Aster L.N.W.R. Jumbo in Gauge 1

A Review by Peter Trinder

(reproduced from the June 1999 issue Garden Rail by kind permission of the Editor)

The Kit - The Chassis - The Boiler - The Rest

The well-known Japanese company, Aster Hobbies Co. Inc, has launched their latest model for 1999. The model is of the L&NWR Improved Precedent class of which No. 790 ‘Hardwicke’, built in 1876, is happily still with us in the National Railway Museum at York.

The ‘Jumbo’ as it is colloquially known is available in ready to run or kit form. It is available in the UK from approved dealers or direct from Aster Hobbies Limited. This review covers the L&NWR kit version – L.M.S. crimson lake and L.M.S. black livery version will be available shortly.

Aster started making Gauge 1 models in 1975 with the Southern Railway Schools Class, examples of which still even today surface in unsteamed condition. In 1996 the Stirling Single No 1 was produced and was a sell out. None are available unless you find one second hand. Aster have always limited their production to just a few hundred for the World-wide market, so they are never a glut for the enthusiast or collector. (The Schools Class was the one exception since 3000 were made).

A comforting thought is that Aster Hobby Co. can nearly always supply spare parts for older models at reasonable prices, however they are not in the business of supplying parts for scratch construction, preferring to support their customers requirements. They have nearly always chosen a locomotive that still exists in a museum or preserved railway and execute them in 1/32 scale, although some early examples and their Japanese outline models are to 1/30 scale). Wheel profiles correspond to the G1MRA standards.

The Jumbo is in a way a natural progression from the Stirling Single, both prototypes were involved in the Races to the North which of course No.790 ‘Hardwicke’ was the winner!

The Kit

The Jumbo kit comes with all parts finished and ready painted so that someone without any model building experience but with common sense in the use of hand tools can assemble it and enjoy the finished result without any trauma! Your reviewer has over the years assembled many of the models Aster have produced and this makes for an interesting comparison. With each new offering the Aster Engineering Team seem to get better and better in their designs and construction techniques so building up the kits becomes more of a pleasure.

The kit is supplied with a small set of tools; screw driver, a box spanner, pump handle and a syringe for emptying the tender after a run, also supplied is a tin of black paint for retouching if required. Previous assemblers will notice that no open-ended spanners are included. The builder will find a Swiss file or two for smoothing any rough edges and a pair of tweezers are useful for placing small screws and fittings. I always have a metric tap around to clean out any paint from the pre-tapped holes mostly 2.0mm. I also use a 'nutlock' such as Loctite 'Loc 'n Seal' on most of the screw threads so that they do not shake loose during service. Aster provides a silicon caulk (like bath sealant) which is used for the gaskets sealing between the cylinder block and the steam chest. It is also used for the tender tank to make it water tight

The Jumbo supplied in L&NWR livery comes with name and number plates for No.790 'Hardwicke'. However I have obtained a substitute set for No. 1183 'Plynlimmon' from Guilplates Ltd, who will be happy to supply your choice to order. The name and number plate set cost about £20. The recent Locomotives Illustrated No.121 has a very useful history of this long-lived class and is still in print. It lists all the names and numbers (there were a total of 166 in the renowned class).

The model is fitted with an axle pump which has been cleverly located on the rear drag beam, thus putting a little extra weight in the correct place and is driven off a scotch crank on the rear axle. Normally with a scotch crank drive it is necessary to have a long ram to give a better bearing surface but Aster have provided a front bearing for the ram therefore giving it good support. Input from Aster Hobbies Limited – the UK Distributor - persuaded the Japanese engineers to adopt this arrangement rather than their first suggestion which had the pump behind the cylinders. Another small point is that the meths tank is now easily removable for refilling, a task performed so much more easily on the bench out of the tender. This is a common feature on scratch built Gauge One locomotives. On previous Asters disassembly of several components has been required before the tank can be removed. No coal load is provided on the Jumbo but I will see what can be done to provide a suitable load.

I do recommend that before you start construction that you first study the excellent Drawings and the Assembly Instructions enclosed with the kit, this will familiarise you with the various components and their location. The parts are stowed in numbered boxes which contain packets into which the parts are grouped. Each packet has an inventory slip numbered to correspond with the drawings. Don't undo these until you need them and I recommend you work through the assembly in the sequence of the Assembly Instructions.

The loco and tender wheels as supplied have unpainted and have highly polished wheel rims and hubs, which in my view make the model look very toy like. I used the paint supplied to good effect on the wheel rims and hubs and also the crank bosses. I did this straight away and left the lot to harden off whilst I studied the Assembly Instructions and drawing.

The chassis

The heart of any locomotive is the cylinder block and careful work in bedding in of the port face using the very fine emery paper supplied will pay dividends. Use a flat surface such as a piece of plate glass or a bit of flat gauge plate and smooth the surface of the block and the valves as described in the Assembly Instruction. Do make certain that ALL emery dust is washed away after this procedure. I used lighter fuel first and then a washing-up liquid rinse through.

The cylinder bores on my sample were of mirror finish so no need to touch these. When inserting the pistons and locating the back covers be careful when tightening the cover bolts to ensure that the whole lot stays concentric with the piston rods and that there is no binding. I found a small fault in my kit when attaching the cross heads to the piston rods. The crossheads are plated lost wax brass castings. The piston rods screw into them but the bosses are left unfettled and on mine this caused the crossheads to go out of square when tightened up. I cured this by slipping them into my milling machine and taking a skim off them. If you have no machine tools careful dressing with a file here would be recommended or ask Aster for a replacement. Again be careful when attaching the slide bars to cylinder black and ensure that the cross heads slide freely. This can be achieved by just nipping up the cylinder mounting screws and adjusting by hand until a smooth movement is obtained. I was very pleased with the result on my example.

