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650 Class test build

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I thought it would be worth-while posting what is hopefully the final test build of this loco, before I release the production version. I have made a number of amendments to the design including adding (non-working) inside valve gear since producing the initial study model in 2014 . The masters for the detail castings are currently with the casters so all going well the production version will be available in early 2019.



Loco & tender chassis fret. The fret is in 0.4mm nickle silver which solders easier and is stronger &  less inclined to flex than the equivalent thickness of Brass

The chassis is designed to allow the alternatives of simple fold up assembly as a rigid chassis in OO gauge, or in 21mm gauge with conventional etched L frame spacers as a rigid, sprung or beam compensated chassis.




Loco chassis, valve gear sub assembly and rear frame spacer.

Metal oragami the sub assembly basically folds, slots and pins together and super glue could be used to lock everything together by those so inclined

The valve gear is based on the Beyer peacock of the MGWR D Class 2-4-0 supplied in the 1880, available information  of the 650 K Class is basically limited to a MGWR/GSR weight diagram from the 1920s. 



Slide bar and valve gear assembly


Designing the gear to fit a OO gauge loco was challenging, I chickened out of modelling dummy let alone working cranks which opens up the possibility of a motor driving on the driving axle so to speak. The slide bars are basically fold up assemblies that slot through the rear of the cylinders and into the motion bracket, the con-rods and Stephensons gear are aligned with pins which hopefully are not to noticeable when the loco is assembled and painted.


Basic loco chassis


I reamed out the bearing holes with a tapered reamer before fixing brass axle brushes.  Bearing holes are normally etched undersized and the holes reamed out due to manufacturing tolerances in the photo engraving process and variations in bearing diameter.


Chassis assembled with Romford wheels. Brakegear to be added


Basic chassis from above. It will be interesting to see if the valve gear is noticeable in the assembled loco.


Tender chassis fret with OO fold-up frame spacers.



  The tender is designed on the Sharman Bogie principal with the leading axles floating and weight of the tender carried by the loco drawbar and tender rear axle.


I used an 18Watt soldering iron with a fine tip with DCC Concepts 145 degree solder for soldering the chassis and valve gear,  I use 25 & 50 Watt irons and a variety of tips & solders for heavier work.


Axle brushes soldered in place and fold lines and joints soldered at rear of tender.

Basic loco and tender chassis.


The build picked up a few blupers mainly half etching a some fold lines from the wrong side which are easily corrected before the loco goes into production.

The next phase will be to fit the brake gear, test fit motor and gearbox before assembling running board and superstructure.

At this stage I have not a final cost on the kit a lot depends on whether there is sufficient demand to release the loco as a complete kit with wheels gears and motor, or buyers are prepared to source the parts directly from the manufacturers in the UK.

Kits of this nature are traditionally supplied without wheels gears and motors, while it would be feasible to supply the loco as a complete kit this would be likely to involve significant additional costs, (shipping & potential VAT liability on importation ) compared with the buyer sourcing the necessary components in the UK. 

Potentially I would require expressions of interest/orders for 20 complete kits to release the locos with wheels gears and motors, this would absorb some of the shipping and stocking costs, but potential higher VAT liability would remain for the buyer on importation.

Edited by Mayner
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Going OT, but if you ever get round to doing an etch for the "Z" boiler/Belpaire firebox to go on a 101/J15, do let us know. Cheers!

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Assembled brake gear, coupling rods, fitted reverser and guard irons to complete chassis assembly. I usually assemble the brake gear as removable sub-assemblies to simplify painting. 



The little miniature drill holder that fits in the pin vice (miniature hand drill) came as a freebie from Micro-Mark Tools and is an invaluable piece of the tool kit for holding small drills, (0.5mm for boring out brake blocks and hangers on the fret.


I used 0.45mm handrail wire to pin the brake blocks to the hanger, the work surface is ceramic fiber board supplied by micromark. 


Loco and tender brake hangers, I opened up the holes in the hangers with a small tapered broach to clear 0.7mm brass wire/rod.


Loco chassis with brake gear, guard irons and reversing lever fitted.


