Ringfield motor drive gear.

[Puffed Out]

A ringfield motor from a 225 Intercity is on my bench.  I was running it last night then it stopped with the motor still running.

On inspection the brass drive gear was spinning on the drive shaft from the motor. And to add to that, the other plastic gears were a bit worn. So the parts are on order for whole gearing assembly. 

Having never replace a brass drive gear, I'm sure it's just an interference/press fit. 

So on replacing the brass gear, should I use a tiny dab of loctite, or press fit it dry. ?

[Going Spare]

It is most unusual for a brass spur gear to become loose on the shaft because they are a very tight fit.  The silver alloy version is far more prone to coming loose. 

Lightly oil the shaft bearing before fitting the new gear.

The bore of the gear is uneven: offer up the wider end first and it will progressively grip the shaft more tightly as the bore size reduces.  No adhesive should be needed.

The new brass gear is best fitted in a vice, making sure the motor shaft is at right angles to the jaws horizontally and vertically.  The old gear can be used as a spacer because the outer face of the gear sits below the end of the motor shaft when in position.  

When pressing the new gear on, leave a small amount of play (no more than 1mm) to avoid the gear binding on the shaft bearing as you say.

[The Duke 71000]

I don't do modern image, but the problem as you describe it has "hit" one or two Hornby steam models in the past.

First I doubt the brass worm drive is affected being metal. The culprit is much more likely to be the plastic drive cog which it engages, and you mention the teeth on that look a bit worn. With the steam locos I was able to get a replacement cog from Peter Spares, who are Hornby's main spares supplier.

However a word of warning. If the plastic cog has worn after only a few hours of use on your model, there has to be a reason. This is most likely going to be the method of how the motor is mounted. If the motor can move slightly at the brass worm gear end, then this will be the reason it has stripped the plastic cog. Replacing the cog will not cure the root cause, so the replacement may not last long either !

You will have to ensure the whole motor cannot move. Hornby have in the past used that sticky black plasticine type product to hold one end of motors. You therefore need to ensure you understand how the motor is held in place at BOTH ends. And ensure whatever system is used the motor on your model is held precisely in place and cannot move even a fraction of a millimetre, or live a life of continually replacing the plastic cog !!!

 

Good luck

The Duke 71000 

[96RAF]

You wasted your time typing all that lot Duke.

 

He is talking about a ringfield motor which has a spur pinion not a worm drive as used on can  motors and the motor is built into a solid housing usually an i tegral part of the chassis, so there is no both ends to come loose.

[Puffed Out]

I think someone has already had a 'jolly' with it. I can actually slide it on and off with my fingers, although tight ish, it's only by chance it ran I would think.......5 circuits.

For a few £'s it's well worth it. Touch wood.

@RAF, thanks for the info. 😀

 

 @ The Duke 7000, thanks for answering anyway.

[96RAF]

Do the 3 and 5 pole motors have different diam shafts. If so it may the big hole gear has been glued on the small diam shaft, but has now come loose.

[Going Spare]

Yes, the armature/commutator shaft is a smaller diameter on 5-pole motors than 3-pole units.  The class 91 did acquire a 5-pole motor so a mis-match is possible: one easy indicator is grey plastic transfer gears for 5-pole, traditional black for 3-pole.  Some class 91 5-pole units also had spoked wheels.  

[The Duke 71000]

You wasted your time typing all that lot Duke.

 

He is talking about a ringfield motor which has a spur pinion not a worm drive as used on can  motors and the motor is built into a solid housing usually an i tegral part of the chassis, so there is no both ends to come loose.

Are you implying that Hornby still use the original Ringfield motor that was an integral part of the bogie or chassis. Because I thought that ghastly piece of junk had been consigned to the scrap heap 25 years ago ?

I had therefore assumed that as many people still refer to even the current "can" type motors as Ringfields including at least one shop, that this was simply a mis-description. So obviously I proceeded on the assumption the model had a can type motor.

The Duke 71000 

[walkingthedog]

The title and text states Ringfield, the OP doesn't say it's a new loco and your view that  it is 'junk' is obviousl wrong as it has lasted a long time and is able to be serviced unlke the modern motors. 

[Going Spare]

Hornby do not now offer Ringfield motors but it is closer to 5 than 25 years ago that they were replaced.  At the time of their introduction, in turn replacing the X04 family of motors, they were a robust and powerful 'means to an end' by giving Hornby the ability to power both steam and diesel/electic locomotives & multiple units with basically the same motor.  

[Puffed Out]

@The Duke 71000.

I have to agree with the others, I find them in general easy to service, the Ringfield motors, as long as there are spares available.

..

As for me, being an 'old newbie', it can be a challenge, but I'm a reasonably quick learner.  My aim is to try and fix them, rather than chucking them into to bin. The best part of my story is buying none runners/broken/dodgy Loco's and their rolling stock.

..

I have bought so many in the last few months, approx. 40+ Loco's, and most are in job lots.  So far, only 2 have been unrepairable. Average cost across the board is about £3 each, and the reason that's so high, is the fact that I've sent 3 away for someone else to repair/service them. This Ringfield motor has come from the last one to be repaired. So for about £3, plus the cost of purchase, it's a bargain.

..

The other 2 that can't be repaired, are being used as donors for others. But from the outside, they look perfect and will make good additions for the scenery in a goods yard.

I also have some brand new Loco's and coaches, and they are far less demanding. 😀

[ColinB]

I had a couple where the alloy type gear became loose, I don't think I have had a brass one go. They probably become loose where somebody takes if off so that they can sevice the motor and of course when you put it back on it is not going to be so tight.

[Puffed Out]

New brass drive gear fitted, and all the other plastic gears. 15 minutes tops. all for the princely sum of just over a fiver plus postage.

.

I used a mini vice to push/squeeze it on, and then a 2mm nut to drift it on further. A bit of end float, approx. 0.5 mm.

Another one saved from the scrap bin.