DJH D20

[coronach]

Winter is a good time to start construction of a new loco kit and so I dug out the DJH D20 from the loft and commenced work. I have already built one DJH white metal kit of a NBR J35, which went together well with low melt solder. This time, instead, I have decided to use adhesive wherever I can. This avoids the risk of inadvertant meltdown!

 

I have used Canopy Glaze glue quite extensively in constructing buildings and accessories and found it to be very effective in attaching metal, plastic and wooden components. It is much easier to use than Araldyte - t dries quickly and the joints seem to be good and strong. Hopefully it will ensure over time

 

Below is progress as of this weekend. I cheated and bought a ready made motor and gear set - it runs very sweetly. I mounted the motor to drive on the front driver, which means that the gearbox protrudes into the cab, which is a shame. I might see if I can turn it around.

 

Most of the castings are good quality however the chimney is a little disappointing. I would like to replace the boiler fittings with turned brass items if i can find a supplier - any ideas anyone ?

 

Edited January 29, 2019 by coronach

[mikemeg]

Most of the castings are good quality however the chimney is a little disappointing. I would like to replace the boiler fittings with turned brass items if i can find a supplier - any ideas anyone ?

 

WP_20190127_17_36_53_Pro.jpgWP_20190127_17_36_27_Pro.jpgWP_20190126_15_46_00_Pro.jpgWP_20190126_15_44_01_Pro.jpgWP_20190126_15_44_42_Pro.jpg

 

Arthur Kimber - North Eastern Kits - produces a full set of castings for the D20, including boiler fittings, backhead fittings, Westinghouse pump, sand pipes, brake cylinders, mechanical lubricators, etc. Arthur also produces an etched kit of the D20 which was the raison d'etre for the castings..

 

Attached is a photograph of North Eastern Kits D20 - test build - with the Worsdell frames as yours has, showing some of the range of castings in place.

 

Chers

 

Mike

Edited January 29, 2019 by mikemeg

[34theletterbetweenB&D]

... I mounted the motor to drive on the front driver, which means that the gearbox protrudes into the cab, which is a shame. I might see if I can turn it around...

 

The counsel of perfection is to have the drive on the front axle and the motor lying forward toward the smokebox, provided that you can contrive sufficient wiggle room (or alter the boiler construction) to permit the mechanism to be removed and replaced in the finished loco body. That frees space above the drivers for a great deal of lead, which gives you a good chance of getting the model's centre of balance between the coupled wheels, overcoming the front heavy nature of 4-4-0s, especially affecting those with cast whitemetal bodies.

 

It's a handsome model in the making, yet another steam class where the surprise is that no RTR has ever been available.

[jwealleans]

Can I point out, in case you weren't aware, that the tender in this kit is wrong, in that the cutouts are lozenge shaped instead of D shaped (as on Arthur's kit and Mike's model above).

 

DJH apparently copied the drawings and didn't check photographs to see whether works had done something different.

 

Edited January 29, 2019 by jwealleans

[mikemeg]

In the D20. shown above, the drive is on the front axle with the motor - Mashima 1420 - facing rearwards. This photo was taken before the rear motor shaft was cropped off, which allows the backhead to be fitted without any interference from the rear of the motor. The internal motion is not part of the kit but was scratch built.

 

It is, perhaps, worth mentioning that this chassis contains quite a lot of lead between the mainframes and directly under the motor.

 

Note that the driving wheel balance weights are located differently on each wheelset due to the internal reciprocating masses on the front axle.

 

Cheers

 

Mike

Edited February 4, 2019 by mikemeg

[coronach]

On ‎1‎/‎29‎/‎2019 at 8:38 AM, 34theletterbetweenB&D said:

The counsel of perfection is to have the drive on the front axle and the motor lying forward toward the smokebox, provided that you can contrive sufficient wiggle room (or alter the boiler construction) to permit the mechanism to be removed and replaced in the finished loco body. That frees space above the drivers for a great deal of lead, which gives you a good chance of getting the model's centre of balance between the coupled wheels, overcoming the front heavy nature of 4-4-0s, especially affecting those with cast whitemetal bodies.

 

It's a handsome model in the making, yet another steam class where the surprise is that no RTR has ever been available.

Thank you for this advice.  I have dissembled the chassis and mounted the motor so that it drives the front axle with the motor forward in the boiler.  I am much happier with this arrangement - not much fettling of the boiler needed.  As you say, the loco is front heavy and I can fill the firebox with lead to balance the loco.

