PS 3 Speed Control Problem

Top suspect would be track and/or wheels and rollers contaminated.  I'd check that first.  Next up would be to make sure you don't have a voltage drop under load in those sections of the layout.

If you face engine in other direction does it speed up and slow down at the same spots?  How about in reverse?  Same behavior at different commanded speeds?

What is your power source and any details about your layout and wiring.

John, Track and wheels are  clean. Checked voltage around track and it reads within 0.3 volts all around.

Stan, Tried the engine in the opposite direction and everything is fine. Turned the engine in the direction I'm having trouble and ran it in reverse and everything is fine. Problem is in one direction forward. Running slow (around 10 mph) it seems to run fine, but at speeds above 25 mph is when the problem occurs. Power source is Z4000 with star wiring.

Next stop would be the tether, what you describe is possibly the tether flexing and perhaps a broken wire or solder joint right at the tether connector or mating plug.

Forgive me, but I thought the cruise crontrol only works with a fixed voltage, not variable like using Z4000 wired straight to the track ? Or perhaps I'm missing somehing.....

John

This engine does not have a tether. It has a wireless drawbar. I will check for broken wires inside the tender and engine.

Hello Ken

I would try the tether more than likely the tender end,   I know that engine, it was my smoothest runner. I never ran it conventional. It always heard the watchdog signal also.

Clem k 

Clem,

You sold me this engine at York and I am happy with it except for this little problem which really is not that big of a deal. I'll keep working on it and if I find the problem, great. If not I will run it the way it is because I like this engine very well.

Thanks,

Ken

So OK going, say, CW in fwd and rev, but only OK CCW in rev.  3 out of 4 conditions.  Whether a traditional tether bundle of wires, or a wireless drawbar which is also a bundle of wires except "printed" onto a circuit board, it sounds like an intermittent, loose, whatever connection.  Two moving parts, engine and tender, so the connections are moving relative to each other. 

While you have it opened up, double check the flywheel striping integrity and the flywheel-to- tach-sensor spacing and for the dime-width distance centered to the flywheel striping.  That speed control problem occurs only at faster speeds suggests a potential 2nd issue independent of the prime interconnection suspect.  Specifically, when the engine goes slightly faster than commanded (but not taking off full speed) this can be due to the tach sensor missing the occasional passing stripe since the tach pulses get shorter and more difficult to detect as the flywheels spins faster.  Probably not your issue but as it only takes a few seconds to confirm...

It should run perfect,  Ken are you running conventional or DCS ?  Did you put a different drawbar on it ?    like I said maybe two hours on it. 

Clem

PS/2 or PS/3 cruise control operates all the time, conventional or command.  As far as the "wireless" tether, I find a lot of them unplugged one one end or the other, it may be as simple as that.

MR_P posted:

Forgive me, but I thought the cruise crontrol only works with a fixed voltage, not variable like using Z4000 wired straight to the track ? Or perhaps I'm missing somehing.....

Part of the confusion maybe the terminology of speed control vs. cruise control.  In PS2/3, there is a conventional mode "speed control" function that can be turned on and off - the default is for speed control to be "on".  Speed control keeps the engine at a more constant speed going around curves and up/down grades when compared to PS1.  Target speed is proportional to track voltage and uses the tach sensor and striped flywheel to determine speed.

"speed control" as used in the title of this thread is referring to command-mode speed control where the target speed is whatever digital sMPH command is sent by the DCS remote (rather than being proportional to track voltage).  So in command-mode speed-control you can alter the track voltage and the target speed is not affected.

Clem,

I am running DCS. No I did not put a different drawbar on it. The engine is  just like it was when I bought it from you.

Ken

John,

I checked the plug and it appears to be plugged in tight. I will check it again to be sure.

Ken

I'm talking about the plugs inside the locomotive and the tender.  Those are the ones that work loose and cause all sorts of oddities. 

I haven't checked those, but I will. Thanks

Thanks again to GRJ and Stan2004 for the cruise update, never realized that.. 

Come on guys.  This is PS-3 and PS-3 controls across a drawbar or tether is totally different.  Speed control is in the engine with the boiler board in this case.

This is a scale engine "-2" correct?  Is it possible track in those areas are binding the drivers?  You say it speeds up.  Does it slow down, at a bind first.  Then speeds up (which would be cruise control trying to correct for the slow down)?  Or is it moving perfectly then speeds up?  Is there another voltage source at that portion of the track?  Because it would be an increase in track voltage that would cause an engine that is moving fine to speed up, than slow down, if all else was fine.

Lastly, when it has this speed up issue, do lights and smoke stop working on the engine?

If your symptoms are correct, the track sounds like the issue.  Is that section of track clean?  G

GGG posted:

Come on guys.  This is PS-3 and PS-3 controls across a drawbar or tether is totally different.  Speed control is in the engine with the boiler board in this case.

Since there have been PS/2 locomotives with the "wireless" drawbar, I wasn't sure what we were dealing with.  However, I didn't look up the locomotive, and it is, of course, a PS/3.

GGG posted:

If your symptoms are correct, the track sounds like the issue.  Is that section of track clean?  G

That was my first inclination, this was my first post.

gunrunnerjohn posted:

Top suspect would be track and/or wheels and rollers contaminated.  I'd check that first.  Next up would be to make sure you don't have a voltage drop under load in those sections of the layout.

