9f and a crumbling chassis

[Tom-367316]

Is it possible to get a repalcement chassis for the 9f, it's a lovely model that is just falling apart.

[Kim-344602]

Much will depend on which model it is. Hornby have produced models over a long period and they have evolved over time. wink

[Tom-367316]

i thought that would be the case, the body is S8296 and the loco number is 92239

[Kim-344602]

OK, Not 100% certain but pretty sure it's R2248. There will be others probably with the same chassis but that should give you a start point to start the search. Looking on the auction sites you might be better off looking for a replacement loco They seem to go for around £40-£50

[AndyMac1707817969]

Numerous parts for 9Fs on eBay, maybe something like this one

https://www.ebay.co.uk/itm/204429554051

[LTSR_NSE]

To ensure you get the best advice (& correct parts):

• is your model loco or tender driven?

• which chassis is disintegrating (affected with mazak rot) loco, tender or both?

[Going Spare]

Although R2248 is the most likely candidate, an outside runner is R264 as that was supplied with alternative numbers which included 92239.

R2248 is shown on the RMweb Mazak Rot list of affected models from all manufacturers and it is the loco chassis block that suffers.

If that is the case, a chassis from any China-made tender-driven loco would be a suitable replacement but obviously beware of one also suffering fatigue. No other 9Fs have been reported with this problem although there have been tenders that have been affected on other versions. Perhaps look for a non-weathered chassis (R2248 is weathered) and transfer the weathered wheels & motion from your loco.

[508006]

Back in late 2009 I purchased 2 Hornby Railroad 9F locos, I cannot remember the R numbers but 2 of them was evening star snd the other was running number 92221.

I had an incident which resulted in major damage to 1 of the loco bodies that could not be repaired and at the time, to get the loco running again I managed to get a body from an older hornby 9F to fit on the chassis after a bit of filing at the front end.

In a sense what I am saying here is that if you have a china made 9F with the fine blackened valve gear and even if your loco is a tender driven version, you can fit the body onto a loco drive chassis and the tender can be stripped of all the motor parts and used for power collection or used on another tender driven loco or diesel using the same motor.

If the tender motor was used in a modern image loco ( class 37, 47 or a 92 ) you could use the metal block from an unpowered bogie in the tender, fit self made pickups and add a realistic coal load, the possibilities are endless in terms of what you can do to return the loco into service.

With my loco's, the 2 chassis were used on a loco project and the body I used on 1 of the 9F's is now on another loco project to return a Britannia loco into service.

The other point I should include here is that if the model is a loco driven version, the problem could be that the tender chassis has failed due to mazak and therefore it is easy to replace again using the unpowered bogie block from a modern image co-co loco ( 37, 47 etc ) as these are an easy replacement for a failed motor block on a loco driven model.

Can I ask please if you could post a photo of the loco in need of attention so that we can further assist with your query and in turn give the correct solution.

Hope this helps.

[Tom-367316]

i didn't notice originally but there is a number on the chassis which is S 4275. The model is tender driven and the chassis that is rotting is the loco chassis

[Dukedog.]

Just a thought as this seams like a fairly common problem could a new part not be 3d printed?

[Going Spare]

S4275 is the part number for the chassis block casting. If you decide to seek just a replacement chassis block, be wary that, if I remember correctly, that part number was used for both UK- and China-made blocks for tender-driven loco's, and they are slightly different. So if your loco is Chinese, there needs to be a tapping on the top of the block for the screw that holds in place the motion bracket at the rear end of the valvegear, which is not present on UK blocks.

[Tom-367316]

Just a thought as this seams like a fairly common problem could a new part not be 3d printed?

It could be, but would need a good cad drawing of the original.

 

 

[Tom-367316]

is there a commercially produced chassis to replace this crumbling mess.

[ntpntpntp]

Reading through this thread the advice on here seems to be to look for an older UK made chassis for a tender-drive 9F and use the block from that, possibly needing a slight mod to create a tapped hole for a screw to retain the motion.

[Tom-367316]

Reading through this thread the advice on here seems to be to look for an older UK made chassis for a tender-drive 9F and use the block from that, possibly needing a slight mod to create a tapped hole for a screw to retain the motion.

