TFW’s workshop

[queensquare]

I must admit I've had problems with the pivot point on weighted tenders being behind the rear axle. I now move them to fall just inside the wheelbase based very much on the Mike Raithby, Nigel Hunt design. That said I suspect the problem was largely down to a lack of weight, I simply glue my motors in the tender so don't have the advantage of Tim's much better arrangement and greater weight of a motor mounting block and flywheel. As Tim says, the fixed fall plate will add greater stability.

 

John Greenwood's,  extended axle design of tender chassis simply gives the front two axles on the tender a mm or so of vertical movement, the rear axle itself then effectively acting as the pivot. 

 

Jerry

[CF MRC]

Even without the fall plate, the tender pivot arrangement gives quite good stability,  as seen on the Club’s test tracks tonight.  Torque rocking effects of the motor and flywheel appear a little less obvious as well, if starting too fast.

 

Tim

[Donw]

Certainly runs nice and steady Tim.

 

Don

[CF MRC]

It’s only a small part of the total, but getting an engine with a front bogie to track correctly requires a means of supporting and restraining the front end, whilst at the same time allowing the driving wheels to maintain traction.  

 

This little pin, spring and curved slot should do the trick for Valour.  The bogie side frames are made up in layers from the etch and the pivot is actually a 14BA bolt, with the threads reduced in the turning areas so as to reduce friction.  The slot is tapping width for the bolt, which screws through it into the shouldered brass pin which also restrains an N gauge coupling spring for downward pressure and a little side control. A washer is soldered to the spring to prevent it insinuating itself through the slot.  I think it is advantageous to have the bogie slot at the bottom of the stretcher, rather than the top, as it will give better stability. 

 

The central brass pin is located in the PCB spacer between the cylinders and soldered to it’s top and bottom sides, respecting electrical neutrality of course.  

 

It is evident that clearances have had to be made for the bogie wheels, which are scale size at 7mm, but of course with oversized flanges.  Experience has shown that clearances need to be far more than you might think!

 

Having the bogie on the front begins to give Valour a racy look. The white muffs will be replaced with a scale axle at the front and a small black muff at the rear. 

 

The video shows the bogie in action. 

 

Tim

 

 

 

 

[CF MRC]

Moving on to the engine bodywork, that clever Mr Easton uses a cradle to support the running plate.  This makes it pretty simple to assemble.  I did, however, use my own piece of larger 5thou NS sheet for the change in direction of the running plate behind the raised cylinder section - this will get trimmed to size later on. The supplied squiggly bit was just too small and fiddly. 

Similarly, the front steps were made out of 5thou strip, being much easier to hold as well as being closer to scale thickness: they are quite large and thin on the real thing.  The strip is held in place but notched where it needs to break before soldering into place. 

The piano front between the frames was made from som 0.6mm thick NS filed to shape: it took quite a while to get it nice and snug. 

Will soon separate the running plate from the jig and offer it up to the chassis.  Kits certainly speed up construction.

 

Tim

[65179]

Tim, do you have any suggestions for ensuring the cradle folds up nice and square?

Thanks,

 

Simon

[CF MRC]

I used some bending bars that I had made,  Simon.  Maybe one of those folding holding gadgets would work.  A vice interferes when you fold up the second side. 

 

Tim

[65179]

Thanks Tim.

 

Did you find the fold lines needed enlarging?

 

Simon

[CF MRC]

No, but you could run a knife along to make it bend easier.  It all went together very well - just need to take care on the fit of components with judicious filing. The curves were bent around steel rods (could be drills) at a small size to ensure that they made the correct diameter, this was especially so at the front, but the back was easily persuaded by hand. 

 

Tim

[CF MRC]

The running plate is now mounted on the chassis with three bolts to locate it.  She now begins to look like an engine. 

Thin double sided PCB, tucked  up behind the valence, has been used to insulate the front running plate from the cylinder assembly.   The smoke box will bolt through the PCB. 

 

Tim

 

[Donw]

I find the Hold and Fold most useful but before I had them I used a couple of pieces of ground steel stock If the bends are very close a steel rule can be helpful.

 

Don

[CF MRC]

I’ve been working on Valour’s cab over the last couple of days.  The windows have etched frames to be fitted - quite fiddly in fact.  The front spectacle frames were too fine for use (over-etched for the thickness) and so some strip was bent up and soldered in place.   The cab roof has some long slots left proud by half etching in order to accommodate the up right of the characteristic T  section external roof ribs.  These etched ribs were thinned down with a file to fit the slot and then soldered in place using my trusty surgical clips to hold them in place. 

