Magnetic force measuring.

Questions and Ideas to track building, how are you doing it? need help? new features? share your ideas.
kiklo
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Magnetic force measuring.

Post by kiklo »

I think it would be of common interest if we could put up a 'magforce' table to help with track building.

Like the 'Magracing-std.' 07 mm piano-wire, flush mounted, giving xx measured (somehow) down force - and maybe even the width of force-field.

We may need to 'calibrate' our wires - measuring our wire force in direct contact (zero distance) with a 5x5 'Magracing standard neo" magnet.

Any ideas on how we could do this ?
Racing Regards

Kim K.
Ned
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Location: Sedona, AZ USA

Re: Magnetic force measuring.

Post by Ned »

Good idea. Would also be helpful to see the relationship, between the strength of the down (vertical) force, and the distance between the top of the wire, and the bottom of the magnet, in 0.001" (0.025 mm) increments. This would help people build tracks with the wire embedded in a slot (groove). If a car slowly crosses a place in the track where the top of the wire is in direct contact with the magnet, the car will "freeze" to the track. If the wire has at least one coat of paint over it, the top of the wire and the bottom of the magnet will always be separated by at least the thickness of the coat of paint. Of course contact with dry paint film will produce friction which tends to slow the car and cause it to freeze to the track. Friction also causes the magnet to wear. A similar chart for 0.813 mm (0.032") diameter wire would be helpful. I use 0.032" wire.

A chart like the one noted above, along with a device (instrument) to measure the force, would be very helpful for someone making a tack with the wire embedded in the baseboard. It would enable the builder to determine precisely the depth of the wire, + or -, relative to the painted track surface which supports he tires of the cars.

I suspect that the width of the down (vertical) force-field is very narrow and not of practical significance. However, the lateral (horizonal) force between the wire and the magnet is extremely important because it is that force that keeps the car following the wire, especially on corners. A similar chart using lateral force instead of down force would also be enlightening.
kiklo
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Re: Magnetic force measuring.

Post by kiklo »

Just did a simple test the other day.

Used 10 cm of 0.7mm and 1.0mm wire, put a 5x5 magnet in between.

Then shimmed up with some sheets between 1.0mm wire and the magnet until it was random which magnet let go first when I gently pulled the wires apart.

Result : at 0.6mm it leveled out.

Not at all ment to be the answer, but I'll use .6mm as a guide building a test-track later.
Racing Regards

Kim K.
kiklo
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Re: Magnetic force measuring.

Post by kiklo »

Then what about phone apps ?

Could we find an app to fill our needs?

Several are available measuring magnetic fields / Gauss.

A few test showed me it take some learning to use them.
You need to determine where on the phone measure mag.field.

Anyone welcome to browse though apps to test. :-)
Racing Regards

Kim K.
Ned
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Location: Sedona, AZ USA

Re: Magnetic force measuring.

Post by Ned »

kiklo, Do you plan to build a test track using 1.0 mm wire embedded 0.6 mm below the track surface?
kiklo
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Re: Magnetic force measuring.

Post by kiklo »

Ned wrote:kiklo, Do you plan to build a test track using 1.0 mm wire embedded 0.6 mm below the track surface?

Hi Ned.
Yes but 1st. some 'dry' testing with wires on the floor with some 0.5 / 0.6 mm sheets on top.
Still working on my 1.st track sorting out minor problems - it was built with 1mm but not as accurate as it should have been.. (pic in track section).
Racing Regards

Kim K.
Ned
Posts: 368
Joined: Sun 13. Apr 2014 01:02
Location: Sedona, AZ USA

Re: Magnetic force measuring.

Post by Ned »

Accuracy concerning the depth of the wire in relation to the track surface is extremely important. I estimate that the guide magnet in my cars clears the paint covering the wire by 0.005" +/- .0004" (0.127 mm +/- 0.102 mm). A strand of my hair measures 0.002". So the average clearance is only 2.5 strands of my hair ! A slightly bump in the wire causes problems. On average, I estimate that there is 0.005" of paint covering the wire in my track. Of course the thickness of the paint varies a little also.

Perhaps a paint thickness gauge like this
http://www.amazon.com/PRO-Gauge-Powder- ... B003CHFXR8
https://www.gardco.com/pages/filmthickn ... augeII.cfm
might help in accurately building tracks with the wire embedded in the baseboard. Has anyone tried using a paint thickness gauge to determine the depth of the wire in a track? Of course it would have to be calibrated for measuring the distance between the top of the wire and the top of the covering over the wire since the gauge is not made to measure the thickness of paint on a thin steel wire. Even without calibration you could determine the consistency of the depth of the wire throughout the track, or in problem areas, which would be helpful.
SlotCarRental_com
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Joined: Sat 10. Aug 2013 08:39

Re: Magnetic force measuring.

Post by SlotCarRental_com »

I have always wondered what would happen if the guide arm magnet was replaced with a magnetic sphere, that was some how mounted in the arm in a way that would allow it to roll and touch the track surface.
Similar to a ball point pen...

Or maybe it can just be a round magnet with a hole for an axle, and act like a magnetic 5th wheel.
Ned
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Location: Sedona, AZ USA

Re: Magnetic force measuring.

Post by Ned »

Very interesting ideas. But keep in mind that with the current design, the guide arm magnet not only follows the wire, it also turns the front wheels, causing the car to steer around a corner.
rex craemer
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Re: Magnetic force measuring.

Post by rex craemer »

i had this idea too, and i am working on it. the problem for me is to drill a hole in the magnet, because its extremly hard. i wrecked a lot of drillers while trying it. the only one i got drilled is not straight, and several broke. i wanted to make a rubbercoat over out of heatreaction electricwire isolation. must find a way to get a clean hole in the magnet.
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