7mm The Derby Line - Rolling Stock

[dibateg]

I'm mulling over the tender of the J6, I think there was a reconfiguration of the 3170 gallon tender at some point. Moving the coal divider forward and down, also changing the tank top behind it to raise the tool boxes higher. They are often shown buried in coal. Most of them appear to have had this change. If anyone has any ideas or contradictions, that would help!

 

[Rob Pulham]

I'm mulling over the tender of the J6, I think there was a reconfiguration of the 3170 gallon tender at some point. Moving the coal divider forward and down, also changing the tank top behind it to raise the tool boxes higher. They are often shown buried in coal. Most of them appear to have had this change. If anyone has any ideas or contradictions, that would help!
View attachment 133007

Hi Tony,

From what I have read/seen in photos J6's had several tenders attached to them. I hadn't realised when ordering this one that David offers three tender options. I had already started building the tender (Ivatt Horseshoe type) when my customer noted that it was the wrong one for his prefered engine. I was able to obtain the required Ivatt self trimming type from David so all is well in the end. With all the optional bits included in the kit and a spare horseshoe tender, my plan is to build myself a 521 series loco at some point.

It's hard to tell from your photo whether yours is the Stirling type or the Ivatt Horseshoe type but it's definitely not the Ivatt self trimming type.

 

[dibateg]

Looking at Yeadons Rob - it looks like all the 3170 tenders had been modified by the LNER. You can see why, there is a photo of one in GN condition and footplate is awash with coal. Jonathan Wealleans on RMWeb confirms the observation - but detailed information is non-existant. It look like one of the tenders in your photo selection had a similar modification, but without raising the tool boxes.

Regards
Tony

 

[Heather Kay]

I recall similar issues with my build. In the end, I agreed with the client that we’d find a good compromise arrangement based on as many photos as we could find!

I think I’m right in saying the J6 original tenders as built were sniffled away for other locos as they were better than some of the older stuff. Consequently, older and rebuilt tenders were attached to the class, cascaded from scrapped locos. That’s why there’s such a mess of styles and types.

 

[Rob Pulham]

Looking at Yeadons Rob - it looks like all the 3170 tenders had been modified by the LNER. You can see why, there is a photo of one in GN condition and footplate is awash with coal. Jonathan Wealleans on RMWeb confirms the observation - but detailed information is non-existant. It look like one of the tenders in your photo selection had a similar modification, but without raising the tool boxes.

Regards
Tony

Good morning Tony, I sent you a couple more photos this morning before reading this I can't post them publicly because I can't recall where I got them from to credit the copyright owner.

 

[dibateg]

Thanks Rob - any info is useful!

I finally came to a resolution of the tender front, with an estimation from the various photographs. The tank top extends to behind the dividing plate, that allows the toolboxes to sit at the height you can see in the photo. The front plate was cut out and then trimmed to fit. They do appear to tilt back. There is a small locker to scratch up for the left hand tank extension. Tool box just plonked for reference.


I've also been distracted by Crosby Hall which has come back from Alan Brackenborough for finishing. That will be the last GW engine here for a while..

 

[dibateg]

The front end is sort of completed, just need to straighten up that wonky gate. The camera always picks these things out. I scratched in the little locker and made up the handbrake from tube. Water valves are from Ragstone. The tool boxes could probably do with a flatter lid profile, but the are on now.. The steps look wide, but we'll see how they look when the loco is done. Just the whitemetal details to add...

 

[dibateg]

I've been trying to work out how to make the motion. It is similar to a 4F with a rocker mechanism to to drive the valves, except that rockers are formed of two cranks on separate shafts as the valves are centred over the cylinders. I can't see how it could be made in situ, so needs to be a removable unit and of course it's all a little narrow. I'll see how far I get with it.


Its all a bit rough and ready and it need a lot of tidying up yet, but the concept sort of works. The top drive rods are combination levers from 4mm 9Fs spare valve gear etch! It won't be 100% accurate, but hopefully will convey the flavour. The only way to convey the drive to the crank is to put a pin through - there are just temporary shafts there at the moment, they don't go all the way across. The other drive arm drops down next to the inside of the slidebars. The slidebar bracket is fixed to the frames by two 14BA screws going in to the flange at the top.

 

[Dave Holt]

I'll watch this with interest, Tony. I hope to build a 4 mm ex-GCR C13 tank with inside valve gear. Like you model, it had offset rockers, so your solution will be off great help.
Looking very good so far, so best of luck with it.
Dave.

