Oh what in 'Z' world am I doing?

[ednadolski]

... as I see it the track and wheels will likely be a weak link. 

This is about as small as they get, and the wheels/track/weight don't seem to be too much of a concern.

This looks to me like it is running on DC, but yes, you can get a DCC decoder for this one.

Ed

[robert3985]

Thanks for the links Doug.  I was aware that there are small decoders usable for Z scale, but most of them have either no, or very little keep-alive capacity. As I see it, the track and wheels must be absolutely spotless for reliable operation.

Yes, sound is possible if installed in a capacious model (like a passenger car).  That decoder has a bank of keep-alive caps which is a good idea because it is a relatively light car (so electric pickup is not ideal). 

Looking at the threads you linked to, looks like Alex discovered multi-layer PC boards, like ESU, ZIMO and other manufacturers utilize for their decoders.  That can sure result in a more compact PC board design.

I'm not dismissing the fact that there are DCC options for Z scale, but as I see it the track and wheels will likely be a weak link. 

So Ed,  you are content with running on old school DC?  Back to block control for running OPS, or you are content with just single train operation (roundy-round)?

I'm scratching my head attempting to discern exactly why Z-scale wheels and rails are going to be any different than N-scale wheels and rails when it comes to effective electrical pickup??  Maybe you Peter @peteski could 'splain that to the group??

I remember back at the turn of the Century when I was running DC on my layout and at shows, I didn't have any problems with unreliability during either mainline running or operations in my yards or industrial spurs...which was without any "keep-alives" installed in any of my engines, just using my old club-made Ntrak corded DC throttles.

I also don't remember having to excessively clean track all the time, even with trains constantly running in a show environment, so...I'm pretty sure that the rails and wheels were far from being "spotless"...and even on track that was not up to my standards on other modules, trains ran well.

Addressing the DCC Sound problem with there much less volume in Z-scale engines for speakers...I think that Soundtraxx and Digitrax might have a solution.  Soundtraxx calls it "Surroundtraxx", and Digitrax decoders that have Transponding to locate the engines.  Here's a blurb from the Soundtraxx site about how it works: After the trains have been dispatched, the block detector will identify the trains' locations, the speed they are traveling, and the point where they will cross into new blocks. SurroundTraxx uses this information to move the appropriate sounds to the corresponding sound channel (six are available) on the SurroundTraxx unit. SurroundTraxx uses an intelligent cross-fade algorithm that factors in train speed, direction, and distance between speakers. This reproduces the sound in such a way that it appears as though it is being emitted directly from the train rather than the speakers on the layout.

I think you have to divide your layout into blocks for it to "follow" your engines...but, here's where the info is at: https://soundtraxx.com/products/surroundtraxx

The smallest transponding Digitrax decoder measures 0.55" x 0.28" x 0.128" and retails for only $34.

Soundtraxx has "Surroundtraxx" on sale right now...pretty expensive at $475.95, but that's 150 bucks off of MSRP...but, you wouldn't need expensive sound decoders for your engines.

I thought it was interesting for anyone interested in a different way to get quality sound in Z-scale...even if it looks to be fairly complicated to do so.

Cheerio!
Bob Gilmore

[peteski]

I'm scratching my head attempting to discern exactly why Z-scale wheels and rails are going to be any different than N-scale wheels and rails when it comes to effective electrical pickup??  Maybe you Peter @peteski could 'splain that to the group??

Bob, my simple Polish logic tells me that the lighter the model is, the less reliable electric pickup will be.  That's it!  That's my 'splanation.
Even smaller scales (like T) use magnetic wheels and ferromagnetic track to improve electric contact and also increase traction.

[nkalanaga]

Peteski's right.  I have several Marklin "4-wheel" diesel switchers.  yes, I know, they have six wheels, but the center wheels are designed NOT to touch the rails, so they don't count.

On my Nn3, I have one that is almost stock, except for a new plastic and cardstock cab.  The other four have Nn3 cast-metal bodies from Republic Locomotive Works.  Same exact mechanisms, except that the center wheels have been removed.  The "N scale" units have much better pickup, simply because they weigh more.  On really clean track, both versions run the same.

[robert3985]

Bob, my simple Polish logic tells me that the lighter the model is, the less reliable electric pickup will be.  That's it!  That's my 'splanation.
Even smaller scales (like T) use magnetic wheels and ferromagnetic track to improve electric contact and also increase traction.

@peteski Peter, ahhh....that's what my old brain was thinking too.  It's not a "wheel & track" problem, it's a weight problem.  All electric trains in all scales have an electrical pickup system that is dependent on wheels making contact with the rails, but...larger engines have more weight, which makes lifting over minute flecks of whatever on the track much less of a problem.

