Accurascale Mk2Bs -- Diagnosing Derailments and Noises

I received my Accurascale Mk2B coaches recently.
I ran into problems with them straight away, with derailments on curves and a constant whining noise.
In this video I diagnose the problems and test a fix for the derailment problem.
00:00 - Model choice and appearance
02:59 - Whining noise from the lighting
04:03 - ABC compatibility
05:19 - Details
06:50 - Couplers and Derailments
07:10 - Roco Couplers
08:45 - Failure to Couple
09:30 - Derailments
12:11 - Testing on a Different Layout
12:50 - Coupler Pocket Position Problem
14:54 - Magnetic Coupling?
15:15 - Fixing the Coupler Pockets
16:18 - Conclusion
17:05 - Where next for Accurascale?

[@DJ_K666]

Love the close couple on those. I fitted the magnetic ones to mine.

[@hillmanhalt]

Great video. I have 4 of the Mk2 B with no issues….but then I’m using them straight out of the box! 🤣

[@theeventhorizon-valebridge9512]

Thank you for these objective and factual observations/experiences. As you say, too many people are so smitten that they've lost their open mindedness. Personally, I expect excellence from all the manufactures and retailers now, with the emphasis on robust functionality and absolute customer service pre and post sale. There are no excuses at the prices now being charged! I am not convinced by any manufacturer's kinematic coupling system. They are all far too poorly/cheaply made, susceptible to sticking under varying load and often snatch, stick, bend, break or lose there springs! A completely new engineered solution with a robust mechanism needs to be developed if they don't re-engineer the current type into something more reliable. Less dependency on distant Chinese manufacture might be a good place to start and the use of metal components, rather than the nasty plastic crap so heavily relied on! They went from plastic wheels/axles to mental, now that evolution needs to continue deeper into our models. Regards Julian

[@DongitsModelRailway]

You might want to have a look at how some of the European close couplers work to see if they fit your requirements better. IIRC you can order the Roco mechanisms separately, including in fleet size quantities and not too expensively. Might make for an interesting retrofit project

[@theeventhorizon-valebridge9512]

@@DongitsModelRailway Who or what is IIRC please?

[@DongitsModelRailway]

IIRC == "If I recall correctly"

[@MistaMatthews]

I switched the couplings for Hornby’s 17mm magnetic ones. Fixed all my issues.

[@Michaelgoestofrance]

Great to see a UK modeller using proper close-coupling. I see so many great layouts with massive attention to detail but equally massive gaps between corridor connectors.

[@DongitsModelRailway]

Yes, it makes a huge difference IMHO -- the difference between a series of coaches and proper train.

[@andrewcalladine2507]

I used the magnetic coupling on my Mk2B's and it seems to work fine, definitely feed these issues back to Accurascale, they're good at listening and fixing where they can.

[@DongitsModelRailway]

I did contact Accurascale about the noise. The support person I spoke to was able to reproduce the issue in-house, but wasn't able to offer a suggestion beyond disconnecting the lighting entirely -- a suggestion which would definitely work, but not without obvious drawbacks.

[@melchestermodelrailway]

They'd go nicely with my derailing Accurascale Deltic!

[@OldcampRanch]

Nothing and no one is above criticism, but these are beautiful looking cars. Thanks for sharing 👍🏻

[@vcs00railway84]

I swapped the tension lock couplings for the magnetic knuckle couplings supplied and have been running a rake of 6 mk2bs with no issues on my less than perfect track 😊 i do agree that removing the tension couplings was tricky. I ended up unscrewing the bogies on most in order to have access to squeeze the ends of the couplings and pull them out and then refitting the bogies. Quite a slow process.....

[@tonybarfield5148]

Very Interesting video.

