David Andrews Princess - Princess Marie Louise 6206

[Rob Pulham]

Today I made up some connecting rods for the inside motion. They came from the scrap etch box and were originally for a Black 5. I cut off the big end bosses from all the pieces and then soldered them together in pairs. Once I had measured the length, I cut them to final size and grafted some Laurie Griffin eccentric straps onto them. I have calculated that the home turned eccentrics will give about 3mm of travel fore and aft but that will be sufficient to give the sense of movement though the holes in the frames.

 

 

 

[Hilux5972]

On 08/06/2022 at 23:32, Rob Pulham said:

Tuesdays have become quite a busy day in the Pulham household so I didn’t have too much time at the bench. One of the jobs that I always seem to forget until the last minute when building are the balance weights. I normally wouldn’t have taken photos of such a simple thing but in this case, I wanted to share the type of adhesive that I used.

 

After reading about it on Western Thunder as being specifically designed for etched metal and clear parts, I thought that I would give it a go and bought some. I am not a great lover of cyanoacrylate type glues, not because of their adhesive properties but because the fumes can leave unwanted residue especially on paintwork etc. which is difficult to get rid of.

 

The glue needs 6 hours to fully harden and to be honest it doesn’t seem to have great “grab” when initially applied. But being able to wipe off any overspill with a damp cotton bud and no residue from fumes is a big plus, assuming that it works.

 

Well, my scepticism was unfounded, the balance weights were nicely stuck when I checked them this morning.

 

 

 

I also added the inner plates for the weights cut from some 10thou nickel sheet.

Do you have a link for it please?

 

Edit: don’t worry I found it on my local model shop website

Edited June 10, 2022 by Hilux5972

[Rob Pulham]

Following a question about parts for the inside motion on the Guild forum, a fellow member posted how he had achieved a similar result to what I am working on but without the use of a lathe. I must off thanks to Harold because his post gave me the solution to one problem that I had been pondering (how to space them apart for soldering) and for prompting me to think that I didn’t actually need to solder them to the axle at all. I could solder them to the bush which acts as a spacer and would allow a hole to be drilled to make use of the taper pin that holds the axle together.

 

 

 

 

In true Blue Peter style, here’s two I made last night before I got my head into gear and correctly worked out the width. They will go in the spares box as I am sure that they will come in for something.

 

[Rob Pulham]

Back to the Princess this week after moving the J6 along.

 

In the end I decided to take a bit more of the edges of the cylinders and then I fitted the covers. Before I did that I soldered the slide bars in place as I didn't want the heat from soldering them in place to spring the cylinder covers loose. As it happens I had to adjust one of the slide bars as I hadn't got it quite square and the cylinder covers are such a good fit that although the solder softened, they never moved. Something to aim for on future builds.

 

 

 

After fitting the slide bars I mated them up with the motion bracket and realised that once I join the two together them crossheads become captive so I need to do work on the motion next to ensure that all is well before I solder the slide bars to the motion bracket.

 

The first hiccup is a result of using extras to the kit. I used the David Andrews Slide bars and crossheads for the simulated inside motion because they don't have as much details as the LG Miniatures versions. Now I come to fit the LG crossheads with the connecting rods which are replacements from Premier Components I find that the LG crossheads are different to those that I have used on other builds in so much as they have a slot in them rather than an open back. This means that I will have to mill the connecting rod ends to get them to fit in the slot.

 

 

A picture paints a thousand words or something like that...

[Rob Pulham]

With the slide bars in place at the cylinder end it was time to start thinking about the outside motion. I decided to do it as two subassemblies and then join them together as I secure the rear end of the slide bars to the motion bracket.

 

Along with the Premier Components coupling rods, came a set of the rest of the motion parts many of them very nice but some just didn’t work (or at least in my view). These are the combination levers and the union links. Starting with the combination levers, those fitted to the Princess Royals were fluted and the Premier examples plain.

 

The union links in the Premier set are represented by a single dog bone shaped rod which is 0.9mm thick. The very visible, prototype union links have forked ends. After exploring options of combining the etches with the premier link I realised that they were each of different lengths so no chance of combining the two.

