David Andrews Princess - Princess Marie Louise 6206

[Chas Levin]

On 31/03/2024 at 15:22, Rob Pulham said:

Progress over the last few days has been excellent so much so that I have backtracked a little and picked up on a couple of items that Paul has mentioned in the past.

 

The first was to replace the hatch knobs on the footplate with some wire loop examples. The knobs have gone in the spares box and will come in at some point.

 

 

The next was this comment from Paul, which I completely agreed with as I had been unhappy with the fit for sometime. But, I wasn't sure how to go about rectifying it then, so I slept on it...

 

"Hello Rob,

 

when are you going to sort out the gap between the chimney and the smokebox?

 

Coat on and the door closed very quietly behind me!

 

OzzyO."

 

The (replacement for the kit provided) chimney was cast from a 3D print by Mike Hopkins and Mike had placed his print supports under the bottom rim. I can see why as they would be least likely to be seen on the finished model. However because the casting also had a tube which fits into the smoke box to aid location, it made cleaning up the bottom rim and getting it to fit flush very difficult.

 

This is what it looked like after my initial cleaning up of the remains of the supports

 

 

Having almost finished the body work, I took the bull by the horns and took the chimney back of back gently gripping it in the vice between two pieces of round bar while applying heat to the inside of the chimney until I was able to ease it off.

 

 

Although I took photos long the way, I am not going to share how I machined the chimney just yet as I want to use it as part of my an evening with presentation later in the month.

 

 

This is it refitted to the smokebox.

 

 

 

Nice vice work Rob: I'd have expected the vice and the metal bars to act as a heatsink, but evidently they didn't do so to a problematic extent.

Unpredictable stuff, heat...

[Rob Pulham]

15 hours ago, Chas Levin said:

 

Nice vice work Rob: I'd have expected the vice and the metal bars to act as a heatsink, but evidently they didn't do so to a problematic extent.

Unpredictable stuff, heat...

 

Hi Chaz,

 

They might have done, if I hadn't been able to get the heat to the bottom of the chimney inside the smokebox. If that had been the case I would have gripped the boiler/smokebox in the vice and heated the chimney casting before using round jawed pliers under the rim to attempt to remove the casting.

[Rob Pulham]

The last items to make for the Princess, are the cylinder drain cocks/pipes. The castings were missing from the kit and I looked at those offered by Laurie Griffin and Ragstone but I wasn't convinced that they were suitable for use on the Princess and decided to make my own.

 

They are not yet complete but this is the first step. The making and alignment of the pipes themselves.

I made a jig from a strip of nickel sheet which I milled a series of grooves in. The grooves were milled to suit the etched holes in the bottom of the cylinders with spacing of 10mm and 9mm

 

I milled them using the point of a countersink bit and supported the material with a shop made machinist jack.

 

 

I did the same on each end of the strip of material to give me a top and a bottom for the jig.

 

 

The two half of the jig were loosely placed together and the legs of the pipes fed into them and the engineers clamp tightened to hold the horizontal parts together. A small G Clamp and a hair grip made sure that the pipes were vertical to each other and couldn't slip while I soldered them.

 

 

I wasn't really concentrating when I cut and bent up the pipes and I ended up with enough for two pairs. To compound that minor error I had placed them in the jig the wong way around and I had the 10mm and 9mm gaps the wrong way around. I could have unsoldered them but felt it was easier to cut some more and add these to the spares box.

 

 

I cut these a little different and left the outflow end of the pipes a bit long to cut down when fitted.

Oddly when I put these in the jig the other way around I didn't need the G Clamp, the engineers clamp was sufficient to hold them in place.

 

[Rob Pulham]

I asked a fellow modeller if he had fitted the cab roof yet, because it too has been yet another challenge to overcome.

 

 

The reason for the challenge is that the profile of the roof rib visible in the shot of the roof below is a different profile to that of the rear frame of the cab which supports the cab roof at the back.

 

 

When I first fitted it the front of the roof didn't go anywhere near the front of the cab (it did fit when I first "rolled" it some time ago. To get around the issue I cut a front rib to fit just inside the cab front which brought the front of the roof into the right shape again

 

 

This left a gap in the middle of the roof at the rear which I filled with solder (just visible in the photo below as is the additional rib at the front of the cab). Not very elegant but it works.

 

[Chas Levin]

One of the great questions of the Modern Modelling Age: to what extent should we worry about ever so slightly less than perfect things which won't be visible once the model's completed, but which we shall know are there?

[Rob Pulham]

40 minutes ago, Chas Levin said:

One of the great questions of the Modern Modelling Age: to what extent should we worry about ever so slightly less than perfect things which won't be visible once the model's completed, but which we shall know are there?