[@StormmyStormmy]

Hi, very good video of issues that occur when manufacturers don’t do their homework, venting your concerns is very acceptable because those who are in any doubt about a product can be see what and where the problems are, Bachmann coaches are the best in my opinion, the fact they don’t develop models that need a wand says it all, Accurascale used the wand concept on their FNA nuclear wagons which was my first bad experience with Accurascale, all Bachmann have to do is restructure their excessive prices then they would sell more units, I’m sure Revolution Trains will have a line of these coaches eventually so waiting is not a problem, Accurascale did a great looking set of RTC coaches but 400 sets worldwide was a bad move and has a negative impact on the secondhand market so I will give Accurascale coaches a miss, I hope you get your issues sorted, thanks for sharing.

[@mccarronfamily]

No wand, but £95 and need DCC?

[@steefvd1]

The problem is in the Roco coupler. Coaches from Hobbytrade, Heljan and NMJ do the same as your coache. Derail when using Roco couplers.

[@AnttiRahko]

These types of Roco couplings are slightly shorter than standard close couplings (Between 1-2 mm). For example Roco universal couplers are of the regular length, just like Märklin and ESU ones. Height adjustable Roco universal couplers are slightly longer (Again about 1-2 mm). The length differences can be used to ensure the gap between cars is appropriate even when the NEM pocket is installed too far or close, or if your layout requires longer or permits shorter coupling to be used. Previously mentioned close couplers also allow same properties regarding slack movement and ridgidity. The also do not uncouple from uneven track, but on the other hand you cannot just pick up a car from a rake without uncoupling. You should note that Märklin couplers are a bit higher and might interfere with low buffers. Also with Märklin only one coupler loop can couple where as Roco unversal and ESU's coupler couple from both sides since they use only bars, not loops. On the other hand only Märklin works with Relex -type couplers or hooks. There are new and old style of these Märklin couplers that look basically identical. The new ones are ever so slightly lower and have allowed Märklin to place their buffer beams at the correct height. I have not found this length information anywhere easily available, but these are my own findings after comparing different European couplers. Hope this helps someone!

[@DongitsModelRailway]

Thanks for sharing, that's a useful review of the various European couplers.

[@neilharbott8394]

I do think that Accurascale (and Rapido) are going way above the attention to detail that the old boys on the block are doing - and they're very good value for money because of it. However, I have found that both Accurascale and Rapido have a few struggles with some of their engineering - I have an Accurascale Siphon, which derails the trailing bogey when run in one direction (as you would say, not ideal - I did catch a video where someone was having similar issues, the solution was to remove the bogey and bore out the hole in the chassis with a fine round file, just slightly... you know a fraction of a millimeter!). But currently it appears the choices are: comparatively pricey, ok quality, reliable mechanical models from H and B, or the less reliable, but better quality from A and R... Dapol seem to fall in the middle... and least so far, with my somewhat limited experience.

[@alanrobertson9790]

Agree with everything you said. For the same money or even a little cheaper Accurascale can produce a more finely detailed model than say Bachmann. The trouble is that this has embedded higher prices rather than driven the market to retain the lower prices, but less detailed models, that we had before. For example the latest Bachmann TEA tanker selling for just under £60 at my local model shop. Fortunately as an older modeller who has collected for a few decades I don't need to purchase more than one or two examples just to see what they are like but don't see how a new modeller could get a rake of TEAs for example.

[@JanjyGiggins]

Never had an Accurascale coach, but I recently had a loud whining/buzzing noise coming from the lighting capacitor on a Hornby Coronation Scot coach. I added a small resistor and that sorted it. I don't use ABC so it's probably not the exact same issue, but might be something worth trying? Though if the lights are already quite dim, maybe not ideal.

[@DongitsModelRailway]

There's already a resistor in these to reduce the charging in-rush, but I'll definitely be looking at the lighting in more detail to see what I can do about that noise.

[@stephenbromley2302]

I’ve got 5 mk2 bs 2 run but seem to be tight going round curves and even in straights checked back to backs is fine I took the bogies off and pushed them and they run fine as soon as I put them back on the carriages they drag again so I’m thinking I may have to file the holes the screw goes through to give them more movement same as the siphon g wagon

[@JulianSaunders]

Will they work with magnetic couplings from Westhill Wagon Works?

