Best Wire for Building a Track

[Ned]

Do not use coiled wire or stainless steel wire. Use standard music wire, also called piano wire. Pieces around 1 meter long work best, especially for curves (corners). Pieces 1 ft long should work fine on straight sections of track.

For cars weighing 65 grams with the battery and with a 3mm x 4mm standard neodymium steering magnet between the front wheels, anything under 0.7mm diameter will not work. Wes’s 1:32 cars weigh about 65 grams with the battery. He used 0.7mm diameter wire for his earlier tracks. He used 0.8mm wire to build one of his last tracks and said it worked “ok for 1/32 cars” but not for 1/24. “In fact the 1/32 cars went so well that I lost some interest in 1/24.” He used 1.0mm wire for his larger track for 1/24 cars.

I used 0.032” (0.81mm) wire to build my large outdoor garden track. My 1/32 cars weigh 65-85 grams. Heavier cars need heavier wire for the system to perform well.

For cars weighing 65-75 grams I recommend a minimum diameter of 0.8mm. 0.9mm would provide better performance. A car is less likely to lose a heavier wire when going in or out of a banked turn, over a bumpy, uneven, track or track joint. Less likely to lose the wire, if the wire is a little low in some spots (implying the track surface upon which the tires ride is a little high). By a little I mean 6 thousands of an inch. The thickness of 2 sheets of computer paper. It is easier and less tedious to build a well performing track with heavier wire.

If your cars weigh more than 75 grams, I recommend a minimum wire diameter of 0.9mm. I plan to use 1.0mm wire when building my next track.

There doesn’t appear to be any disadvantage to using 1.0mm wire. I thought that the heavier wire might pull the steering magnet much closer to the track causing the magnet to often scrape the paint covering the wire. I tested 2 unmodified chassis that I bought from Wes and 6 that I designed myself and had printed at Shapeways. I found that the clearance between the magnet and the wire (embedded flush with the surface supporting the tires) was less with 1.0mm compared to 0.81mm wire, but only .003” on average, the thickness of one piece of computer paper! That can be easily offset by adjusting the arm holding the magnet .003”-005” higher.

A larger diameter wire provides sufficient attractive force between the wire and the steering magnet to control the direction of a car with a larger gap between the wire and the magnet. Thus less precision is needed when building the track.

If anyone has any evidence or experience to the contrary please let us know.

[kiklo]

I agree with you Need, going for a thicker wire will make an easier build. For me building from coiled piano wire, turns are no problem, but you will need to straighten it before laying straights. You do save some cost buying coiled wire.

[Ned]

I started building track 10 years ago. I seem to remember having trouble using coiled music wire with soft foam insulation board (XPS). I think other people also had trouble with coiled wire. But I am not certain.
Kim, how did you straighten the wire or get into the shape you wanted?
If you are gluing the wire on top of a baseboard, I think coiled wire would be difficult to use. If you are forcing and gluing it into a tight fitting groove cut into a fairly hard baseboard material, perhaps it would work quite well. In that case the wire can probably be forced to take the shape of the groove. I don’t think XPS foam board is hard enough or tough enough to shape coiled wire or hold it in a groove.
What do you think Kim?
You are correct about the cost. 1mm diameter coiled music wire costs about ½ as much as 1 meter long pieces of 1mm dia straight wire.

[kiklo]

Hi.
As I am using MDF and routing the path coiled wire works ok.

But the trick to straighten a coiled wire is by running/pull it through a tight hole in a wooden block at a slight angle. It will give you an almost straight wire.

[kiklo]

Something like this :

IMG_20240226_093236 (Custom).jpg (20.49 KiB) Viewed 1227 times

[Ned]

Very clever Kim. I see. Thank you very much.

[Francesc Xavier]

Hello guys,
4 years ago I made an attempt to set up a test track on an MDF board by making the grooves with a BOSCH manual milling machine with a 0.8mm DREMEL milling cutter. Making these grooves on top of this material is very laborious and slow, I broke several cutters. I tried to place the coiled piano wire which keeps the bend vice and makes it very difficult to get a good hold inside the groove. After a lot of trying without success to address it, I gave up due to lack of time and being very clear that this cable format is ideal for curves. It is clear that in roll format it is 50% more economical but it is not useful for straight sections. It would be interesting to be able to address the coiled wire as you say, Kim, try that. I assume you do it over short stretches. Currently I have resumed trying to build a track to test with MagRacing cars. Finally I found a supplier in Spain that supplies the cable in straight cut format, I found it in the model aircraft sector.
Hello.
Xavi

[kiklo]

I get mine coiled from this supplyer. Delivers to all over Europe.

https://www.fjaer.net/tr1020 0.7 mm

https://www.fjaer.net/tr1028 1.0 mm

[Francesc Xavier]

Hello, Quim and colleagues.
I have visited this website and I find that the price is three times what I can get at the hardware store in my town. Specifically, for a 90gr roll. which contains 30 meters approximately costs €3.42 €0.11/m. VAT included. It's what I used in my essay 4 years ago. I have updated the information and it is still available at this price. I can send this small envelope by regular mail anywhere in Europe for very little money. If anyone is interested I can send it to them at cost price. You can contact me privately and we can talk about it.
Regards,
XAVI

[Ned]

Wow! €0.11/m is really inexpensive! That's equivalent to $0.12/m in the U.S. A 20 meter coil of 1 mm music wire costs twice as much per meter in the U.S. One meter long straight pieces cost the equivalent of €0.55/m ! That's 5 times what you pay for coiled wire Xavier!
Xavier if I were to build a lot of track, I might want you to mail it to me in Arizona, U.S. !