 

[mickoo]

I've been trying to work out how to make the motion. It is similar to a 4F with a rocker mechanism to to drive the valves, except that rockers are formed of two cranks on separate shafts as the valves are centred over the cylinders. I can't see how it could be made in situ, so needs to be a removable unit and of course it's all a little narrow. I'll see how far I get with it.
View attachment 133558

Its all a bit rough and ready and it need a lot of tidying up yet, but the concept sort of works. The top drive rods are combination levers from 4mm 9Fs spare valve gear etch! It won't be 100% accurate, but hopefully will convey the flavour. The only way to convey the drive to the crank is to put a pin through - there are just temporary shafts there at the moment, they don't go all the way across. The other drive arm drops down next to the inside of the slidebars. The slidebar bracket is fixed to the frames by two 14BA screws going in to the flange at the top.
View attachment 133559

You have my sincere sympathies

I found small one hour sessions were as long as I could stomach, before the over-riding urge to hurl it over the fence Botham style became too great

 

[dibateg]

I've been nibbling away at this for days on and off and finally got it all to fit in and work. I couldn't fit the droplinks to the upper ends of the expansion links ( just not enough width for them ) , so they are lifted from the bottom. It's not 100% accurate, but close enough as I can get it without spending weeks scratchbuilding the whole lot... Anyway I managed to make it so that the whole assembly and crank axle can be removed from the frames...

 

[Dave Holt]

Lovely. Can you show us a bit more of the assembly and how you've made it removable? I keen to steal your ideas!
Dave.

 

[dibateg]

Thanks Dave -
I'll take some pictures once it is apart again. You can see there is a 14BA screw just at the top of the frames each side between the wheels that goes in to a tapped hole in some brass angle soldered to the motion plate. Then the stepped N/S plate at the front has a nut soldered into it to take a 12BA screw that goes through a stretcher soldered between the frames.

Cheers
Tony

 

[Ian@StEnochs]

It is much easier if you can assemble the valve gear off the main frames. I do something very similar to what Tony does but as I work in S7 there is a bit more space between the frames.

This is the only photo I have and it shows the arrangement from underneath. There is a single screw at the front of the cylinder block and two more which go in through the frames into tapped holes in the motion plate just like Tony’s. However unlike Tony’s on this model I chose to make the valves static and only the pistons and connecting rods move. Actually you can hardly see the motion when the loco is static and you certainly cannot see it moving when it runs past!

Ian.

 

[Dave Holt]

Thanks very much for the explanation and ideas. Stored away for future use.
Some time ago, I did some worked on the chassis of a friends LMS 4F (4 mm P4) which had full working valve gear. Beautifully made and very smooth operation, but to be honest, the visible movement was so small, it did make me wonder if it was worth all the effort (says he doing inside valve gear on a re-built Royal Scot - almost invisible from normal viewing angles).
Dave.

 

[dibateg]

Very neat Ian - I wish mine looked as tidy as that and its pretty well the same fit to the frames as mine. What a luxury to have all that room between the slidebars.
Thanks for showing us.

And yes - there is only a small amount of movement to the valves, it was more of a challenge to myself to see if I could do it. You'd have to have amazing eyesight to see them moving as the loco negotiates the layout. It is a bit rough and ready. I needed to fix the top rockers to the shaft, so came up with the idea of drilling through and fitting 0.6mm pins. They ended up by being fixed with two broken off 0.6mm drills instead.....

Regards
Tony

 

[Ian@StEnochs]

Tony,

Overhead valves with their rockers are a bit more obvious and you can, just, see movement if the engine is moving slowly. These I do try to make work but it does take a lot of time. I have removed the feed pipe and clacks from this one so you can see a wee bit more. My phone kept focusing on the pipe and blurring the motion!


I try to make my moving pin joints from .7mm or 1mm wire. Fewer drill breakage and the wire looks nearer the size of the collars if filed flat. I have some ready chemically blacked do the solder doesn't take and just clean off where I want to solder.

Ian.

 

[mickoo]

.................They ended up by being fixed with two broken off 0.6mm drills instead.....

Regards
Tony

Not just me then

Like Ian I've now moved up a bit to 0.8 and 1.0 mm pins.

 

[dibateg]

Life goes on -

It took me ages to work out what to do with the injectors, it looks like the LNER replaced the original GNR ones and that there were two types. So with a bit of cutting and moving flanges, I came up with a representation.


Cab doors on, chimney on, injectors, and there is a blinking pipe on each side along the running plate. Nearly there... Just the loco frames and back head to sort out. I am pleased with this engine, it has a lot of character.


Pesky injectors....


There is a big gap, between the boiler and running plate, so that inside motion is easily visible:-

 

[Heather Kay]

I am pleased with this engine, it has a lot of character.

I have to agree with you. The one I put together (I say that as I didn’t put half as much effort in as you and Rob have) still remains one of my favourite builds. It’s probably because it didn’t come from Swindon…