[@jamtart606]

An interesting, quite well put together video talking about both the positives and the negatives (as the way it should be these days!) Although one thing I'm not exactly sure about are those Roco couplers, sure they do give off a nice close coupling look but it's a double edged sword. You get a nice realistic close look at the cost of being able to run them on any sort of curve radius less than 3 without derailing and I also don't really like how much of a faff it looked to actually get them to uncouple either but that might just be me. Of course this doesn't take away from the fact Accurascale didn't get the length of the NEM pocket quite right which is something that other manufacturers who've done 4mm before hasn't gotten correctly before and I do feel there needs to be a rule made to make a pocket that is both the correct length and the correct height (without the stupid dips that the Bachmann Mk1s & Mk2As have) so that there's a smaller chance that derailments will occur when fitted with something that's either a tension lock or a magnetic coupler. For me the solution to permanently fix this would be to buy a set of Hornby Magnetic couplers and test which one works best (as the Hunt Couplings from West Hill wagons are extremely brittle)

[@DongitsModelRailway]

Apologies for the one handed faff with the screwdriver -- doing anything one handed while holding a camera and trying to frame a shot always makes it look incredibly difficult. On review, I've really not sold the couplings well. They uncouple really easily. If you've got one of those plastic "plate on a stick" tools that uncouple tension locks, it works on these too in the same way. If you have a tension lock uncoupler mounted in the track (the motored kind that lifts up) that will also work on these. If you have a spare hand to use the controller to pull the loco away while pressing up, it works even better. And unlike tension locks, picking one vehicle up also uncouples them -- no "string of sausages" effect. With a correctly positioned pocket, that coupler will go round a radius 2 curve and still give you touching gangways on straights. I think the coupler you're calling "hook and loop" is the one often found on old European models -- I've heard it called the "toilet seat" before, as the loop lifts kinda like a toilet seat. That also doesn't maintain pocket alignment between the vehicles, so won't operate the close coupling mechanism correctly unfortunately.

[@Simon-Davis]

Another thing I'd like to see them address with the Mk2c release and any future batches of Mk2b is the ride height. The real things are supposed to have a buffer height of 3' 5 1/2" which is 13.8mm in 00, but when measured all of mine are reliably lower than 13mm. You can see it with yours in the video where the gangways don't quite line up with Bachmann Mk2 gangways. Much the same as the Bachmann Porthole coaches, these will need a spacer inserting between the bogie and coach to lift them up to the correct height.

[@DongitsModelRailway]

Interesting -- I hadn't spotted that, thanks for pointing it out. A spacer between the bogie and the chassis is easy to add, but could interfere with how the pickups work.

[@Simon-Davis]

@@gppsoftware Whether other coaches are right or not, I measured to the centre of the buffer shank on my Accura Mk2bs from railhead, they came out varying between 12.6mm and 12.8mm. At best the body is sitting (on average across the 5 I have) 1.2mm low on the bogies, or the slop in the pinpoints are causing the wheelsets to sit out of position. Otherwise the buffers sit a minimum of a scale 3 inches low in relation to the body if the roof height is correct. If the buffers are in the correct position in relation on the body and the roof is the correct height, then the whole body is too deep.

[@Simon-Davis]

@@gppsoftware Consistency is definitely the key here. The trouble rears its head when a manufacturer gets a model absolutely spot on, but when sat next to these erroneous models the accurate model looks wrong. The Bachmann class 47 is a case in point, its buffer height is spot on at 13.8mm which scales out at 3' 5 1/2" and that is dead on with the GA drawings. Couple up a Bachmann 47 to the Accura Mk2bs the 47 towers over them and looks out of scale, even though its the 47 that matches up correctly dimensionally. Buffer up the comically poor new Heljan 47 and that one, because its ride height is out of whack and the cab fronts are questionably dimensioned (to put it politely), and the crap model actually looks halfway decent to the point where you start questioning whether you should be lowering the (correct) Bachmann 47 because you start to believe its too tall.

