Arnold S2 cracked gears interesting phenomenon

[peteski]

(I would post a photo, but for some reason, it says I'm not allowed to.)

Well, there is a good reason.  Here's why: https://www.therailwire.net/forum/index.php?topic=43673.0
There are also other helpful sticky threads in the FAQ section. https://www.therailwire.net/forum/index.php?board=41.0

[ogre427]

OK, thank you for the clarification.

[nscalbitz]

Not going to add much, other than this is a 30 year old issue.
IIRC I read about the marvels of the model; then some pickers found the grease and used that as a reason they wouldn't run efficiently- ie as fast as Bachmanns etc.
Then came the 'gear noises' etc... I bought two models s/h well after release (the DRGW models sold out very fast) and happily moved them at 5mph where I thought they should be.
I'd post a pic but, having archived the hobby, so are the pics...
Best of luck,

[Peachymike]

For anyone that still has one or more of these and would like a less expensive fix for the wheel sets than the NWSL sets, I have found the the Bachmann S-4 wheel sets are a good option. I bought 4 trucks and took the wheel sets out.The gear has a boss on each side that must be trimmed off, but this can be done without removing the gear. Simply use a sharp knife and roll the wheels back a forth till the boss separates and then cut it off with a pair of flush cuts. Bonus is you get decent sized flange in the deal. About $8 per truck, so $16 got mine running smoothly again.

[Doug G.]

This thread reinforces my assertion that stuffing a metal axle into a hollow plastic sleeve is a very poor design. I have never understood why most seem to disagree with me. Look at all the Bachmann disabled locomotives for the same reason.

It really is a simple matter of materials and their characteristics.

Doug

[Albert in N]

   Click on Fifer Hobby vintage page link and scroll down.  He has 3 Arnold S-2 switchers each at $39.99 and looks like in original box still with Rapido couplers.  A few weeks ago, I bought two of the old 1990s Atlas/Kato diesels and they appeared new in original box with no visible wear.  They run great.  Of course this thread is Arnold S2, but my gut feeling is that some collector owned them.

https://www.fiferhobby.com/vintage_items/

[peteski]

This thread reinforces my assertion that stuffing a metal axle into a hollow plastic sleeve is a very poor design. I have never understood why most seem to disagree with me. Look at all the Bachmann disabled locomotives for the same reason.

It really is a simple matter of materials and their characteristics.

Doug

Well, if the design is sound, and quality plastic is used, there is no problem.  Kato's first contemporary loco using those plastic axle tubes (low friction trucks) was U30C in 1989.  I have that loco and the plastic axle tubes are still intact.  Same goes for similar truck design from other manufacturers.

They have very good designers and use quality plastic.  I think the other reason is that they use a stainless steel rod of a fairly small diameter while the axle tuube has rather thick walls.

Bachmann OTOH, used cheap plastics and the axles were turned on a lather along with the wheel (single piece of metal).  The axle is also very thick.  The machining is sloppy, so many of the axles are oversize, jammed into those thin axle tubes made from low-grade Nylon. A disaster waiting to happen - and it did.

Kato is not perfect - they had their share of cracked axle tubes in some of their steam locos and some universal shaft coupling, but their diesel truck design seems to be bulletproof, while also allowing  for insulating each half of the axle for low-friction electrical pickup.  That is why I disagree that Kato's low-friction truck design is bad.

[peteski]

  Click on Fifer Hobby vintage page link and scroll down.  He has 3 Arnold S-2 switchers each at $39.99 and looks like in original box still with Rapido couplers.  A few weeks ago, I bought two of the old 1990s Atlas/Kato diesels and they appeared new in original box with no visible wear.  They run great.  Of course this thread is Arnold S2, but my gut feeling is that some collector owned them.

Warning: just because the model is new, and spent last 20 years sitting in its jewel box, does not guarantee that the gears will not be cracked.  They can crack without any use on them.

[JMaurer1]

Bachmann bases the shipping on the cost. Bought some other things and suddenly the shipping went from $11 to almost $30. High shipping and having to pay CA tax made me take some items out of the cart at that point (almost $50)

[Doug G.]

Kato's engineers, as relates to the diesels, obviously saw that the plastic tube had to be much thicker-walled in relation to the metal axle diameter to ameliorate the cracking problem. It's still a better design to have a plastic axle stuffed into a metal tube, however, like the original Con-Cor/Sekisui PA-1.

Doug

[Peachymike]

Over the last 30+ years I have done repairs and decoder installs for a LHS, and imho Kato is second to none. Their designs are robust, built with quality materials, and relatively easy to repair. There is always room for improvement, but for my money they are the gold standard. Kato’s designs revolutionized the n scale market, gave us units that ran as good as they looked, all at a reasonable cost.

[peteski]

Over the last 30+ years I have done repairs and decoder installs for a LHS, and imho Kato is second to none. Their designs are robust, built with quality materials, and relatively easy to repair. There is always room for improvement, but for my money they are the gold standard. Kato’s designs revolutionized the n scale market, gave us units that ran as good as they looked, all at a reasonable cost.

Preach it Mike! 
Also, no glue is ever used for shell assembly. All the parts precisely snap together.