Time for a pressed/sintered powdered tungsten chassis or cast depleted uranium ones.  Hey, if the military/industrial complex can do it, so can the model train industry, right???

Cheerio!
Bob Gilmore

[peteski]

@peteski Peter, ahhh....that's what my old brain was thinking too.  It's not a "wheel & track" problem, it's a weight problem.  All electric trains in all scales have an electrical pickup system that is dependent on wheels making contact with the rails, but...larger engines have more weight, which makes lifting over minute flecks of whatever on the track much less of a problem.

Time for a pressed/sintered powdered tungsten chassis or cast depleted uranium ones.  Hey, if the military/industrial complex can do it, so can the model train industry, right???

Cheerio!
Bob Gilmore

Yes, using denser materials would be a good idea.

Dapol's N scale Terrier 0-6-0 loco has a pressed/sintered powdered tungsten weight in the cab, and I'm sure you know that NTRAK Jim FitzGerald's BIG BRUTE engine has depleted uranium weights.

Yes, it would make sense for manufacturers to more widely use tungsten chassis/weight in small scale locos.  We know that using tungsten is more realistic than have manufacturers sell models with depleted uranium. 

Even going back to lead would be an improvement over the relatively low density white metal currently used.  But that is likely a non-starter due to the current government regulations.

Another possibility would be to cast chassis from brass.  It can be cast fairly easily, and it is denser than the white metal.  It is likely more expensive, but I would be willing to dish out some extra money (who knows, maybe $5 or $10?) to have a model with a brass chassis.

[ednadolski]

larger engines have more weight, which makes lifting over minute flecks of whatever on the track much less of a problem.

IDK what this all means, but it sounds good:

https://en.wikipedia.org/wiki/Contact_resistance

Surfaces of metallic contacts generally exhibit an external layer of oxide material and adsorbed water molecules, which lead to capacitor-type junctions at weakly contacting asperities and resistor type contacts at strongly contacting asperities, where sufficient pressure is applied for asperities to penetrate the oxide layer, forming metal-to-metal contact patches.

https://deepblue.lib.umich.edu/bitstream/handle/2027.42/95929/umpeng_1.pdf?sequence=1




Ed

[peteski]

That sounds like good explanation to me. I never really looked at the poor electric contact from a scientific  angle.

[Chris333]

Nothing a little clipper oil won't fix 

[ednadolski]

Just for grins, Z scale cars on a 22" radius curve don't look too shabby.... 



Ed

[Sokramiketes]

22" R is pretty good in Z!

I was trying to balance train length to radius for Trinidad Loop, so the 8ft trains still came back around each other.  So I went to 18" or so.

[ednadolski]

22" R is pretty good in Z!

About the same as 30" r. in N scale.

However, 30" r. in Z scale would be just about 100% of full scale for a 10-degree curve






Ed

[Scottl]

Loving how many contour maps have appeared on TRW of late.

[garethashenden]

Yes, using denser materials would be a good idea.

Dapol's N scale Terrier 0-6-0 loco has a pressed/sintered powdered tungsten weight in the cab, and I'm sure you know that NTRAK Jim FitzGerald's BIG BRUTE engine has depleted uranium weights.

Yes, it would make sense for manufacturers to more widely use tungsten chassis/weight in small scale locos.  We know that using tungsten is more realistic than have manufacturers sell models with depleted uranium. 

Even going back to lead would be an improvement over the relatively low density white metal currently used.  But that is likely a non-starter due to the current government regulations.

Another possibility would be to cast chassis from brass.  It can be cast fairly easily, and it is denser than the white metal.  It is likely more expensive, but I would be willing to dish out some extra money (who knows, maybe $5 or $10?) to have a model with a brass chassis.

Most modern chassis are Zamak, which is mostly zinc with a little aluminum. Brass is copper with a bit of zinc. The base material ends up being twice the cost, and while it can be diecast, its less common. So finding someone who can and will would probably drive the cost up. Brass also corrodes more than zinc. Brass does machine very nicely, so for a smaller run it might be easier to machine it.

Tungsten is hard to machine. Its hard and abrasive and wears through tooling quickly. It also needs to be preheated before machining. No model train manufacturer is going to bother doing that. It's also expensive. Zinc is about a dollar a pound, copper three. Tungsten is $15 per pound for just the material.

[Chris333]

pressed/sintered powdered tungsten

I wonder if that is more dense than 100% lead. Powders tungsten is not, but being pressed might make it win, but by how much?