Tomix Shinkansen 500 DCC install - train stutters, then stops completely

[mr.dunkelwald]

hi there!

Last year I installed a DCC decoder in my Hello Kitty 500 Shinkansen.

The issue this train since then always had is that after 4-8 loops around the layout, it first begins to stutter (randomly stopping, then starting again) and after a while completely stops, being completely dead. After a while (few days) it's possibly to use it again, but with the same issues.

I suspected the motor overheating, so what I have tried is:

- soldering the decoder wires not to the springs, but directly to the motor -> no change

- checking whether the motor is seated right -> no change, I suspect that if that's the issue, it will slowly change it's position because of the vibration when driving

leaving the bogies and seat cover off and putting current directly to the metal strips -> works for quite a while

 

Has anyone had the same issue? I am running out of ideas why this is happening.

 

Moritz

Edited October 9 by mr.dunkelwald

[Doddy]

Replacing the decoder with another would be start. Looks like the IC circuitry is shutting down.

[chadbag]

I would agree that it sounds like an issue with the decoder.  What decoder is it and how did you install it?  I've done the HK 500 as well as a couple other similar Tomix and not seen this though I have not driven them recently.

 

[Kingmeow]

Before you do any dismantling I would do a decoder reset first.  Just to make sure the firmware hasn't been scrambled due to a plethora of reasons.

 

Like chadbag said, what decoder do you have?

[bc6]

It does sound like a decoder issue, Have you reset the decoder yet if not give it a try if that doesn't help send it back.

[mr.dunkelwald]

I have no idea why, but you all are right!

Tried a decoder reset (it's a Kuehn N025 btw) and now it works like a charm. Thanks for the help!

EDIT: nevermind, after around 15 mins of operation the issue resurfaces. Maybe I'll try swapping the decoder sometime. Although I wonder what the reason is since I had this issue on another Tomix Shinkansen. Could it be that the motor draws more current than the decoder is rated for? The decoder is rated for 800mA, i don't know what Tomix motors can draw.

Edited October 10 by mr.dunkelwald

[bc6]

Maybe a Christmas present to yourself can be a multimeter to help you figure out the current draw of motors. Sorry the reset wasn't a permanent solution to your problem. I would consider sending it back if there's a warranty on the decoder. 

[chadbag]

9 hours ago, mr.dunkelwald said:

I have no idea why, but you all are right!

Tried a decoder reset (it's a Kuehn N025 btw) and now it works like a charm. Thanks for the help!

EDIT: nevermind, after around 15 mins of operation the issue resurfaces. Maybe I'll try swapping the decoder sometime. Although I wonder what the reason is since I had this issue on another Tomix Shinkansen. Could it be that the motor draws more current than the decoder is rated for? The decoder is rated for 800mA, i don't know what Tomix motors can draw.

 

I wouldn't think they'd draw that much -- I've been using D&H DH05C and PD05A, both of which are rated at 500 ma on KATO Shinkansen and other trains and not had any issues...  (I used them on KATO with the EM13 boards that were posted in the forum like 6 years ago -- I had a bunch made and have been using them exclusively for my EM13 needs)

 

SO I'd try swapping them.  If you're in Europe try a Zimo or D&H (or the DM-Toys branded D&H that they sell which are DH05C with fewer extra capabilities) or ESU. If in the USA try ESU or TCS.  They all make small ones and all suport things like Railcom and stuff that Digitrax doesn't and also they don't typically shrink wrap (heat trap) their decoders.

 

[mr.dunkelwald]

Hey again,

I think I got closer to the mystery.

Tried starting the train, which only made a buzzing sound (similar to a short circuit, but only at a higher speed setting).

Then removed the Decoder and put analogue signal (with a multimeter in between) directly to the motor.

It had a really short start-up phase of a whopping 1,4A before running again with the regular 140mA (and staying there).

So I guess the issue all along was that the motor sometimes needs a really high measurement to get going, but then runs like normal.

I'll try getting a decoder that can handle 1.5 (or even 2) Amps and hope that it's the end of that.

