Arnold Coupler vs Knuckle Coupler

[Kotori]

This may be a dumb question, but I’ve noticed a lot of Japanese freight rolling stock models from Kato use Arnold couplers as opposed to the knuckle/close couplers which seem to be prototypical.  If I were to put two cars coupled together with an Arnold coupler beside two with knuckle couplers, would there be much of a space difference?

 

[Kamome]

Yes, depending on your choice of knuckle coupler, you would either notice a small or large difference. Most importantly, you would notice as most Arnold couplers are enormous and leave a very spacious gap between stock.

 

I'm really not a fan of Rapidos and sacrifice the easy coupling ability for more realistic looking couplers. My "GO TO" for intermediate stock in a rake is the Kato short coupler, (28-187 or 28-188 depending on colour) I have used these on Kato, Tomix and Microace stock without issue as I particularly like some of the Tomix Wagons, but generally favour Kato locomotives. These leave very little space but do look much better. Obviously if you have tight corners, you may have to use something slightly longer. Greenmax also produce a similar, more detailed and scale accurate looking option but I find them a lot more difficult to procure than the Kato ones.

 

These short options are just moulded plastic without any moving parts so cannot be push-coupled. I am currently testing an idea of having short fixed rakes of wagons with the above couplers between them, but have a magnetic coupler on each end of the rake, to either connect with a loco, or another rake. This has meant the choice of wagons at the rake ends has to be Kato as I'm trialling Kato magnetic couplers.

 

 

[Kotori]

@Kamome  So is Kato’s short coupler the same as 11-731 or is that a different product?  I couldn’t find 28-187 on their product search page.  
 

Is it possible to convert a standard Arnold/Rapido coupler mounted to a bogey to a short coupler?

 

Also, the racks of wagons sound like an excellent idea.

[Kamome]

This Coupler 11-731 looks like a Shibata style coupler which is found between EMU coach sets rather than freight.

 

11 minutes ago, Kotori said:

Is it possible to convert a standard Arnold/Rapido coupler mounted to a bogey to a short coupler?

Yes, parts are generally available to switch to body mounted couplers for coaching stock but less so for freight wagons. Modern Kato coaches have body mounted couplers generally. Tomix coaches you have to cut off the bogie coupler mount with some nippers than you can fit their TN couplers.

I never found bogie mounted couplers on freight wagons like Kokis much of an issue and the rapidos can be switched out for knuckles to reduce the gaps.

[disturbman]

My personal gotos are GM short and medium shank knuckle couplers, GM 8056 (short gray), 8055 (short black), 8054 (medium gray) and 8053 (medium black). They are the most prototypical looking on the market and have a very small knuckle. They are compatible with Kato locomotive knuckle couplers but do not couple without a helping hand.

Variation in the shank is needed as not all coupler pockets are at the same distance from the end of the car and shorts can then rub against the body.

The main "downside" is that you then need either one car with a single Rapido to connect to Tomix locs or buy an aftermarket adapter (from Re-color) to be able to fit Kato EF66 coupler on your Tomix locs. But it's not a big downside.

The generic Kato knuckle couplers (11-702 & 10-707) do not change the distance between cars.

Edited January 18 by disturbman

[Tony Galiani]

@Kamome - hope you will post your results with the Kato magnetic couplers.  Currently, I am working my way through previous coupler threads looking for good options for a coupler to use for shunting.  Thinking of a small cameo style layout on my desk to mess around with some Kokis when I take a work break.  I know the MicroTrains couplers are an option though they have that slinky effect so wondering if the Katos would be better.

Cheers,

Tony

[Kamome]

@Tony Galiani Results have been mixed at present. I’m testing the Kato magnetic couplers with the magnetic uncoupled track.  Initially it was an idea for changing over sleeper train locos or dividing full formations for separate destinations. (e.g. Nagasaki/Sasebo)

 

I’m finding the tolerances for the magnetic bar are very small. I’m only referencing my knowledge of HO scale Kadees which Kato’s are similar in idea. Kato’s don’t come preassembled and due to the smaller scale there are some challenges with the height setting of both the coupler and the magnet bar to balance; a. push coupling, b. uncoupling, c. not picking points. 

 

Im not yet convinced that these are worth the bother but i’ll persevere. 

[Kotori]

@Kamome  How would you convert freight stock from Rapido to knuckle couplers if they are bogey mounted?  Is there a thread on here that covers the topic?

[disturbman]

@Kotori I think, it's so straight forward that nobody ever thought of making a post about it. You just twist the Rapido out of the coupler box and install the new coupler in its place. Some installations can involve removing a metal cover/plate, but that's limited to Tomix. It can help to unscrew the bogies when changing couplers. Though it's not an absolute necessity.

[Kamome]

@Kotori Yes I think it can be daunting at first as there is a huge range of different couplers available for various applications.

For bogie mounted stock, you need just replace the coupler head part. This is the case for the majority of bogie freight stock but I imagine there might be the odd exception. So you’d just switch the Rapido for which ever compatible knuckle you wanted to use. 

 

Converting from bogie to body mounted is mostly possible with passenger coaches. Kato’s newer coaches tend to come with body mounted but the old coaches were all bogie mounted. There actually aren’t that many options unless Kato have released an updated version and produce a part that fits to whatever generation of model you may have. I have an old 10 coach 211 series commuter train that will not accept body mounted parts without some cutting and glueing. 

 

Tomix produce a wide range of body mounted coupler housings for their various trains. You can usually find the compatible part number in the included documentation. You need to cut off part of the bogie which feels counter-intuitive on a brand new model. 

 

Here is an example of a shibata type coupler for an EMU.

 

 

I think if you have specific stock you want to change, ask on the forum and many can let you know what would be suitable.

Edited January 21 by Kamome

[MeTheSwede]

This all reminds me of why my very first post on this forum was titled Please help me before couplers make my head explode. 😵

[railsquid]

9 hours ago, Kamome said:

@Kotori Yes I think it can be daunting at first as there is a huge range of different couplers available for various applications.

 

 

Slightly OT, but experience with the dispersive effects of gravity has taught me to keep small, loose items bagged-up.

 

 

(I have another, less organized - but still bagged - drawer full of the things).