Loco and tender chassis and brake gear sub assemblies.


Coupling rods.

The test assembly picked up a number of glitches in the chassis that will be rectified in the production artwork. Coupling rods need to be beefed up, packing pieces to aid brake gear assembly, some details engraved on the wrong side of the sheet.



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And now to the loco body!

The fret includes parts to assemble a member of the MGWR Ks/GSR/CIE 650 Class (G2) with round topped superheated boiler post 1918. The kit includes 3 alternative cab types and smokeboxes for superheated and saturated boilers. Cab interiors suitable for OO or 21mm gauges.

The MGWR had a policy of renewing or replacing locos and rolling stock at a 25 year interval and commenced rebuilding the K Class with superheated boiler and canopy cabs in 1918, although the GSR CME Bazin appears to have been opposed to superheating smaller locos the rebuild programme continued at Broadstone after the Amalgamation. 

Although some locos retained their "flyaway" Attock style cabs the majority were rebuilt with low wrap around GNR/Stirling style cabs which were eventually replaced by cabs similar to the J15 and other GSWR classes possibly as a result of problems with enginemen hitting their heads on the low GNR style cabs.

The locos with "Inchacore" style cabs were fitted with circular spectacle plates and retained laminated springs on the leading axle with distinctive hangers, the locos received rectangular spectacle plates and volute springs were fitted to the leading axle following or possibly during the Emergency.




Running board/valence/buffer beam fret.


Support valences while bending up running board valence sub-assembly


Starting to look like a MGWR loco with deep valences!


Running board overlay half etched to dress over running board assembly.


Running board overlays temporarily bolted to running board subassembly, the overlay is dressed by hand around the curves with small diameter brass rod or dowel (artist paint brush handle) clips are to check fit before final assembly.

The half etched brass is reasonably soft, I worked from the front buffer beam backwards  making sure everything was in line, dressing the overlay over each arch before temporarily bolting down at the end.

I soldered the overlay in place by tinning the running board with 145 solder and phosphoric flux using a 25Watt soldering iron with a large tip. I then cleaned the iron and slowly worked back heating the overlay.


Running board fitted, now time for cab and splasher assembly! I decided to assemble the loco in MGWR condition with a canopy cab. Cab and splashers are fitted with tabs that are intended to slot into the running board.


I 1st tacked one side of the cab to the spectacle plate, checking for square, there is a half etched rebate in the cab front to assist alignment.


I dressed the cab sides & roof around the spectacle plate using the spectacle plate and brass bar as a template, funnily enough the fit was good same as the initial test assembly 4 years ago!

Splashers fold up with the splasher tops level with the sides, the splasher tops are slightly over long and need to be carefully filed back when fitting to the running plate.


Really starting to look like a loco, excess solder to be cleaned up with a scraper on running board, splasher/cab joints.


The challenges of building an Irish Broad Gauge steam loco to run on OO gauge! Scrunched up inside valve gear, main frames and wheels in the completely wrong place.


Ks/650 progress so far, next stage assemble and fit smokebox, boiler and firebox!

I will leave the motor and gears until I fit the boiler, firebox, smokebox subassemblies.

Funnily enough wheels apart steam locos are reduced to similar sub assemblies while going through the works.


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Now to assemble the boiler, firebox (wrappers anyway! and smoke box. The boiler is rolled from brass sheet and firebox formed to shape, the boiler and firebox and smoke box are designed as sub assemblies that bolt together and to the footplate.



Preformed boiler and firebox wrappers. I used a strip of scrap brass to simplify joining the boiler and firebox together, a strip of brass will be provided for this purpose in the kit.



Reinforcing/jointing strip soldered inside the boiler wrapper. Stainless steel clips to secure firebox wrapper while soldering to boiler.


Assembled boiler & firebox wrappers. The disc at the front is used to align the boiler and smokebox wrappers.


Riveted smokebox assembly for superheated boiler. The smokeboxes on the saturated locos were shorter and flush riveted with a smooth finish.


The smokebox back and front fold up into a box to support the wrapper.  A captive bolt is used to bolt the boiler and smokebox sub assemblies together.



