This is probably not good for my PS2 Decapod

If I had to guess, the dogbone drive shaft. The chuffing indicates the flywheel and optical tachometer on the motor are spinning.

Cheap easy fix might be likely. PART 17 below

https://www.mthpartsandsales.c...lists/227?type=lists

No fear, we go to alternate

In stock

@Vernon Barry posted:

If I had to guess, the dogbone drive shaft. The chuffing indicates the flywheel and optical tachometer on the motor are spinning.

Cheap easy fix might be likely. PART 17 below

https://www.mthpartsandsales.c...lists/227?type=lists

EH1200002

DOGBONE / DRIVE SHAFT / O GAUGE / 16mm L / ALT# EH-0000002 (Out of Stock)

17

No fear, we go to alternate

In stock

EH0000002

DOGBONE / DRIVE SHAFT / O GAUGE / 15.6mm L / PREMIER STEAM ENGINES

$3.00/ea

Thank you, Vernon.

Peter

As a side note, a while back when I got back into 3D printing last year, I found a dogbone driveshaft OPENSCAD and edited it for making driveshafts.

https://openscad.org/

This is a great thing and I think we should have more items in the 3D printing section that are specifically OPENSCAD- AKA parametric designs- allowing the end user to customize the CAD and resulting STL.

I will say, buying a factory molded one is likely stronger than the 3D printed version, especially glass filled (meaning glass fibers injected with the plastic), however, I did use printed versions and they hold up well enough. If you need a custom drive shaft or flat out just cannot get one for the exact length and size, it may be an option to get one 3D printed.

@Putnam Division posted:

One minute running fine……..then, after a few more times around the layout, the engine is stopped but the sound system is still “running at speed”. I suspect a drive train issue.

This is my long term workhorse, a Rail King  Pennsy Decapod that has been flawless for close to 24 years…..I purchased it new in late 2001 from our long gone local shop (Chesterfield Hobbies) and it has been a great engine over the years. It was the 1st engine I ever ran in DCS when the TIUs and remotes became available in 2002.

Any thoughts on what it might be? I’m not a repair person…….

Peter

Peter,

Please allow me to join you in the "What's up with my RK Decapod?" thread.

I have the exact opposite problem.  Even after a Engine Reset, I still do not have a chuff sound.  Everything else seems fine.

Headed back down for another round of RESETs.  Thanks, Peter, for joining your thread.  Good luck with yours.

Lou N

I know this probably sounds dumb, but did you un-seat and re-seat the tether?

Peter: this is a reach.  As you know, I am far, far removed from being a techie.  But I have an engine that shares that problem and agree with the above comment about reseating the tether.

Mine is a PS3 steamer. Yes, it has a drawbar and not a tether but MAYBE the issues are the same.  For mine, if the drawbar connection becomes even slightly loosened the engine stops but the sounds continue.  Again, not knowing your engine, mine has its 'control center' and speaker in the tender so only the engine exhibits a problem.

sorry if I am wasting you time here.  Just trying in a small way to help.

walt

Since a couple of people said it, i want to try to get us all on the same page. Yes, ensuring drawbar seating and or tether for PS2 and PS3 engines is good general advice.

PS2 and PS3 steam engines get the timed chuff from the tachometer strips and rotational distance of the flywheel. In other words, unlike quite a few Lionel engines, all MTH PS2 and PS3 engines MUST have a working tachometer and motor subsystem to then get chuffs.

There is clearly a video showing of the engine not moving but sitting there- slowly chuffing away at a slow steady rate that is ONLY possible if the motor is spinning, the flywheel with the stripes is turning with the motor (so not loose flywheel) and the tachometer is working- hence implying this is NOT likely to be electrical.

Also, this engine is a bit unique in that many Railking engines directly have the worm gear on the motor shaft rather than a coupling. So this is not a super common failure mode- but knowing this engine specifically has a dogbone driveshaft coupling plays heavily into the troubleshooting and diagnosis.

I cannot stress this enough- this is how you can actually test boards and wiring harness controls for PS2 and PS3 engines- the fact that chuff and speed control work indicates tach and motor drive are both working.

Again, at the end of the day- if you have a PS2 or PS3 engine and it is chuffing at a steady rate but you lost drive to the wheels- there is a high chance that is a mechanical driveline issue- not electrical.

PS-2 and PS-3 architecture is completely different with respect to boards and the effect of the connection between tender and engine.  Hence symptoms and diagnostics would be different Walt.  So Dog bone, or worm gear engagement, possibly slipping FW seem most probable.

Lou, if you have no chuff are you sure you have speed control?  You should not if the chuff is missing.  Unless all your sounds are off which could be the bad speaker issue with Star 5W speakers.

If you do not have speed control but do have smoke most likely a bad tape on the FW, bad tach sensor or broken wire on the sensor and most probable a bad tether (orange tach wire) or the PCB pin connection on back of engine.  G