 

After consultation with the gent that I am building it for, I went with the DA etched combination levers and union links but used the Premier parts for the rest of the motion.

 

 

For me the most difficult bit of building motion, inside or out is “how do I fasten it all together”. For the front half I have tapped the valve rod 14ba and put a screw through from the inside. Visible in the photo below.

 

 

The union links I have riveted with 0.8mm brass rod. I have a small piece of steel that I use as an anvil so I drilled a shallow depression in one corner to use to form rivet heads. Once inserted I peined them over with a small ball pein hammer.

 

I also turned up some oil pots for the connecting rods. Not quite prototypical but they do look nice.

 

 

While I am using the Premier Rods, I still need to use the DA etched expansion link and that’s where I was second guessing myself

 

 

On all the other outside Walschaerts valve gear that I have built before, the radius rod is connected via a pivot below the main pivot of the expansion link.

 

I thought I had assembled it wrong but after searching through a number of photos and reviewing the outside motion GA for 6203-62012 on page 38 of the Wild Swann book. It seems that on the Princess Royal there is no lower pivot point. Phew!

 

 

 

Finally, I was pondering the brass bearing cap on the eccentric rod where it attaches to the return crank. There are some etched covers included but since the whole kit is etched nickel, they are nickel not brass. So, I had a quick go at mocking one up on the lathe.

 

 

Although it doesn’t have the small screw heads and the oil pot it does look more three dimensional than the etch and of course it’s brass. I will sleep on it and see where I decide to go next with that one.

[georgeT]

Looks very neat and tidy Rob great job, l am struggling with the valve gear on a DJH Fairburn tank. 

[Rob Pulham]

Thanks George,

 

I have done a few DJH kits before without valve gear issues  but not a Fairburn. Or rather the only issue I had, was one of my own making where a drill bit broke in a valve guide casting.

 

What's the problem?

[georgeT]

Hi Rob, They are too flimsy and ill fitting, so l have got Dave at JPL Models to make me a set up, he says this is not the first set he has made for the DJH Fairburn ? ...

[Rob Pulham]

Ahh, got you. No need to say anymore...

[ozzyo]

On 03/07/2022 at 05:28, georgeT said:

Hi Rob, They are too flimsy and ill fitting, so l have got Dave at JPL Models to make me a set up, he says this is not the first set he has made for the DJH Fairburn ? ...

 

Hello George,

 

one of the main problems with the DJH Fairburn is that it uses the same valve gear as the BR

2-6-4T IIRC and this puts all of the valve gear geometry out.

 

OzzyO.

 

PS. the bodywork is not to bad apart from having a BR standard back head.

[Rob Pulham]

I have really struggled for motivation this week so haven’t achieved as much as I might have liked.

 

I decided that the etched return cranks were a little under nourished and 2D so I added a bit of detail.

 

 

First a turned a spigot on an offcut of rod and soldered the rear etch to it and drilled out the four bolt holes using 90 degrees spacing on my Proxxon mini pillar drill using the dividing head.

 

Next, I soldered them to a piece of scrap etch from the kit drilled through the holes to transfer them to the other layer and cut around them with a piercing saw. I forgot to take photos of that bit.

 

Then I made up eight (actually nine) studs from rod and microbore tube filed to a hex head and cut to length.

 

 

And finally I assembled all the parts.

 

 

Magnified as they are they look a little rough around the edges but it’s not visible at normal viewing distances.

[sjp23480]

On 03/07/2022 at 05:28, georgeT said:

Hi Rob, They are too flimsy and ill fitting, so l have got Dave at JPL Models to make me a set up, he says this is not the first set he has made for the DJH Fairburn ? ...

I try to use Comet valve gear on my DJH builds - much more resilient.

Steve

[Rob Pulham]

The first stage of fitting 3D printed brake blocks is the hangers. Sadly the nice cast brass hanger are far too thick for the replacement block so it was either make some new from nickel sheet or try to mill off the shoes from the etches supplied in the kit. with the make new ones as a back up plan I decided I had nothing to lose in trying to mill of the shoes and use the existing brake hanger etches.