 

It was easier to solder the back rib in place with it still attached to the etch. 

 

The roof is very rigid with the extra ribs. 

 

 I couldn’t resist putting the splasher with integral nameplate in place.  It may, in fact, be the next job. 

 

Tim

Edited August 31, 2019 by CF MRC

[CF MRC]

The splashers are now fitted and the cab footplate & inside splashers made. I have used a slab of brass to support the cab floor, putting weight where it’s needed. This will also be drilled and tapped to take a longer pivot screw for the tender.

 

The line drawn down the middle of the cab front corresponds with a line drawn down the underside of the cab roof, which helps to align the two (not my idea, but Graham Nicholas’ who wrote up the 4mm example instructions).  The UJ cap will push forwards a little on final assembly and clear the back head which will be made as a brass lost plastic casting and fixed to the removable footplate. 

 

I’m not quite sure how to do the Belpaire firebox, as it is 45 years since I last made one.  There are etchings included in the kit, which might wrap around a slightly reduced diameter boiler turning.  There should be plenty of weight over the driving wheels, as the drive head sits nice and low between the splashers. 

 

Tim

 

[t-b-g]

Looking good Tim. You are racing ahead of me know.

 

I don't know how much effort you want to put into the cab interior as it will be well hidden in 2mm but I fear that the etches supplied are more guessed at than based on the real thing.

 

The cab interior has two curved edge floor sections raised up and splashers that are boxes rather than conventional curved splashers.

 

I am adding a photo of the 7mm version so you can see what I mean.

 

[CF MRC]

That's much better Tony.  I didn’t like the look of the etched splashers as they are ugly and bear no resemblance even to Butler Henderson, so its an easy one to modify at this stage. 

 

Tim

Edited September 1, 2019 by CF MRC

[Donw]

7 hours ago, t-b-g said:

Looking good Tim. You are racing ahead of me know.

 

I don't know how much effort you want to put into the cab interior as it will be well hidden in 2mm but I fear that the etches supplied are more guessed at than based on the real thing.

 

The cab interior has two curved edge floor sections raised up and splashers that are boxes rather than conventional curved splashers.

 

I am adding a photo of the 7mm version so you can see what I mean.

 

 

Tim might well see that as a challenge to match the cab detail. I am also minded that that view of the 7mm one gives a good view of the shape of the firebox.

Nice work from both of you.

 

Don

[t-b-g]

I have added a bit more since that photo was taken. There are still some details that could be added but I am beginning to think that enough is enough!

 

I am looking forward to seeing the improved 2mm version. My guess is that it will be rather lovely!

 

Valour and Butler Henderson have almost identical interiors as far as I can tell. The main difference is the extra bank of lubricating gear top right as Valour has extra cylinders.

 

 

 

 

Edited September 2, 2019 by t-b-g

[CF MRC]

Looks like the demise of Tinypic has wiped out most of my photos: very tedious. 

 

Anyway, Valour now has a kettle, machined and filed out of a lump of brass.  All up weight is a very chunky 75g for the engine alone. 

 

Robinson fireboxes have some subtle curves. 

 

Tim

 

[Donw]

A thing of beauty Tim

 

Don

[Atso]

That's absolutely stunning Tim!

[CF MRC]

I have resumed work on Valour’s tender front.  There are some pleasant little details around the front tool box. The top is still loose (hence the bad horizontal front joint), but it now has the motor cover in place.   The engine will probably have a fairly empty tender, as it will be working on the up Sheffield Pullman, coming in to KX. 

 

Tim

[CF MRC]

The rear cylinder covers were originally made oversize lumps to allow filing into shape for the piston stuffing boxes, studs & nuts. 

These have now been fettled into the correct lozenge shape. 

Afraid I drew the line at wiring the nuts in position to lock them.  Valve gear to follow.  The piston is 0.5mm diameter. 

 

Tim

[65179]

I hope you'll be adding the oil pot Tim ;-)

 

Simon

[CF MRC]

6 hours ago, 65179 said:

I hope you'll be adding the oil pot Tim ;-)

 

Simon

You mean that one, Simon?

(No 0.3mm drills were harmed in the making of these oil pots).

 

Tim

Edited September 17, 2019 by CF MRC

[CF MRC]

I have continued filling in the valve gear and drain cocks / linkage and cylinder covers. Quite fiddly. 

The nearside works plate will need a slight trim with a sharp chisel. 

Tim