David Andrews Princess - Princess Marie Louise 6206

[Battledown]

Don't you just love it when you drop a small part and it bounces more unpredictably than a Shane Warne googly.

 

I'm always finding bits I dropped months ago, but never seconds ago!

 

[Rob Pulham]

This weekend has been about working out how to fix the firebox and boiler together and to the footplate. I put a couple of 12ba screws through the bottom of the firebox utilising the two holes etched in the footplate. The ultimate intention is to use adhesive but also to use the hole to dd a mechanical element to the fixing so the screws are temporary to allow me to get everything in place. I would also like to get all the soldering done around where the firebox and the lower sections will sit since resin is susceptible to heat damage if I am not careful. Picking up a tip from John Dale I elected to screw the front end of the boiler in place and I was rather reluctant to use just a nut on an internal curve as I didn't want it to come adrift sometime in the future. A rummage in my useful bits of brass recycling box yielded a former frame spacer from a set of frames that I had replaced with new ones. As a bonus it was already tapped 8BA. I filed the ends to help it seat in the curve and after marking and drilling a hole in the front saddle casting and transferring that through to the bottom of the smokebox I soldered it in.

 

 

A dry fit of the boiler and firebox and all of a sudden it starts to look like a loco.

 

 

[Rob Pulham]

The next bit of the puzzle before permanently fitting the firebox, is the vacuum ejector pipe running from the casting at the firebox to the smokebox pipe elbow fitted some time ago. Making up the pipe was relatively easy, make up the bends and kee trimming the ends until it fit in the right place.

 

 

The ejector pipe is retained by four pipe clips. In the kit these are provided by 1.5mm wide etched strips.

 

 

However upon checking photos these retaining clips were not flat but rounded like a big handrail knob. A couple of years ago when a friend passed away I inherited a box of 1 metre x 1.5mm brass brazing rods. I cut five lengths and soldered them to a piece of thick brass to hold them while I worked on them.

 

 

I then milled off 0.75mm leaving them as half round pieces.

 

 

 

These I removed from the block and scraped off most of the solder. I annealed them and then bent them round a length of the 1.5mm brass rod to form what are effectively brass split pins.

 

 

Finally I cut them to length. They look much bigger than they are in the photos

 

 

Next up is drilling the boiler and firebox to accept them.

[Rob Pulham]

till working on the body details, I next approached the Injector pipe that runs along under the footplate on the right hand firebox side.

This is the casting supplied.

 

For Christmas, I received a new four jaw chuck for the lathe and wanted to give it a try so I decided to make the jointing flanges first. I had a length of brass bar which was the right outer size without further machining so I centred it and drilled it 3mm. Just to be sure I also ran a 3mm end mill through it. Finally parting it off to length

 

 

I turned a 3mm spigot on the end of a piece of rod from the useful bits box and fitting the workpiece to it I mounted it in the dividing head and used the stub of a cheap carbide drill that I had reground after it broke off to spot drill each corner. These cheap Japanese carbide drills are very good but incredibly brittle even the act of bringing them down to the workpiece can break them off, if you are slightly heavy handed.

 

 

Then I drilled them 0.7mm and fitted wire and tube hex nuts to complete the part.

 

 

 

Next I turned a small top hat flange for the other end and then bent the pipe to shape before finally adding retaining straps from scrap etch strips and more 0.7mm wire.

 

 

 

Onto the next...

[Chas Levin]

That giant 5p piece is really working out as a good investment for you Rob!

 

Seriously, I always enjoy seeing your beautifully detailed work and I promise I will stop joking about large coins... 🙃

[Rob Pulham]

8 hours ago, Chas Levin said:

That giant 5p piece is really working out as a good investment for you Rob!

 

Seriously, I always enjoy seeing your beautifully detailed work and I promise I will stop joking about large coins... 🙃

No problem Chaz,

 

I needed to use my two 5p coins for their proper purpose earlier this week, so no more extra large 5p's until I get my hands on another. I will have to find something else to relate scale to.

[Rob Pulham]

There were no other pipe castings included in the kit. But there was a casting for a pipe flange for the smaller diameter pipe but only the one.

 

In the end up I wasn't happy with the first pair of smaller pipe flanges because I hadn't managed to get the centre hole in the middle. The cross section of the bar that I used was too small for the 4 jaw so I put it in a collet to drill the centre hole.