[coronach]

[rowanj]

I built a DJH D20 recently, and enjoyed it. You can follow my build on the link, including the mods I made to fit my BR period. 

John

[micklner]

It will never run with the motor facing forward. A High Level Gearbox would be much better option as well. 

 

Picture of my DJH D20 , old awful kit . The Tender was sold off and a Alexander Models version used. A lot of reworking and added parts on mine.

[coronach]

1 hour ago, micklner said:

It will never run with the motor facing forward. A High Level Gearbox would be much better option as well. 

 

Picture of my DJH D20 , old awful kit . The Tender was sold off and a Alexander Models version used. A lot of reworking and added parts on mine.

Why won't it run like this?  Surely the gearing works the same way.  I will try it and if it doesn't run the I will turn the motor around and cut off the motor spindle so it didn't protrude into the cab.

Your D20 looks superb.

 

Edited February 2, 2019 by coronach

[34theletterbetweenB&D]

I have built several mechanisms motor forward for balance or concealment using a variety of gearbox arrangements, and every single one has worked just as well as motor behind driven axle mechanisms. RTR manufacturers too go 'motor forward', the very useful mechanisms in Bachmann's 57xx and Jinty for example.

[micklner]

It is a 4-4-0 which being white metal is very nose heavy . For a 4-4-0 to run well all the weight needs to be as far to the rear as possible. 

[coronach]

I plan to fill the firebox space with lead to counterbalance the front end.  It was front heavy with the motor over the wheels.  Time and progress will tell.

[rowanj]

I'll be interested to see if the motor location works. I don't see why it shouldn't, on the face of it. I'm currently building a B16 with the motor driving that way round, albeit on the rear wheels, and previous builds of the class worked out fine. You may have trouble getting the body on and off with that big motor in the boiler.

I suggest you drive off the leading pair as per Mike's photo,cutting off the rear shaft. For extra balance, I replaced the awful bogie swing arm  with an etched pivot from Wizard/Comet to provide greater adhesion. That, alongside using the tender connection to keep the rear driver's on the track, was enough. The kit is heavy enough without packing more lead into it, in my view.

Hope all goes well..there is no right way to build locos,..just the way that works.

John

[coronach]

Well, the motor forward arrangement fits the boiler like a silk glove and is easy to remove.  I have enjoyed fitting some of the parts to the loco this afternoon.  I am pleased with progress so far but I must admit that some of the white metal components need a bit of fettling before fitting.  Compared with the brass PDK D30 kit I built last year, this one is quite crude and clunky - but it is still pleasing to build.

[coronach]

some pics.....

[34theletterbetweenB&D]

23 hours ago, micklner said:

It is a 4-4-0 which being white metal is very nose heavy . For a 4-4-0 to run well all the weight needs to be as far to the rear as possible. 

And that is specifically what placing the motor forward of the coupled wheelbase enables. A motor is relatively light, the same volume of lead will be double the mass, and with no motor above the coupled wheelbase of a 4-4-0 it is very simple to pack the entire body void above and behind the coupled wheelbase solid with lead, usually enough alone to place the centre of balance of the loco within the coupled wheelbase. (Obviously, more can be done such as reducing wall thickness of heavy castings at the smokebox end.)

[micklner]

Looking at the photo of the chassis, fitted with DJH gearbox. 

 

1. The gearbox due its width maybe/will  be visible when fitted to the body.  e.g Tony Wright has shown photos on his thread of them fitted to 0-6-0 Locos facing backwards and they can be seen protruding past the Firebox into the space under the Boiler. High Level Gearboxes can be fitted into Locos and be invisible after fitting, as in Mike Meggisons photo of his D20 chassis, this was also the type of Gearbox used on my D20 shown above .

 

2. The sheer mass of the body on the D20 is forward of the front driver. To compensate for that the whole of the firebox would probably need to be filled with lead for the loco to balance. At this point the Loco will be extremely heavy/overweight and the motor will suffer/burnt out in due course.

 

3 The motor will have to be locked into position to stop any whipping movement as that will disturb the balance of the Loco very time power is applied. As the motor is now locked it in a fixed position, it will be very hard/impossible to get the chassis to fit the body without cutting a large hole in the bottom of the Boiler.

