DJH Streamlined Coronation – From Woe to Recovery

From “Woe to Recovery”, it sounds like the title of a book or film
Where do I start, when assembling the cylinders, one of the jobs was to drill out the valve guides. When I drilled the first one I managed to break a drill bit of in the middle of it. I attempted to get it out by cutting off the rear spigot and drilling small holes around the end of the drill bit but didn’t succeed in getting it out. I popped a bit of rod in the other end and it went a fair way in so I reasoned that I might get away with shortening the rod because the valve stems don’t appear to move that much.
This was what was peeking out of the end of the casting but it wasn’t quite enough to grip.

DJH Streamlined Coronation – Motion – Getting out of trouble with a broken drill bit in a whitemetal casting

When I broke the drill bit off in the first casting, I decided to make a collet to allow me to better grip the second casting without damage and I was able to drill the second one without issue.
This is the collet and another view of my attempts to remove the offending drill bit stub

DJH Streamlined Coronation – Motion – Getting out of trouble with a broken drill bit in a whitemetal casting

DJH Streamlined Coronation – Motion – Getting out of trouble with a broken drill bit in a whitemetal casting
I advised the gent that I am building it for what had happened and that we may need a spare casting but I was going to attempt to work my way past it. During the assembly of the valve gear I carefully measured the amount of valve stem and progressively shortened it until it fit.
Fast forward to giving it a test run and it dropped out of the guide jamming up the valve gear.

DJH Streamlined Coronation – Motion – Getting out of trouble

When this happened on Tuesday evening I took the wise course and stopped to ponder.
First thing yesterday morning as I was getting up for work, Chris said I have the solution to getting the drill bit out and proceeded to explain the idea that she had dreamt while asleep. The idea was basically, to cut a cut down the side of the casting to relieve the grip from the whitemetal and then drift the stub out.
After dinner I went into the workshop to take the valve gear to bits and unsolder the valve guide casting. I then out the casting in the collet and after a bit of a fiddle managed to get the seam of the casting lined up with the slit in the collet and gripped in the vice.

DJH Streamlined Coronation – Motion – Getting out of trouble with a broken drill bit in a whitemetal casting

DJH Streamlined Coronation – Motion – Getting out of trouble, making the cut

That done and using an old Exacto Blade, I proceeded to cut through the side of the casting using some odour free white spirit as a lubricant (made more essential by the fact that this Exacto blade has a slight kink at one end). I kept steadily cutting until I felt the blade grating on the side of the drill bit stub (why I used an old blade) and then removed the casting from the vice.

DJH Streamlined Coronation – Motion – Getting out of trouble, making the cut

The next bit’s I forgot to take photos of but using another broken drill bit as a drift I placed the bottom end of the casting on a block of wood which I have on my bench with the protruding stub of the drill over a hole that I had drilled when going through something previously (it doesn’t quite look like swiss cheese but there are a good few holes in it).
The drift moved the drill bit out a few millimetres further, to the point where I was able to grip it in a pin vice. I was then able to grip the casting in my hand and a twist of the pin vice had it free.

DJH Streamlined Coronation – Motion – Getting out of trouble, success at last

I then filled the seam with 70 degree solder and using the collet as a heat sink I soldered the casting back on and cleaned it up. In the photo below the seam is uppermost and is to all intents and purposes invisible.

DJH Streamlined Coronation – Motion – Getting out of trouble, casting repaired

Lastly I dismantled and remade the valve stem. The original is two layers of etch. I made the replacement from a piece of 1.10mm brass rod. I am not too happy with the boss so I plan to have another go later this morning.
This is the shortened version.

DJH Streamlined Coronation – Motion – Getting out of trouble, shortened valve stem

This is with the bit that I had cut off

DJH Streamlined Coronation – Motion – Getting out of trouble, shortened valve stem

Lastly this is the replacement.

DJH Streamlined Coronation – Motion – Getting out of trouble, replacement valve stem

DJH Streamlined Coronation – Assembly of the motion

Despite many distractions recently I have made slow progress on the Coronation.
One of the easier wins over the weekend was to epoxy the balance weights on – the instructions have you do this much earlier in the build but I seem to have a tendency to do them as late as possible and I am not sure why.