[@willthompson9597]

I've found it's the sloppy wheels which cause the drop in height. Converted mine to EM using 26mm axles and their running height is much improved and match the Bachmann mk2f exactly

[@chrisvaughan159]

Hi, great analysis. Do the coaches couple easily in the "working" mode with them reversed that you tried? I've used one Roco and one Hornby successfully, but your method of fine-tuning the coupling pockets is marvellous and I'll probably crib that in future! While I do agree that Accurascale are not necessarily the "best thing since sliced bread" and the level of invisible details do make me wonder what that's all about, they are on a learning curve and will take critical comments on board. Clearly, when dealing with the balance of tolerances that define coupling mechanics and closing the gap it seems they are on the cusp of what's possible. But the "solution" of supplying different tension locks does not stop the "Telescoping" in service you describe - something I too find irksome. Thanks for your examination. Chris.

[@DongitsModelRailway]

The coaches don't couple easily with one reversed -- they require the same manual coupling action to get coupled. Tension locks really don't work on close coupling mechanisms. I think I'm going to have to do a coupling video explaining what's necessary to use them properly. The telescoping of tension locks is actually an intentional feature, intended to reproduce the slack action of loose coupled unfitted goods wagons. Good for it's intended purpose, maladaptive when used outside that purpose.

[@odenviking]

check out marklin`s short couplers. they have the same nem standard as roco ones. but i think that the roco ones are the way to go if you want a more realistic coupling between the chaches. 👍👍👍👍🇸🇪🇸🇪🇸🇪🇸🇪🇸🇪

[@ModelRailwaysUnlimited]

Hi, very interesting. I'm badly in need of some mk2s in late 70s early 80s condition but don't really know what that would be. I've looked at these but bypassed them due to cost. However I was very interested in the whining noise, does your block detector use AC? Sounds like the charging circuit is not properly protected against stray AC or RF??

[@DongitsModelRailway]

Late 1970s - Early 1980s condition would be Blue/Grey with 'Inter-City' branding. As to which variant of Mk2 you need, that depends where you are modelling. Different versions of Mk2 went to different places. The block detector does not inject anything into the track at all, they are just coils around the block wire making a transformer, and it detects the presence of anything which draws current from the DCC signal. It's definitely the presence of ABC which is causing the noise.

[@ModelRailwaysUnlimited]

@@DongitsModelRailway Hi, thanks for the reply. I'm here in the south of the UK, routes of interest are Portsmouth, Brighton and Reading. Got you on the detectors. But that makes this a complete mystery then as if as described they should be completely passive???

[@DongitsModelRailway]

That's because it's not the block detectors doing it -- it's the ABC modules. They change the amplitude of the DCC in one direction only. That's a relatively widely used and fully published standard though.

[@physiocrat7143]

The prototypes had whining lights.

[@jimperkins2446]

I have no problems running the coaches on 2,3,4 radius curves. Only prob I've had is on a reverse module attached to my triangle Jcn. My change over track IE the length of a loco but as soon as the coaches hit it it shorted and burnt out.

[@DongitsModelRailway]

The coach pickups are wired to all four axles of the coach, which are effectively in common. This means any track that one bogie is sitting on is electrically connected to the track the other bogie is sitting on, via the coach wiring. Any reversing section used with lit coaches like these (not just Accurascale ones, but other manufacturers too) will need to be the full length of the train, not just the locomotive. My reversing section on this layout is around 4m long.

[@Midsussexrailway]

Try bachmann DMU couplings on them (the loop type) I've never found couplings which completely eliminate slack to be any good (magnets included)

[@mccarronfamily]

The issue is the roco coupler - use the supplied options!

[@gc7820]

After an interminable wait my Dinmore Manor went straight back - obvious quality fail manufacturing error I couldn’t rectify nor did I want to try given how much I’d paid. Accurascale ain’t infallible as are no manufacturer.

