David Andrews Princess Royal - 6206 Princess Marie Louise

Hi Andy,

Just to be clear, the roll of lead isn't that thickness all the way and the smoke box is separate. Due to the taper of the boiler there is a centre section at a much narrower diameter with a thicker collar at the wider end of the boiler.

 

Following on from my An Evening With session last night (which I thoroughly enjoyed and I hope all those that joined me, did too) I can now share with you how I managed to hold the chimney centrally in place when soldering it.

Whilst machining the base of the chimney I had deliberated from the outset how I might best hold the chimney in place after machining and I had considered boring the base out and adding a short length of tube to locate it when it occurred to me that solder doesn't stick to aluminum so why not use the arbour to centre the chimney.
I parted the end off the arbour and machined the sides so that the chimney sat down properly the other way up.







Then using a makeshift arrangement of blocks and strips of wood I fed the modified abour up through the chimney hole in the smokebox.











There was enough solder remaining on the smokebox from where the chimney hadn't sat down flush initially, so some flux and a waft with my microflame had in place in no time with no cleaning up.

 

Thanks Steve, almost there now.

The loco body is finished and I am just sorting the drawbar. Which just leaves working out how to fit the sand pipes so that they can be removed. Otherwise because the wheels are mounted permanently on the split axles you can't get the wheels out. Then final testing to ensure that it goes around corners.

 

These are the drawbar options as supplied. I have a confession to make at this stage. I couldn't find them and had asked a couple of fellow modellers who have the same kit for dimensions. As it happens one was able to supply part numbers and the other the key dimensions.

Then as is often the way, I opened a box where I keep useful bits (actually looking for a piece of plug pin to see if it would be suitable to make a draw bar from) and there on top of all the bits and pieces was the square of etch containing the two missing drawbars.



While I completely understand why they would be supplied as etches I wanted to see if I could make something more 3 dimensional.

I made a complete hash of my first attempt due to getting the machining operations in the wrong order. I had started by milling and drilling which left the part too weak when I attempted to turn the dog bone section.



This was at the end of the turning operation on the second attempt.







This is the end result greatly enlarged of course. The insulated bushes were made from knitting needles. sadly the only one I had of the right thickness was green. I did think that I had a suitable grey one but having turned one and subsequently dropped it, it landed with a decidedly metallic click. Further investigation revealed that it was in fact aluminium not plastic so not much cop for insulated bushes...

 

The Princess is keeping me entertained to the end.

Almost the last thing to fit are the sand pipes but in order to do that I needed to refit the brakes so that I can work out how the sand pipes will fit around them.

Previously after fitting the 3D printed shoes I had fixed the hangers to the frames via soldered pins with the top of the hanger slipping over a square rod (the holes were etched square) for mounting. Having come back to it I wasn't happy with that arrangement so I removed the pins and substituted some lengths of 12BA stud instead (cut down screws) next I soldered the square end into the hanger brackets. Then I enlarged the holes in the frames so now I can insert the studs through and put nut on the back to hold them.

A bonus to this approach is that not only will it be easier if a little fiddly to get them on and off the studs will rotate in the frames before being fully tightened so that positioning of the shoes against the wheels will be more adjustable.

 

After fitting the brakes, I have spent far too much time in the last week trying to fit the sand pipes. What's so difficult you might as yourself? Well they fit inside the frames and they also need to fit in such a way as to allow the wheels and brakes to be removable (the wheels won't come out unless you remove the brakes). the key issue has been getting the pipes to bend in a tight enough bend to allow them to fit without touching the next wheel along.

In the end I have started again by stripping all the pipe work off the brackets and the plan is to reinstate them with finer soft brass and copper wire. I have cut all the parts and I will share picture when I have them reassembled ready to fit.

 

Well I have the replacement sand pipes assembled ready for fitting let's hope I have more luck in fitting these. One pipe is soft brass and the other slightly thinner one is copper.



Below are the first ones that I made earlier in the build. I made myself a rod for my own back (if you will pardon the pun) by using hard brass rod for the thicker of the two pipes which when it came to it, was almost impossible to bend where I needed it to go.

 

he sand pipes are now fitted without interfering with anything. I did get them fitted a couple of days ago but when I added the front bogie they stopped it from moving. I removed the two front ones and moved them slightly further back which did the trick.




This who are observant will notice the jaunty angle of the return crank in the top photo. This was to come back and bite me later.

 

Initially I just thought that in lifting the loco up I had dislodged it causing it to unscrew and come loose. However no matter how much I tried I couldn't get it to tighten back up in the right place. I tried shortening the bush but realised too late that the crank pin itself must have shifted in the wheel. Then having shortened it I found that when tight it was nipping the conrod and coupling rods so that they wouldn't move.

Making a replacement bush was the order of the day.


Replacement return crank bush

 

You are a harsh man Mr Moss, I know that it might feel like it's been that long (it certainly does at this end!!!) but I didn't actually start building it until May 2021...

 

Now you're starting to sound like a politician... a slippery slope!

 

The last week and a bit of modelling time has been spent tracking down shorts on the tender and isolating them. This has required me making a number of additional bushes and delrin/acetal washers.



I also had to rethink the way that I had mounted the two U shaped brackets which fit across under the tender. Unthinkingly I had mounted them in the same way as on the MOK Stanier tender using small pieces of brass angle drilled and tapped for 14ba screws. Sadly when assembled these frames touch the brakes which although the shoes are insulated the hangers are not and between the two breached the insulation between tender chassis and body.

I made up some wire supports and then shortened the brackets to clear the outer frames. Below are a couple of shots of the sets that I used to get them soldered vertical to the brackets and then cut them off to the right size. I read recently on one of the forums someone say that you cannot have too many engineers clamps. I agree wholeheartedly although when used as soldering aids they do have a tendency to rust. I do have a cunning plan to get around that, I have a length of brass bar that I have had for about 10 years which will be just enough to make a pair of brass jawed clamps which shouldn't rust.



I used the Expo pliers that I recommended recently to bend the corners pretty uniformly.



I also had a feeling that the washers which I had used to reduce the side play in the axles, might have been bigger than the insulation gaps in the wheel hubs thus creating a short, hence my making the delrin washers.

 

Since my last post I have been beavering away identifying and curing the shorts on the tender which I am happy to say that I have done.

As with many things in life getting there required at least one side project. During last Thursday’s GOG online modellers meeting the consensus was that I really needed to dig my multimeter out of the depths of the shed. On friday morning I bit the bullet and started to pull out plastic stacking boxes (having first removed the lawn mower, petrols cans, oak kitchen cabinet doors and finally my router table). An hour and a half later I had retrieved one of my two multimeters and put everything back.

Sadly the one that I found was the one with the missing probe, the wire was there but the common probe which had broken off in the dim and distant wasn’t with it. Before embarking on making a new probe I fitted a new battery to test that it still worked which thankfully it did. The metal section of the probe was made from a length of brass rod which sat atop my useful bits box on the workbench and I quickly drilled one end to accept the wire and turned a step onto the other to fit snugly into the yet to be made insulated delrin handle.

I didn’t take photos along the way but this is the finished article alongside the original ‘live’ probe.



Once I had it I reassembled the tender chassis test along the way without find any further shorts.