 

So far so good. I now need to trim off the remains of the shoes, solder the fronts and backs together and then probably file a little more off to make the shoes fit.

 

[Rob Pulham]

Lack of modelling mojo not withstanding I have managed to progress this a little in between life getting in the way.

 

First, I modified all the etched hangers in the kit to accept the brake 3D printed shoes

 

 

Then having stripped all the previously built brake gear down into components parts as needed, I started to fit the new shoes/hangers to the tender first

 

 

 

More to follow as it happens.

[Chas Levin]

Nice use of ceramic tweezers Rob! 👈

[Rob Pulham]

More progress has been made this week and the loco and tender brakes are now complete.

 

 

The loco brakes were a bit more interesting in that I didn't have to re-drill the mounting holes. However the brake hanger etches have a square hole in one end and a round one in the other so using some 1mm square bar, some tube and some 0.9mm rod I made up some mounting brackets

 

 

These fitted nicely except for the rear pair which wouldn't fit between the rear wheelsets without touching. Not to be deterred I rounded the end of a couple of pieces of 1mm square bar and fitted that instead. I also had to shorten the brake cross beams by approximately 1.5mm either side so that the brake hangers didn't splay out beyond the wheels.

 

 

 

The red bits are electrical sleeve, there to retain the brake hangers until I am confident that I can solder them up.

[Rob Pulham]

After fitting the brakes I decided to return to the loco body to move that forward. 

 

That started out as a one forward one back because I had to re-solder the boiler section as for some reason the soldered seam had failed. Still better that it failed now than when the loco is finished. That little job done I looked in the box and sighted the chimney casting so decided to tackle that.

 

There was quite a bit of discussion about the David Andrews Chimney, or to be more accurate about all the chimneys in the kit's that are/have been available for a Princess Royal with the consensus being that none of them were accurate. Mike Hopkins was commissioned to draw up and have cast an accurate replacement (by David Hill at Gladiator I think). Noting that I was building a Princess Mike dropped me an email and asked if I would like a replacement for the kit provided casting and I took him up on it. 

 

Now I have to confess, having used one of Mike's chimney castings on the Class 5A, that I am not wild about the way that Mike designs the flare/inner chimney. I understand that being 3D printed the chimney needs to be supported and that those supports have to be cleaned up so adding them at the bottom makes sense I much prefer to remove the usual screw thread/stub from the bottom of the chimney, drill it out and them use the smoke box wrapped in wet and dry to smooth out the flare to make it sit on the smoke box properly.

 

 

Although I forgot to take a photo of the Princess chimney before I started I had a J63 chimney in stock (for when I get around to swapping the lopsided one off my J63). The Princess chimney was similar to the photo above in that it had the remains of the casting sprue attached to one edge of the hole and the remains of the supports around the bottom of the inner chimney and the flare.

 

I started by cutting off the casting sprue and then had made a start on the laborious job of filing out the rest when I thought that I could pop it in the lathe and use a tiny 3mm boring bar to remove the remains of the sprue from inside the chimney. To stop the rim getting marked I wrapped it in a strip taken from an aluminium drinks can (I have a few cut down cans in the workshop for just such tasks). Suitably protected I put the chimney in a collet and centred it as best I could (it still had a slight wobble). Then working steadily taking 0.1mm cuts I bored out the remains of the sprue. I also shortened the inner chimney by approximately 2mm which took care of the stubs of the supports.

 

 

That done I used a diamond coated mini drill attachment to grind of the remains of the stubs on the base of the flare.

 

 

At this point the hole in the smokebox is only about 1mm in diameter and I was wonder about the best way to enlarge it as the inner chimney is just over 10mm in diameter. I decided to use the practice smokebox that I ad created to ensure that I could successfully roll the thick material of the smokebox.

As luck would have it I have a 5mm centre drill which up to now has been too big for anything that I might have needed. It was perfect to drill a hole and then use the countersink part of the bit to slowly open out the hole in the smokebox until the chimney would fit.

 

 

This confirmed that the chimney would sit flush on the smokebox so now I just need to open out the hole in the proper smokebox to suit.

