Ruston 48DS in EM Gauge

[Barclay]

Looking back through other threads I see that it's more than 2 years since the Saltport Harbour Authority acquired a new locomotive. 2 main line interlopers, not to mention a small American layout, have effortlessly used up my modelling time it seems, but now it's time to set matters straight.

 

I bought this kit at Expo-EM a couple of years ago. I could have had the Judith Edge kit for less, and I'm sure it's at least as good, but there's always been something about the Impetus range that has drawn me - perhaps that lovely box artwork, perhaps just the fact that they were being released when I was reading those early MRJs and being deeply inspired by what I was seeing.

 

 

The kit came with Sharman wheels and a Branchlines + Ultrascale gearbox, and the plan is to use those. The loco. will only have 2-wheel drive, as originally designed. I know I could do better these days, with the High Level Quad-driver gearbox, etc. but that would exclude the Sharman wheels, with their 3/32" axles, so I have decided to keep it simple and use what I have. The motor is a small Mashima open-frame example, and the power train has been set up and is running very nicely, so I'm hoping that with the right weight and balance the thing will at least be able to pull a couple of wagons! The gearbox has been cut away at the lower corners in order to preserve full daylight underneath.

 

Reference is available aplenty, thanks to @Ruston's thread and book. The kit represents an early-ish example, with the open cab entrance, and the 'RUSTON' script painted on the front, which suits the period of my layout nicely. It's 1947 and they will soon have two diesels - they are obviously more progressive than I have previously given them credit for !

 

[Captain Kernow]

Good luck with the build!

 

I have one of these in P4, but built by a fellow club member years ago and eventually sold on to me.

 

It's also got one axle drive and one or two wagons is just about it's limit, despite the additional lead that I packed in various places!

 

[Ruston]

Was this kit only ever designed to be powered on one axle?

[Barclay]

Yes I think so, and in the mid 80's you only had 20:1 gears for wheels this small, so you could probably pull wheelies with it!

[Adam]

56 minutes ago, Ruston said:

Was this kit only ever designed to be powered on one axle?

 

No, the Impetus Simplex was too, and possibly the 88DS? When dad built his Simplex, he used gears from a dead Mainline Warship. With both axles driven it pulls fairly well - more than a regauged EM LIMA class 20 on one occasion.

 

Adam

Edited February 11 by Adam

[cctransuk]

29 minutes ago, Adam said:

 

No, the Impetus Simplex was too, and possibly the 88DS? When dad built his Simplex, he used gears from a dead Mainline Warship. With both axles driven it pulls fairly well - more than a regauged EM LIMA class 20 on one occasion.

 

Adam

 

Read Ruston's enquiry carefully - I think that your answer should be 'Yes'.

 

Your answer indicates that two of the Impetus kits had single axle drive.

 

CJI.

[decauville1126]

Mine (P4) also suffers from the wheelies and nosedives due to the single-axle drive. Just like over-enthusiastic motor cycling! I spent a long time experimenting with weighting in various positions but never reached a satisfactory solution. But there is no doubting the character of the loco, and if wanting to portray a bashed-about example then it, and Mike Edge's later model, are good starting points rather than the Hornby one. That said, the Hornby version is a superb runner and I managed to convert one to P4 relatively easily.

 

At the time of it's release the Impetus one was a welcome delight and can still an hold it's own against the other versions when well built. 

[pete_mcfarlane]

My 48DS is from the A1 kit (with a RT models chassis) and is also single axle drive (with a High level gearbox). It will manage about 5-6 wagons, depending on how heavy they are. 

 

The thing is packed full of lead and has a brass flywheel on the motor, and even has a whitemetal crew rather than plastic. So you can get decent performance out of a single axle drive. 

[5050]

I'm surprised that the motor/gearbox unit actually fits!  My Hornby one in P4 with a High Level power unit has a haulage capacity far in excess of the prototype!

[Barclay]

7 hours ago, 5050 said:

I'm surprised that the motor/gearbox unit actually fits!  My Hornby one in P4 with a High Level power unit has a haulage capacity far in excess of the prototype!

About 10 loaded coal wagons, on the level. I don't think I'll manage that. As to whether it will fit, that's a 'probably' !

[Barclay]

Crikey - I was intending to show this build as a blow-by blow account, as usual, but just a couple of sessions have seen most of the work completed!

 

The chassis was assembled in the usual way, using the spacers provided. Bearings in the front, for the driven axle, and a rocking tube bearing at the back to give a little compensation. There seemed little point in going the whole hog with hornblocks when the axle concerned isn't even driven, let alone connected to the other one by coupling rods.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The drivetrain fits nicely - the motor will be in the cab of course but there'll be a crew to hide it (sort of), and room for plenty of lead under the bonnet.

 

The body started with a fold up platform, to which cab and bonnet are added. The brass is a little soft and care was needed to avoid distortion, but the bonnet folded up very easily. The louvred bonnet overlays were added with superglue because I could imagine it all falling to pieces again if it was soldered. The next stage will be to wheel it up and add pickups so the running can be checked. After that I need to see what I have for the front grille, because the one supplied, as @Ruston has advised, is completely wrong. I have some proper mesh that is rather coarse, and some Scalelink etching that's much finer but may not be 'open' enough. I will submit photo's in due course and see what others think.

 

Looking at this photo., I realise I have forgotten to add the cab beading - lucky I haven't fixed down the roof yet!

 

 

 

 

 

 

 

 

Edited February 18 by Barclay
Trying to get rid of that big gap!