DJH Streamlined Coronation – Balance weights fitted

Then on to the fun bits, I wanted to make the valve gear removable for painting so some mods were needed
This is what the front of the frames looked like with slots where the cylinders fed through to attach to the top of the frame spacer.

DJH Streamlined Coronation Tender – Loco Chassis Brakes and minor details fitted

This was what they look like after a visit from my piercing saw.

DJH Streamlined Coronation – Cut outs to make motion removable

Then I needed to make some spacers to attach the two cylinders together

DJH Streamlined Coronation – Spacers to make cylinders removable

Doing this meant that the 2mm diameter screws provided were not long enough so I retapped the holes 8BA and added some longer 8 ba screws. to hold them on.
next I soldered the slide bars to the motion bracket frame and started to assemble the valve gear

DJH Streamlined Coronation – Assembled motion

DJH provide 14ba screws/nut to assemble the valve gear which I have used but I have also done a belt and braces approach by tapping all the holes 14ba too which allows the nut to be locked on. Most of them also needed to be filed back for clearance purposes.

DJH Streamlined Coronation – Assembled motion

Last night I fitted the motor into the basic chassis and ran it for a while with the connecting rods attached. It was a good sign that nothing decided to unscrew itself while it ran (which can be a sign of something amiss).
Hopefully tonight will see the valve gear fitted and tested before stripping it back down ready for Warren to paint.

Crank Pin Bushes

My method (it’s not my idea just one I have picked up from other builders) of fitting Crank pins to Slaters wheels.
For this build the front and rear drivers have the standard 12ba crank pin as provided by Slaters with their wheels. The centre axle has had the 12ba cheese head screw replaced with a 10ba countersunk screw. This is to allow the crank pin bush to be tapped 10ba and an additional bush to be added and again tapped 10ba so that they can be screwed in opposite each other to house both the couple and connecting rods (on this particular kit the extra bush was available because a pair of smaller bushes had been provided for the front axle to ensure clearance for the crossheads).
As well as tapping the crank pin bushes 10ba, I also tap the wheel itself allowing the screw to be tightened and retained.
I must admit for my own builds I tend to replace all my crank pins with 10ba and blacken the wheels but I was told not to for this build.

Use of 10ba crank pins for return cranks

You can see the difference in screw sizes from the back of the wheel.

Use of 10ba crank pins for return cranks

I also drilled and tapped the return crank itself but it will be soldered to the bush once I have cut it to the correct length and made sure that the crank is in the right orientation.

Use of 10ba crank pins for return cranks

Use of 10ba crank pins for return cranks

DJH Streamlined Coronation Front Bogie

With the trailing truck behind me (see what I did there), I started on the bogie.
Sadly having rescued the and fitted the springs where they should go you don’t see much of them once it’s assembled.
Now you see them….

DJH Streamlined Coronation – Bogie

Now you don’t….

DJH Streamlined Coronation – Bogie

DJH Streamlined Coronation – Bogie

DJH Streamlined Coronation – Bogie

I also made a start on the valve gear but more on that later.

DJH Streamlined Coronation Trailing Truck

After doing battle with the cylinders and struggling with a drill bit broken off in one of the valve guides which I have yet to resolve (but I do have a fall back position should I need it) I decided that for a bit of light relief I would make up the bogie and trailing truck.
I started with the trailing truck for now other reason than I had some of the bit’s already removed from the fret during the course of removing other bits.

DJH Streamlined Coronation – Trailing Truck

DJH Streamlined Coronation – Trailing Truck

DJH Streamlined Coronation – Trailing Truck

DJH Streamlined Coronation – Trailing Truck

Sadly I had got to this bit when I realised that I had made an error in my interpretation of the instructions. You get two options of spring/axle box for the trailing truck. You get an axle box and full thickness spring combined and an etched spring separate axle box and some hanger castings. There are also a pair of thinner springs which I had attached as in the photos above.
The idea being that you use the full thickness castings for loco where they are to be used on track radius of greater than 7 feet or use the etched ones for less than 7 feet radius. It was only when looking at the bogie that I realised the the thinner cast springs were in fact for the bogie rather than the trailing truck and it all made sense. thankfully it was the work of a few minutes to swap them over and put the etched ones where they belong. There were some castings provided for the spring hangers as I mentioned but 2 of them were missing so I cut some off the thicker castings to make up the set.