 

 

However I made the mistake of leaving it full length rather than cutting of a short length and I think that the length of the bar, not being properly supported by the round collet was pulled out of square by the length of the bar. So I milled a stub of round bar into a square and remade them. In the end I made five and chose the best three for the pipework.

 

 

Working out the pipe runs required study of the GA and reference to photos but I think that I have it now.

 

 

Other than the fitting of the handrails I think that these might be the last parts to make for the upper body/footplate but I will double check to be sure.

 

 

[Rob Pulham]

Of course sod's law dictates that I had just nicely finished assembling these when I found a second casting on another sprue that was identical to the first.

I guess that I must have picked up both sprues separately at different times, thinking that they were both the same sprue...

[Rob Pulham]

Despite having a few things going on in the real world this week, I have made some steady progress on the body details.

 

While I had the boiler in place I fitted the front pipe clips for the vacuum ejector pipe.

 

 

Then I fitted the pipes for the top feed which took quite a bit of filing to get them to sit snugly on top of the splasher without the boiler rocking.

 

 

Then having removed the boiler I drilled a hole in the bottom of the elbow fitting for a small pipe which is visible on most photos no matter what period.

 

 

That done, I moved onto fitting the twin oil boxes and their frames. This area still needs much cleaning done.

 

 

Then it was the front vacuum pipe and associated pipework which was included as nice castings in the kit. I did make the bracket to hang it from the rear of the buffer plank after adding a pipe union from brass tube.

 

 

Finally for this update I chose what I viewed as the easier set of pipework to add first. Not before I replaced the etched mounting brackets with some from flat bar after peering at photos and noticing that they were plates with two holes in them rather than straps wrapped around the pipework.

 

 

Now to work out how to fit the injector pipe on the other side.

 

[Rob Pulham]

The Princess continues to challenge.

 

The replacement for the live steam injector pipe took much tweaking and test fitting before it fit snugly with the chassis in place.

 

 

Once I got my head around how the pipes ran, the two front oilers didn't present too much of an issue although I had to look at a good number of photos before I worked out where said pipes ran.

 

 

 

Next I removed the pin rom the bottom of the steam pipe castings and drilled and tapped them 10 BA so that I could screw them to the footplate through the mounting holes

 

 

As can be seen from the snips below there is quite a gap between the boiler and the steampipe flange. At the moment I am not sure where the problem lies, whether it's in the placement of the mounting holes, in the dimensions of the castings or something else. Initially I tried turning down some washers to fill the gap but I don't think that's the answer.

 

 

 

[Rob Pulham]

Plan A is to recreate the flanged sleeve as a separate entity which will sip over the end of the main steam pipe and allow movement to hopefully take up the gap.

 

I started by fly cutting both ends of a piece of nickel bar to the radius of the smokebox.

 

 

Then, I turned down the diameter and drilled out the centres before parting them off.

 

 

The backing disks were turned from small squares of 0.2mm thick scrap etch.

 

 

The disks were turned, by super gluing the square offcuts to an arbor made from the remains of the nickel bar that the sleeves were turned from. I could have used solder to stick them to the arbor but reasoned that super-glue would be easier to get off the finished disks and so it proved.

 

 

The next job is to remove the cast sleeves from the end of the steam pipe castings.

[Rob Pulham]

Removing the cast sleeve was a bit of a challenge and I used a combination of a piercing saw, a wood chisel and old files dipped in talc. This did remove the sleeve but it was hard work and left the stub slightly oversized and not remotely round.

 

I decided to make a tool to cut the stub into a regular round shape. I started with a length of steel round bar which I had recovered from an old printer fuser unit that I had replaced. I salvaged all the useful parts which included the bar, several springs and a number of screws. I am not sure what type of steel it is but it's probably the most free machining steel that have used to date.

 

I cut off a short length and faced off the end. Then I drilled a 3.2mm hole in the end. Once drilled I then took it over to the mill where I secured the length of bar in a square collet block. Finally using a bit of trial and error I cut teeth into the rim. The series of photos below show some of the milling process. I had already took a small cut to establish where the teeth would be before thinking to take photos.

 

 

 

 

 

 

 

The opposite end of the rod had a stub turned on it (which it located in the printer). This allowed it to be gripped with ease in a pin vice.

 

 

It made remarkably short work of truing up the misshapen end of the casting.

 

 

 

 

The next job is to test fit them to the footplate and see if I have resolved the problem.

 

[Rob Pulham]

It was with some relief that my test fit this morning proved that my efforts had indeed solved the problem. Now I just need to add the missing bolt head detail.

