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How much trouble do I have?  My Big Boy was starting up my helix on ten foot diameter curves pulling 22 excursion passenger and support cars.  It stalled and headlight started flashing.  Now it won't restart.

Big Boy is to the left just starting up helix.

Sml01stalled4014

Three of the 22 cars.

Sml02center4014

More cars.

Sml03PattyBack4014Sml04KatyFback4014Sml05end3cars4014

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  • Sml02center4014
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Original Post

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Clues:

Pulling 22 cars up a grade, also in a curve= higher current draw

MTH PS3 does not have any blinking function or indicator of a fault as diagnostics- that's a LIONEL feature typically

MTH PS3 requires a good drawbar connection between the engine and tender and sometimes, under load and stress this can come unplugged. That is why there was either the factory drawbar lock piece or people would stretch various rubber washers or tubing over the post to keep the drawbar pushed up.

Given any kind of grade, there is an easement where you transition from flat to the grade. Specifically with the PS3 wireless circuit board drawbar design, this puts pressure and stress and would tend to unplug the drawbar connection.

https://ogrforum.ogaugerr.com/...9#152477234777138439

MTH part FB0000037 https://www.mthpartsandsales.com/shop/search/

Alternative DIY solution https://ogrforum.ogaugerr.com/...ps3-wireless-drawbar

@Ralph4014 posted:

I agree that MTH should do something about it. I like your solution Scott. Here's antoher idea. I used silicone fuel tubing from RC planes and cars. With the small diameter and the silicone's ability to stretch it makes a pretty good colar and it's non conductive.

drawbar2

drawbar



Ralph

Other replies in same topic

@Former Member posted:

Bibb washers. Found these at the hardware store looking for an o-ring type fix. These are hard elastomer with a good thickness. The inner diameter (looks like about 1/8 inch) is about right. The outer diameter is big enough so that you can get your fingers under it to pull it up the post to seat the connector with the train on the track. Color is black. Test results with my problem PS3 engine have so far been great.





BibbWasher

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Again, things it "could" be given the info provided:

#1 current draw up the grade caused the engine to find a weak spot in the track power system (lack of power feed, loose or dirty track pins). Engine just happens to be on the dead or intermittent power feed section.

#2 Something shorted or derailed in the curve and grade and the transformer or power supply is kicking in and out (self reset overload circuit). Again, grades can be problematic and the easement between the level flat and then the grade is where anything can hit and intermittently short to 3rd rail.

#3 Drawbar on a PS3 engine under load can become loose and intermittent connection

Now the bad stuff

#4 Let's say between current draw of the motor pulling up 22 cars up some steep grade and curve exceeded the current limit of the motor driver section of the boiler board inside the engine in a PS3.

#5 The drawbar coming partially unplugged under load causes certain pins of the 6 pin connection to open circuit while others are connected. This causes an incorrect voltage differential popping both the boiler board and/or tender PS3 board.

I would move the engine down to a flat level section, and preferably with a power source with meters for voltage and amperage draw slowly power up the engine after carefully checking and seating the drawbar connection. If the track has DCS and the engine won't respond to DCS, then attempt conventional testing using only a transformer and no TIU.

Susan, beautiful helix...........So had that big boy ever made it up that helix or did the stall happen during it's first attempt? Those look like premier passengers. 22 seems like alot. I am pulling 7 Lionel 21" cars and 1 heavy MTH aux tender. With both smoke units turned on and up a grade of  5.5" in 15' sometimes mine will stall completely or spin the wheels. OK maybe my grades are too steep and maybe I am pulling too much, but why do my P2 big boy and challenger laugh at the grade and the load they are asked to pull? I am not completely sold on P3 restoration Big Boy yet. Did you hear a humming noise from the loco when it stalls? Don't know about why the headlight would flash. If you have a P2 heavy articulated loco, try pulling those 22 cars up that helix.

