David Andrews Princess Royal – Motion Adjustments.

A major personal issue has kept me away from the bench for a few weeks apart from a few intermittent sessions. I will reveal the issue when I know if/how it’s going to be resolved.

During those sessions I have managed to move the reversing support rod so that it now passes through the hole in the frames. Once I have finally set the ride height, I may need to make further adjustment.

Nick Dunhill kindly supplied me with a few replacement parts at Barnsley show and I have managed to refit a slightly shorter combination lever.

David Andrews Princess Royal Revised Motion.

Tamiya Panther Tank – Road Wheels Fitted

I finally managed to get a little more done on the Tamiya Panther at recent arts and crafts group sessions and I have managed to fit the road wheels.

Tamiya Panther Tank
Tamiya Panther Tank

Sometime during the build I have managed to lose one of the wheel hubs. A lady at our arts and crafts group was offering various item free to anyone who wanted them. In amongst them were a pair of 5.5mm knitting needles and I recalled that a fellow Gauge O Guild Member had mentioned how well they turned. So I asked for them and turned a replacement hub. I still need to do a bit of work on the face but I am pleased with how it’s looking so far.

Replacement wheel hub

Back on the Recycling Trail

I did a little more potentially useful recycling today. Earlier this week I discovered a brand new round file which needed a handle. The very next day we received our grocery order and in it was a new dish washing brush which meant the old one was being discarded as being worn out. As I was about to put it in the recycle box I wondered if the handle was solid as an idea was forming. I popped it in the workshop and this morning I had 10 minutes to saw the remains of the brush head off to see if the handle was solid.

Having determined that it was solid, I measured the file tang and cut the brush handle to length leaving the comfort grip. I drilled out the cut end to accept the file and a few bashes with a rubber mallet later and I now have a file that is really comfortable to use.
I have to admit that the colour is not great but I am not too fussed about that.

Modified by CombineZP

David Andrews Princess Royal – Outside Motion Update.

A wider discussion on the subject over on Western Thunder has highlighted that there is more wrong with the motion than just the reversing rod supports.

So far I have modified the Radius Rod, moving the pivot hole nearer to the slot by 1mm. I have also modified a spare set of Combination Rods as those supplied are too long too.

Nick Dunhill had a replacement set of motion etched when he built his three. He has very kindly offered me some of his spares which I will collect at Barnsley. Progress on the chassis will be put on hold until I have the alternate etches.

David Andrews Princess Royal – Outside Motion Fun

The last couple of weeks have been steadily working towards getting the outside motion working as smoothly as the inside motion. It has fought me much of the way.

Some of the issues have been of my making, mostly due to my clumsiness in dropping bits on the floor which subsequently disappeared into the black hole in the workshop floor.

As I was working my way through the motion and I got to the motion bracket, I discovered that he support rod for the reversing mechanism wouldn’t go through the chassis due to it hitting the middle wheel set.

DA Princess Royal Outside Motion

Initially, I wondered if the cast wheels were slightly oversized but they aren’t and a bit of further investigation got me to the support brackets which are too long when compared to the GA drawings in the Wild Swan book. I wonder if other people who have built the DA kit have experienced the same issue?

DA Princess Royal Outside Motion

David Andrews Princess Royal – A Romford Screwdriver Never Goes Out Of Style

Still working my way through getting the chassis running and I now have the inside motion running forwards at least.

As an aside I have reversed the front crankpin bushes to look more like the prototype and to give additional clearance for the motion. I was wondering about how to tighten the reversed bushes and remembered the late David Smith talking about making peg spanners as he called them. I chose a similar route but instead of pegs I used the same approach as the 4mm scale Romford screwdriver (I still have one in my modelling toolbox).

For those who haven’t a clue what I am talking about this is a Romford screwdriver

Original Romford Screwdriver

This is the leading crankpin bush that I am talking about

Front crank pin nut

This is the custom big boy’s ‘Romford’ Screwdriver that I made to tighten them. The business end is 3/16 silver steel and the end was shaped with a 3mm end mill with the rod held in a square collet block so that I could keep flipping it over to take the same amount off each side.

8BA Romford Screwdriver

If I wish to use this method of securing the coupling rods to the front wheels again in the future I will probably need to make another one with a smaller diameter to fit reversed Slaters bushes. The crankpins on this build are 8BA so bigger than most builders make them (the wheels were already tapped 8BA for the crankpins when I received them with the kit). Continuing my current ‘Dremel’ tool theme I used a ball burr in the mill to make the grip. Previously I have used the ball burr in a similar manner to an end mill by cutting into the top of the work piece. This time I did it differently and side milled it. This gave a much better finish and was easier to do. I milled the grooves before turning the taper.

MOK 8F 8425 – Replacement Brake Clevis

In between times I have managed a little more on the 8F. The next job was reassembling the brakes. One thing that has bugged me for a few years is that one of the clevis castings hadn’t fully formed when casting.

Misformed Clevis casting

It would have been easy enough to just solder it on and have done with it but I remembered fellow modeller Tony Geary making some clevises to add detail to the brakes on one of his builds so I decided to have a go at one myself.