 

 

[Rob Pulham]

Well, what an absolute beggar making those turned out to be.

 

I have made at least eight or more of these plates before getting the bolt heads in the right place and mounted to the sleeve correctly. Quite embarrassingly, it was for the most part due to my failure to add up correctly when working out the degrees of spacing around the circumference...

 

Still I got there in the end.

 

 

 

[Chas Levin]

Superb looking addition to the model Rob! I'd say well worth the effort (though I know it's much easier for me to say that perhaps than for you!).

[Rob Pulham]

Thanks Chaz,

 

I agree, they are indeed worth the effort.

 

I treat all such frustrations as learning experiences, but it doesn't stop me muttering at the time.

[Rob Pulham]

The last few sessions at the bench have been spent working on fitting the Silvertown lubricators which I made earlier in the build. After some thought I decided to drill and tap the bases/footplate rather than trying to solder them on.

I did this for two reasons

 

1. They would be removable for painting

2. Being solid brass, soldering them would require quite a bit of heat, potentially disturbing some of the other details fitted previously.

 

 

 

I have soldered all the wire tails to a strip of etch to keep them tidy but I may have to revisit the length and position of them once I refit the chassis.

 

I also noted a couple of etched holes in what looks like an inspection panel on the top of the footplate so I turned a couple of small knobs to fill the holes I am not sure how prototypical this is as I couldn't find any photos which showed the inspection panels.

 

 

[Rob Pulham]

I finally took the plunge and fixed the firebox to the footplate

 

In order to do so, I needed to attach the firebox in two planes, to the footplate and to the cab front. I was sure that If I attempted to use adhesive for both it would be a recipe for disaster. In so much as I would end up with epoxy smeared where I didn't want it on either the cab front or the footplate.

 

To overcome this, I made up a plate that fits inside the firebox with two studs in it (1x 10ba and 1x 8ba). They pass through the cab front and are secured by nuts within the cab. They are hidden by the back head when it's in place.

 

 

 

 

Knowing that I could stand the footplate on blocks of wood cab side down and put epoxy on the bottom faces of the firebox print while being able to slide into final position on the cab front made it so much easier. Finally two 12ba screws held the firebox to the footplate while it set. The plan was to remove them and replace them with studs that will screw into the holes and then hold the two lower firebox pieces into place until the epoxy sets on those. Leaving the studs in place will give a degree of mechanical strength to the glued joints too. 

 

You can see these studs in the photo above as I took the photos after I had fitted the firebox.

 

[Rob Pulham]

After the fitting the firebox and checking the fit of the lower firebox sides with the chassis in place I was wondering how to hold them in position while the epoxy set.

 

After trying and discarding a number of different clamps that I have in the workshop ranging from a small engineers clamp to a pair of 1" G clamps I decided to make a custom clamp to do the job. On my bench I just happened to have a short length of 14mm dowel which would do perfectly for what I had in mind. The bottoms of the lower firebox sides slope so I reasoned that dowel being round would allow clamping along those slopes.

 

Next I cut a short piece of 5mm square boxwood to a length that would sit on the footplate inside the firebox and drilled a hole through the middle. I had planned to use a 1" 10ba screw as I have quite a stock of them. Sadly it wasn't anywhere near long enough so I decided to turn myself a custom screw and to make it a bit easier to handle a longer length in the lathe, I decided to make it 8ba rather than 10 ba. I started with some 3mm brass rod and turning around 10mm at a time to minimise deflection I kept easing a bit more from the collet until I had a 30mm length that could be threaded 8 ba.

 

As I started to run the die down it I realised that I didn't actually need to thread the whole length so I just did about 12mm. As it turned out that wasn't quite long enough either but rather than start again I worked out that I could just counterbore the dowel to allow for enough thread to tighten the clamp. I created the counterbore with a 6mm 4 flute end mill which allowed enough clearance to use an 8ba nut spinner and for me to add a washer. As it was only to hold the parts in place there was never any need for it to be anything more than gently tightened.

 

 

 

 

There is a hole in the upper surface of the lower firebox sides which locates over the studs mentioned in the previous post. The clamp then holds down the rear and to be belt and braces I also placed a reel of solder on the on the flat section at the front to be sure that it sat down flush on the studs and stayed there.

 

[Rob Pulham]

Most people reading my threads regularly, will have gathered by now that I am a bit of a tool junkie and that I don't do well with the smaller imperial measurements.

