7mm David Andrews Princess - 6206 Princess Marie Louise

[Richard Gawler]

Even so, milling round wire to make it half round, whatever happened to just filling a flat on it

I expect four different modellers could each use a draw plate, a file, a mill and some stock. None would have the 'better' method as long as they enjoyed their efforts and were satisfied with the results.

 

[Rob Pulham]

Even so, milling round wire to make it half round, whatever happened to just filling a flat on it

If I had just needed the one short length, I would have done just that, but I needed a few and I have a large stock of 1.5mm brass rod and a milling machine. That and the last time I wanted some 1.2mm half round I couldn't find any. Metal Clays 4U you were out of stock and everyone else only had sub 1mm

 

[mickoo]

Fair enough

Just seemed a really long way to get from A to B, made me smile.

 

[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...

 

[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...

 

[OzzyO]

Hello Rob,

where do these pipes fit. Could you post a photo showing them in place (one showing them on the real loco would be better).

Nice looking build,

ATB

OzzyO.

 

[Rob Pulham]

Hi Paul,

Here you go

 

[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.

 

[simond]

Rob,

in your photo of the real thing, the “fat cylinder” is fitted to, and tight on, the smokebox. The bent pipe is a “loose fit“ in the cylinder.

might you be able to do the same?

just looking at your pictures, the “fat cylinder” looks a bit longer in the real thing than the castings you have, maybe that’s where the missing bit should be?

atb
Simon

 

[OzzyO]

Hello Rob,

you have the drawings. So I'd check the length between the centres of the steam pipe, from the footplate to the entrance to the smoke box. You may have to make new steam pipes by cutting gashes using a V shaped cutter on it's side I'm not sure if Tony made patterns for the Princess steam pipes? If he did they could be in the Renalds range of castings. I can't remember who sells them.

Coming along nicely
ATB

OzzyO.

 

[Hobbyhorse]

Hello Rob,

you have the drawings. So I'd check the length between the centres of the steam pipe, from the footplate to the entrance to the smoke box. You may have to make new steam pipes by cutting gashes using a V shaped cutter on it's side I'm not sure if he made patterns for the Renalds range of castings.

Coming along nicely
ATB

OzzyO.

Tony didn't do any patterns for the outside steam pipes.
I've got two ways that I've used in the past with issues like this, it will be easier to talk about them on tonights Online Modellers Meeting.

Simon

 

[Rob Pulham]

Rob,

in your photo of the real thing, the “fat cylinder” is fitted to, and tight on, the smokebox. The bent pipe is a “loose fit“ in the cylinder.

might you be able to do the same?

just looking at your pictures, the “fat cylinder” looks a bit longer in the real thing than the castings you have, maybe that’s where the missing bit should be?

atb
Simon

Hi Simon,

According to the GA the fat cylinder is only 0.3mm shorter than the drawing suggests it should be on the surface. The washers which I tried in place to fill the gap are 0.7mm and they dont fill the gap on one side.

However because as you suggest, it's a sleeve and that sleeve passes through the smokebox then there will be variations on just how much protrudes out either side I am sure.

I am now exploring options as to how best resolve the issue. I am going to start with a 3D drawing and then work on to more traditional methods Which may involve a top hat type sleeve fitted from inside the smoke box.

 

[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.

 

[simond]

Rob

I guess you’ll want to keep as much pipe length as possible, so “thin them down” rather than “cut them off”?

 

[Rob Pulham]

Rob

I guess you’ll want to keep as much pipe length as possible, so “thin them down” rather than “cut them off”?

Hi Simon,

Yes, that's my plan.

 

[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.

 

[OzzyO]

Hello Rob,

nice to see the result of your bit of sideways thinking.

ATB

OzzyO.