 Ken stated that it slows in the curves only in one direction. Binding of the drivers would be the same in both directions. If Clem says it ran smooth for him and it doesn't now, another possibility is damage to the draw bar during packing and unpacking. I would take a look at the ground rod on the draw bar. Sometimes the solder that keeps the rod spring loaded breaks loose. That ground rod must apply pressure to the stem on the tender at all times. It's possible the rod keeps good pressure, in a curve, in one direction but not the other.

Stan, I got a bit confuse with your explanation of speed control vs. cruise control. Is "speed control" the term to be used when in conventional mode and "cruise control" the term to use in command mode?  Also, how do you shut off the speed control in conventional? Is it done using the bell and whistle. I enjoy the sound of a diesel throttle fluctuating when it's going around the layout and wish you could get that effect with command control.

Dave, I still do not think symptoms fit.  And drivers may not always bind in different directions.  The wheel axle shifts in a different direction.  And why would a draw bar failure only occur on one curve not all the other same type curves.  Also it DID NOT SLOW Down.  It SPEEDS UP. PS-3 loosing a drawbar connection or having a loss of AC Voltage CAN NOT Speed up.  Rather is stops, or jerks.   Also it runs fine slow just not with speed.  Again if only speed is issue and all other engine functions are working I think the drawbar is less of an issue.  I guess the other question is this running in 2 Rail or 3 Rail. 

I would swap that track out, or refine what is actually seen or answer if there is a track activated accessory or some other voltage source just after this curve that is boosting voltage and giving that momentary speed up before the speed control slows it down.  G

I opened up the tender and locomotive yesterday  and all solder connections, plugs, and wire nuts were fine that I could see. I found no broken wires or or bared wires touching anything. I looked at the tach wheel and checked the space between the reader and wheel and everything looks fine.I put it back together and made sure the ground rod is touching the pin. Now for the strange part, I put it back on the track (running in the same direction I was having trouble with) and on the first lap around it did the same thing as before. I ran it around again at the same speed (30 mph) and it ran smooth as silk. I let it run for several more times around and still smooth. I guess the electrical ghosts and goblins gave up and went home.

Ken

Dave Zucal posted:

...

Stan, I got a bit confuse with your explanation of speed control vs. cruise control. Is "speed control" the term to be used when in conventional mode and "cruise control" the term to use in command mode?  Also, how do you shut off the speed control in conventional? Is it done using the bell and whistle. I enjoy the sound of a diesel throttle fluctuating when it's going around the layout and wish you could get that effect with command control.

Someone correct me but I don't think "cruise control" is official MTH terminology used for the function whether it be conventional or command.  That is, the speed control is likened to automotive cruise control - but unlike your car where the controls actually say "cruise" on it, I don't think there's a button or menu softkey or whatever that's actually labeled "cruise"(?).  I was simply pointing out how the target speed is set differently in conventional vs. command.

Right.  In conventional you use the B and W button to turn speed control on and off.  You might want to turn off conventional speed control to, say, run a PS2 or PS3 engines in a MU/consist with a PS1 engine which did not have speed control.  That way, the two engines would be more closely matched in speed vs. voltage behavior.  In practice, what I've discovered is turning off speed control in conventional can be a handy troubleshooting tool to, in effect, take all the fancy-dancy PS2/PS3 electronics out of the equation when diagnosing problems with engine jerking, speed-up/slow-down issues, etc.  When speed control is OFF in conventional, the tach is not used for motor speed...it's simply the raw track voltage (converted to DC) directly driving the DC motor old-school (e.g., like a basic DCRU). 

As for diesel sounds in command, you could always "take charge" by using the Rev Up/Dn buttons to control the sounds.  But I think you are thinking the engine out to do this by itself when entering a grade or whatever.

Thanks for clarifying Stan. The term cruise control may have developed out of conversation on the forum. When you think about it, it would be nice to be able to "quick set" the speed in our vehicles without playing with the gas peddle, like we can with our toy trains. Getting back to the original post, if Ken knows someone in his area with a layout that he can try that engine on, he would know immediately if it was his tracks or the engine.

I think GGG may have hit the nail on the head. When the engine slows down, it seems more like a bind. When it speeds up it is just for a short distance and then slows to the set speed. I'm going to check for binding in the rods and drivers. I checked the track voltage in the area it speeds up and it checks within 0.2 of the blocks on either side of it, so I don't think it's a voltage surge. 

Make sure no loose rod screws but if it only stops on one piece of track I would think it is damaged some how.  I would replace the track.  G

It doesn't stop on the track, it only slows down and then speeds back up to the speed setting that is set. On the times it does not slow down, it does not speed up when it reaches the specific area of the layout. Since this slowing down does not occur on every lap around the layout, this is why I think something is binding up. 

I have the same problem with one PS3 locomotive.  My other PS3 and the PS2s all work OK.  The voltage and track signal are fine.  You run up the thumbwheel when it slows, hit direction and it takes a long time to slow down as it were going at the faster speed.  Turn off the smoke unit and it perks back up on those slow spots.  This engine was a Mikado from the 2016 catalog.  I'm wondering if that is some sort of defect in that run, since others have reported the same problem.  It usually slows above 30 mph, with or without cars.