 

At this point is see zero advantage in fitting the motor forward of the driving wheels. In particular due point 3 sheerly for cosmetic reasons alone if no other. 

[coronach]

The photos above show the kit with the motor fitted forward of the front driving wheel in the boiler.  Neither the motor nor the gearbox is visible, and the cab is completely free.  Very little metal needed to be removed from the underneath of the boiler.  Plenty of room behind the front driver to pack the boiler with lead.  

[mikemeg]

19 hours ago, coronach said:

The photos above show the kit with the motor fitted forward of the front driving wheel in the boiler.  Neither the motor nor the gearbox is visible, and the cab is completely free.  Very little metal needed to be removed from the underneath of the boiler.  Plenty of room behind the front driver to pack the boiler with lead.  

 

Re this sequence of photos, could I make the following observations :-

 

I think that the footplate steps should be mounted behind the valance and not in front of it. As mounted, these steps will compromise the overall width of the loco.

 

The vacuum pipe could, perhaps, benefit from the straightening of the angled portion over the junction between smokebox and boiler.

 

The pipe from the smokebox to the Westinghouse pump should be straighter and parallel with the footplate and the pipe down from the smokebox to the footplate should surely be straighter, though the photo of 62387 shows this pipe bent.

 

Cheers

 

Mike

 

Edited February 4, 2019 by mikemeg

[coronach]

Thanks Mike.  Yes of course, the steps should be onboard of the footplate.  I will gradually tidy everything up but only to the extent that it would be right at the end of the life of the loco.  When i first fitted the pipework, it looked too pristine, however i have possibly gone overboard with knocking things around LOL.

 

The only other DJH loco kit i have built is the J35 - see page one of my layout pages.  That kit contained a much superior set of parts to the D20.  I presume this kit is much older.

[coronach]

Another satisfying afternoon.  The loco body is almost complete.  Needs a bit of tidying up....

 

[micklner]

It look like you need to either make the Smokebox handrail knob smaller or use medium knobs on the Boiler .

[mikemeg]

On 09/02/2019 at 18:35, micklner said:

It look like you need to either make the Smokebox handrail knob smaller or use medium knobs on the Boiler .

 

The 'standard' handrail knob approach - at least using Alan Gibson handrail knobs - on these North Eastern boilers with a larger diameter smokebox is, as Mick suggests, to use the short knobs on the smokebox and medium on the boiler. This should preserve a straight and parallel handrail to both boiler and smokebox. On the left hand side of the smokebox (looking forward) the handrail was terminated just in front of the blower valve with the blower valve rod, from the cab, being enclosed in the left hand side boiler handrail. The attached photo shows this just under the chimney on the smokebox side!

 

Also, look at photographs of the curves of the handrail (the earlier photo of 62387 shows this very well) around the front of the smokebox. These curves are flowing but compound curves i.e the horizontal curve from the smokebox side through 90 degrees is of one radius, the vertical curve on the smokebox front, upwards, to meet the profile of the smokebox top curve either side, is of another radius. So, two planes and two different radii.

 

I normally make a scale drawing of the front curve profiles of the handrail, the distance from the top of the handrail to the sides and the total width from side to side,  across the boiler. This drawing then acts as a template for the front of the handrail and shows the limits of the curves into the sides of the handrail. The actual bending up of the handrail is done around formers of various diameters from 22 mm to 2 mm diameter, remembering that a wire bent around any former will spring to a sllghtly larger diameter.

 

The prototype photos, courtesy Mick Nicholson, show a D20 in its LNER days - pre 1946 numbering - and the last survivor - 62396 -  in 1957, its final year. This was the only D20 to ever carry the later BR totem on its tender.

 

Worth noting that the double whistle, initially installed on these locos, was replaced during LNER days by a single whistle, latterly mounted on the cab roof. Also, by their later years, the Ross pop safety valves were mounted directly onto the firebox top, without the casing which is shown in the second photo below. Changes were also made to the arrangement of the brake rodding, the smokebox doors (though not on all locos) and the buffers - though not on all locos - and buffer beams, where the North Eastern steel/wood/steel 'sandwich' was fitted on the loco but not the tender, in later years.

 

Cheers

 

Mike

 

Edited February 11, 2019 by mikemeg

[Pebbles]

There should be sufficient thickness in the smokebox casting to allow the handrail knob to be partly countersunk, lining it up with the handrail knobs on the boiler