Brecon and Merthyr Stephenson 2-4-0 locomotive parts and assembly.

[Timber]

While the chassis is receiving its final clean up and paint spray I have started to prepare the wheels.

 

As shared in other posts, the wheel centres are 3D printed using Markit S Scale axles and society tyres.

 

The wheel centres arrive to me from Shapeway in a strip with the ballance weights as part of the print.  You may notice that there is an error in these prints, the wheels should be a PB rather than IL, but having made the mistake I am going to use them not waste them.

 

Since earlier posts on wheels, the quality of the 3D prints has improved, I am using nylon not plastic and I have tightened up some of the measurements to improve the overall quality.

Edited February 5, 2021 by Timber

[Timber]

The wheels are given a quick spray and after 30 - 40 mins before the paint has hardened, I place in the society tyres using a bead of super glue run around the inside edge and then pressed home nice and firm.  The glue softens the paint and the overall bond is much stronger.  Inevitably, some glue  is squeezed on to the surface of the wheel.  It can be quickly wiped off but does leave a gloss residue.  In a day or two I will brush the wheel surface with matt vanish so that they have an even finish.

 

I then finish the wheels by adding a Markit Crankpin.  These self tap into the crank pin holes. 

Edited February 5, 2021 by Timber

[Timber]

Turning attention to the 3D boiler.

 

There are a number of choices for the boiler material depending on budget.  I have chosen the Shapeway smooth nylon which is somewhere mid price in the options.

 

Regardless of the material it is very difficult to see the amount of smoothing that will be required without applying some spray paint.

 

I use Rusto-leum multi purpose paint (not primer) as it appears to be slightly thicker than some other brands and naturally introduce some smoothing without killing any detail.  I plan to paint this loco WW1 war time black so have chosen a black paint.

 

I will let the paint harden for a couple of days before taking any action.

 

 

[Timber]

Returning to the cab....the next step is to prepare and solder the cab sides....

 

These are then held in place while they are soldered, taking care not to bend the tank surround as any kink is difficult to remove....

[Timber]

Now to fix the tank and cab sides to the footplate.  There are two tabs, one at the front of the tanks and the other at the front of the cab that slot into the footplate.  

 

There are a couple of cautions...the folding of the tank side around the tank inner does not always make for parallel sides as there is always a degree of variability into the etching process.  To navigate this, if the sides do taper, then cut the front tab, this allows the tank sides to flex.

 

Then solder the rear tab first keeping the cab central with the footplate and then straighted the tank sides that they are also nice and straight to the edge of the footplate.

 

The second caution is to not let the cab sit too  far back.  This is some lateral movement in the tab and slots, make sure that the cab and bunker are both possitioned to sit correctly over the drivers steps....hence why it is good to have the bunk temporarily in place while the tank and cab are attached,

Edited February 7, 2021 by Timber

[Timber]

Finally solder the tank and cab in possition....

[Timber]

Chassis is now painted and assembled.

 

Assembly is very straight forward.

 

Post painting, exercise bearings in the frame to make sure that there is the requirement movement.

 

The connecting rods are a pair that solder back to back to form a 1mm thick piece.

 

I use my own design plunger pickups but the etch is designed to support Allan Gibson which work fine and is a good place to start.

 

Spot of light oil and it should be good for a test drive.

 

Wheels will have to come off again to fit the brakes but I "run in" before I fit the brakes.

 

 

Edited February 10, 2021 by Timber

[Timber]

Next step is to start to fit the boiler into the body.  In the footplate there is a 6BA clearance hole, likewise in the base of the smokebox.

 

The bolier slides into the tank; be very careful not to scratch the boiler...

 

Then with a piece of wire feed a 6BA screw (1/2 inch) into the boiler and through the connecting holes.   It may help to gently open up the smokebox hole to assist in fitting the screw.

 

Once the screw is in place, fit a nut to the underside of the footplate.  This nut sits within the clearance hole in the frame.  Do not cut the screw as this will be required to hold a mounting plate that holds the chassis to the body.   A similar arrangement will be added under the bunker, creating the two fixing points.

 

In the photo it is just possible to see that before fitting the boiler I smoothed any 3D printing surface marks......most of the attention is on the smokebox door.  The 3D printing orientation is biased to trying to secure the best finish on the boiler surface.  However, this then results in a little rework on the smokebox door face and around the smokebox door rivet detail.

Edited February 11, 2021 by Timber

[Timber]

Fit handrail knobs to the cab and bunker before refitting the bunker with 6ba bolt (1/2 inch) and nut as before.  Do not cut the 6BA bolt, it will be used to fix the chassis, Once in possition, solder the bunker to the footplate through the recesses in the footplate floor.  The cab roof can be either the etched metal or in this instance a 3D print....if you are going to use a soldered etch roof then fit the backend as once the roof is on it will not be possible to fit.