 

Late last year I came across a Chesterman Height Gauge which measures in both imperial and metric, at a price that I didn't need to sell a kidney to afford. It came in its original box with all the attachments including a holder for a dial test indicator. When I was looking for one, even those with no box or attachments were fetching good money. I already had a good quality imperial Height Gauge which I was able to sell to recoup some of the cost, thus making it a worthwhile investment.

 

For those that don't know, height gauges are used not only to measure and compare heights but also for marking out when machining and they come with at least one hardened tools for scribing. To use it, you cover your workpiece in layout fluid/marker pen and then scribe in your horizontal layout marks with the workpiece and and the height gauge on a surface plate of some sort.

 

Because I didn't want to scribe the boiler, leaving marks that might show through the paint, I thought that I might be able to use the dial test indicator attachment to hold a pencil. Sadly all the pencils that I could find in the house were all the standard hexagonal type which were all too big to fit in the holder. Having a box of brand new pencils to hand I had no problem in turning the end of one of the pencils down to fit the DTI holder.

 

 

I used a flat ended HSS tool bit and although I have a corrugated way cover I immediately vacuumed the sawdust off the lathe to prevent any staining of the metalwork.

 

I sat the loco on a pair of 1-2-3 block on a sheet of plate glass to do the marking of the horizontal line down either side of the loco.

 

 

 

 

Since taking the photos I have chopped off the thinned down end of the pencil and it now lives in the box with the height gauge as I suspect that over time I will make much use of it for marking boilers.

 

[Chas Levin]

Superb! Custom-built clamps are a step up... 

[mswjr]

I have done similar but with a toolmakers scribing block, I too had to turn my pencil to fit, I am amazed how many people build wonderful model locos that are ruined by non straight handrails. And unlike you Imperial is better , But i done my apprenticeship in imperial, much easier to understand. Really nice work, look forward to your posts.

Edited March 28 by mswjr

[Rob Pulham]

Having learned metric at school, I suspect that if I had gone into engineering, I too would have had to learn imperial measurements. As it was I became butcher and had to learn imperial weights rather quickly. I am okay with the bigger imperial measurements I just struggle when I get below an eighth. I am much more comfortable working in 10's but I suppose that's where thousandths of an inch come in.

 

I too would have used a scribing block if I hadn't bought the height gauge. Indeed I have used a scribing block to check if parallel boilers were sat level on previous builds but since buying the height gauge I have been itching to put it to good use.

[Rob Pulham]

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.

 

 

Edited March 31 by Rob Pulham
Italicise some text

[Rob Pulham]

Although I had fitted the handrail knobs to the boiler and smokebox earlier last week, I hadn't added those on the resin firebox. This was for no other reason than the superglue was upstairs in the fridge and I thought it easier to crack on with something else and bring the superglue down later.

 

When I did subsequently fit the remaining knobs in place, those on one side were fine but for some reason both on the other side didn't seat properly and the glue set as I was trying to push them home. I tried pushing them in with pliers and gently tapping them but I was very concerned that the resin firebox might crack if I was too vigorous. They didn't stick out by much but I wasn't happy having put so much effort in with re-seating the chimney etc. It was during commode time (a term picked up from an american machinist who I watch on Youtube) that an idea came to me.

 

This morning in between making the end caps for the handrails I plucked up the courage to give it a go. I got a short offcut of the 0.8mm piano wire that I have made the handrails from and put a small bend on one end gripping the wire in a pin vice just in front of the bend.

 

 

I popped the bent end through the hole in the first offending handrail knob. I chose the one that was furthest in, to try the proposed solution on. Then I connected the negative terminal of my RSU to the piano wire which protruded from the handle end of the pin vice. A quick touch with the probe and a slight twist and the knob thankfully popped free without issue. Buoyed by this success, I repeated the same on the second offending knob and I had barely touched it before it popped out.

 

As a precaution because I was heating superglue/resin I had the extractor fan running at the side of my bench just in case any fumes were created. I was probably being over cautious as the glue just seemed to slightly soften rather than melt.

 

Then it was a simple job to re-drill the holes making sure that the knobs were a loose sliding fit before attempting to apply more glue. It was at this point that I found out why one of them wouldn't seat properly. There was a slight rim around the shank on one which prevented it from seating flush. It wasn't really visible but when I ran my nail across it I could feel the ridge. To save time I swapped it for another one from the stores and both were fitted properly.