New Kato motor

[Chris333]

In this video at ~1:09:00 there is a new Kato motor listed as "slotless"

[Maletrain]

Since I don't understand Japanese, I am clueless about the new motor.  All I see is a static picture of the motor or 3 talking heads who are speaking a language I don't understand at all.

So, can you tell us what you know about the new motor, please? 

[greenwizard88]

Some of the titles on the slides are "smooth, silence, torque, compatible", so I'd assume it's a compatible motor that's slightly quieter but with smoother drive characteristics and higher torque.

Conjecture:I wonder how much of that is related to the switch to PWM DC instead of variable DC from their power pack. Either way, since DCC also uses PWM whatever improvements there are should carry over to DCC.

[wcfn100]

Conjecture:I wonder how much of that is related to the switch to PWM DC instead of variable DC from their power pack. Either way, since DCC also uses PWM whatever improvements there are should carry over to DCC.

I think a slotless motor no longer needs PWM.  There's no cogging to overcome.

Jason

[up1950s]

There is 2 , a GM-3 and a GM-4 .

[peteski]

Judging by the winding outside the iron armature (which is visible between the windings, it appears like a hybrid between regular iron-core armature and a coreless motor.  the iron core probably has no slots in it, with multiple separate winding being the sort of seamless "poles".

Sort of like coreless motro that was turned inside out.  Not sure what the point is, except maybe the wanted to come out with a motor that is nor cylindrical in shape.  Leave it to Kato to keep on innovating the model train design.  But then again, sometimes they "jump the shark" too.  I guess when that thing gets out into the wild, we'll be able to asses its benefits.  Or maybe when someone translates that video. 

[OldEastRR]

A motor for which scale? KATO makes both.

[Chris333]

Slotless motors are designed to optimize smoothness and create predictable torque output with minimal non-linear effects. Commonly referred to as slotless motors when rotary and air core motors when linear, slotless motor designs place only copper phase coils in the air gap of the motor. These coils, when placed properly, interact with the permanent magnetic flux to create force or torque. Cogging torque is eliminated because the discontinuous iron teeth are removed from the motor air gap. Slotless technology is especially effective with direct drive precision systems because all torque is a function of phase current and there are no unwanted or uncontrolled torque disturbances from the motor

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I know nothing about the Kato motor, but I'm sure sooner or later we will see it in US models (if it works out).

[peteski]

Chris, while the "slotless motor" is a new term for me, I can tell you that the Portesacap seems nothing like the Kato motor.

Portescap is a brushless  motor it has more than 2 wires feeding it, and requires electronics to drive it.  Magnet is its rotor, and the coils are stationary.  This type of motors are used in electric RC airplanes and in many cordless power tools.

From what I see in the Kato slotless motor is that there are only 2 terminals feeding power (so it can be used in existing models, and the coils appear to be wound around some sort of an iron rotor. It likely has brushes too.  Well, unless the coils visible in the video are stationary, and the magnet rotor is not visible (hidden inside the motor), and the electronics to drive the motor are also integrated inside.  That doesn't seem feasible, but I guess one never knows for sure until we have the motor in-hand.

[wcfn100]

It likely has brushes too. 

Slotless motors appear to use Hall sensors instead of brushes.

Jason

[peteski]

Slotless motors appear to use Hall sensors instead of brushes.

Jason

Correct, as I  mentioned the Portescap slotless motor is brushless and requires electronics (magnetic sensors, driver transistors, sequencer) to drive it, but I also  pondered about Kato's version of slotless motor which does not appear to require external electronics (it has only 2 power terminals).  As such, it will require brushes to sequentially power the windings.

[C62-2]

Most of the key points of the video are pretty clear from the few English words on the slides, but the new motor took ~5 years to develop, they're very proud of it, it's very quite, very smooth (i.e., good low speed performance), and very strong. Part of the development was getting rid of vibration in the motor. It's a drop in replacement for the GM3 motor, so you can upgrade older models. It will be available at the Kato store at the end of the month, and in new models starting with releases in June or July (-ish). There was also some mention of needing to keep the track clean (i.e., if you have trouble with uneven movement, it's the track, not the motor). The price will be "not expensive" (no specific number was mentioned). In the demo, they didn't really have a mic near the demo track, but the first subway car had a GM3 motor in it (you can kind of see GM3 on the tape on top of the car), and it made noise that could be heard by those in the room (but not the video). The second subway car (with スロットレス on the tape) was claimed to make about as much noise as a trailer car (i.e., the clickety clack sound, but no motor sound). I think they mentioned something about it having brushes. They definitely did not mention anything about complicated circuitry.

[peteski]

Thanks C62-2!
I can't wait to get my hands on one of these to dissect it.  At least with this motor nobody will complain about straight-wound armature. 

Sounds like this is a great development.  It is nice that this motor is designed for retrofitting the models with the GM3 motors.  I wonder if the new motor has lower rpms.

[Chris333]

Yes thanks. I found it on Twitter where most of the Japanese modelers seem to hang out.

[Chris333]

From the Twitter:

At the technology development corner, a demonstration exhibition of the next-generation motor "slotless motor" currently under development will be held! The stuttering during rotation called "cogging" is reduced to the utmost limit. In addition to being able to run at super slow speeds like never before, it has also achieved high quietness by suppressing extra vibration. Please take a look at the amazing performance

https://twitter.com/kato_team/status/1426788242872020998

They show an N scale model running.