steel braided system transmission loss is indeed the largest factor in voltage drop (assuming the braid is continuous).

with best regards,
See less See more
QUOTE (300SLR @ 10 Apr 2012, 13:08) <{POST_SNAPBACK}>To recap what I was saying (and I think John was saying rather the same thing?)

The effect of a loop conductor is the same as a pair of power taps to wherever the car is on the track. In a sense that is a "semi infinite" number of power taps,
but with only two of them working at once.

Yes, exactly...that perfectly describes the one point I was trying to make, 300SLR. And I do acknowledge as well the argument you've been making about that
positive and negative are running in opposite directions/ratio of two unequal lengths, etc. Clearly we agree (and Slotracing Al was correct about that). Thanks
for taking the time to make that clear, and please forgive my earlier crotchetyness...I believe I may have PTSD from previous such discussions *grin*

with best regards,
1 - 7 of 30 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.