 

 

That's what i've done, and i'll have a go at drawing this up in solidworks for 3d printing.

[ntpntpntp]

@Tom I would imagine a 3D printed chassis block will be too light unless designed to be hollow and filled with something like lead micro-shot as sold for increasing the weight in models.

It might need brass bush inserts to support the axles? Resin probably doesn't react well to lubrication, and without it may wear rapidly.

[Tom-367316]

@Tom I would imagine a 3D printed chassis block will be too light unless designed to be hollow and filled with something like lead micro-shot as sold for increasing the weight in models.

It might need brass bush inserts to support the axles? Resin probably doesn't react well to lubrication, and without it may wear rapidly.

 

 

hollow is a good idea, for adding weight. Doesn't the wheelset have brass bearings on the axles, mine does.

I'll try some oil on some of my prints and see if they deteriorate.

[threelink]

It might be worth checking your nearest toy and train fair. I went to one in Coventry a month ago or so and there was one stall with a box full of all sorts of chassis and a few other stalls with smaller numbers - all cheaper than auction sites. Good luck in finding something suitable.

[Tom-367316]

It might be worth checking your nearest toy and train fair. I went to one in Coventry a month ago or so and there was one stall with a box full of all sorts of chassis and a few other stalls with smaller numbers - all cheaper than auction sites. Good luck in finding something suitable.

 

 

i tried a model show last weekend but only found Mazak versions.

[threelink]

@Tom. I can understand your reluctance to go for a mazak chassis again - once bitten twice shy but I have been buying old mazak chassis for years and never had a problem. The only mazak rot I have ever encountered was with a Lima crab loco where a weight had succumbed. The biggest problem seems to be with some Chinese made Hornby items - I don't think their quality control is/was all it should be. Rot is caused by impurities in the alloy mix and by nothing else, something that was well known to UK manufacturers decades ago. If you find an old UK made chassis unaffected by rot it is highly unlikely to develop it now. I do hope that you find something suitable soon.

[Tom-367316]

@Tom. I can understand your reluctance to go for a mazak chassis again - once bitten twice shy but I have been buying old mazak chassis for years and never had a problem. The only mazak rot I have ever encountered was with a Lima crab loco where a weight had succumbed. The biggest problem seems to be with some Chinese made Hornby items - I don't think their quality control is/was all it should be. Rot is caused by impurities in the alloy mix and by nothing else, something that was well known to UK manufacturers decades ago. If you find an old UK made chassis unaffected by rot it is highly unlikely to develop it now. I do hope that you find something suitable soon.

 

 

i've ordered one from the bay which is silver in colour for £10, so we'll see if that one is good, it looks ok. I saw a grey/black one and you could see the rot setting in and a couple of crumbs in the picture.

[ColinB]

From what I gather Hornby were on top of the issue when locos were made in the UK, it was when the Chinese started to make them the problem reoccurred. It seems to take a while for the Chinese to get a grip on materials. The Royal Scots are really bad for it and the Princess Elizabeths they made for a M&S trainset were really bad, then there are the 9Fs. My 9F is later but that didn't stop them making the tender out of plastic which splits when you put the empty ringfield motor chassis into it. When I was looking for a replacement chassis for my Princess Elizabeth it seemed they rotted around where the motor goes, similarly on the Royal Scots.

[Tom-367316]

well the chassis has arrived and it's a lot nicer than the original, no sign of any crumbling and the wheelsets sit nicely. This one was not designed for this model so it needs a hole drilled and tapped for the valve gear bracket to fit, which looks like 8BA.

[Tom-367316]

here's the chassis and a handy box for loco's i'm working on (courtesy of "ome baargins", as we say around here)

[Going Spare]

That looks as if it might be a basic chassis block casting for a UK-made model. Have you compared the new and old blocks or tried a trial fit of the motion plate and body on the new block? The new one might need modifying slightly to allow the body to sit down on the block properly. UK-made 9Fs had an unprototypically large gap underneath the boiler but this was reduced on Chinese models. Has it been tapped to take the various screws? If it has, the threads will be imperial rather than metric but your screws may cut their own threads.