Part 4 – Twins! and tribulations

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November and December ’09


A problem soon emerged once things were being put together; it had been spotted earlier on but it was hoped that it wouldn’t present a problem. The narrow gauge profile wheels were the same overall diameter across the flanges as the standard gauge profile wheels that Mike had previously used and was hoping to use again for this project, and around which the plans were based. However, the flanges were deeper, therefore the tread diameter was smaller than the other standard gauge profile wheels.

This meant that the clearances on the drive gear to the rear jackshaft axle wasn’t as great as we would have liked; and the thought of the main chain drive taking a clonk on pointwork wasn’t very appealing!

There was only one thing for it; the jackshaft axle would have to be raised. This meant dis-assembling the loco chassis, bolting the frames up against each other and putting in the mill so the axle slots could be lengthened, see below.


Well, while you’re doing one set, you may as well do the other set of frames too! Criccieth Castle is born, seen on the rear workbench.


All the way through this project, even though one loco was being built before the other for testing purposes, both sets of parts had been made up as we went – so it wasn’t long before Criccieth/Cardigan caught up with Harlech.


This one is Harlech Castle, showing the rear jackshaft drive re-fitted and the wheel bearings all fitted up. You can tell its Harlech as it has the Maxitrax coupler block – Criccieth/Cardigan has a single slot coupler, the same pattern as Harlech’s front bufferbeam one.

Below: Criccieth/Cardigan’s motor mounting setup, something that didn’t get photographed before on Harlech. The C shaped piece of metal has three holes to which the motor is bolted. The arm on which it sits has had cut-outs made for the chain to clear, and also for fingers to be able to get in and around.

The hoe-shaped piece on the opposite side, the motor end simply rests on that, but a retaining strap is fitted to keep it still.


And here’s a motor attached to Criccieth/Cardigan! The bolting arrangement and retaining strap can be seen clearly here. The tape on the motor is covering the ventilation holes, the last thing you want is for swarf to get into a motor worth £100!

The different rear coupler can be seen on CC, and the moveable bearing slots are more ‘square’ on this loco.


Moment of truth time… Harlech goes all goo garr as it is powered up. This was to check out the chain drive, tensions and clearances. Pleased to say it all worked nicely! The controller and batteries were borrowed from the red Class 04; these will be a standard feature for all these locos.

Now we know the drive system works, we could press on sorting out the wheels. And press them on we did. The axles are made of 20mm steel bar and the gears and wheels reamed out to 20mm to ensure a snug fit.


To aid setting and fixing the back to backs, some top-hat shaped collars were made up. These were made deliberately to be a tight fit and were hammered on carefully. The whole axle was put onto the lathe to be set up, back to backs and treads were checked out.


Once it was all correct, it was clamped still and the collars were drilled through into the axle and a steel pin hammered in so they were set solid. A weld on top of the pins secured them.

The wheels were bolted to the collars so the whole set up is very rigid, you can see the end of the bolts coming through from the wheel face to the collar. In the above photo, you can see the holes made for the bolts.


Dumb bells… or axles? Could be used for both!


Hang on a moment… thats not right?


Late December ’09 – More bearings, gears and motors 


The winter months may be long, cold and dark but still stuff gets done at the Adelaide Loco Works. Admittedly, much tea gets drunk as well but this is for its warming effects on both the hands and the insides as well as the usual thirst quenching!


Things have been moving along steadily, bearing in mind there are now two locomotives to receive attention on a creaking workbench, and CC (rear) has to catch up with HC (fore).


This project has a happy moment: Mike built this steadying device for his lathe as a project many many years ago, but had no use for it until now. It sat in the workshop gathering dust (and swarf) for donkeys – but it was dusted off and brought into service for turning the ends of the axles down to 20mm.


Very much more of the same as the last update, but we are playing catch up for loco no 2! Here, drive gears are being drilled and grub-screws fitted, wheels being set up and fixed on.


Once the wheelsets were finished, into the frames they could go. Here you see the bearing, with packing strips and bolts and cap screws all installed and working. The springs look compressed already, and they are. However, this is intentional and there is still a total of 10 to 12mm compression left to go before ‘bottoming out’ – more than enough when there are rods involved. The wooden template for the cranks is fitted to check clearances etc… these parts are in the second batch of laser cuts and will be made from 10mm steel.


The workshop supervisor, Bop the Blackbird, keeps stopping by and makes sure we prepare plenty of her suet pieces.

During the colder days, more time has been spent indoors in the warm – sensibly! – researching and asking difficult questions of manufacturers and suppliers! The recent subjects have been Ellis Components, our source for the Bosch 750watt motors – the true bi-directional model has been discontinued! The other 24v models are set for one-way operation only; in that the motor brushes are angled and will provide excessive resistance and wear on the commutator should they be reversed.

The original motor Mike has been using on the Class 04s and was intending to use on this project was the Bosch GPA 24v 750w, part no 0 130 302 014 (the 14 is important, the 12 and 13 models are for single direction running, refer to Bosch website to see which is which) nominal current 40amps, nominal speed 3,300rpm.

The replacement motor, part number F006 B10 274 photographed below, is 99.9% identical, made in Brazil but the ventilation fins are set for clockwise running – forward direction once installed in the loco. Short bursts of reverse won’t hurt it, so it will do for us. Physically, its the same and will fit into the loco precisely.


While we wait for the laser cuts, we can be doing a few bits. One of which is annoying 4QD and asking them many questions about how to set their controllers for double-headed locomotives!

It was originally intended to use the Pro 120 control boards, but after several enquiries, out of stock items and thunking (the plural of think, according to one of Mike’s old schoolfriends), we settled on the VTX system. This would arrive in stock soon in the New Year, the multiple working set up is much simpler than the Pro series, and it will do all we want it to, and it will save about £30 to £40 per loco over the Pro 120.


Above: how the locos will be wired in multiple working mode. Harlech has its multi socket on the lead bufferbeam and Criccieth/Cardigan has one on the rear. They can only work in multiple this way round – we did originally think it could be wired like this…


… but it gets complicated! so we forgot it!

The multiple working set up involves an expansion 6 pin IDC socket on the main controller board, off which a cable goes up to a 6 pin Bulgin socket on the bufferbeam of each loco – the locos are linked by a separate 6 core cable of which 4 cores are used that connects the two bufferbeam sockets. I have used the same colour notation on the pins as per the 4QD standard (however, black and blue are not required) The leading loco will act as a slave to the inside locomotive, which will have the controller handset plugged into its rear bufferbeam.


And here the handset connection socket has been drilled into Harlech’s rear bufferbeam


Eyeing up the interior, working out where to place components such as the double pole isolator switch, the small batteries for the lights and horns….

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