 

Edited February 11, 2021 by Timber

[Timber]

Where the boiler meets the tank top, there will be small gaps.  To help reduce the gap and create a seamless connection, I mix up some araldite with a small brush and from within the tank paste araldite down the length of the joins, gently filling the gaps.

 

I have found that the wipes that can be purchased in hardware shops for removing grime are great at removing semi hardened araldite so if the araldite runs or smears it can be cleaned with a wipe from the top.  

Edited February 14, 2021 by Timber

[ianb3174]

Is there a specific type/size of buffer for this kit? 

[Timber]

I have not found an exact match but use Markits Sprung 16" head BR Std.  They have broadly the right profile but possibly a little bit chunky in the stock.

[Timber]

Adding the boiler pipe work.  1mm brass that sits in the smokebox and connects back into the cab.  On the prototype it appears that this pipe is fixed with a fastening possitioned between the inner tank side and the boiler.

 

This prototype fastening would be too fragile to model so I use a Slatters 7mm long handrail knob placed into the boiler skin.  There may be better ways of doing this but the possition of the pipe makes it vulnerable to handling so the rational is that something relatively robust to prevent the pipe from flexing too much is preferable.  There may be a better way...

 

The cab hole for this pipe is slightly missaligned.  Better to realign with the pipe in possition and then some solder to fill the original hole.

 

The nylon boiler has better heat resistant properties than plastic and so can take a little heat but please take care.

 

The front handrail will also need some attention.  I produce the 3D in Fusion 360 and the etch artwork in Visio.  It is tricky aligning some details between these two systems and the boiler handrails where they attach to the tank ends is one example.  Aligning the handrails has been a challenge.  With each print and etch I get closer but better to fill the hand rail knob hole and redrill in situe...a small job.  

Edited February 14, 2021 by Timber

[Timber]

Front and rear headstock detail added.  The vacume pipes are Markit and held in place with two 7mm short handrail knobs, drilled out to 1mm.  The coupling hook is oversized, closer to 7mm....this is my choice as I find it easier when running and shunting.  Markits or similar 4mm components will also fit.

 

Edited February 16, 2021 by Timber

[Timber]

[Timber]

Next up is to make the safety valve and test fit.  The safety valve is part 3D print (body), part lever (etch) and a 2mm spring from ebay.

 

Cut the lever carefully from the etch.  You need to retain the long spine.  The spring goes through the spring and inside the 3D print.  The spine will protrude from the bottom of the print and secured in place with a blob of solder.  Through using this technique you avoid any solder on the valve itself. 

 

Once open up the hole in the cab front a little, possibly flex the lever downwards and test fit.  Do not fix in place this will be completed after painting.  But better to test to avoid scatching the fresh paint.

Edited February 16, 2021 by Timber

[Timber]

Now to the clack valves.  These are in the spirit of keeping things simple.  A piece of 0.7mm brass wire, 7mm short hand rail knob and a 14BA screw is what I use.  This is modest to some of the beautiful detail I have seen from fellow members.

Edited February 16, 2021 by Timber

[MarshLane]

Superb topic and inspiration for doing similar things myself!

[Timber]

Thanks MarshLane.....mabe we will meet you at our autumn meeting?

 

Back to the footplate.

 

First fitting the bunker floor.  Remove the 6BA nut and bolt.  Adjust the base so that it slides to the bottom of the bunker.  Replace and refit the nut and bolt and then solder to finish the job.

[Timber]

Rear steps are part folded, base of step upwards and then the second step tab soldered in.

[MarshLane]

23 hours ago, Timber said:

Thanks MarshLane.....mabe we will meet you at our autumn meeting?

 

Hi Timber,

Well you never know! Assuming we are let out by then .... I am just starting my S Scale journey, having struggled with space for the kind of layout I want I have decided to approach a different way, start with building a coach or two (Gresley Full Brake in this case) then progress onto scratch building a reasonably simple (he says!) LNER J50 - hence the comment about providing inspiration!  Keep going with the thread, its a fascinating walk down a road that is rarely shown in so much detail.

 

Rich

[Timber]

Fit front hornblock and bearing....this is a 3D print.

[Timber]

3D printed sand boxes, two at the front of tank and one in cab.

 

The plastic extrusion on the two front sand boxes go into the holes at the front of the tank so that they are firmly in place and then araldited into possition.

 

 

[Timber]

Rear Sandbox sits at back of cab on bunker

[Timber]

Quick dry fit of the 3D printed roof to ensure it sits cleanly in the cab...may require some gentle filing where the cab front meets the side to clean any solder and to make sure that it is a good fit.