Model Railways / Model Railroads

Monday, August 12, 2019   7:20 AM

Improving Tomix "Second Generation" mechanisms (part 2)

In a previous entry, "Improving Tomix "Second Generation" mechanisms", I provided a suggestion to improve the mechanism of these models by applying tape to the worm gear case to stop it vibrating against the chassis.

A year older and wiser, I've since discovered that while this mitigates the underlying issue somewhat, it's not a particularly effective solution.

The underlying issue, it turns out, is the interaction between worm gear and worm gear case - without sufficient lubrication, the worm gear will cause the case to vibrate, and sometimes "stick" slightly, causing the car to stutter, and possibly put more strain on the motor/and or cause a higher current draw than it should do.

The solution is simple, effective and obvious: lubricate the interface between worm gear and worm gear case.

Tomix worm gear box lubrication

Using a toothpick/cocktail stick I applied dabs of grease to the "tunnels" on inside of the case (above right) and to the worm gear itself one either end where it rotates against the case. Excess can be remove with the toothpick, and wiped on the exposed part of the worm gear (though this really doesn't need much lubrication).

Before doing that however, it's worth cleaning both worm gear and the case, to remove any existing grease/oil residue, and in the case of the worm gear, remove any built-up fibre which may have ended up wrapped around it (quite common with second-hand stock, and something I evidently missed last time).

Friday, September 7, 2018  10:53 AM

Overview of JNR ED7x class locomotives


ClassWheel arrangementNo. builtYears in operationRegion of operation
ED70 Bo-Bo 19  1957 ~ 1975  Hokuriku Main Line
ED71 Bo-Bo 55  1959 ~ 1982  Tohoku Main Line
ED72 Bo-2-Bo 22  1961 ~ 1982  Kyushu
ED73 Bo-Bo 22  1962 ~ 1982  Kyushu
ED74 Bo-Bo 6  1962 ~ 1978  Hokuriku Main Line, Kyushu
ED75 Bo-Bo 302  1963 ~ (present)  Kyushu, north-east Japan
ED76 Bo-2-Bo 139  1965 ~ (present)  Kyushu, Hokkaido
ED77 Bo-2-Bo 16  1967 ~ 1993  Ban'etsu-Nishi line
ED78 Bo-2-Bo 14  1967 ~ 2000  Ōu Main Line
ED79 Bo-Bo 34
 1986/87 ~ 2016 [1]
 1989 ~ 2016 [2]
 Seikan Tunnel

[1] date of conversion from ED75

[2] newly constructed batch

Friday, July 13, 2018   4:07 PM

Improving Tomix "Second Generation" mechanisms

See Improving Tomix "Second Generation" mechanisms (part 2) for updated advice on this issue

Older Tomix N gauge trains are infamous for their "spring worm" drive mechanism, whereby the motor is connected to the bogie gear tower via a long spring-like metal spiral. While presumably cheap to manufacturer, it does result in somewhat noisy operation, so from the late 1980s (IIRC) Tomix gradually phased this out in favour of a more conventional mechanism with cardan shafts connecting to a worm gear on top of the bogie gear tower. This second generation does however seem to have retained the older electrical pickup mechanism, with copper forms pressing down on the axles inside the wheels (similar to what Lima did, e.g. on the Class 31), which is more reliable than wiper-based pickups but not as elegant as current axle pinpoint pickups.

Anyway, while this second generation of Tomix mechanisms is basically robust and reliable, some can be surprisingly noisy. I'm not sure whether that was the case when they were new, or whether something's deteriorated with age, but certainly annoying on otherwise decent models.

After some investigation it seems a common issue is that the worm gear case is slightly loose and prone to vibrating against the chassis. This can be mitigated by applying strips of electrical tape to hold it in place, as seen here on an older Tomix 115-1000 series:

Tomix 115 Series with modifications to the mechanism

While it doesn't bring the mechanism up to contemporary standards, it does change the running qualities from "annoyingly rattly" to "decent runner".


Wednesday, July 11, 2018  12:45 AM

"Nine Scale World" maintenance guides

The bi-monthly magazine "N" (エヌ) by Ikaros Publications has, for the past couple of years (from volume 77 onwards), been publishing a fairly regular feature detailing how to clean up/improve older Japanese N gauge models. This was originally called "ジャンク活用術" (janku katsuyou-jitsu, "Making use of older models") but in recent issues it's been titled "Re Model". (Note: "ジャンク"/junk generally refers to second hand models which are basically not in as-new tip-top condition, typically missing packaging, accessories etc., or have some minor repairable damage; it can refer to genuine spares-or-repairs candidates but 95% ot the time something labelled as "junk" will be perfectly usable).

This is an overview of the available articles for reference; articles from volume 100 and earlier are taken from a listing in that edition which contains an overview of articles in all 100 magazines to date.