I started with some square bar and turned a round spigot on the end. Then I reduced the next few millimetres down to the size of the arms of the clevis using a small Dremel burr as a milling cutter

Dremel Type Burr

a bit of hand filing gave me the basic shape

Basic Replacements

Then I drilled a couple of holes in either end of a stub of brass bar and temporarily soldered the two parts into it.
This allowed me to cut the slots. I do have a full sized slitting saw for the mill but a couple of years ago while in one of the cheapo trading stores I bought a set of slitting saws for a Dremel type tool (notice a theme here?). I think they were a fiver for the full set.


I fitted it into the mill with a 0.8mm blade (the pack has several different thicknesses from 0.4 – 0.8mm) and I was really surprised at how little run out it had.


This is the end slit and then finally the finished clevis


David Andrews Princess Royal – Return Cranks and Eccentric Rods

I got around the problem last night by modifying a 12BA screw and soldering the etched covers on, making a small bush from tube threaded 12BA and a small spacer. Once I get them assembled, I may not need the spacer but if I don’t they will go in the spares box.

David Andrews Princess Royal Return Crank and eccentrics
David Andrews Princess Royal Return Crank and eccentrics – Constriuent parts

I still need to add oil corks to the eccentric rods.

David Andrews Princess Royal – much ado for nothing….

Recently there has been much work but not a lot to show for it. I returned to the chassis in an attempt to get that running before carrying on with the body and cab. much of the time has been spent fine tuning the fit of the gearbox so that it doesn’t rub and getting the rear axle to pass through the gearbox and be a tight fit but still be removable for painting etc. This is more interesting because of the wheels being fixed to the axle stubs and the gearbox having ball races which want to grab onto the axle.

I also had a rather frustrating time trying to make a pin for the outer end of the return crank which attaches the eccentric rod. I had tapped the small end of the return crank 12ba and the plan was to make a small shouldered pin threaded 12BA with a large flat head that I could attach an etched cover to.

Return Crank Pin

This gives an idea of the desired pin with the etched covers below

The observant amongst you will note that the threads look very undernourished on the pin. This was possibly my fifth or sixth attempt and I kept putting it down to my having the pin too thin, too thick etc. as each time the thread came out too small for 12BA. Eventually I examined my 12ba die under some magnification and realised that one of the three cutting edges is out of line with the rest and is what I am sure was causing all the failures.

I can’t actually recall if I have used the 12BA die at all (I use the 12 BA tap set regularly but generally for fitting bought hardware) and if I have I would have only used it on brass or nickel so I very much doubt that I have deformed it. It has been consigned to the bin and a new one ordered from Chronos. in the meantime I will probably modify a a couple of 12BA set screws to get on with the job but when the new die arrives I will have to make another to prove once and for all that it’s not something that I am doing wrong.

Drill Chuck Key Comfort Handles

This may not be as relevant to some in these days of keyless chucks but here goes.

I have got into the habit of watching Youtube videos on my phone while having coffee, usually on lathes or machining of some sort. During one such video yesterday a guy in the US had made comfort handles for for drill chuck keys and when he explained why it struck a chord.

Today while at the lathe making return crank bushes for the Princess I decided to have a go at a handle for the chuck key for the drill chuck that I use on both my lathe and mill.

Chuck Key Handle
Chuck Key Handle

Really quick to make and it doesn’t need a lathe to do it. A Drill and a file would suffice. I made it so the handle was a tight interference fit and I did such a good job that I had to drill a 1mm hole in the end to let the compressed air out to allow it to push into the bottom of the main hole in the handle. It got quite a bit of use while making the bushes so this evening and it was so much more comfortable to use that I made a second one for the much smaller chuck key for my Proxxon Mini Pillar Drill

Chuck Key Handle

Both handles are made from offcuts of Delrin rod that I had in stock but they could be made from pretty much anything. I had eyed up wooden dowel, aluminium bar and brass rod before remembering the Delrin.

David Andrews Princess Royal – Cab Details

More detailing of the cab has ensued since my last update. The reverser is a mixture of David Andrews and Ragstone castings. 

David Andrews Princess Royal Cab details
David Andrews Princess Royal Cab seats

The David Andrews Seats are reasonable castings but I was struggling to work out how best to fit them. They look like the idea is that the two pegs fit into holes but I didn’t really want to be drilling holes in the cab side sheets for them. With the pegs removed there is very little to secure them so I made some replacements with a rear strip to solder to the cab side.

David Andrews Princess Royal Cab details

What is unclear is whether they fold up or down. At the minute They just drop down but if they fold up I can make a couple of stays to hold them when folded down.

David Andrews Princess Royal – Back Head Bling Refitted

Here is it is with most of the bling refitted – just resting in place it will be soldered in from the back later.

David Andrews Princess Royal – Back Head refitted
David Andrews Princess Royal – Back Head refitted

I say “most of”, because the production locos from 6203 onwards had a double regulator handle and I have only just got around to making it.

David Andrews Princess Royal – Regualtor Handle

MOK 8F 8425 – Solving The Enigma Was The Easy Bit!

