Help! How do you dismantle R3207?

[Topcat2018]

I have two LNER P2's, which I got out today to measure the tractive effort in connection with another post about 9F R3987 motor issues. One of them is a Railroad version that I bought new but unboxed about two years ago from Jadlam, so I don't know the model number. The other is an unused as new-in-box R3207 that I inherited in 2020 from a friend who died.

I tested the one from Jadlam and found that the tractive effort was 0.5 Newton at 5.3 V and 220 to 240 mA, which I think is poor for a loco of this size and worse than loco-drive Chinese-made A3s and A4s.

When I unboxed the R3207 and tested it, it turned out to be a complete dud, total short circuit when on the track and .025 ohm when measured with a multimeter, so it can't just be seized up.

Does anyone know how to get this thing apart so I can fix it? The service sheet gives no indication of what screws actually hold it together.

[Going Spare]

Looking at the Service Sheet, there is a tower at top front of the chassis block so my guess is that it serves to guide screw passing upwards to a capture in the body. The head of the screw may be hidden above the pony truck. In Hornby tradition, there may be a lug at the cab end of the chassis block so, by releasing the screw at the front end and pulling the chassis forwards as you lower it the rear lug should come free.

A loose DCC blanking plate may be the culprit.

[Topcat2018]

@GS

Thanks for your suggestions. I've found it!

At the back of the chassis there is a lug that projects into the cab, so there is no vertical movement possible at that end. At the front end the chassis is right up against the buffer beam, so removal must consist of unscrewing whatever is holding the chassis down at the front, lifting the front over the buffer beam then sliding it forward to disengage the lug at the back.

There is a hole in the front bogie (is it a bogie with only two wheels) at the bottom of which is a screw. Unscrew that and the bogie can be lifted out.

[Topcat2018]

Well the motor is definitely knackered. I took out the dummy plug from the DCC socket and there was no short between the wheels. When I applied an ohmmeter to the motor and turned it by hand I got various resistance readings. When I applied power the motor was drawing 3 amps at 12 volts (the limit of my lab power supply) and not running. If I turned it by hand it would spin but was drawing almost 700 mA. There is obviously a dud armature winding in there.

Pretty poor for a loco that's never been out of its box. I'm glad I didn't buy it. I wish I had tested it when I was first given it. It might still have been in warranty.

Can't even find a replacement motor anywhere. Hornby Product Support says "parts and spares" but no spares for anything seem to be listed. The line for spares etc. doesn't even highlight when you hover over it. Have Hornby stopped selling spares entirely? Everywhere else I've looked out of stock. Very poor for a product that is only a few years old. Very disappointing!

[Topcat2018]

After looking at photos of the P2 motor from various suppliers (all out of stock) it occurred to me that the motor in my P2 has no suppressor capacitor fitted. I'm wondering if this has led to arcing that has caused a short somewhere.

[Brew Man]

If I pull down the 'Shop' menu at the top left. then, 'Train Sets and Rolling Stock', then 'Parts and Spares' I get 32 pages of parts and spares. Whether there is a P2 motor among them is another matter.

[Topcat2018]

@BM

This is very strange. Everything works on the Product Support page except for spares etc. The lettering on that line is in italics and does nothing when I click on it.

[Brew Man]

That is odd. Works fine for me, well as fine as most Hornby web site pages work grin.

[P-Henny]

@Topcat

The page you have described is not the same page that @Brewman has described. The italic phrase you have described is not a clickable link. Following the navigation that @Brewman describes takes you to this page.

https://uk.hornby.com/catalogue/train-sets-rolling-stock/parts-spares?

The spares pages are not navigatable from the "Support" menu. I do agree however that they should be. Hornby appear to treat the spares as "Shop" items. The reference to 'spares' on the 'Support' page looks to be an error, maybe a legacy left over from the previous Hornby website.

[Topcat2018]

@PH

Thanks for clearing that up. However the replacement motor for R3207 (X6665) is not even in the Hornby spares list, so a loco that is only a few years old is now completely useless. Rather gives the lie to the statement made by the boss man on the TV series about Hornby, to the effect that a Hornby train set is "not just for Christmas".

I've seen comments to the effect that some other motors, albeit without flywheel, can be used in the P2, but as I've no idea of the dimensions of the numerous motors on sale or the size of the worm gear, I don't know which ones. Any suggestions would be appreciated, though it would pain me to pay some of the outrageous prices being asked for what are really cheap and nasty motors.

[96RAF]

P2 TTS service sheet shows motor as X6644 from memory. - search support for P2.

[Going Spare]

X6644 is certainly the P2 motor assembly but as you say, not available (for some while).

There may be two avenues to pursue: I have seen suggestions on the web that the Railroad A1 (Gresley and Peppercorn) motor X6331 may be a substitute - Lendons of Cardiff may be worth contacting as they have that motor (just 1 as the complete assembly but stock of the bare motor to which they offer to fit your worm and flywheel if required); or wait to see if ColinB picks up on this post - I seem to remember he has experience of remotoring this chassis but it may not have been the A1 motor that he used.