DJH Streamlined Coronation – Trailing Truck

DJH Streamlined Coronation – Coupling Rods

Following on my my note on the coupling rods I managed to get a couple of photos of them now that they are soldered up.

DJH Streamlined Coronation – Coupling Rods

DJH Streamlined Coronation – Coupling Rods

And then a couple that will hopefully show how much I had to file out of the cylinder castings….

DJH Streamlined Coronation – Cylinders

DJH Streamlined Coronation – Cylinders

Essentially the slots bottom left and top right were almost full of whitemetal so I used an older square file to remove the material. Now that I have the lathe with the milling attachment I suspect that I might have used a burr to mill out the material much more efficiently. Something to remember should I encounter anything similar in the future.

DJH Streamlined Coronation – a Bit of Improvisation

I was cracking on quite nicely with the chassis but when I got to the next phase of the instructions I found one of the castings missing.
This is the offending article, there should be one at each side.

DJH Streamlined Coronation – Motion Bracket

After umming and ahhing as to what to do I decided it would be simpler to scratch another than to wait for the owner to source one from Tower/DJH.
Poor photo  but this is it made from scrap etch and some wire filed half round.

DJH Streamlined Coronation – Motion Bracket

DJH Streamlined Coronation – Motion Bracket

DJH Streamlined Coronation – Motion Bracket

Last night saw me make up the coupling rods which all went swimmingly until I got to pinning them together at the joint. The instructions have you tapping one side 12ba to screw a cast threaded pin into. Having done the first side I quickly realised that the thread on the pin is way smaller than 12 ba Bah!! :headbanger:
The other side I tapped 14ba and I ran a 14ba die down the cast thread,  I screwed it into the tapped hole and the threaded section promptly broke off in the hole:hammer: Tonights task is to solder the pins into the back of the hole as I would have done with a rivet of Premier Rods. Onwards and Upwards…..

DJH Streamlined Coronation – on with the Chassis

So it’s onto the loco chassis,
I made a start on Saturday afternoon and up to last night I had made it to

DJH Streamlined Coronation Tender – Basic Loco Chassis

DJH Streamlined Coronation Tender – Basic Loco Chassis

DJH Streamlined Coronation Tender – Loco Chassis Brakes and minor details fitted

DJH Streamlined Coronation Tender – Loco Chassis Brakes and minor details fitted

DJH Streamlined Coronation Tender – Loco Chassis Brakes and minor details fitted

DJH Streamlined Coronation Tender – Loco Chassis Brakes and minor details fitted

DJH Streamlined Coronation Tender – Loco Chassis Brakes and minor details fitted

Which brought me to the end of drawing number 2 of the chassis instructions.
I made one minor error in that I got one of the chassis spacers/supports the wrong way up which meant that the hole for the brake cylinder was in the wrong place. Rather than take the chassis apart again I just redrilled the hole at the other end of the spacer and filed the tabs of a couple of brackets that should have fit into some slots. Job done and brakes fitted as they should be.

DJH Streamlined Coronation – It’s getting busy back there

Once the rear bulkhead was soldered in, next up I concentrated on getting the many details on the rear of the tender added.

DJH Streamlined Coronation Tender – Side farings and rear bulkhead attached

DJH Streamlined Coronation Tender – Side farings and rear bulkhead attached

DJH Streamlined Coronation Tender – Side farings and rear bulkhead attached

It’s quite busy back there…

More DJH Streamlined Coronation Tender Moments

Where had we got to?
Once I had the sides to the right shape and soldered to the bunker rear I set about detailing the front and rear bulkheads. As I mentioned in York Paul’s thread I fitted all the whitemetal castings to the rear bulkhead prior to fitting it. Those on the front bulkhead await fitting.
in true perverse DJH fashion, although the front bulk head and many of it’s constituent parts are half etched the rear bulkhead is full thickness.
Front Bulkhead

DJH Streamlined Coronation Tender – Bulk heads and other sub assemblies

Rear Bulkhead

DJH Streamlined Coronation Tender – Bulk heads and other sub assemblies

Streamlined Cover and Ladder for the rear of the Tender.