I used various brass tube and bar of various diameters to preform the smokebox wrapper.


Wrapper is attached by working around from one side, using 17 watt soldering iron with small tip and very little solder in a similar manner to the cab roof.


Smoke box front attached by sweating, cleaning the soldering iron tip before touching the riveted detail. 


Starting to look like a loco!  I could not resist taking a picture though the chimney and dome are a bit pissed. I have started detailing the loco fitting boiler bands, leading springs and leading splashers, though I still have to sort out the cab splashers. 

The boiler fittings were lost wax brass castings prepared from my originals by a Morris & Watson a precious metal merchant fabricating and casting business in Auckland. The lost wax castings were also used as masters for the production pewter castings by another business in Auckland

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Tender Assembly: The tender is designed to be assembled in MGWR/early GSR with coal rails or with plates to the bunker sides in late GSR/CIE conditionIMG_3145.thumb.JPG.6abee44385000799cfc20d0976a17323.JPG 

The tender is designed to be assembled in three sub-assemblies, underframe, tank sides and coal plate.


Underframe and drag beam/firemans platform.


Tender superstructure, the half etched rebate in the tank rear plate are a guide for drilling/cutting slots for rear steps that were fitted to some tenders in CIE days.


Flares formed to tender sides using bending jig. (The kits will be supplied with flared tender sides)


Tender main sub assemblies, coal plate, tank top and end plates, tank sides, underframe.


Tender sub assemblies, beading and coal rails fitted to tank sides.


Assembled tender test fitted to chassis.


Loco and tender with production chimney, dome and safety valve castings test fitted.


Final detailing and fettling still required to loco structure, I assembled the smokebox back to front and haven't gotten around to fitting the cab front splashers.

The 650 will be followed by a MGWR Standard Goods L (J19)  at some stage in 2019, the castings are common to several MGWR loco types including Standard Goods, Achill Bogie and Heavy Shunting Tank.

Class J19 - 607 - M&GWR Class L 0-6-0 - built 1889 by Broadstone Works as M&GWR No.69 ATHLONE - 1904 rebuilt with Belpaire boiler, 1925 to GSR as No.607, 1934 rebuilt, 1945 to CIE - withdrawn 1962 - seen here at Athlone in 1953.


I will post pictures of the completed loco in about 2 weeks.


Edited by Mayner
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looks great john , I would be interested in one . I think it would be best to get the parts you mention direct form the uk . ( before Brexit !! )   

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Superb work there - very impressed with the crispness of the etchings and how well they go together.

You have me sorely tempted with this one, as I have a soft spot for the 2-4-0 class, both tender and tank.  My next build will most likely be a 423 2-4-0T used on the DSER line; hence the earlier query about leaf spring castings.


I rather like the bending jig you have for flaring the tender sides - perhaps you may provide some more info?


You show rivet details on the smokebox, etc.  Are the rivets part of the etching process or do we need to add them ourselves?


From your earlier comments regarding the gauge, I assume these can be made up in 21mm?




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7 hours ago, DiveController said:

THat's a good point actually, Brian, although you;d probably not expect to pay UK VAT after Brexit but probably get stuck with importation taxes instead!



Import duty/higher Irish rate of GST should not apply if you buy your wheels gears and motor from a UK supplier before the 29th March 😊

Being outside the EU my kit prices do not include VAT or other purchase taxes, but may be subject to import duty & VAT/purchase tax upon import to the EU, Ireland or other countries.

I am pricing the option of supplying the 650 as a  complete kit with wheels gears and motor for OO gauge users. 


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2 hours ago, KMCE said:



Superb work there - very impressed with the crispness of the etchings and how well they go together.

You have me sorely tempted with this one, as I have a soft spot for the 2-4-0 class, both tender and tank.  My next build will most likely be a 423 2-4-0T used on the DSER line; hence the earlier query about leaf spring castings.


I rather like the bending jig you have for flaring the tender sides - perhaps you may provide some more info?


You show rivet details on the smokebox, etc.  Are the rivets part of the etching process or do we need to add them ourselves?


From your earlier comments regarding the gauge, I assume these can be made up in 21mm?




