Farish 4MT motion locking issue

[N_GaugeModeller]

Hi

I have read that Graham Farish STD Class 4MT Locos are known for suffering from a motion locking issue.

Did this just effect the tender version or the tank version as well.

Thanks

NGM

[Dr Al]

Not a big issue on either. Just a case of making sure nothing has moved (particularly the eccentric rod) or is bent - all too common that one or the other is the case, and folk cry that the model has a flaw (which it hasn't!).

Cheers,
Alan

[Newportnobby]

Probably to Dr Al's disgust I put the teeniest drop of oil (Gaugemaster GM619) on all the joints of the motion and find it works just fine.

[Bigmac]

My tender version locks solid in either direction. I can't see anything in the motion jamming. More like excessive play in the loco axles. Just needs a slight sideways nudge and off it goes again.

[Dr Al]

My tender version locks solid in either direction. I can't see anything in the motion jamming. More like excessive play in the loco axles. Just needs a slight sideways nudge and off it goes again.

Unlikely the cause, they all have lateral motion, as does any loco - it's simply necessary for wheels to follow through tight curves.

Most likely you are just uncatching the bit of motion that is catching when doing so.

Cheers,
Alan

[Dr Al]

Probably to Dr Al's disgust I put the teeniest drop of oil (Gaugemaster GM619) on all the joints of the motion and find it works just fine.

The *vast* majority of repairs I see are due to excessive oiling, which is why I don't encourage that - if motion sticks without oil then it should be investigated in that state first.

Cheers,
Alan

[N_GaugeModeller]

Oddly enough just after asking the above question my STD Class 5MT started random lockups of the motion.  Turned out to be the screw on one side of the centre wheel set was loose, it took a couple of goes getting the part that was also held by the screw in place (Don't know the correct name for all the individual parts that make up the motion) and now its back running nice and smooth, will be keeping an eye on the screw just in case something is making it work loose.

NGM

[PLD]

Hi

I have read that Graham Farish STD Class 4MT Locos are known for suffering from a motion locking issue.

Did this just effect the tender version or the tank version as well.

Thanks

NGM

The 4MT tender loco has prototypically exposed motion which is known to be prone to damage through mishandling by less-careful owners which may lead to it locking up...

I've never seen one lock-up that wasn't due to bent rods.

[Dr Al]

Turned out to be the screw on one side of the centre wheel set was loose, it took a couple of goes getting the part that was also held by the screw in place

Not uncommon. A lot of the time these screws aren't tightened much (but you don't want to overtighten them either), so the eccentric rod can move relative to where it should be and in the worst case drop off.

Watch for any incorrectly set rods, that may indicate this and nip those screws up quick smart.

Again, handling these when they aren't always hugely tight from the factory can accelerate this occurring.

Cheers,
Alan