The crank assembly comes already fitted with the connecting rods, the main drivers have stub axles which fit into the crank assembly and will then require quartering. As the rear drivers are already quartered this makes quartering up the main drivers simple. There are 3 grub screws on each side to hold it all together (one of which forms the stop for the slip eccentric). I found that by having one side screwed up tight and the other just lightly nipped up that I could adjust the rotation with the side rods on until there was no binding.

The oil pipe from the lubricator is attached to the lubricator with a nipple which did not seem to be steam tight so I soft soldered the nipple to the copper pipe after putting the nut on the pipe of course!

The front buffer beam is a lost wax brass casting and the two fixing holes have been countersunk. On mine this caused two mini Vesuvius like protrusions, stopping the screws from holding the beam squarely, so I milled the back smooth in way of these holes. You can't file it as it’s recessed. Small point but annoying, especially for those without milling machines! It will go on but might not be square! I later discovered that the footplate will square up a drooping buffer beam if you cannot smooth out these holes. Aster Hobbies Ltd subsequently advised me that if a customer has this problem then the part would be replaced without charge.

I gave the chassis an air test after liberally lubricating the moving parts. During the test apart from checking that it all goes round, look for any leaks from the cylinder covers, steam chest or pipe joints. Mine performed well. So I proceeded to the next stage which is assembly and fitting of the water pump. This was straightforward and it all fitted superbly.

The view above shows the pump block on the left, the burners in the middle and the crank axle on the right.

The Boiler

On then to the boiler assembly. This proceeded without any bother following the instructions. The silicon sealant supplied works well for the threads of the bushes, but I prefer Loctite Pipe Sealant 572. This is a white sealant with PTFE in solution. A very small amount seals any joint and is OK for live steam joints. The downside is that it only comes (I bought mine several years ago) in 50ml dispenser and it cost me £14 then, it must be beyond its manufacturers’ shelf life, however it still does work wonderfully, but don't get it onto clack balls!

I hydraulically tested the boiler on the chassis without the outer cladding to confirm that all joins so far fitted were tight.

I then proceeded to fit the cladding and mount the boiler. The water feed pipe goes from the pump block under the rear axle not as stated and shown in the manual. Be careful cutting the two dummy pipe fittings on either side of the smokebox. Aster uses the same casting for left and right. The drawing shows you what has to be removed. I actually left these two and the handrails off until I had finished tuning up the engine under steam to avoid scratching the parts.

The Rest

The footplate, cab, and other loco platework are all easy stuff and you should soon have these assembled.

The Tender is straightforward too. The buffer beam should be black not red as supplied. The tin of paint, included, was used to correct this. I had a little difficulty with the front footsteps but with care they went in. Aster Hobbies Ltd sent me a Jumbo ‘Tune Up’ leaflet in which they warn that water can slop over the top of the tender internal bulkhead and get into the meths sump, so its a good idea to caulk this with the silicon sealer.

In these ‘Tune Up’ notes they mention that you may get better steaming by cutting the wick tubes down by about 3-4mm. If you do this then you MUST lower the breather pipe on the tender meths tank by adding a piece of silicon tube about 4/5 mm long or a piece of brass tube soldered on. I would suggest lighting it up and running it jacked up by some means. In this way you can run it in and also experiment with the bypass on the axle pump. This pump is very efficient and can soon fill the small boiler if fully closed, so an hour or two experimenting with this would be time well spent. I had one problem when I first steamed mine. I had failed to notice that the boss of the steam pipe connection on the valve chest cover had an over run of silver solder so was not sealed. Despite this blow the loco ran! So I stripped it down removed this blemish and resealed the steam connection adding a thin black fibre washer and sealant.

I re-tested the loco on air via the water inlet on the pump block and applied soapy water to see any leaks. All was tight. Two days later I opened the blower valve and was surprised to be squirted with water. A well sealed boiler! One minor criticism. The springing on the front axle is too light so when the loco is uncoupled from the tender it is slightly nose down. Joining it to the tender levels it up but not quite! Aster say this is as intended. I personally will add at least one or two more leaves to the front spring using some thin phosphor-bronze flat spring plate from my scrap box.

After writing the description above I have now had a chance to re test the locomotive under steam on rollers. The steaming rate with the lowered wicks is much better and I was very impressed with the power developed. Running on rollers allowed me to apply a load and also play with the bypass valve to see how this affected the running. Shutting it fully certainly knocks the performance back but with it partially shut I was able to maintain a the water level. At one stage I actually filled the boiler up until I carried over the water. All in all I am very satisfied, and look forward to some runs on track.

In summary this Jumbo is a delightful model, sensibly priced and will look pretty on the collectors mantelpiece or even better steaming at the head of a rake of 4/5 L.N.W.R. coaches. The kit has no significant problems and a sweet running model will reward careful construction. Aster Hobbies have plans to do a short run of Jumbos in L.M.S. red with the name ‘Novelty’ and a plain L.M.S. black version - ‘Snowdon’.

I say ‘Well done!’ the Aster team especially Andrew Pullen of Aster Hobbies Limited, Barry Applegate, David Jenkinson, Ted Leech and Edward Talbot and of course not forgetting Mr Inoue's team of engineers in Japan particularly Mr Sasaki the real genius at Aster. Now chaps how about a Dunalastair or Cardean to complete to journey to Glasgow!

June 1999