[JeffP]

Quite brave really. The lathe use, I mean.🙂

I have a set of TiN coated conical bits that came from Lidl that are useful for opening out holes in thin material.

[Rob Pulham]

11 minutes ago, JeffP said:

Quite brave really. The lathe use, I mean.🙂

I have a set of TiN coated conical bits that came from Lidl that are useful for opening out holes in thin material.

I have exactly the same set and they would have been the next port of call had the centre drill not worked.

Re the lathe work, slow speed and light cuts in brass were not too stressful. If I hadn't used a collet, I wouldn't have been as confident that the part would have been gripped securely and probably wouldn't have even tried it..

[Rob Pulham]

Since my last update the loco seems to have fought back a little. I am not sure whether it was that I had folded the sides of the cab floor too tightly but the sides needed trimming down to fit. That said it's a snug fit in the cab so it's probably unlikely.

 

 

 

My next task which again needed a lot of work for very little to show for it was the upper frame sections that fit between the splashers. Each piece was between 1mm and 2mm two long so they had to be patiently cut and filed until they fitted in the space between the splashers and seated properly.

 

 

Still a bit of cleaning up to do.

 

Having sorted the cab floor I looked at the upright pillar that support the cab doors. These have a pair of slots in them to take a half etched tabs on hinges of the cab doors. Again I am not sure if it was me but once I had folded the small section that is bent at right angles the slot was completely closed. To be fair that wasn't an issues as I had already decided based on past experience to make the cab doors removable.

This I did by soldering a couple of short lengths of micro bore tube in between where the holes should be (even though the holes were no longer visible, there was a half etched recess). Then I used a small broach as a spacer and folded the half teched tabs on the doors around to make a hinge and inserted a cut down dressmakers pin to hold the doors in position while leaving them free to move and removable by lifting out the pin.

 

 

Next I fitted the rear cab roof arch and started to form the cab roof.

 

 

The cab roof was a challenge in it's own right and required quite a bit of coaxing to get it to curve to the right shape being half teched nickel I was very conscious of it wanting to crease across the top where the two strips either side of the opening are.

 

 

In the end to get it to stay in shape with a chance at being soldered to the top of the cab I used a piece of scrap etch as a former/stay. this fits just inside the rear arch frame. I dropped lucky in that where one of the sections of arch was removed from the etch left this strip which was at exactly the same curvature as the front/rear so perfect for the task once the cusp etc was cleaned up.

 

 

[JeffP]

I do like the working, but removable, cab doors.

[Rob Pulham]

If you liked them before Jeff you will like these even more.

 

Following my previous post fellow Guild member Chris Simpson contacted offline me to tell me how he had articulated his doors both to the body and in the middle. Chris's method was to use a piece of tube and a piece of rod. Never one to shy from the challenge I used Chris's method to articulate the middle of the doors which is a massive improvement in my opinion and one I shall use again in the future.

 

 

 

Here's a shot of them in situ in the cab.

[JeffP]

Those are very good indeed.

As always, the idea is relatively simple...but someone has to come up with it.

[Rob Pulham]

More done on the Princess in the last day or two.

 

Fitted the window stays above the windows in the cab these are extra from now extinct HobbyHorse Range.

 

 

I also fitted the Chimney and the boiler bands. Normally Warren doesn't like boiler bands fitting as he prefers to do them to scale using transfers. The problem in this case is that they are designed to be fitted to hide the joints between the smokebox and boiler and once you add one you need to add the others...

 

Finally I am working on cleaning up the top feed casting which although nicely shaped had quite a castings step in it which is taking a bit of work to clean up. Here it is part way through the clean up process.

 

 

 

[Chas Levin]

All looking very nice Rob; that's awkward re. the bands if you'd have preferred thinner ones but as you say, if one of them has a structural function too, you've little option. I was surprised at how many people have quite strong feelings about metal - however thin - bands on a model, let alone cast ones. It's never seemed terrifically noticebale to me, even once I'd become aware of it and usually that's a killer, once you've seen something, because it then stands out. This model is a good example of what I mean: those bands don't look over-thick to me, even though I'm looking at them in your pictures with that thought in mind. And once all the other distracting things are in place and a lovely paint job...