Having worked out how it all fit turned out to be the easy bit!
Assembling all the elements together with the balance weights was like trying to plait fog. You have to slip the cross pin through eight separate holes in the subassemblies. Much muttering ensued before I got it all together.

MOK 8F 8425 Water Scoop Mechanism
MOK 8F 8425 Water Scoop Mechanism
MOK 8F 8425 Water Scoop Mechanism
MOK 8F 8425 Water Scoop Mechanism

Although they are shown on the isometric drawing there is no provision for or mention in the instructions of the support adjuster rods for the scoop. I made them from some lengths of rod and microbore tube.

MOK 8F 8425 Water Scoop Mechanism

I have made a few of these Stanier Tenders by now and this is certainly the most detailed that I have done to date.

MOK 8F 8425 – My personal Enigma Finally Solved

Today I finally cracked my enigma. One of the reasons that the build stalled back in 2018 was that I couldn’t for the life of me work out how the water scoop mechanism went together.

At this point I need to say a big thanks to fellow Guild member Ian Allen for pointing me in the right direction. As with all things when you know what to look for it is there in the instructions it’s just not that clear.

My problem was the arm that goes alongside the inner chassis.

MOK 8F 8425 Tender Water Scoop Mechanism

I initially had it located in between the clevises at the front. When it needs to fit behind. This meant that when trying to fit the wheels the rod fouled them

MOK 8F 8425 Tender Water Scoop Mechanism

Once I knew this it made things a bit clearer then I discovered that I had the linkage that the water scoop attaches to upside down.

MOK 8F 8425 Tender Water Scoop Mechanism

With that corrected I was able to get it to fit together. It still needs fixing permanently in place but I have the balance weights to fit yet so I will wait until I have done that before making anything else that I might have to undo!

MOK 8F 8425 Tender Water Scoop Mechanism

Cheap and Cheerful Home Made Nut Spinners

For those of you not wishing to spend a packet on BA nut spinners from Markits et,al a chance conversation with a friend brough back a memory of a much missed GOG Member whom I have referred to in the past David Smith (known on various forums as DLOS). He was really a model engineer and he had mention in a posting a few years ago that he had made BA nut spinners from appropriately sized caps screws using the hex head as the socket.

Having a spare couple of hours last night I rummaged through my screw box and found that an M4 and M5 cap head screws were just right for 8 and 10 BA and a couple of grub screws suited 12 and 14BA.

Home made Slim Line Nut spinners 8-10-12-14 BA

Although I used the lathe they could be made by anyone with the ability to drill and tap metric threads. I did turn down the heads of the cap screws but again nothing that couldn’t be achieved by putting it in a drill chuck and applying a file.

A tip worth mentioning: If you use grub screws for any of them, in order to get enough threads to engage the grub screw, you need to drill the hole a bit deeper. This means that the head of the grub screw wont stay at the end. My solution was, once threaded, I screwed the grub screw in as far as it would go and then with a bit of brass rod I measured how far in the head of the grub screw was from the end (1.5mm and 4.5mm respectively in my case).

I then cut a couple of short lengths of brass rod that would slip inside the threads (2mm I think I used) This allows you to tighten the grub screws against the bottom of the hole while the head is level with the end. I was planning on Loctite-ing them but I don’t think that they need it.

The handle parts were made from a length of bent 6.35mm brass bar which equates to a 1/4 inch (I must have bought it as quarter inch but any suitable sized bar would do. Hopefully it’s the last bent piece in my stocks as there is nothing more irritating than trying to tun something that you have to lose half it’s thickness before you get it to run concentric.
It’s not visible in the photo but the bend in the bar meant that the grooves look a bit like Zebra stripes, in that go they go thick then thin as the bar flexed away from the cutting tool as I turned them. You don’t need them for the tool to be functional but I can’t help messing.

David Andrews Princess Royal Back Head Ready for Paint.

David Andrews Princess Royal Back Head

That’s about it unless I think of anything else. I am struggling as to what was fitted the 1930’s and what was fitted later. The Wild Swann supplement has a photo of Princess Elizabeth as built and there is a lot less on the back head than is shown in the GA in part one.

All the parts are removeable until I have painted the main casting. 

David Andrews Princess Royal – Cab Hand Wheels and a Lubricator

The back head is well on it’s way now but when I got so far I realised that the only hand wheels I had were the teched nickel silver ones that came with the kit. Nickel of course looks different when you are trying to represent brass so I thought I would have a go at turning some.

I did one to work out how, but the four holes came out all over the place. Once I had a method that worked I made the three that I needed. They actually looked the part when fitted to the back head but what was missing were the handles.

Cab hand wheels
Cab hand wheels

At this size I couldn’t see any sensible way to add them to the ones that I had made so I had a rethink.
I modified the technique and made rings to solder to the face of the etches and then added half round rod for the handle. This is the best of both worlds. the right shape and three dimensional.

Modified cab Handwheels

Out of the castings that I have from the various sources the one that is missing is a sight glass lubricator which sits at the upper left above the brake valve.

Sight Glass Lubricator
Sight Glass Lubricator