Hattons Dapol OO 121 Bubblecars

[Matabiau]

I have just taken delivery of my four Hatton's/Dapol class 121s. They all look the aprt but I am having running problems with three of them. They derail leaving bends (third radius), the inside axel hovers above the rails so the bogie doesn't return to the correct alignment following the curve. The bogies appear to have very little vertical movement, the weight of the train itself is insufficient to force the bogie to see-saw.

In addition on one of the models the steps foul the undercarriage details preventing rotation. Am I the only one to suffer this?

[davy crockett]

IF. the 121 is the same design as there 122 i would suspect the top of the bogie has broken off. 122 have suffering this.

Edited December 16, 2017 by davy crockett

[Matabiau]

Thanks for your suggestion. I had a look at the tops of the bogies and they are fine. However, I did find that on some of the bogies the wires coming from the wheel pick-ups were not sat properly in the little grooves provided and were fouling with the bogie support bar on the chassis. Teasing those back into their grooves has remedied the problem on two of my 121s. (You have to loosen the bogie pivot screw to do this).

The other two have in addition steps fouling the undercarriage detailing. I have removed on of those (not glued in place) but there is nothing to be done as it was correctly seated in the first place. Hattons have asked me to return them which I may well have to do unless anyone has a suggestion on how to improve the clearance on the underside of the train.

[metropolitan cammell]

I picked mine up from hattons and they tested them on the test track in the store, we went through several and they all did it with the steps clipping the air tanks when the unit goes around a curve and derailing the bogie.

 

You will have to trim or remove the steps or only run it on gentle curves.

Edited December 17, 2017 by metropolitan cammell

[adb968008]

Mine runs fine around my curves, varying from 2nd radius to 4th, and over points, but I find even on full power then run approx half speed of most of my other stock, I have two.. Blue/Grey and the GW150 and both pretty much run equal speed... but comparatively slow to almost all my other stock.

I find the same is true with my Dapol class 73's, is this a known/accepted issue  ? (i'm on DC using a Gaugemaster Handheld).

Edited December 17, 2017 by adb968008

[mevaman]

adb968008

 

My 122s needed quite a lot of running in before I could achieve speeds comparable with my other stock. I also had problems with the motors vibrating in their housings and filled gaps with blu-tac.

 

Hope that this helps.

[Pteremy]

Mine are definitely getting faster with 'running in'. I have the 121 pulling a Lima 117 Driving Trailer for additional drag. But i now realise that i have no idea what an acceptable scale speed would be on my low tech DC layout.

[Matabiau]

I ended up sending back to Hattons the ATW and GWR150 versions that were impossible to remedy. I received the replacements today but they were even worse! On the ATW unit the steps on one bogie were butted up agains the underrcarriage detail even in the straight position. Back to Hattons again for both of them, I only hope this time they will honor their promise to test the units prior to dispatch.

 

Has Dapol had anything to say on this, after all the source of the problem lies there, not with Hattons, their customer? I have tried contacting DCC supplies asking for advice but have received no reply.

[ruggedpeak]

So, having run my Arriva 121 on my micro layout backwards and forwards, I put it on an oval of track to run it in.

 

With my Gaugemaster controller it required nearly 50% power to even move, then went slowly and slowed significantly to go around R2 corners. After about 3 laps it then stopped, the controller cutout having cut in. It appears once it is warm it really doesn't want to run.

 

To check that it was not a controller issue (and everything else ran without problems) I attached a basic Hornby train set controller from the Santa Express. It ran better without stopping, still needed lots of juice to move, but made the most horrendous electrical hum. Other locos had a slight hum but nowhere near as bad.

 

 

Any thoughts as I can't fathom out what is going on beyond it isn't working properly? Why such a difference between the controllers?

 

(the sockets are hanging off the wall as we are decorating!!)

Edited January 16, 2018 by ruggedpeak

[mevaman]

I have found that all my models initially ran very slowly and drew more amps than usual. I use Gaugemaster hand-held non-feedback controller.

