Hi Akers,

Wow! I bet you would never have guessed that your question would result in so many responses!

My layout is Scandinavian. As Roco manufactures quite a few loks and wagons for those railways, I have their products running on my layout. The locomotives run beautifully. Very smooth operation, and the sound dekoders are excellent. As far as the wagons are concerned, both their AC and DC wheels run fine on my c-track. I have yet had to change out wheelsets on a Roco piece, or any other manufacturer for that matter.

If you really have your heart set on the Roco lok, go for it!

Paul B

Well said, cannot agree more.

I have been "practicing" Marklin for over 60 years now, and it has always been excellent quality....but, occasionally here and there something strange would appear.

For example, I remember when the pretty 3049 BR E04/104 appeared, it was a "hit and miss" in terms of gear noise. That's when I learned to analyse gear teeth profiles and discovered that some gears were really good, some others were terrible. At the time most gear were stamped with a die. Smart to do so because an inexpensive process, but only valid if you keep the die within tolerance. It seemed at the time that Marklin may have "pushed it" a bit producing lots of gears that were no longer acceptable. That's also when I started curing the problem by replacing/ cutting gears myself.

Again today those quirks appear here and there (not just with M, with everyone!)

The various versions of the recent Re 4/4 I of Marklin (I have 5 of these ) are at best "uneven" in running quality!
The one from my Bavaria set is an absolute Marvel, but the exact same one in one of my friends' set s a real coffee grinder, especially in curves.

My copy of the new Lyria TGV is also puzzling: two identical powered cars obviously from the smae production batch, one is silky smooth, the other one is shaky as hell , although they are both driven from the same one and only decoder

The new Rae TEE is fantastic, super finish, the lights are perfect, runs as a dream, but the couplers are made of non resilient, non flexible material: they don't couple reliably, and ultimately break after multiple attemps to re-connect. And I won't talk about the corny set of sounds! (This is supposed to model the Cisalpino ,Paris to Milano, and the platform announcement is a goofy "Gleis funf TEE nach Amsterdam" in some colorful Swiss dialect)

I have recently bought a few ROCO because Marklin does not make the models. Beautiful , and perfect so far in terms of running characteristics but some of the detail pieces continue to fall off!

I agree that it is very hard to try to both obtain 1 dpm (defect per million) level in model RR production, because it is costly to implement thing like SPC (statistical control process)

Why is it hard?

Because we, the Marklin users, are probably not ready to pay Marklin the price that would allow them to implement systems for design and production that would guarantee even a 100 dpm defect levels.

The closest I have come to such levels at affordable prices was KATO, made in Japan, but that was back in the 1990's. And the price was very affordable, because that's how they had engaged in manufacturing systems from the very start!

So ***I live with it***, and try to mitigate by myself most of the really annoying problems I sometime find on some of my new locos.
Those who fail become shelf-queens until I get a new ideaon how to fix it.

And that's also where I find pleasure with my model RR activity.

To each his own.

Cheers

Not the "politically correct" solution, -but definatly a practical well-working one, is to assure that the wheel-spacing for Märklin M and K tracks is exactly 13,9mm. Even with incorrect wheel profile, this solution will eliminate derailing problems over all switches.
I simply PRESS the wheels together with a pair of plyers. (Normal DC wheel-spacing is around 14,1mm).
If I need un-isolated wheels, I first separate the wheels from the axle, and then insert a small piece of a copper wire into the holow plastic-axle, and then fit the wheels again; -You know; that flismy hair-thin wiring that you can find in older telephone and ethernet calbing.
Even works on my latest string of 6 1:87 length (303mm) Rheingold D-wagens from Rivarossi.

Edit; Sorry to add this later; @RayF; I used a plyer once, but the better way is of course to tap away lightly on the wheel-set (sandwiched between wooden blocks) Of course one must be careful, and not too heavy-handed! lol