David Andrews Princess Royal - 6206 Princess Marie Louise

Cheers, I have been on a bit of a roll (if you will pardon the pun) today.

 

Looking at all the rivets to be pressed out I decided that I would finally get around to doing something that I had been promising myself for years. That’s to make a more comfortable handle for the GW Models rivet press. Those who own the smaller of the two models will understand where I am coming from. The bigger 7mm/Gauge 1 version has a round end to the handle the smaller version just has a rectangular bar which gets mighty uncomfortable when pressing a lot of rivets.

My solution was to drill a 13mm hole in a piece of 20mm acetal rod and tap it onto the rectangular bar.





So simple but so much more comfortable.




It didn’t make pressing the rivets out any quicker but it saved the hand, some grief.

Ordinarily I would have taken the slight curl out of the sheet by setting the rivets using a jeweller’s stone setting tool, a technique picked up from Peter Dunn. However, because I plan to roll this and the curl is in the right orientation, I left it as is.

To roll the smokebox with the rivets embossed I backed it with a piece of card from a biscuit packet (Tesco Finest Chocolate Gingers – other sources of card are available).





Once I filed the etching cusp off the rear former it dropped straight in.

 

Thanks Jim,

It does help when there are half etched dots for you to follow. Free hand it's much harder. But when looking at lines of rivets on 12" to the foot locos, they are not always very straight.

 

There has been quite a bit of conversation over on the Guild forum about the Smoke box saddle for the David Andrews Princess. It seems that the main saddle casting which is brass is 2mm or so too deep. Oddly there is a second casting which is white metal. I find it most strange that they are made from two different materials

A couple of fellow Guild members whom I have corresponded with on the subject, had the second casting missing from their kits (both bought second hand) and I wonder if was actually there, but like me they missed it because they were looking for a second brass casting. I certainly did until it was pointed out that it was white metal.









Before I go any further I need to assemble the cab (I have already soldered the inner and outer cab sides together) and I am sure that I will need to remove some material from the middle splashers to get the boiler to seat properly between them.

 

Good question Brian, who knows the mind of a kit designer...

My guess and it is only a guess, is that the brass one pretty much wont be seen once the smokebox and two side plates that fit between the two ribs are fitted. Whereas the white metal one will be more visible at the rear of the smokebox. On that basis I am at a bit of a loss as to why he has added rivets to the underside of the brass one.

 

I set myself a couple of goals for the session, the first was to get the smokebox door ring to fit in the smokebox barrel, the second was to assemble the cab.


Staring with the smokebox door ring, I had decided that filing it would be a complete pain and a last resort if I couldn’t work out how to hold it in the lathe to turn it down.


The amount of rim left after turning would be miniscule so no chance of griping it by that and being able to turn it. I didn’t have any material of a large enough diameter to make a mandrel so I decided to try holding it on the outside of the jaws. Because it’s white metal it would be really easy to distort or mark it. I cut a strip of aluminium drinks can to length so that it would wrap around the circumference of the inner ring but not overlap to throw it off centre. Once inserted I carefully opened the jaws until they were just gripping the part.


I started off by attempting to have it hard up against the jaws in an attempt to get it running concentric but the rivets on part of the ring prevent it from sitting flush so I had to move it away from the jaws and then use a pair of thin parallels inserted between the jaw and the face to ease it until I reduced the wobble to an acceptable level. Despite trying to get it perfectly flat on my glass sheet I wasn’t able to without damaging said rivets so I had to accept a little wobble.


I had the lathe running at about 100rpm or less, I set the carriage stop so that I wouldn’t inadvertently chop of the front rim and then moving in 0.050mm at a time I skimmed the rim at the back of the part. The first cut quickly proved that the outside of the part wasn’t completely circular either. I patiently took cuts until the rear rim was completely concentric, all the while checking the fit of the smokebox front after each cut.


In the end I took off a depth of 0.750mm which equates to 1.5mm overall. That would have been a killer with a file while attempting to keep it circular.














Having got that to fit successfully I turned my sight to the cab. I have never had something so simple be such a complete pain in the posterior to get together squarely. Today’s attempt was my third go at it, and it still took both sides being removed and refitted twice before I was satisfied that it fit as I thought it should. The problem is finding some part of it in between all the rivets and window frames inside that you can put a square against, to hold the sides at right angles to solder them.


Next, I spent some time with a spirit level adjusting the horn block screws to get the chassis/footplate to sit level.


Having the cab as a datum I can now see that the Firebox needs a slight trim where it goes over the rear splashers so that it will sit level. Once I have done that I need to sort out where the boiler is currently riding on the centre splashers. The problem here being that there isn’t a great deal of clearance between the wheels and the splashers so I think that I will have to cut into the boiler clothing to get it to seat. Once I have the boiler seated, I can consider what to remove from the saddle(s).














I will start by soldering the cab to the footplate and trimming the firebox…


PS just as I was posting this, I moved the loco from the photo area to my workbench and managed to drop the cab on the floor. Now the first job is to solder one of the cab sides back on....

 

Thanks Brian
It may have been a blessing in disguise. Better it come adrift now than when it's fitted to the footplate.
Thankfully it went back together without further angst and it's now tacked to the footplate.

 

Nothing much to report on the Princess front (or indeed any modelling). I have rebuilt the cab and tacked it to the footplate to give a datum for fitting the firebox, boiler etc. The wheels are very close to the splasher tops and I need to remove some material to get the boiler to sit horizontal. I asked for advice on a couple of forums how others might have gone about it and there has been much discussion on the subject.

The upshot of which is that a kind gent provided me with lots of dimensions for firebox and where in relation to the footplate/tops of the frames, the smokebox fits. I now need to work my way through them before I can move forwards.

Over the weekend we went to Kidderminster to collect Chris's paintings from the exhibition and on Thursday I am working on the local election, with some preparation today and tomorrow. So I doubt I will have much head space this week for anything too taxing modelling wise until next weekend when I have recovered from the 17 hour day.

 

Since my last post I haven’t had much time to spend on modelling but having tacked the cab on I did get to drilling and fitting the firebox to the foot plat with self tappers so that I have a datum to work from for seating the boiler.

I am not sure how others have managed it but I am having real difficulty with the size of it seeing what’s level and what isn’t so I have resorted to nibble a little bit, fasten the foot plate to the chassis add the boiler/smoke box and then take a photo that I can study without trying to juggle to loco in my hands while squinting at it.


By taking a photo of each side and comparing them, I can immediately see that I need to take a little more off the left side middle splasher. This is because it’s not seating down flush with the front of the firebox at that side, but it is at the other. This means that it’s being pushed over to one side slightly, this is backed up by it appearing to seat on the secondary saddle at the right side but not at the left. And of course, looking at it from the front.









Useful things photos, and it is a slight pain assembling it and disassembling to take a bit more off but I can’t think of a better way of achieving what I need.