DJH Streamlined Coronation Tender – Bulk heads and other sub assemblies

Dealing with the thickness of the metal has been a real learning curve on this one because my 80 Watt Ersa solder station won’t touch it with 145 degree solder at my usual 340 degree setting.
I have had to whack it up to 400 to get the solder to run. This has meant that much of the soldering has been done with the microflame including (and this may want some of you to lay in a darkened room…:facepalm:) the whitemetal bits.

Sorting out Tender frustrations – DJH Streamlined Coronation

Following on from my earlier post , the tender sides are battleship plate thickness. They come pre bent to shape to follow the bulkheads – what a shame the bends were too low

DJH Streamlined Coronation Tender – Reforming the flare

DJH Streamlined Coronation Tender – Reforming the flare

I used my my cheap cooks torch bought from Lidl just before christmas. I have found it’s too hot and uncontrollable for soldering but it’s great for annealing.

DJH Streamlined Coronation Tender – Reforming the flare

DJH Streamlined Coronation Tender – Reforming the flare

DJH Streamlined Coronation Tender

However, before you get to the tender sides in the instructions, the next section has you making up the coal chute and coal pusher which went together perfectly.
Finally I popped along to the NRM at York and was able to get on board Duchess of Hamilton and take a comparison photo

DJH Streamlined Coronation Tender

How I do return Cranks

For this build the front and rear drivers have the standard 12ba crank pin as provided by Slaters with their wheels. The centre axle has had the 12ba cheese head screw replaced with a 10ba countersunk screw. This is to allow the crank pin bush to be tapped 10ba and an additional bush to be added and again tapped 10ba so that they can be screwed in opposite each other to house both the couple and connecting rods (on this particular kit the extra bush was available because a pair of smaller bushes had been provided for the front axle to ensure clearance for the crossheads).
As well as tapping the crank pin bushes 10ba, I also tap the wheel itself allowing the screw to be tightened and retained.
I must admit for my own builds I tend to replace all my crank pins with 10ba and blacken the wheels but I was told not to for this build.

Use of 10ba crank pins for return cranks

You can see the difference in screw sizes from the back of the wheel.

Use of 10ba crank pins for return cranks

I also drilled and tapped the return crank itself but it will be soldered to the bush once I have cut it to the correct length and made sure that the crank is in the right orientation.

Use of 10ba crank pins for return cranks

Use of 10ba crank pins for return cranks

DJH/Tower Models Streamlined Coronation Build

On Easter Sunday afternoon I had a phone call from a gent that puts a lot of work my way asking if I could fit in building a DJH Streamlined Coronation as soon as possible. The Gent that I am building the J6 for is in no rush so I decided to have a bash.
The kit was dult delivered on Sunday evening and by bedtime I had the basic tender chassis together.
Another couple of hours on Monday morning had the tender chassis complete, so far so good.

DJH Streamlined Coronation Tender

DJH Streamlined Coronation Tender

DJH Streamlined Coronation Tender

To a degree I feel that any criticism that I make of this kit is a bit like sour grapes given that I chose the David Andrews kit over the Tower/DJH version when I bought mine.
That said, hiding what I find doesn’t help anyone else who may decide to build one of these.
The key issue with the tender chassis is that the cross members that fit between the wheels are  a single half etched layer in the middle section, which makes them very vulnerable to bending. This and other areas where key parts are a single half etched layer (more on that later) are particularly noticeable to me when this build comes right on the heels of building the MOK LMS tender which is prototypically similar in many respects.
Although I don’t know the name of the loco that the model is to ultimately represent I have been asked to build it as one of the double chimney red ones – Apparently there were some differences on the red ones over the first few blue ones (I had originally planned to build mine as Duchess of Hamilton in Blue when Coronation was masquerading as DOH while DOH went to America masquerading as Coronation, confused yet…..). Luckily the kit also came with a loan of the Wild Swan/NRM Loco Priles book for the Coronation Pacifics.