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Rob P's Railway workbench - Currently David Andrews Princess Royal and an MOK 8F

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I said that I would start a thread on Albergman's P2 thread, it took a little longer than anticipated..


Despite being an LNER modeller during the grouping years (1923-1948) The two locos currently in progress are both LMS locos, albeit when I set out building the 8F in 2009/2010 the plan was to finish it as an LNER 06, one of those built for the War Department and loaned to the LNER for the duration. However last year I bought the full sized Hooter/Whistle off 8F 8425 which was another wartime build but this one was built by the Great Western for the War Department but it was always planned to be returned to the LMS. My good lady who bought the 8F kit for me as a gift suggested that I might finish it as 8425 instead so that's what I intend to do.


As the title says the 8F is a Modern Outline Kit (MOK) and is all nickel silver etches with many brass castings and a few whitemetal ones.


The Princess Royal which is to be built as 6206 Princess Marie Louise one of the production batch of locomotives depicted in the late 1930's just after she was fitted with a coal pusher tender from a David Andrews kit. The gent that I am building it for paid extra to have all the etches done in nickel so it's quite unusual that I am building two nickel kits at the same time as many loco kits are etched brass rather than nickel.


Both kits are 7mm scale (1:43) O Gauge and as they have both been in progress for some time it's not my intention to back track but to document where I go to from recent works. As I will be flicking backwards and forwards between the two I will clearly label the post so that it's clear which one the post relates to.

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MOK 8F. 


I only picked this build up again over the Christmas period having last touched it in 2018. Having made the decision to build 8425 there is a small amount of backtracking to do to change the loco to a Swindon built example. 

Sadly I had already built the tender as a riveted version whereas the GWR built tenders were all welded. Sadly I used the optional welded sides on something so I no longer have the option to change those so it will have to have had a tender swap at some point.


One of the first jobs I did was to turn up  replacements for the whitemetal brake cylinder and water scoop dome.



These are as supplied - I believe that these have been changed to brass castings in the intervening years since I bought my kit.



These are the replacements along with the tank vent castings which I also cleaned up in the lathe to make them sit square on the tank top.


Edited to add a photo of the castings in place on the tank top on the rear of the tender


Edited by Rob Pulham
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David Andrews Princess Royal.


Although I don't plan a full recap of the build to date I will share some of the more interesting bits (or they were interesting to me at any rate).


Starting with the Tender which I generally build first to get a feel for the designer and then when you have finished to loco the tender is done so the build is finished.


Like most kits, this one came with etched lamp irons. I must confess that I find etched lamp irons to be very fragile long term so I try to replace them where I can. Normally I would by some aftermarket castings from LG Miniatures or one of the other suppliers but when I looked I couldn't find any LMS specific ones. I decided to have a go at milling my own from some brass pins recycled from redundant 13 amp plugs.







I used a small hand vice as a vice stop so that I could turn the part over to mill the other side and get it back in the same place.




I used a 0.5mm slitting saw to cut between each lamp iron before machining the back so that the cutting action of the saw didn't snap the irons off the base material.




I made a couple of different types, those mounted on the vertical plate and some L shaped ones to sit on the rear footplate.





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14 hours ago, Circloy said:

Thanks Rob I'd never looked at plug pins as a source of raw material for components  - something else not to throw away.


I hang onto any most 'waste' metals, even going as far as stripping appliances down before disposal to see if there is anything worth keeping in them.


My compound Mitre saw died last year after 20 years of service and when I took it to bits there were lots of useful bits of steel and metric nuts screws washers etc. Just this week I used the steel post that supported the clamp for holding material in place while cutting, to turn a couple of buffer heads for the tender of the 8F



Edited by Rob Pulham
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While on the subject of steel, a top tip for blackening steel items such as buffer heads is to hot blue them. 


Give the item a wash to get rid of any grease which inhibits the blackening process. Heat the steel item up over the gas ring or using a microflame/ cooks torch until it changes colour on its way to getting red. Get a small jar with some cooking oil in it (any oil will do the job but the smell of hot cooking oil is usually more acceptable in doors than 3 in 1 or engine oil) , drop the heated item in and put the lid on. Then leave the item(s) in the oil overnight.


DO Remember that it's hot and take adequate precautions when holding and heating the items: Use pliers/ tweezers etc.

This is what they look like after they come out of the oil.



Edited by Rob Pulham
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Beware though, at around the temperature it starts to glow (cherry red) steel starts to harden & when quenched becomes more brittle. In reality anything that may be subject to hard or sudden shocks needs then to be tempered to prevent failures in use.


In normal model railway use tempering is unlikely to be required however it would be essential if producing your own tools/cutters.


When done right some beautiful surface colours can emerge.



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Making replacements for poor or undersized castings seems to be a recurring theme of my loco builds as does having to square up the ends of vent castings so that they sit correctly on the top of the rear plate. The Princess Tender was no exception.



There wasn't actually a great deal wrong with the tank filler casting as regards shape etc it was just undersized when compared to the GA drawing This is a replacement that I turned and added the hinge to.





The difficulty with turning castings is actually holding them securely in this case I made a split collet from a piece of aluminium bar.




The vents and filler test fitted to the tank top plate.



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Lovely model engineering going on here Rob.   Will be following this despite not being LNER!   😉

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Princess Marie Louise (6206) was quite unique in that she was the only Princess Royal class loco to be fitted with a coal pusher fitted tender. The kit doesn't cater for this option but the gent that I am building it for had purchased a castings set from Finney7 from their Duchess kit.






I had to make the connecting rods myself from strip.


