Continuing MTH Erratic Behavior Question

Peter,

There are some things of which you should be aware:

• The battery in a PS2 engine does not maintain the engine's speed when power is momentarily interrupted, rather, it keeps it making sounds and keeps it in DCS mode.
• If it's all of your PS2 engines, it's unlikely that the issue is related to a defect in the engines.
• I'm not aware of anything in DCS that could cause the issues that you're experiencing.
• The fact that your other, non-MTH engines don't have batteries has no bearing on the problem.
• What you're experiencing is power-related, not DCS-related, so DCS signal strength isn't at all a factor.

I suggest that you look at the spacing of the pickup rollers and also at the non-traction tired wheels of your offending engines. It's possible that you may be momentarily losing either Hot (center rail) or Common (outside rails) due to the engine's wheel and pickup roller geometry.

Further, some steamers may not have a good Common connection via the tether between the wheels on the tender and the engine itself.

If the problem happens most often around switch tracks or uncoupling/unloading tracks, loss of Hot or Common is a reasonable possibility.

It would also help to know exactly which PS2 engines exhibit the offensive behavior, as well as more information about the track topology where the issues occur.

Are you running them with the smoke on? Try turning it off.

When you say "Every time this occurs, I test the areas where these locomotives slow down ...."

You test them after running with your meter. Do you have any transformers with amp and volt meters built in? Can you borrow one or install meters?

What gauge wire goes to these blocks? how long is it? how are they connected to the tracks?

how long are these blocks and how many joints?

what type of track are you using?

What type of power?

Does your Lionel engines that run fine, include newer larger steamers with chuffing smoke?

Ooops, Barry chimed in while I was typing. Listen to him.

Thanks for helping me trouble-shoot.  Here's additional data to help:

• I typically run the steamers with smoke off, although this occurs whether smoke is on or off. 
• 5 different Premier locomotives including N&W J, Allegheny, Daylight and Mohawk. 
• Atlas track throughout. 
• As I said, the issue happens wherever. Usually on areas where there is uninterrupted rail (I don't have uncoupling/loading track and the issue rarely happens, if ever, where there is a turnout). 
• As I said, I wired as closely as possible per MTH/Barry recommendations, so I have one centrally located drop in each track block that is composed of 9-11 track sections.  Mostly 40" straights with minimum 072 curves, and often 081, 090, 099 and 0108. 
• The power drops are equidistant OGR wire of 14AWG wire of varying lengths, with none longer than 20', soldered to the track - although this sort of seems irrelevant given the problem happens randomly all over the layout and in track blocks that can have 6' wire runs or 20' wire runs. 
• Barry - I think your tether point would be a good place to look - but I would point out that I just had MTH replace the tether on the N&W J (the existing one decided to just fall apart during operation).  Maybe this is the problem (?) but to me it seems rather unlikely given the mathematical probability that I could buy 5 different steamers (from 4 dealers) over the course of 4 years and each and every single one having the exact same tether issue from almost day 1. 
• Barry - per your comment "I suggest you look at the spacing of your pickup rollers and...," can you elaborate?  I'd like to follow up on this, but don't exactly know what to do.  Also, I'd point out that distance between pickup rollers is not the same between steamers (and I've replaced them on 2 steamers in the past year with the more robust version sold by MTH - and this has made no difference), and wheels geometry is also different between steamers. Also, as mentioned, today the issue could happen for (say) steamer 1 every time it is in track block 3 (straight track only) and steamer 2 will experience this today in block 6 (straight leading into 081 curve). Tomorrow, steamer 1 experiences it only every time it is in block 5 (099 curve and some straight) and steamer 2 only every time it is in block 4 (just straight track). 
• Barry - if by "track topography" you mean straights, curves, etc., then I think the data is above. If, however, you mean are there inclines and declines, then the answer is yes and no.  I have very gentle inclines and declines on the layout but again, this issue happens everywhere.  On perfectly flat areas as well as elsewhere.  There is no increased occurrence level in blocks with inclines/declines over perfectly level blocks. 
• TIU is rev. L. 

Thanks again for for the help

Peter

Peter,

Atlas track throughout.

Do you have both outside rails connected together? If not, try jumpering them together in one of the offending blocks.

Also, meter connectivity between each rail and the adjacent rails within each offending block.

Your problem is almost certainly a loss of contact between the engine's pickup rollers or wheels, and the track, or a loss of connectivity between a power wire and the track..

Signal interference may be your issue.

See recent post, Signal Interference Found! No Need for Cherry Bomb Cannon

Barry Broskowitz posted:

Peter,

Atlas track throughout.

Do you have both outside rails connected together? If not, try jumpering them together in one of the offending blocks.

Also, meter connectivity between each rail and the adjacent rails within each offending block.