[Barclay]

With a borrow of my friend Chris' 3/32" reamer I was able to get the chassis assembled, and all pretty straightforward, though as you can see, when adding the 603 to secure the gearwheel I forgot to make sure the gearbox was central - luckily it still just fits. The wheels each had 4 holes drilled in them before assembly - these Sharmans are very nice and fine. They were always a touch finer than Gibson but these look more like P4 - perhaps they are? It seems to work anyway.

 

Since the photo was taken pickups have been added and the loco has now moved on the layout under its own power. Some weight has been added in the form of lead sheet, and it is very clear that any weight rear of the back axle is counter-productive to traction. The jury is out on whether the loco will be able to perform any useful work when it is finished! I mean it ran superbly with a brass EM back to back gauge perched on top of the bonnet but it did spoil the appearance somewhat!

 

 

 

[Barclay]

I've been looking at this thing this morning, whilst working (honestly!), and I have started to develop doubts about the length of the bonnet. It's the proportion of it compared to the cab that looked slightly out, a little short. Measurement suggested the cab is 91% of the length of the bonnet, whereas the drawing in @Ruston's book suggests it should be about 85%. But where is the problem? The drawing also suggests that the front of the radiator should be pretty much flush with the front edge of the frames, and the kit is not so.

 

So - moving the bonnet forward to the desired position gives a gap at the rear of about 1 - 1.5mm. This can be filled, but before I do it, do these thoughts seem reasonable? 

 

On a more positive note, more room for lead! Photo also shows cab beading now in place. Not the etches supplied but 0.33mm brass wire.

 

 

Edited February 26 by Barclay

[Barry O]

Comparing it to @Rustons photos on his thread thevlatest position looks more "correct"

 

Some other Impetus kits seem to have mysterious  "gaps" where there shouldn't be.. 

Baz

[Gordon A]

I used a High Level Quad Drive unit that gives you four wheel drive with a bit of rock in one axle.

[Barclay]

That definitely would have been the sensible option!

[Barclay]

This week the bonnet has been lengthened at the back with fret waste. The assembly hasn't been attached yet so if the primer coat shows a need for filler this can be dealt with. It is also now full of lead, apart from where the motor and gearbox intrude. All up weight at this stage is 76g and it won't get a lot heavier as there is nowhere left to put it - not at the front end anyway. Putting weight in the cab achieves nothing unfortunately. This means the loco can now handle a couple of wagons happily, and while that's not very good, I am very pleased with it, it is extremely slow, smooth, and controllable, which is quite important for a loco that could only manage 9mph! That hint of rock in the back axle also keeps the pickups working, and it is proving a reliable runner. Buffers and couplings have now been fitted though I can't see any way of making the buffers operable. The cab roof isn't yet fixed in place, and won't be until after painting, but it has been drilled for the exhaust, which is the slimmest brass tube I could find, turned down as far as I dared. Nearly ready for a good clean up now, if I can stop playing with it for long enough...

 

 

[5050]

On 27/02/2024 at 09:48, Gordon A said:

I used a High Level Quad Drive unit that gives you four wheel drive with a bit of rock in one axle.

The one that Chris sells to power the Judith Edge 48DS.  I used it to power my Hornby bodied one.

[davknigh]

3 hours ago, 5050 said:

The one that Chris sells to power the Judith Edge 48DS.  I used it to power my Hornby bodied one.

It’s also the drive unit in the Judith Edge kit. 

 

Cheers,

 

David

[fulton]

Nice build, I am building the Impetus 16" Hunslet, I also have the Sentinel kit which is designed to drive on both axles, I bought the kit in 1990, in the box is my original SAE (stamped addressed envelop, remember them) from Robin giving the prices, Sentinel kit plus Tenshodo motor, gears, EM wheels, £52+£1 p&p, I needed to supply Sharman 2x24 tooth gears £1.10 each. Around that time I also built his 16" Bagnal, which I still have, I think 1991, it was running on a friends layout at EXPOEM, Robin remarked it was the first one to be finished and he had sold one more of the twelve kits he had produced in that run.  I lost interest in British 4mm modelling and tried selling various kits, the offers were insultingly low, so everything went into storage, now twenty years later I am back into British 4mm, pleased I kept the kits!

[Barclay]

The re-railing beams were delicate etches but went together fine. Cab steps went on too but I couldn't seem to make one of them look decent so it's back off at the moment pending possible renewal.

 

Apart from that nothing to report, except that we'll have the EM Gauge Society stand at Alexandra Palace again this year and I'll be there on the Saturday with the Ruston if anyone wants a closer look (at how not to do it!). 

 

 

[Ruston]

I know what it is that's been bugging me about this kit now. The windows are too large.

[Barclay]

1 hour ago, Ruston said:

I know what it is that's been bugging me about this kit now. The windows are too large.

I'm glad you didn't mention that before, I might have felt obliged to do something about it, and that would have been a right pain!

[Ruston]

22 hours ago, Barclay said:

I'm glad you didn't mention that before, I might have felt obliged to do something about it, and that would have been a right pain!

I should have known already. A few years ago, someone brought out a 7mm 48DS kit that appeared to have the exact same layout of the etches and repeated the same mistake with the windows. It was basically a rip off of the Impetus kit and I corrected the windows on the kit that I bought.

[Barclay]

I think it's as far as it needs to go now. The first pic shows the loco assembled and looking pretty mucky, but it cleaned up OK and the primer coat is on. The original etched grille is incorrect, as @Ruston has pointed out some time back, so I have considered my options: I have some proper mesh that is too coarse; some etched stuff from Scalelink Fretcetera that I bought for a US loco. I thought then that it was too opaque and I still do, so have gone for a very fine etch by A1 models - for a modest sum you get a random selection of etches that can be very useful indeed. Not wanting to clog it up with paint I have soaked it in Carr's Metal Black and will install it at the very end. 

 

Paint next week? Perhaps!