DJH Caley tank kit K8 0-4-4: rtr chassis?

[Julian]

Has anyone tried to fit a Hornby M7 chassis to the DJH Caley 439 0-4-4 tank body (kit K8)?  Just a thought since the necessary motor/gears/wheels purchase looks costly and I don't know how well I could get the loco to balance. A r-t-r chassis from the M7 looks like it might be a whole lot easier, if the DJH body can be made to fit the chassis, albeit the M7 driving wheels may be a scale 2 inches smaller than those on the Caley tank. I could live with that.... 

[34theletterbetweenB&D]

The balance problem will still be there to be solved if using the Hornby running gear. The Hornby plastic bodywork with metal ballast located over the driving wheels will have a far further forward centre of gravity than an all metal DJH body (that's a guess, but from experience). And there is no suspension as such provided for the Hornby bogie, the pick up wiring supplies what little there is to keep the bogie on the track should there be any off level elements on the layout. So you would need to plan on a rebuild of the bogie mounting rather than use what Hornby provide.

 

Then there's the wall thickness of the castings in the smokebox and front of boiler where the Hornby's fair sized motor and drive train is located, likely to be a tight fit.

 

In your shoes I would be thinking of trying a carve up and plasticard modification to the M7 body to create the larger tanks, with cast parts to replace characteristic features like the chimney. staying as close as possible to the weight distribution of the Hornby body, or even shifting the CoG a little further forward if possible.

[Londontram]

In your shoes I would be thinking of trying a carve up and plasticard modification to the M7 body to create the larger tanks, with cast parts to replace characteristic features like the chimney. staying as close as possible to the weight distribution of the Hornby body, or even shifting the CoG a little further forward if possible.

This is the route I'm taking with my Caledonian conversion from an old Hornby M7, I'm not sure about fitting the chassis to a kit body but the 439 is about 4mm shorter than the M7 so I've had to chop the chassis at the front and back to get the length right so would guess you would have to do the same if fitting the chassis to a kit but as 34theletterbetweenB&D (wish you had a shorter name) said the big problem will be the balance as the mid point on the Hornby chassis is right behind the rear driving wheel and the kit is going to have a lot of weight hanging over what on the early chassis is just a sprung piece of brass strip pressing down on the rear bogie.

Here is a link to my thread if it helps http://www.rmweb.co.uk/community/index.php?/topic/77470-rtr-locos-to-caledonian-locos-class-439-104-782-and-others/

[david.hill64]

but as 34theletterbetweenB&D (wish you had a shorter name) 

Hatfield perhaps?

[Thane of Fife]

I have built two white metal 0-4-4T's. Neither balance, and if you use the springing system, the rear drivers will tend to lift and reduce haulage power. I got round the problem by a Comet bogie pivot and making thick washers to go between the bogie pivot and a fixed frame spacer. The bogie can then move downwards slightly, but not upwards. This is not perfect but it works for me. 

The same problems arises with 4-4-0's, but there you can use the tender to hold the cab end down.

 

Thane of fife

[34theletterbetweenB&D]

... 34theletterbetweenB&D (wish you had a shorter name) ...

 34C will suffice! That's what I wanted to be, but as one of the 15% who 'fell off' in the great migration I was not allowed to re-use the name by 'the system'. If we have another such event I'll be '34thelettermidwaybetweenAandE'

I have built two white metal 0-4-4T's. Neither balance, and if you use the springing system, the rear drivers will tend to lift and reduce haulage power. I got round the problem by a Comet bogie pivot and making thick washers to go between the bogie pivot and a fixed frame spacer. The bogie can then move downwards slightly, but not upwards. This is not perfect but it works for me...

Exactly what Hornby have done on the M7. The bogie hits the top stop with all wheels running on the same plane. Works beautifully if the track is all in one plane, sudden loss of traction with any gradient transitions, especially those that raise the driving wheels relative to the bogie!