Your problem is almost certainly a loss of contact between the engine's pickup rollers or wheels, and the track, or a loss of connectivity between a power wire and the track..

Barry,

Thanks again.  All three rails are wired (jumper between commons) in most track blocks and I've run 2 multimeters over each and every piece of track (measured twice - using center and each outside rail) with zero power drops. Also ran 2 Premier locos over the entire layout at 2-3 smph to check for voltage as well as DCS signal strength. Voltage is per multimeters (18+ v) and signal is 10 throughout.  But I'm thinking you're right about power drop.  Can you elaborate on "spacing of pickup rollers/geometry of wheels" comment?  Any other suggestions?  By the way, I know we're trouble-shooting, but keep in mind that my RK Scale and Premier diesels and every Lionel locomotive I own does not experience this issue.  That's what has me thinking it might be a power/tether issue? 

Susan - thanks, but there is zero metal interference - other than the rails themselves and the Atlas screws that hold it down (the TIU is vertical and sits equidistant in the layout). Purposely designed it this way given some such issues discussed wrt Legacy and Lionel locomotives (since we also own several of these). 

Peter

When you measure, is that area under a load?

Is this happening with lash-ups or long heavy trains?  You may be pushing the limits  of the engine. Does it happen  with just  the engine?

Gregg posted:

Is this happening with lash-ups or long heavy trains?  You may be pushing the limits  of the engine. Does it happen  with just  the engine?

Engineer-Joe and Gregg - just the locomotive. No lash-ups, no cars at all. Going anywhere from 10 smph to 60 smph.  Thanks for your help.

Peter

Barry Broskowitz posted:

Peter,

There are some things of which you should be aware:

• The battery in a PS2 engine does not maintain the engine's speed when power is momentarily interrupted, rather, it keeps it making sounds and keeps it in DCS mode.

 

Not to derail getting advice on my issue, but I just re-read the above quoted piece  and I'm confused.  According to the MTH DVD from a few years back that intros its products and DCS, there is a scene where they have an MTH train on a track and a non-MTH train on a parallel track.  Along each track there are sections of rail covered with tape, meant to purposely cause a loss of power and signal. The narrator indicates (and the accompanying footage demonstrates) how the MTH PS2 locomotive, with its battery back-up, will keep going - at the same speed - despite the intermittent loss of power. The other train, as expected, craps out.  So, is the purpose of the battery misstated in the MTH DVD or ...? 

Thanks

The other train, as expected, craps out.  So, is the purpose of the battery misstated in the MTH DVD or ...? 

The battery absolutely does not power the motors. It just keeps the board working. Momentum keeps the engine moving.

Sounds like poor conductance at center or outside rail pins.  If the latter, locos pulling different length trains may behave differently.

If a running train loses signal but not power, it will continue running at the same speed until (1) collision, (2) power shut down, or (3) regaining signal and receiving a command.

RJR posted:

Sounds like poor conductance at center or outside rail pins.  If the latter, locos pulling different length trains may behave differently.

If a running train loses signal but not power, it will continue running at the same speed until (1) collision, (2) power shut down, or (3) regaining signal and receiving a command.

Or (4), derailment.

True, or (5) Armageddon

Have you made any observations if you:

1a) turn the engines around and head them in the other direction

1b) run the engines in reverse

Since this doesn't occur on diesels (no tether), 1a) might reveal if "bending" the tether into a left vs. right turn might be in play.  1b) might reveal if the roller/wheel spacing relative to bumps, "potholes", worn-spots on particular sections of track might be in play.

Also, since this apparently occurs at 10 sMPH (or so), when the steamers slow down do the chuffing sounds also slow down and exactly follow the 4-per revolution cadence?  I realize you say the slowdown is only for a few seconds but it might be a diagnostically useful to note if the engine "thinks" it's going at the commanded speed (chuffing sounds don't change cadence) but the mechanics slow down due to a gear slip or some other mechanical anomaly.

If you have a real short 0-4-0, like a Docksider, run it around the layout, deadhead with no cars, in conventional mode.  This will show up any bad grounds.

Barry did ask you to post the loco model numbers, with good reason.

Do any of the problem locos NOT have a ground wiper on the rear truck, or NOT have a rear truck.

Is the top of your center rail still black? I had a similar problem with MTH Real Trax. I was able to temporarily resolve the problem by applying Rail Zip Track Cleaning Fluid. Eventually, I gave in and took a Scotch pad to the center rail.

The black on the top of MTH RealTrax must be removed or DCS signal strength will often be degraded.

This and a whole lot more is all in “The DCS Companion 3rd Edition!" This book is available from many fine OGR advertisers and forum sponsors, or as an eBook or a printed book at OGR’s web store!