 

I agree Chaz,

 

Fixing it wasn't that big a deal, what baffled me is that they had been drawn to different profiles, when surely the simplest thing to do would be to copy the first, to create the second?

 

I shared the experience so that if someone else builds the same kit in the future it might not catch them out.

[Rob Pulham]

Today saw the last of the tiny components that make up the cylinder drain pipes made and assembled. I also ended up with a nice little bag of extra nuts. I made six for the operating bar and then decided they were a little big (lengthwise) so I made some smaller ones.

 

Each one is made from 16 individual parts and the valves are a bit of a work of fiction because I couldn't find any clear photos of what is actually under there but they pass muster when compared to the castings that I have in various kits and at least they fit this particular loco.

 

The clips that hold the pipes together are still loose and able to slide along the pipes at the minute until I get them fitted and can determine their final position.

 

[Rob Pulham]

The last parts to be made and fitted are the cinder guards that fit on the cab side. Even though they are nickel on this kit, they are very vulnerable and a friend mentioned that he always models them folded back which seems like a good idea. but I was concerned about painting around them. I also had the idea that I would like them to fold in like the real thing and so I decided to experiment with the extra etched frame that David supplies.

 

 

I cut off the two pegs that fit into holes etched in the cab side and soldered a length of 0.5mm piano wire on the back of the frame. Then I drilled a length of 2mm x 2mm brass angle at the ends and soldered in some filed down brass dressmakers pins which I cut down to fit through the holes in the cab. I then drilled the other leg of the angle to accept the pain wire and once soldered to the cab it folds back just like the real thing.

 

 

Having got the first one fitted I made up the second. Which I took a photo of. Keen eyed readers will note, that there is only one bracket. Sadly, the second made a bit for freedom as I was shortening the peg after a test fit. So unless a miracle happens I will be making up another.

 

 

 

 

[Chas Levin]

On 08/04/2024 at 10:17, Rob Pulham said:

 

 

 

 

That is just superb, Rob: my favourite bit of modelling so far this year!

[Rob Pulham]

Thanks Chaz,

 

I confess that attempting such a thing has been on my to do list for some time but once I thought about the use of piano wire it became really simple even if the brackets were a little fiddly.

 

I am sure that the one that pinged off will be sat smuggly smiling at me in the next few days. 

 

Aside from making an insulated drawbar and fitting the sand pipes, that's the construction finished.  I need to reassemble it, wire up the motor and test run next before it goes for paint. 

[Rob Pulham]

The last week or so has been spent on lots of little jobs that don't seem to change much visibly on the model. The visible bits are the trimming of the cylinder drain pipes and having to rethink how I planned to mount and retain the motor from moving.

 

I also milled a hex on the ends of the front crank pins to replicate the fitting on the prototype.

 

 

I had initially envisaged that the mtor would sit flat and I did add a nut on to a frame spacer to retain it via a strap around the motor but it wouldn't fit through the hole in the firebox with it in this position. My final solution was to replace the rear frame spacer with one that is removable. This was needed because the large final drive gear on the ABC gearbox wouldn't pass between the gap under the existing frame spacer and the top of the rear frame section. A different motor gearbox combination might not have needed this solution.

 

Now that it's removable, the motor/gearbox can be lifted out for maintenance etc. and the position of the spacer once fitted, also acts as a stay preventing the gearbox from rotating about the axle. Win, win.

 

 

[Rob Pulham]

One of the things that I have never been entirely happy with on previous locos is the fitting of additional lead weight to the boiler. Tank engines are a bit simpler because the lead sheet can be fixed in the tanks and enclosed. It's not so much the fitting of the lead, so much as how to retain it and stop it from shifting over time.

 

Previously where needed I have used epoxy or 100 degree solder to fix it in place (I have built a number of DJH kits and on those the weight of the cast boiler was more than enough without adding additional weight). This time I thought I would try a different method first I rolled up some sheet lead and then some adjustment to make it fit. I used a hollow punch to cut out a section to fit around the base of the top feed which helped to hold the lump of lead in place next I drilled the bottom of the boiler being careful to site the hole behind the middle splasher so it wouldn't be seen from the side. Then I tapped the hole as deep as I could 10ba and then screwed in a 1 inch 10 ba screw being soft lead once the screw got beyond the tapped section it continued to cut it's own thread and now the ballast is held firmly in place.

 

 

 

 

I would be interested in the methods used by other builders to retain lead ballast in boilers.

[Chas Levin]

That's very interesting Rob; likewise I've been troubled by lead fixing methods and thought solder better than glue where possible, but mechanical fixing is better still. My first builds were araldited, then moving to solder and now, a combination of solder and/or mechanical.