The chassis is designed to be assembled in OO or 21mm gauge.

The OO gauge chassis basically folds up into a box structure, conventional L shaped frame spacers are used in 21mm with slots and tabs to aid alignment.

The bending jig is basically a section of round tube or bar of suitable diameter bolted to a section of rectangular bar or box section with a fixed stop.

I basically use round bar/tube of differing diameters to form curves in sheet metal.


Crude but effective I originally used the jig in combination with rolling bars to for the elliptical roofs for my 4w van kits.

The raised smoke box rivets are formed as part of the photo-engraving process by etching half way through the metal to produce relief detail, the same process us used to represent raised coach panelling.

An alternative is to mark the position of the rivets by etching little dimples on the reverse of the metal and then punch the rivets using a riveting tool, I used this technique with the "Inchacore" pattern cabs where the riveting pattern varies considerably from locos to loco.


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7 hours ago, DiveController said:

John, if the kit is assembled in OO can it subsequently be converted to 21mm or once you've made a choice that's it?


Almost anything is feasible but re-gauging an assembled  chassis from OO to 21mm would involve a certain amount of wasted time and effort.

Dismantling and re-assembling the chassis would basically involve replacing the OO frame spacers and motion bracket with 21mm gauge parts supplied with the kit, replacing brake riggings (0.7mm wire), replacing loco and tender axles this would only work with Alan Gibson or Ultrascale wheels. Ultrascale probably supply the best quality wheels in 4mm and will supply 21mm gauge wheel sets, but have ceased to take new work on account of an order backlog. Alan Gibson supply suitable wheels, but axles have to be cut to length for 21mm gauge.

If you are thinking of changing gauge at some stage in the future a better option might be to build a second chassis so that you have the option of running the loco on either OO or 21mm gauge.

I can supply an additional chassis fret with the kit or at a later stage if you decide to re-gauge or build a second chassis.

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Test builds nearly complete, some minor changes to the artwork to get the cab interior to fit and I had forgotten the ashpan sides leaving a lot of daylight in the area between the driving wheels!


657 (MGWR 33 Arrow) as rebuilt with superheated boiler in1925, before receiving a saturated (original style) boiler and presumably GSR cab in 1939, rebuilt with CIE Y superheated belpair boiler 1953!


Loco is on a OO Chassis. Funnily enough I have only found a photo of one superheated loco (23 Sylph) in this condition fitted with tender coal rails. Which indicates that at this time coal was of high quality and the superheated locos very economic of coal and water which was the whole point of the exercise.


654 late GSR/CIE condition.  Originally MGWR 23 Sylph this loco went through four re-builds/changes of boiler between 1924 & 1959 and eventually ended up with a Y Class superheated Belpair boiler the model covers the 1939-59 period.

I assembled this loco lat week in a bit of a hurry and haven't bolted the back end of the loco to the chassis with the cab sitting a bit high.

The kit includes parts to build the loco with either MGWR or GSR/CIE condition including alternate cabs, boiler fittings, leading axle springs, tender coal rails or coal plates. 

There was a lot of detail variation between individual locos as the class was overhauled/re-built by the GSR & CIE particularly around cab handrail location and rivet detail.

Handrail and rivet locations are half etched on the inside of the cab side sheets and drilled out or embossed to taste by the builder.


3/4 front view 21mm gauge loco.


21mm Chassis with inside valve gear & Mashima motor & Hi-Level Road-Runner+gear box fitted. I have assembled the chassis with an equalising beam suspension system rather than as a compensated or sprung chassis for comparison.


Rear view of the chassis, I seem to have mislaid the gear wheel for the final drive! Motor is an old stock Mashima 12x20, the 10X20 motor is considered to be a better motor and currently available through High Level.

Gear ratios are pretty much a personal thing the 650 Class were mixed traffic rather than express passenger locos, 40:1 or 53:1 should provide reasonable torque and range of speed for these locos.

Wheels are vintage Mike Sharman and unfortunately no longer available, Alan Gibson Workshops supply suitable wheels to an EM or S4 profile and extended 1/8" driving axles.

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