Kato slotless motors magnets effecting Tomix points

[cteno4]

Bit of a bummer they are charging so much for a fix, I would have expected them to do it cheap or free. It is a competitor but folks cross over a lot and it does seem all due to the very strong magnetic field of these motors. Seems like they are not doing this at cost.

 

jeff

[Madsing]

I agree. For the 20+ points of my layout, that would cost me more than ¥20,000. I'll try to find a cheaper solution if I face the problem.

[railsquid]

Right, tomorrow I will pop along to the Kato shop as I need some bits anyway and will pick up a coreless motor to see what all the fuss is about.

 

 

[MrLinderman]

Ok have a weird issue, the Tomix train runs over the electric switches fine, but if I try to use my Kato Yamanote E235 as soon as the "engine" carriage hits the point it causes the point to jump and I have to either manually switch the point or flip the lever twice to get it to go back. 

 

Is the Kato train possibly giving off something that's causing the point to switch, or power to somehow flip it?

 

Using stock power system.

 

It only occurs when the switch is in the open position, the kato train seems to force to the close position when the engine hits it.

 

In the closed position I can see the little manual slider jump when it passes but it stays closed.

 

Did some more testing, it's even doing it on some of the switches that are not wired. Unless internally they are the same just mising the wire and switch box?

Edited February 14 by MrLinderman

[disturbman]

So it does happen. I thought Kato had solved the issue.

When Kato released their first train equipped with their new slotless motor, there was one post that did the rounds saying that the new motor magnetic field would flip Tomix points. Everybody was rather bemused that Kato hadn't tested their motors with one the other main national brand of tracks. Had never heard someone reporting this until now.

Just to be sure, you haven't removed the mechanism (electrical or manual) from the switch?

Edited February 14 by disturbman

[Yavianice]

@MrLinderman This is a real issue that was confirmed when the KATO slotless motor was introduced. In the meantime KATO started selling these sheets that you can retrofit your tomix points with. https://www.1999.co.jp/eng/10947765, or to retrofit your KATO motors with https://www.1999.co.jp/eng/11024549

whichever is more suitable for you.

Edited February 14 by Yavianice

[MrLinderman]

8 hours ago, disturbman said:

So it does happen. I thought Kato had solved the issue.

When Kato released their first train equipped with their new slotless motor, there was one post that did the rounds saying that the new motor magnetic field would flip Tomix points. Everybody was rather bemused that Kato hadn't tested their motors with one the other main national brand of tracks. Had never heard someone reporting this until now.

Just to be sure, you haven't removed the mechanism (electrical or manual) from the switch?

 

Didn't mess with the switch at all just stock out of box.

 

7 hours ago, Yavianice said:

@MrLinderman This is a real issue that was confirmed when the KATO slotless motor was introduced. In the meantime KATO started selling these sheets that you can retrofit your tomix points with. https://www.1999.co.jp/eng/10947765, or to retrofit your KATO motors with https://www.1999.co.jp/eng/11024549

whichever is more suitable for you.

 

I thought it might be the case, so those are out of stock, will see if I can search for them, im wondering if they are just 3m magnetic strips but super thin I might be able to buy it in bulk from a 3m supplier and cut them to size myself 

[brill27mcb]

Even the unpowered Tomix switches have a small magnet in the moving slider inside that serves to keep them toward one side or the other. The strong magnetic field of the Kato slotless motor overwhelms this function and makes the moving slider change sides as it passes over. The metal strip is supposed to shield the magnet in the switch from the field of the slotless motor.

 

Rich K.

[disturbman]

9 hours ago, MrLinderman said:

Didn't mess with the switch at all just stock out of box.

👍 didn't assume you did. Just wanted to rule out that unlikely possibility because without the mechanism, trains can flip the switch when passing on it.

[MrLinderman]

Any thoughts what I can use as those items from Plaza and seems everywhere I look is sold out. Should I look for 3M metal strips?

[disturbman]

Yes, that's the speculation: that Kato is selling overpriced 3M metal tape.

I don't know that anyone figured out which one they are. But that would be a useful information to have.

[MrLinderman]

For those interested I have confirmed that a ferros metal placed underneath the switch negates any stray waves and keeps the switch locked in place till the solenoid activates.

 

Tested with 3m, 1mm thick steel flexible non-metalic strip, now I know what can be used to fix the issue ill test some metal strips allot thinner as 1mm isn't really suitable for a flat wood table im doing my testing on, fine if your building on foam as you can carve out a small pocket.

 

Gotta make sure its a metal that is attracted to magnets but not by itself magnetic.