[Brew Man]

As useful as Lendon's are, in my experience they won't go looking for you. You have to know what you want and they'll tell you if they have it. Not sure either if they would tell you if other other parts are a substitute or not.

[Topcat2018]

@GS

Thanks for that info. I have ordered the complete assembly from Lendons. Cost £24.99 but as the loco was a gift it's worth it. I don't foresee any problems provided the motor is not too big (slightly undersize would not be a problem as it could be packed out) the flywheel is the right size and the worm gear is the right pitch and diameter. If the motor is the right size but the worm and flywheel aren't OK I will re-order just the motor and take the worm and flywheel off the existing motor. I wouldn't try to take them off a good motor as they are a very tight fit and will probably have to be removed by heating, which will destroy the motor.

[Dukedog.]

is it this one

https://www.ebay.co.uk/itm/143865529007

[Topcat2018]

@Dukedog

Thanks for your reply. I've come across this one before. They claim it fits but it's not a genuine Hornby part and only has a plastic worm gear, and unfortunately it's out of stock. Hope that my order from Lendons will be the solution.

[Topcat2018]

An update on re-motoring my P2 with an X6331 motor assembly from Lendons of Cardiff, as suggested by GS. I've managed to do this, but it was quite fiddly.

The first problem is that the X6331 motor has a bracket around the motor instead of just a small clip with two screws. As the flywheel is fixed there is no way of removing this in one piece, so it has to be cut off. The flywheel is a lager diameter than the original but fortunately fits inside the body.

There is only a fraction of a millimetre between the motor and the boiler sides, so in order to make the motor fit inside the body it was necessary to do the following:

1. Flatten the terminals right down.
2. Instead of running the original four wire loom that carries the suppression capacitor and ferrite bead, run just two wires from the dummy DCC socket to the motor and mount the capacitor flat on the side of the motor with short leads to the motor terminals so they don't contact the motor body.
3. Make sure the solder joints are as flat as possible.

The ferrite bead is too fat to be mounted on the capacitor leads at the side of the motor, so I omitted it. To be honest, in the original wiring the capacitor and bead weren't mounted close to the motor terminals, so I don't know how effective they were at suppression. As I run a lot of old locos that only have a capacitor I'm not going to lose sleep over it.

Having done all this the loco does run very smoothly.

Finally, has anyone noticed how flimsy the fake plastic valve gear is on these locos? You only have to look at it and it breaks.

[ColinB]

Sorry didn't notice this one. The P2 uses the 3 pole can motor, I replaced it with a Pendolino motor. I had to remove the flywheel and worm drive off the old motor using an extractor. There is a YouTube video from some guy explaining it all. I don't remember it being that difficult. The Pendolino motor is exactly the same as the original in size and terminals but it has twin worm drives that are shorter (hence why you use your originals).

[Topcat2018]

@ColinB

Thanks for your reply. The Pendolino motor does indeed look identical to the X6331. I decided to buy the assembly complete with worm gear and flywheel as I didn't know about the Pendolino motor at the time and I had quite a job removing the worm and flywheel from the old motor, so I didn't want to risk damaging a new motor by trying to refit the worm and flywheel.

I can't figure out why the X6331 was such a tight fit in the loco body.

 

[ColinB]

I didn't realise X6331 was the motor out of a Tornedo, that should fit ok, which obviously it does. Have a look at the location of your wires to the motor, on most of the locos I fix I find if is not located properly it makes fitting of the body difficult. I normally black tack them to the top of the motor with a covering of tape ( stops the black tack sticking to the body when it is on), then feed the wires down the space where the motor narrows because of the brushes.

[Topcat2018]

@ColinB

When I first dismantled the loco a bundle of four wires fell out. Two wires went from the DCC socket to the capacitor and ferrite bead, and a further two came back to the motor. It wasn't obvious where these would fit and the service sheet is useless in this respect since it doesn't show the wiring. This is why I routed two wires from the DCC socket straight to the motor and mounted the capacitor flat against the side of the motor, discarding the ferrite bead. I'm sure with a bit of thought they could have made the wiring simpler.

[ColinB]

Topcat from opening many locos, wiring is not a top priority on Locos for Hornby. I must admit on the newer ones it is a lot better. I think they have started to employ decent electronics people. On the Royal Scot/Patriot it is so bad that when you pull off the body the base plate generally separates from the boiler. When they were put together pushing the chassis in the wires slide easily but they "ping" apart once in the loco, hence why when you try to pull it apart it is extremely difficult. I find I have to use that super thin tape in most cases, instead of normal insulation tape. Generally on virtually all my Hornby locos with a tender I put the decoder in the tender as it makes the wiring easier but I must admit on my P2 it is still in the loco as I added firebox flicker and a front headlight. If you want to add sound there is just enough room to put a YouChoos IceCube speaker under the cab.