@leapinlarry posted:

@Susan Deats, Forgive me for responding as I have no clue how to resurrect your Big Boy; I just wanted to compliment you on having such a nice helix, it’s a work of art. I would be curious as to what percent the grade is? I admire your work very much. Happy Railroading Everyone

Larry - click on the link to her "Run Room" at the bottom of her post.  On her website their is a link to the helix design under her Technical Info menu.

-Greg

@Greg Houser posted:

Larry - click on the link to her "Run Room" at the bottom of her post.  On her website their is a link to the helix design under her Technical Info menu.

-Greg

OK, and doing so, in the DIY whistle and Bell box, she added a polyswitch style of self resetting current limiting. https://slsprr.net/features/SoundBlkProtect.htm

I cannot tell from the other description the exact power path to this portion of the Helix where the engine is sitting. https://slsprr.net/features/controls.htm

"Co-Installed Conventional and Remote Controls

The Track and Engine controls for the rest of the layout are installed on 2 tier carts that roll under the tables and hide behind the table skirts. The Main table cart is below and holds one postwar Lionel ZW for accessories and turnouts, one MTH Z4000 with remote receiver box for Conventional remote control, 2 postwar Lionel Zs for track power through MTH TIUs, and 2 MTH DCS TIUs for controlling engines, turnouts, and accessories. The 2 DCS TIUs power 8 areas of track.  TIU 1 is linked to 3 AIUs that allow wireless remote control of the Ross Switches."

Given that according to the above the TIUs are powered via Zs (or ZWs??), I would hope that there was some form of secondary circuit protection for overcurrent. In this application, I would think possibly the Polyswitch might not be ideal as a slow and heavy load increase might trip and produce problems. To be fair, the pictures provided also shows the passenger cars lit up (especially the observation) but it's unknown if that is in the same block of power as the engine.

Polyswitch (auto reset)60 max V 3.75A hold/7.5A trip1Mouser Electronics650-RXEF375

So when it stalled did just headlight flash or did markers, number board, smoke, sounds have issues too?  Probably the biggest issue with PS-3 versus PS-2 is that Positive voltage is generated in the tender and AC power usually comes from engine.  2R-3R complicates the power to tender since track ground has to go through brushes on right side wheels to get to the harness.  So along with 5V, PCB ground the PV is sourced to the boiler board to run all things in on the engine.  Motor, smoke, lights.  The fact that you can not restart indicates to me, the tender is no longer seeing AC power.  I would suspect the drawbar pins/solder joint, along with a good connection to the tender.  If that is all good, then I suspect the boiler board may have had a major failure and that effects the Tender board.

Having an amp meter to read when you apply power can really help point you in the right direction.

Take the BB to a bench test track, reconnect drawbar and apply conventional power.  If it does not startup, pull the boards and test on the bench tester to see if boards are good.  If so, you know it is a harness/drawbar issue.  G

Vernon, thank you for the reply.
"higher current draw"  My project for the past year has been replacing all the incandescent lamps with leds to prevent high current draw.
  The Big Boy won't even start up a grade without the graduated rise to begin. Fortunately when I built the Helix access rise I took that into account.
  The engine now sees the DCS signal and the sound works.

  The draw bar suggestions are appreciated.  When I get the Big Boy down and onto the test roller bed I will know more.

Interesting tire wear just noticed on both sides of the rear truck.  The back truck wheels are obviously binding on the curves.  I'm not surprised after hearing the full size Challenger screeching while turning on the Ys in Laramie and Denver.  All the black paint has worn off the front wheel on the rear truck.

DriveWheelBare1DriveWheelBare2


jini5, yes, the Big Boy has run up and down the helix with lighter loads with no problems.  To be honest, I didn't think it would pull the 22 cars and I didn't "break" it on purpose.
  "Did you hear a humming noise from the loco when it stalls?"  No, just stopped and had blinky headlight.
  When I get the Big Boy down I will try a premier diesel and see if it will pull them.

Rich, thank you for the encouragement.  As it is now, I can barely see the drawbar pins and they appear to be a little bent due to the pulling strain.

Vernon, the power between the transformers and TIUs is protected with 3.75hold/7.50trip amp Polyswitches.

