David Andrews Princess Royal - 6206 Princess Marie Louise

This week has mainly been about working on the backhead, one of my favourite parts of a build.

I started by making a driver's heatshield. The size and shape was worked out from an oblique photo and referencing it to other items located in the cab.




Once I had the basic shape I took a short length of nickel rod and filed it to half round to create the edging strip. I did have it fixed in place but then when I fitted the Drivers brake valve in place and started to consider the other pipework I realized that there would need to be some relief above the fire door rails to allow pipes to pass behind the shield.

The other castings that you can see in the photos are some of the few David Andrews parts that I have. The ready made holes in the back plate itself are causing a few issues as most are over sized and the ones on the fire hole door needed their placement adjusting to get the levers that open and close it to sit correctly with the two mounting brackets adjacent to the bottom rail.
The shelf on the other hand fitted perfectly .

 

It was kindly pointed out over on Western Thunder that I had the drivers brake valve upside down and that it was too close to the centre line of the engine/heat shield. I measured it up and compared it to the Wild Swan drawing and sure enough it was 0.9mm too far inboard.
As you can see I had made a small brass bush to reduce the size of the hole but moving it gave me the chance to re-drill at the right size for the brake valve stem.


Here we are nicely aligned.


As you can see I have also made a start on piping up the steam fountain.



The brake valve is piped up the right way up now too.



I had to remove a section from the inside edge of the heat shield to allow pipes to pass through it. The pipe at the side is one of the two main pipes coming down from the steam fountain and one thing that stands out on both drawing and photos is that there is a chunky union on the lower section.

These are the parts that will make up a representation of those unions.

 

Hi Andy,
A bit of both, the main (thicker) pipes were bent to shape before soldering to the fountain but the thinner ones are soldering and then bent to shape.

 

Still working away at the back head, yesterday I added the other main pipe and the visible pipe unions. I took a phot of them before they get obscured by additional pipework. In my view they were well worth the effort.

 

In that case I will take more photos as I go along. This afternoon I filled the holes for the sight glasses with 70 degree solder ready to redrill for the casting stalks but as I was doing it I was distracted by the postie bringing the production print of the Firebox so I will pick that up later this evening or tomorrow.

 

As I mentioned above I received the production version of the firebox this afternoon.

After discussion with Mossy, we felt that he had taken it as far as he could but was struggling to work around the limitations in terms of his set up. We concluded that it may have taken another half a dozen test prints before we got the sizing correct to compensate for the shrinkage let alone any layering issues.

As the Princess is not for me I decided to let Mike Hopkins of Scale-Factor print the firebox on one of his Formlabs printers. Mike is the gent who does my brass castings. For those of you who are unaware of Formlabs printers I suggest a quick Google but make sure you are sat down when you have a look at the prices. Mossy and I are still scheming as to how to win the lottery for one...

This is the print as it came out of the packaging.
















This is after I had carefully removed all the supports. I still have to rub down the base and the cab end but a test fit on the boiler has it fitting perfectly. A slight friction fit.

 

Still working on the back head, because I am using a mixture of David Andrews and Just Like the Real Thing castings, I have had to move/reduce the size of all the holes except the one for the regulator mounting boss. The JLRT castings are really nice (as are the couple of David Andrews castings that I have) except for the cab dials which are a bit misshapen and the 'unions' for where the pipes are proving impossible to drill. The simplest and quickest way was to make some more swarf by turning some more.




Then I realised that I also needed a smaller version





It made sense while I had the set up to do some for the Rebuilt Scot at the same time.


Then I dug out the mountings and attached the dials to them.

 

I was pleasantly surprised to find a package from Ragstone in my letterbox today. From the enclosed invoice it looks like it was the second package that had been sent to my old address and returned to sender.

It seems that I did Royal Mail an injustice (I had no confidence at all that they would manage to get it back to Andy even though I had asked him to send it on if it arrived).

So thumbs up to Royal Mail and a big to Andy Beaton at Ragstone.

 

Pretty much as Paul says, if there are any parts you are unsure that they are what you need Andy will send photos.
If you order something that's out of stock he sometimes needs a nudge to remind him that you are waiting for them. But if he has them in you get them quickly.

 

The back head is well on it's way now but when I got so far I realised that the only hand wheels I had were the teched nickel silver ones that came with the kit. Nickel of course looks different when you are trying to represent brass so I thought I would have a go at turning some.

I did one to work out how, but the four holes came out all over the place. Once I had a method that worked I made the three that I needed. They actually looked the part when fitted to the back head but what was missing were the handles.



At this size I couldn't see any sensible way to add them to the ones that I had made so I had a rethink.
I modified the technique and made rings to solder to the face of the etches and then added half round rod for the handle. This is the best of both worlds. the right shape and three dimensional.


This is a cruel close up but they look pretty god at normal viewing distances.

Out of the castings that I have from the various sources the one that is missing is a sight glass lubricator which sits at the upper left above the brake valve.


Two turnings and a bit of rod and tube later...

 

I don't have too much trouble seeing them, assembling and holding for soldering is the hardest bit. There are five parts to the sight glass lubricator.
What I enjoy most is the challenge of 'can I make one'
I do have a small plastic tray (one of the brown ones that Slaters pack parts in) which is full of test parts, made to work out, how to do it/how to hold it etc. I keep them because I have managed to use some of them for jobs that they weren't originally designed for.