[@Agamemnon2]

It's a pity these have such issues, the interior detail and lighting looks really convincing.

[@DongitsModelRailway]

The detail and lighting is really well observed and very convincing. Honestly, the issues with these coaches are solvable, there's nothing here which is insurmountable.

[@michaelscott231]

Never seen these couplings before -does anyone use them?

[@DongitsModelRailway]

Several members at my local model railway club use these couplers within rakes of coaches. I have lots of coaches already fitted with them. They are also recommended by Keen Systems as the alternative coupler for their close coupling system. The buckeye Keen supply with their kits does not actually uncouple on the layout at all -- If you want that feature this is the coupler they recommend.

[@wolvertoncentresidings5676]

Hi, Great informative video. I've been hanging back buying any Accurascale coaches because both my Accurascale locos have developed "issues" I do have plenty of Oxford mk3s and have found everyone to be faulty from the box, if the coupling issue on Accurascale coaches and the whine noise are the only issue I think I'll go ahead and buy some! Btw, There is definitely a " fan boy" element in the hobby who'll take umbridge at anything negative said about their favourite Manufacturers. They, like the rivet counters need to grow up!!!

[@DongitsModelRailway]

I have issues with both of my Accurascale locos too -- not quality issues thankfully (I think I've been lucky there), but I think issues relating to how the electronics have been designed. My InterCity Swallow livery Oxford Mk3A coaches have all had quality issues. Steps dropping off is particularly common. All mine were in the box, just not attached to the coaches. The lower bodyside colour is also wrong on these. The Blue/Grey ones were a different story -- I'm happy with the livery on these and the steps all stayed attached. No issues with these ones!

[@wolvertoncentresidings5676]

@@DongitsModelRailway My Accurascale cl 92 have both started slowing then speeding up but smoothly. They do this on my own layout and at the club house so it's not my trackwork or wiring or dirty track. I first thought it was voltage drop but have since tested and it's not. Possibly due to the stay alive?

[@michaelderozario5626]

These look like great coaches (asides your issues). I’m finding it hard to understand criticism from some of being 1.2 mm wrong on height when you’re running them on track that’s 2.35mm too narrow

[@DongitsModelRailway]

Now I've had it pointed out that they are sitting low, I can see it -- it's there in the comparison between the two vehicles and how they line up. It's very much like the track width actually -- provided you get the sleeper spacing correct, the extra 2.33mm is most noticeable when you line the two up next to each other. Have just the "wrong" one on it's own, and it's not that obvious.

[@robinedwards598]

Fleischmann had close couplings years ago. German engineering 😴🤣. I think we are getting too involved with perfection today. It’s just a model railway, after all.

[@alanrobertson9790]

A fact based account which I can't dispute. Personally I don't use close coupling, let alone Roco close couplers. What % of modellers do you think do, so is that a significant criticism? Not all products work with all other products or all tracks. The trick surely is to combine the things that work rather than complain about the things that don't.

[@DongitsModelRailway]

The real trick is to work out why it doesn't work, and how it can be fixed :)

[@alantraish3368]

Disagree about the Hornby coach. Unless you are a Gresley expert on how it should exactly look these are extremely minor faults. They look absolutely fine to me.

[@niallkelly2514]

To be fair, it's not Accurascale fault that they derail when retrofitted with another manufacturer's couplers.

[@DongitsModelRailway]

It is their fault that the NEM pockets aren't in the right place according to the published standard though, which is why they derail.

[@James47298]

A magic wand over the top? Problems with running and whine? This is why I don't bother with the hobby, the extortionate prices were justified because of the quality?

[@Haymarket47]

😂😂 You don’t bother but you watch a video about a model coach….🤷🏻‍♂️

[@neiloflongbeck5705]

Prices have always been high. As a percentage of average weekly wages the cost of models has not changed significantly (less than 1% change since 1979).

[@gamerfan8445]

You could just buy second hand.