 

It could be that your model is particularly ‘tight’ and is drawing more current than the cut-out on your controller. Of course, it could also mean that you have a drive-train fault.

 

I continued to run mine for about half an hour and they all freed up. In essence, they need running in.

 

Hope that this helps.

 

Andrew

[ruggedpeak]

I have found that all my models initially ran very slowly and drew more amps than usual. I use Gaugemaster hand-held non-feedback controller.

 

It could be that your model is particularly ‘tight’ and is drawing more current than the cut-out on your controller. Of course, it could also mean that you have a drive-train fault.

 

I continued to run mine for about half an hour and they all freed up. In essence, they need running in.

 

Hope that this helps.

 

Andrew

Thanks. Do yours slow down going round corners e.g. 2nd radius?

[Market65]

Hello, Tony. Both issues are known, and a solution has been provided in the Dapol Class 121 and 122 thread. Here's the link to the relevant post:

 

http://www.rmweb.co.uk/community/index.php?/topic/65775-Dapol-class-121-and-122-in-oo-gauge/?p=2985254

 

Basically you need to remove the cardan shaft from the passenger end of the unit. For whatever reason, this eases the unit so that it draws at least 50% less power than it uses straight from the box. Then going round curves, and also up hills, etc, become no more of a problem. I've carried out the fix on my 121 and 122's, and the transformation is quite remarkable. They even can be run in multiple with a Bachmann class 108 unit without any problems!  I hope this will be of use to you.

 

With best regards,

 

Rob.

[ruggedpeak]

Thanks Rob. Hadn't appreciated the grinding round corners was also fixed by removing the shaft.

 

Shaft now removed, thanks to adb968008's instructions. Runs beautifully without tripping the controller.

 

Kind regards

[Market65]

That is excellent news, Tony. I don't know exactly why it is like that, but the fix certainly works.

 

Regards,

 

Rob.

[adb968008]

That is excellent news, Tony. I don't know exactly why it is like that, but the fix certainly works.

 

Regards,

 

Rob.

I’m guessing it’s out of balance.

 

Like a steam loco on a turntable, if it’s not evenly weight distributed over the pivot, it’s impossible to turn the loco without additional disproportionate levels of energy than if it were balanced.

 

By removing a shaft your not fixing the balance, just removing a source of tension.

 

I’ve not had the motor out of the chassis yet to confirm, but i’m Suspecting the motor itself isn’t evenly balanced, perhaps the motors weight is bearing down on one end more than the other, causing one shaft to be climbing, and the other falling meaning they are fighting each other. The motor itself looks to be mounted evenly in the chassis, but the motor design is not identical at each end. It could also be lateral movement of the shaft itself (ever wondered why angular mounted x04 motor locos work better one way than the other)... going one way energy is screwing down on to the gear to drive it, the other energy is unwinding upwards away from the gear. I think maybe the 121 is doing both at the same time, winding at one end, unwinding at the other.

 

When I looked at it, the gears, gear tower, motor and bogies are all snug fit tight with no resistance to moving parts, so I can only speculate it’s within the motor.

I did a similar exercise with a troubled batch Heljan 17, there it was clear.. the gears were too tight in the gear box and hard to turn even by hand.. this isn’t the case...they are free moving, but fit snug.

 

On my first pass I removed the shaft from the DCC chip /guards van end, but on learning, i found it’s easier to remove the shaft from the seated end for the other two I have, but I found it made no difference which shaft I removed, as long as one was removed the performance jumped.

Edited January 18, 2018 by adb968008

[centraltrains]

Why on earth is the limited edition quantity confidential information?

 

Surely knowing the quantity produced is a big part of buying a limited edition item?

 

Given they call it "Limited Edition" one expects a total number at the very least. As otherwise one would expect it to not be labelled as non limited edition. The vast majority of model trains are not sold as limited edition, often to a larger quantity produced but AFAIK usually still only one batch made to which I suggest this is more like being they don't want to give the number made.

Edited January 19, 2018 by centraltrains