GGG, I didn't notice the markers or number boards.  I just shut it down when it stalled.  The smoke was off.
  You said, "Having an amp meter to read when you apply power can really help point you in the right direction.
Take the BB to a bench test track, reconnect drawbar and apply conventional power.  If it does not startup, pull the boards and test on the bench tester to see if boards are good.  If so, you know it is a harness/drawbar issue."

Thank you, I will test it with my Z4000 so I will have an amp meter.

I will be able to check it out toward the end of this week.

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You want that to rub off.  Ground on PS-3 2r-3r is not the best.  The right side wheels which are isolated from the left side are the only source of track ground from the engine other than the small metal pin wire that is on the drawbar and touches the tender metal pivot assembly.  It connects via brushes and one of them is the traction tire driver.  For reliable 3 rail I recommend repurposing one of those brush leads directly to chassis ground.  Now the right side wheels wiring which goes from the engine to the tender is hardwired to the chassis of the engine via that lead.  So you have better ground.  G

To continue playing with my Big Boy, I will have to resume weight lifting paused while injured shoulder healed.

SUCCESS!!  My stalled Big Boy is off and running.  The 4014 has already wiped out some of my people that live in an egg carton on a curve.

The first try on the test rollers was a success.  Before test, all wireless drawbar connections were examined.  The Tender socket wasn't as snug in the mount as it should be and I dabbed Liquid Tape around the exposed wire contacts with a tooth pick.

1TestOne

Here is the drawbar "Pin-Out" for my Big Boy #20-3714-1 .
8DrawbarPinout

Fortunately my "test bench" is an old dining table with drop leafs and can be as big as needed.  The tracks behind the sofa are my 2 half loops for the Christmas tree.
2TestBench

While set up on rollers, I changed the Sound File of engine #20-3714-1 to #20-3775-1's restoration sound file.  #20-3714-1's whistle was the worst I ever heard.  The new sound file came from the restored Big Boy live sound.

4SoundLoad

Now, layout testing can proceed to find out what it will take to pull the Excursion Consist up the helix.

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Images (4)
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@Susan Deats posted:
While set up on rollers, I changed the Sound File of engine #20-3714-1 to #20-3775-1's restoration sound file.  #20-3714-1's whistle was the worst I ever heard.  The new sound file came from the restored Big Boy live sound.

I did the same thing!  The sound file of 20-3714-1 sounds like a wounded cow!  I'm stunned that MTH wasn't embarrassed to release it with that sound file!

just a comment here. My new PS3 Big boy would not run with my Lionel 180w bricks. I had to attach a handle from a Z4000 and turn it up full. Still had issues. So I added another power drop to an area of the layout where the engine with a full load of train, struggled to climb just a slight incline. The engine ran OK at first. The sound would get flakey and skip chuffs. It got worse until the engine even ran jerky. After the added drop and extra power, no issues.

Now that inner loop is fine for the bigboy. Trouble is I did not fix my outer mainline the same way. So our grandson decided to move the Williams Challenger (with PS2) to the outside main and it kept tripping breakers. That engine gave me so much trouble, that I replaced it without thought that it may have been the layout.

I should put the other handle of the Z4000 on that outer loop, as well as some more wire drops. My laziness bites me again.

That's really odd Joe, I've never had any issues with stuff like that and I have all PH180 bricks.  I have the 2017 MTH BB, it runs fine.

The newest versions (2020, 2021) have grounding issues, especially the 3 rail ones. I've got a 20-3807-1 20-3807-1 | MTH ELECTRIC TRAINS (mthtrains.com)

The locomotive would run fine on my layout with no smoke units on or one of the two smoke units one. With both smoke units on it would slow on curves and speed up on straights. I've got tubular track (both outside rails connected) and 180W bricks for power. The ground on the locomotive was poor, only coming from the spring pickups on the engineer's side drivers in the locomotive. Since I'm never gonna run the thing on 2 rail track I bypassed the 3/2 rail switch and added ground wires to the fireman's side drivers. After that it runs fine.

Last edited by Lou1985

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