N7 Jerky running

[thesteambuff]

I have 2 oxford N7 tank engines with the same fault which is very jerky at normal speed but ok at maximum speed.

Any ideas.

[RFS]

DC or DCC? If DCC, which decoders?

[thesteambuff]

Hi Robert.

1 DCC and 1 DC.

[thesteambuff]

I have tried them both on analogue.

[Izzy]

If on analogue don’t use a feedback or very old type controller as they have coreless motors and will be unhappy driven by such. Use a modern day non-feedback controller for best smooth running at all speeds.

 

Bob

[thesteambuff]

hi Bob

Yes i use a modern controller,but it shows the the same fault on DCC.

[Izzy]

3 minutes ago, thesteambuff said:

hi Bob

Yes i use a modern controller,but it shows the the same fault on DCC.

Ah that’s a shame, in the sense I thought it might be an easy answer/fix solution! One point to watch out for is that quite a bit of present day RTR gets coated in too much grease in the chassis /gears which can make locos struggle at slower speeds. If you feel confident in taking the chassis apart it can often be the solution, clearing it all out and just lightly re-lubing. I had to do this with both my Hornby J15 and the Oxford N7. Might he worth a look.

 

Bob

[Bucoops]

19 hours ago, thesteambuff said:

I have 2 oxford N7 tank engines with the same fault which is very jerky at normal speed but ok at maximum speed.

Any ideas.

 

Have a look here - 

- you may need to replace the motors unfortunately.

[thesteambuff]

Thanks Bob I'll check to see that there's not too much grease.

[The Johnster]

As well as the grease check, for which you'll probably have to remove the keeper plate anyway, also check that the bearings and axle slots are clean, the crankpin bearings are running freely and that the wheels are revolving square to the chassis, the coupling rods are straight and not fouling on anything, and that the pickups are bearing correctly throughout the range of sideplay for each axle.  When you replace the keeper plate, check that there is no crud that prevents it sitting flat on the bottom of the chassis block, and play with the retaining screws, tightening and loosening a quarter turn at a time, to ensure that the best compromise between free running and firm gear meshing is achieved.  When the best performance is achieved, keep thim in position with a spot of pound shop superglue, which will break easily should you ever need to remove them in future.

 

You will never regret removing the grease, which picks up crud and goes off hard over an unpredictable freestyle time scale of it's own choosing out of your control, becoming more of a stifficant than a lubricant.  I believe it is used to prevent drippage in transit and storage.  Replace it a sparingly as possible with a plastic friendly non-mineral machine oil; I apply it with a syringe (keep this away from any other syringes in the household whatever purpose they are used for) but a droplet on a pinhead is just as good.  I do this on all my locomotives as they come into my posession.

[Il Grifone]

You are not suggesting that pound shop superglue is rubbish by any chance, are you!

(If so, I agree 100%!)

 

That white grease is deadly. It kept us busy repairing VCRs back in the day.

 

Rivarossi Memories refers to it as 'Grasso-Torrone'  (Grease - Superior* Italian version of Nougat.)

(*At least Italians think so....)

 

http://www.rivarossi-memory.it/Tecnica/Grasso_Torrone_ALC420/Grasso_anni_90.htm

 

(Sorry only Italian - Google Translate)

The English part of the site only extends to model descriptions and was last updated in 2012!

I could help, but...

(So many trains! So little time!)