 

Kind regards

Moritz

[chadbag]

54 minutes ago, mr.dunkelwald said:

Hey again,

I think I got closer to the mystery.

Tried starting the train, which only made a buzzing sound (similar to a short circuit, but only at a higher speed setting).

Then removed the Decoder and put analogue signal (with a multimeter in between) directly to the motor.

It had a really short start-up phase of a whopping 1,4A before running again with the regular 140mA (and staying there).

So I guess the issue all along was that the motor sometimes needs a really high measurement to get going, but then runs like normal.

I'll try getting a decoder that can handle 1.5 (or even 2) Amps and hope that it's the end of that.

 

Kind regards

Moritz

 

Maybe the motor has an issue.  It shouldn't require that current spike to start up.  My Tomix shinkansen work with decoders that have max 500ma.  I'm running one with D&H dcoder that has max motor  load of 0.5 A and total load of 0.5 A

[mr.dunkelwald]

Yeah, could be, but for now I'll try it that way. Getting a replacement decoder is way quicker than getting a replacement Tomix motor to Germany.

The 1.4A were just after being stalled, but since than it has stayed at 160-200mA.

[Wolf]

Spiking AMP in a motor sounds more like the motor needs a cleanup, dirt or anything seems to short, no?

As Tomix is about to redo the 500 Shinkansen, spareparts should be in the making too, although motors are usually not that hard to get.

Stephan

[Kingmeow]

Yeah, that 1.4A start-up spike for these little motors are a little suspect.  I would keep an eye on a new motor availability while you try a new decoder.

 

Would you be able to spin the motor by hand to see if it spins freely 360?  The commutator might have a nick, etc...

[chadbag]

Also DM-Toys sells all sorts of replacement motors and here is a link to someone who fixed a Tomix Shinkansen Series 200 (may be old).  My Tomix Shinkansen are all packed away due to imminent move so I cannot check what sort of motor it uses but maybe a replacement from DM-Toys or another parts seller might fit and work?

 

 

[cteno4]

That is sounding like there may be some schmutz inside the motor. Over the decades I’ve had a few train motors that were open ones that sucking I a small bit of schmutz that made that first few turnings of the motor really hard (and drawing a lot of current) before taking off. Digging out the schmutz fixed it. I remember one was a small pice of some sort of metal grit as it was stuck to the magnet and very hard to get it out. Closed motors not much of a possibility but maybe something in there. Or maybe a brush or rotor wipe that’s just rough. 
 

sounds like a new motor would be a better solution to a high amp decoder as that just does not sound good on a long run.

 

jeff

[mr.dunkelwald]

Hi guys,

 

soldered in a new DH10C Decoder. The train ran for about 1-2 hours (intermittently having the same start/stop issue as before). Today, it stopped completely and made that buzzing sound again, so I took off the shell to find smoke coming from the Decoder. So it's completely fried. Removed it, wired the the motor directly to analogue control and measured 120mA (looks normal to me).

 

I still have no idea what could have caused all that fuss, maybe some micro short circuit that only happens when the wheel pickup strips come into contact with the chassis? But that also does not make sense.

My 0 series Shinkansen (where the motor holder broke so I glued the motor in directly) still works so I try to let it run one hour continously to find out if it stays that way.

Anyways, I'm completely fed up with Tomix models right now. No idea if I'm dumb or there's something else that causes this problem, but it just isn't fun.

 

I have also thought about replacement motors from DM-toys, which would be my next step.

 

Edited 4 hours ago by mr.dunkelwald

[Kingmeow]

Sounds like there's a "high" spot somewhere in the mechanical drive train that gets hung up intermittently.  Not enough to do it every time but randomly once in ah while and that one time will cause a stall which pull too many amps through the decoder.

 

If you can't see it in the trucks or drive shafts then it's 99% the motor.  Could be a rough spot on the commutator or some other abnormally inside the motor that you can't see.

 

I know these things cause a lot of frustration and makes you just want to throw the loco away.  If you are at that point, just put it in a draw and go back to it later, like a month later.  🙂  Been there, done that, got the t-shirt!  🤣

Edited 18 minutes ago by Kingmeow