Black Tape and Shorting.

[Mallard 1410]

I have just been running in my flying scotsman digital version. I noticed it had the infamous black tape which seemed to be causing issues with the front boggie. I removed the tape, as has been advised everywhere I've read, and by Simon Kohler himself on a YouTube interview. However the bogie wheels began to short against the body of the train. I had to trim the tape and replace to prevent this happening. Has anybody else had this issue?

Also 3 sets of wheels don't turn on the tender as the electrical pickups are pushing too hard against the wheels. Worst of all, the central driving wheels have a distinct wobble. I will be contacting hornby, and I imagine it will have to go back.

[Rallymatt]

The wheels in the front truck are insulated from side to side and the chassis is not electrically live, so it’s unlikely to be a wheel touching the loco chassis or body (plastic) that’s causing a short.

The tender wheel contacts are such delicate phosphor bronze strips I would not think they can exert enough pressure to prevent a wheel tuning. They need to touch all the time in all extremities of travel. Check the pick ups are not tangled in the wheel spokes (I doubt they are) it’s more likely a restriction on the axle, if you are capable, pop the keeper plate off and see, if not call Hornby on Monday.

I would always check the wheel gauging on the front truck as most likely cause of shorting out, it happens over points as too narrow a back to back allows wheel to float too far over the metal frog rails on the point. (Rare on Hornby Points but common on Peco ones) The wheel backs should be 10.5mm apart (target) but 10.3 seems to work on Hornby track fine.

The centre drive axle has some freeplay, it allows locos to negotiate tight model railway radii, what’s excessive is hard to determine without close examination. Just to repeat, if you are anything less than confident removing screws and making adjustments, give Hornby a call, they are super helpful and efficient

[Mallard 1410]

Thanks, that's interesting. I was running Flying Scotsman on the scotsman train set track. The train was shorting going round right hand bends. The left wheel appeared to touch the body where the screw is. I'd hear a spark and the train would stop dead and lose contact with the app. Replacing the tape seemed to sort the problem, but I haven't had time for extensive testing. Flying scotsman pulls the three pullman coaches really poorly with wheel spinning. Blink Bonny performes much better and doesn't have the wobble that Flying Scotsman does. I don't have the time or confidence to fiddle with it myself, so most likely I'll let hornby look at it, if possible.

[ntpntpntp]

I agree with @Rallymatt: on my A4 from the Easterner set the chassis block is metal but it is not live to the wheels nor pickups at all (neither side). The front bogie wheels are insulated from the axles on both sides, so that front bogie is electrically dead. I checked it all out thoroughly with a multimeter. Therefore I don't understand why tape was fitted as there's no possibility of a short. I removed it on my loco.

Maybe some early models were different or had an assembly fault making the chassis block live and caused a short if a bogie wheel flange touched the block on a tight curve? That might have resulted in an instruction to add the tape at the factory? I've had a similar issue with an N gauge loco years ago, I ended up applying the same fix - a piece of insulation tape :)

[Rallymatt]

I think there was a comment back in Feb (possibly SK) concerning the insulation tape, that it was on there as part of the assembly process and didn’t serve any purpose in service.

Try running it in the dark, it could help identify exactly where any spark is occurring,

[5Dublo2]

Would it be possible for the wheels on both sides of the bogie to touching the rails and touching the chassis at the same time as that would cause a short.

[david_watts1]

Send it back, with that many faults for a 200 quid loco it's not acceptable. My Blink Bonny had centre wheel wobble and the valve gear rubbed the white lining off.

[Mallard 1410]

Good idea about running in the dark. I probably won't have time to do that, but it would be interesting to see. It's all packed away out of reach of my kids. As David said, with so many things wrong with it, it'll be going back.

[Moccasin]

They’re very good with repairs. Mine came back within 10 days. A real shame that these faults are still occurring.

[Rallymatt]

@Mallard1410, can completely understand this, sometimes a small thing can be dealt with and we have our trains running sooner but ultimately it’s not really down to the end user to sort things out. This is why I absolutely detest ‘computers’ and all the nonsense around them, they never actually work as advertised. Miraculously my iPhone does, hmmm., anyway call Hornby, get a return case number, tell them your details for the refund of postage (they usually tell you) and send recorded so the value of your loco is covered should something go wrong with the post. You will be up and running in no time 😁

[ntpntpntp]

@5Dublo2

Would it be possible for the wheels on both sides of the bogie to touching the rails and touching the chassis at the same time as that would cause a short.

 

 

An interesting thought. Theoretically yes, though on my A4 the chassis block in that area seems very well coated with paint. I couldn't get any continuity along the block other than via the screw heads or by removing the screws and testing the threaded hole, so it would be a miracle to get anything just from the wheel flanges touching the chassis.

[Rallymatt]

I did a similar test to Nick with same results as well as trying to replicate how wheels could get to a point where they would even touch enough electrically connected parts simultaneously. I couldn’t.

I do think this particular issue is elsewhere

[Mallard 1410]

Update

I've received Flying Scotsman back from Hornby. The packing note said they'd changed the tender chassis and the decoder (looks like they've replaced the entire tender to me). I had quite a fiddle getting the new decoder linked up and working, but it seems to be running fine now.