 

Will pop to the hardware store and see if I can get anything thinner, it's also possible the train I have does have the plate installed inside but maybe it's not thick enough or has moved, I might check that also.

 

Video after, also worked on the switch that would fully flip, but did it on the one just blipping for convenience: https://drive.google.com/file/d/1Sn2WIYIPShsPazebOWCnRK8i1TnCMCS0/view?usp=drivesdk

 

Video before:https://drive.google.com/file/d/1SoJ5fEfITC9GntPBDvBrHX05IaBg1u_i/view?usp=drivesdk

[brill27mcb]

Your solution will probably be less expensive and more readily available than the Kato product, which always seemed like a "kludge" to me. I think they offer this solution only begrudgingly to users of competitor Tomix's track. It was the Kato slotless motor that precipitated this issue, and it is an unfortunate side effect of a truly innovative design on Kato's part.

 

Rich K.

[MrLinderman]

So I did some further testing, got a bunch of different thickness iron sheets from ebay (china).

 

Can confirm that you can use 99% iron sheet 0.05mm thick, so super thin, and it works perfectly to block out any stray magnetic waves effecting the switches.

 

Did a bunch of runs over them and the non modified kato motor does nothing to them now even at speed. 

 

Best thing is as its so thin it can be easily cut to the exact size of the magnetic plate under the switch area and either glued on on double sided tape should work. 

 

And it's cheap at about $3 per 100mm squared

[Madsing]

Interesting. So placing the sheet under the switch is enough, I don’t know how to say, to “deflect” the magnetic field from the motor so that it does not affect the switch position. 

[cteno4]

Excellent solution! Thanks for experimenting on this and coming up with an inexpensive solution.

 

yes the magnetic field lines from the motor end up interacting with the sheet of iron more instead of just the bits of the point motor mech so it does not have enough umph to prove the blades at all. Basically sets up a different magnetic field shape there between the motor and the point that does not end up dragging the blades.

 

cheers

 

jeff

[MrLinderman]

This is my interpretation but could be wrong

 

Going by the internals of the switch it appears that the new kato motors basically produce a stronger magnet field than the magnets inside the switch can hold against, meaning that without some type of additional help the little internal magnet that flips from one side to another (and moves the blades) is effected by the motors more than the "holding" magnets on either side of the switch.

 

If you look at the holding magnets they are also orientated so that only a tiny fraction of the side of the magnet is intersecting with the moving "magnet" in the switch, this surface area is small, very small, so a strong field intersecting it does effect its holding power and seems to bump it over to its opposite side.

 

The plate acts like an anchor, so the magnet that flips back and forth and the magnets inside the switch combine to create a tighter control of the moving parts so that when the motor passes over it has little to no effect. as the plate is "flat" or "in-plane" with the magnetic slider it has a decent holding force on the part so when the motor moves over the part the effect of the magnetic force just compels the part to move towards the nearest magnetic source which in this case is the plate instead of towards the opposite side of the switch.

 

At least that's my interpretation of how it works. 

 

 

Edited March 13 by MrLinderman

[MrLinderman]

It's highly possible the coils are also being effected by the motor as i don't see any problems with switches that are 100% manual. Only those with coils seems to get effected allot without something to absorb or block or assist.

 

I did some size testing and this is all you need to neutralise the new motor effects on the Tomix switches. I just stuck it down with sellotape over it all.

 

It's only covering the "coil" electric portion of the switch.

 

Works like a charm 👍

 

For those interested i got the sheets from here: https://www.ebay.com.au/itm/273986269684

 

If your smart with your cutting one sheet should do around 8-9 switches 

Edited March 13 by MrLinderman

[katoftw]

On 3/13/2025 at 4:28 PM, MrLinderman said:

It's highly possible the coils are also being effected by the motor as i don't see any problems with switches that are 100% manual. 

It's not highly possible.  That is the problem.  It's been well documented in the past 4 years.

[brill27mcb]

I think he is differentiating between whether the slotless motor's magnetic field is acting directly on the small permanent magnet that moves back and forth when the points are thrown, or whether the slotless motor field might be inducting a magnetic field in the turnout's coils.

 

Rich K.

[MrLinderman]

1 hour ago, brill27mcb said:

I think he is differentiating between whether the slotless motor's magnetic field is acting directly on the small permanent magnet that moves back and forth when the points are thrown, or whether the slotless motor field might be inducting a magnetic field in the turnout's coils.

 

Rich K.

 

I did notice that two of the switches I have that don't have coils also flipped over today, so I've done the mod on all switches now including those without coils. 

 

All sorted now, thanks for the tips all.

[cteno4]

Interesting, so the magnetic field of the slotless motor is pushing the blades themselves.

 

jeff