I scratch built further details for the rear of the tender.


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David Andrews Princess Royal - Tender 


I replaced the damper rods on the spring castings with brass rod to get them to fit better.




I also made up a couple of replacement windlass handles.






Once the detailing of the front was complete the tender was pretty much done.






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More lamp Irons for both locos


Needing a break from the metaphorical drawing board, I decided to make the lamp irons for the Princess footplate.


I milled them from a length of brass bar. Initially I milled a length of angle and then cut slices off with a piercing saw. Then I soldered them edge on to the other end of the bar that I milled them from. Once soldered on, I milled the edges flat. I then turned them over soldered them on again and then milled them down to final size.




They were then finished by hand with a file but I notice from the photos that some of the bases need deburring.


Whilst making the lamp irons for the Princess my thoughts turned to the unusual (to me at any rate) double lamp irons that Swindon fitted to the 8F's that they built so that GWR and LMS lamps could be fitted.



For those unfamiliar with what I am talking about this is a snip from a web image to illustrate. 


The MOK kit does provide etches to make up this version of the lamp irons but I am not keen on etched lamp irons. I also thought that I would like to do them from nickel as the rest of the kit is nickel but I didn't have any square nickel bar thick enough. I do have some 5mm nickel rod so my first step was to machine the end square in the mill.


Then it was a case of working out how best to mill out the bits in between the lamp irons.


I milled a groove down one corner of the square section and then rotated the part to carefully mill from the opposite corner to leave the two upright irons






The tops were then rounded with a file before cutting off the main piece. I could have transferred the work piece to the lathe and part it off but I just cut it with a piercing saw them popped it in the vice jaws and milled the bottom flat.




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Leaping ahead before I go back and fill in some of the gaps one of the things that is apparently wrong with the Princess kit is the firebox. This was discussed at length on one of the forums that I inhabit but I must be honest and say at the time I didn't really get what the issue was so carried on as I was. The subject came up again and I decided to take a closer look. I managed to get my hands on a whitemetal cast firebox which had been included with one of the iterations of the kit for comparison purposes.
















The result of this was that I decided to draw up a replacement for 3D printing.




Then it was mentioned that the lower firebox casting was also wrong in so much as the cast on cladding bands didn't match those on the upper firebox so I ended up drawing the lower parts too




A friend printed them for me and they turned out well but I had made a mistake with my measurements and the upper firebox was too tall. Back to the drawing board...


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Hopefully all my recent talk of lamp irons is not putting you to sleep.


I made what I hope are the final type of lamp irons for the two locos today and the only reason that I am posting it is that the method that I used could be replicated by someone with a file rather than the milling machine that I used.


I started with some flat nickel bar



I cut off four 40mm lengths and soldered them together.



Once soldered together I milled all the edges flat. I needn't have done the ends but with the mill it was a simple task. Here I have milled out the front of the iron.



Then I turned the block over and milled out the rear



This is the finished job before cutting off with a piercing saw and separating them.



The finished individual lamp irons ready for final clean up with a file.



From the 40mm strips, I got eight lamp irons and I have enough material left already soldered together for a further eight which I will cut and put in the spares box.


Finally I left two of them still soldered together and gripped the 'iron' section in the vice then I annealed the support bar and bent it forward so that the lamp iron can be mounted on the smokebox door. Then they were separated to be finished with a file.


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I have now drawn the revised firebox and it's ready to send off for printing.

It was pointed out that I had missed out the mud hole covers from the original design so I had to learn a few more fusion skills to add those.













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Moving onto the chassis of the Princess for a moment.


There is a hole in the forward frames where the movement of the crosshead for the inside cylinders can be seen moving backwards and forwards.




he gent that I am building it for said that while he wasn't bothered about full inside motion he would like to see some movement behind the frames.

The loco kit as supplied came with Alan Harris cast driving wheels on telescopic axles. The nature of the telescopic axles precludes the fitting of cranks to the axle. This meant that I needed to come up with another way of creating movement that didn't involve cutting the axle.


The idea that I came up with was to create two eccentrics and use those to impart movement to the cross heads. The Cross heads and slide bars, and eccentric straps are LG Miniatures castings, the eccentrics are home turned and the connecting tods are spares salvaged from the kit because they had been replaced by milled examples from Premier Components.


The motions bracket and cylinder front is scratch built.






I then had the bright idea of making a bush to maintain the spacing between the eccentrics which would also double up and make them removable via the taper pin which holds the axle halves together too.








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Hi Pete,

This one has Finney hornblocks on the drivers and David Andrews supplied top hat bearings on the rest. Although David may well have bought them in from Slaters originally. 

I only tend to turn my own bearings if those in the kit or my spares box won't suit for some reason. Because I tend to fit hornblocks to driving axles, I do gather a few spares.

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That's good Rob


I have always found the Slaters bearings make a good base for suspension on big drivers as they can give good flexibility with cantilever suspension designs.


I look forward to following the build.



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Over the weekend in between checking over the Princess Firebox drawings, I fitted all the new lamp irons on the MOK 8F and I am happy that the upper tender is now complete.





I have subsequently straightened that middle lamp iron after taking the photos


I also replaced the etched Irons that are built into the MOK etches for the storage of spare lamps on the tender front.






I really should have made a better job of rinsing and drying it after washing too, the cleaning agent (Flash liquid) has left a bit of residue.






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Nice work Rob it's a complex tender to build the frames are fun to put together and keep square.


Try washing the assembly in a bath of IPA which will glean off the flash residue and and give a good surface for painting.




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