Hornby Black 5 stalling on curves in one direction

[JPinza55]

Hi, my brand new Hornby Black 5 fitted with TTS worked perfectly initially, however after swapping the direction the loco was facing (on the same track), it has started to frequently stall/stop on three out of four curves around my layout. Is this a power issue or is there a potential issue with the loco?

[DCB]

Stalling or shorting? The worm wheel  Layshaft fouling the driving wheels and shorting out is common on some Hornby Locos. With all those pickups it shouldn't stall if the inside corner of the rails are clean.    Our Black 5 suffered an inability to pull the skin off a rice pudding until we filled the Decoder space with lead and ditched the tender pickups. That improved traction and didn't affect pickup...

[JPinza55]

It's stalling- sometimes it recovers on its own and goes again, sometimes it completely stops and is only retrievable by pressing the emergency stop button twice.

[Butler Henderson]

Are the pick ups correctly aligned?

[JPinza55]

Hi, the yep all pick ups look to be touching the wheels (which I believe is correct?). It has also been established that is 100% an issue with loco, as opposed to the track.

[Chrisr40]

Worth cleaning the wheels and wheel backs, even new locos can have yuck and filth on them.

Chris.

 

...also try reducing the volume and see if that helps. Years back I had an 08 that was default set at max and wouldn't run reliably until the volume was reduced to a sensible level.

Edited January 9, 2021 by Chrisr40

[John Tomlinson]

Probably not the problem, but worth checking that the sandpipes or other details are not jamming in the spokes in certain places.

 

John.

[Butler Henderson]

30 minutes ago, JPinza55 said:

Hi, the yep all pick ups look to be touching the wheels (which I believe is correct?). It has also been established that is 100% an issue with loco, as opposed to the track.

Have you pushed the wheels out as far as they will move and checked they are still touching. If one set of pick ups have got compressed then as the axles slide to allow the loco to go round a curve then if the compressed pick ups on the outside current pick up will be interrupted.

[Harlequin]

Have you turned the loco around again and tried it in the direction that it originally seemed to work?

 

Or by "swapping the direction" do you mean you changed the value of CV29? If so, are you sure you got the binary maths right?

 

 

[Brit70053]

You say the loco is TTS fitted, so I assume your control system is DCC, which I'm not familiar with, but am vaguely familiar with the principles. First thing to check is does the plug and wire connection between loco and tender come under any additional strain when negotiating curves in the direction you have the problem with. Are you able to run the loco with the tender top removed so you can see if anything in the area of the chip is disturbed  when the loco is moving in that direction?

As Butler Henderson has said above, can you check if the wheels are free to move an equal distance to each side of the chassis frame and do all contacts remain touching the wheels on both sides when you do this. Sometimes the drive gear is  fitted in such a way that the driven axle is not laterally central and needs to be moved slightly on the axle to allow it to 'centre'.

Finally, is there any distortion on any of the coupling or connecting rods which might be forcing the driving wheels against the direction of the curves ?

Hope some or any of this might give you a starting point to enable a resolution to be found.

 

Regards, 

 

                  John

Edited January 9, 2021 by Brit70053
Correction

[The Johnster]

As Butler Henderson suggests, check the side play and any vertical play in the pickup wheels so that you are sure the pickups are bearing properly on the rear face of the wheel treads in all and any conditions; it is not enough to simply verify this by turning the loco upside down and looking at the wiper pickups.  In the same vein, check the back to bakcs and that the wheels are at dead right angles to the axles, and not fouling on motion or parts when they are at their full lateral play deflection.  As this is occurring on curves, it may well be as you say an issue related to the loco's ability to negotiate curves that your other locos have no problem with, but it is still worth confiming with a straight edge and spirir level that the traick is level and smoothly laid adjoining the adjacent piece.  It may have been perfect when you laid it but baseboards can warp or track distort because of exansion and contraction. 

 

Another point to look at might be the drive gears, since the problem is directional.  Is the drive forcing the driving wheels down,, up or sideways (or some unholy combination of those) when the worm is rotating one way, but not the other?  If so, the meshing between the worm and the drive cog may want looking at, and replacing if they ae worn.

[JPinza55]

Thank all, after a quick MOT it seems to be running fine- touch wood

[The Johnster]

Purely out of interest, what was the problem?