  Volume Page Title (original) Title (translated
* 108 42 TOMIX DD51 (旧製品) Tomix DD51 (old version)
* 100 42 TOMIX 113系 Tomix 113 series
  99 42 中村精密 蒸気機関車 Nakamura Seimitsu steam locomotive(s)
* 97 46 しなのマイクロ国鉄事業車編 Shinano Micro JNR departmental vehicles
* 96 90 TOMIX 国鉄キハ02形 Tomix JNR Kiha 02 series railcars
* 95 52 KATO 103系(一般型) Kato 103 series (original Kato version)
* 94 90 KATO 24系寝台特急「あけぼの・日本海」 Kato 24 series sleeper "Akebono/Nikonkai"
* 93 90 宮沢模型 381系パノラマしなの Miyazawa Mokei 381 series "Panorama Shinano"
* 92 90 エンドウ 103系・73系 Endou 103 series / 73 series
* 91 90 KATO 165系 Kato 165 Series
  90 90 マイクロエース 485系 MicroAce 485 Series
  89 90 KATO マイテ49 Kato maite 49 (saloon end car)
  88 90 KATO EF65ゆうゆうサロン Kato EF65 "Yuu-yuu Saloon"
* 87 90 エンドウ都営地下鉄 10-100形 Endou Toei Chikatetsu 10-100 Series
* 86 90 KATO 103系低運転台 Kato 103 series (low cab version)
  85 90 KATO クモニ143 Kato kumoni 143
  84 90 KATO キハ40・キハ58 Kato kiha 40 / kiha 58
  83 90 TOMIX サロ481 Tomix saro 481
  82 90 エンドウ 京王5000系 Endou Keio 5000 series
  81 88 KATO 205系・103系 Kato 205 series / 103 series
  80 88 KATO 189系 Kato 189 series
  79 88 KATO 189系 Kato 189 series
  78 96 KATO コキ10000 Kato koki 10000 (container wagon)
  77 90 宮沢模型 165系「なのはな」 Miyazawa Mokei 165 series "Nanohana"

(volumes denoted with an asterisk are in my personal possession)

Back in the increasingly dim and distant (well for me at least) 1980s, when diesels were blue and trains were still done properly (loco at one end hauling coaches or wagons), the Class 27s were very much a far and distant (from my Midlands perspective) Scottish class, rarely if ever sighted.

However as with many of the early "pilot scheme" classes, they started off life elsewhere, with quite a few being allocated to Cricklewood and Leicester during the 1960s. Though I've always been aware of that, they still seemed utterly unconnected with my main region of interest, the West Midlands, until I came across entirely by coinicidence a photograph of one topping the Lickey Bank at the head of a freight train.

Interest piqued, further research revealed more evidence of the class in the Birmingham area (though an awful lot of hits were false positives triggered by the the "B" in "BRCW", not the location of the photograph or sighting) - Quite a few seem to have made it west and south of the city. Following is a list of online references I've found, in rough chronological order.

Also of interest is this thread on RMweb: Leicester class 27's

Tuesday, April 17, 2018   9:27 AM

Lists of N scale (N gauge) models

One question which frequently comes up in various N scale forums and groups is "is there a list of all N gauge models ever made?"

To which the answer is "no", but there are a number of sites providing comprehensive lists of models for particular manufacturers, subject areas etc.. This is a (incomplete and work-in-progress) "meta" list of such sites:

Other useful links:

Thursday, July 20, 2017   9:15 PM

Lima N gauge Class 31 D5518 (220209G)

The Lima N Gauge Class 31 from the 1980 Lima catalogue.

Lima Class 31 D5518 (220209G)

A much more recent photo:

 Lima Class 31 D5518

The first and worst rendering in N gauge of the Class 31 (Brush Type 2), an early (and relatively long-lived) modernisation plan diesel with the unique (for the UK) A1A-A1A wheel arrangement.

Inside it's the classic Lima chassis design:

Lima N gauge Class 31 D5518 (220209G) - chassis

Diecast metal chassis with the motorized bogie on the right, pickup bogie on the left


Lima N gauge Class 31 D5518 (220209G) - pickup bogie (underside)

Mmmmh, lovely thick pizza cutter wheels. The pickup arrangements is actually not too bad, with what look like brass pickups pressing down on the axles, and held in place by a small rim on each side. The screw which holds the body in place visible on the right.


Lima N gauge Class 31 D5518 (220209G) - driving bogie (underside)

The motorized bogie; the way the motor is mounted seems to make it impractical to power more than two axles.


Lima N gauge Class 31 D5518 (220209G) - driving bogie (motor)

The motor; the brass (?) strips on each end, which the wires are soldered to, reach around the motor block (see next photo). Not entirely sure what the purpose of the oval copper (?) strip in the centre is, it serves no electrical purpose and doesn't hold anything in place.


Lima N gauge Class 31 D5518 (220209G) - driving bogie (motor, brushes)

Motor from the other side; the brass strips wrap around from the other side, and hold two copper springs in place, which in turn secure the brushes against the motor and provide electrical contact.


Friday, March 10, 2017  11:26 PM

Replacing Arnold couplings with Kato ones

I recently aqcuired a rake of Kato Taki 1000 oil tank wagons (set 10-1167) to go with my EH-200, and while they're perfectly decent wagons the default Arnold couples really do stand out and look clunkier than usual. Normally I'm not too bothered by Arnold couplings and can "unsee" them, but these had to go - replaced by the Kato coupler (part number 11-707). Mildly fiddly to assemble and put in place, but they make a huge difference:

Kato Taki 1000s with Kato coupler