Walschaerts gear on a G8

Here we see the original loco on the right hand and the new rebuilt on the left. As you can see some small items are still to be done such as the new numbers on the smokebox etc.

The original Arnold model has the motor partly in the cabin and firebox. Therefor the firebox and boiler dimension are overscale and this probably leads to a nearly 2 mm overwidth cabin. All due to a much too large motor. Further the model has a Knorr preheater which was not characteristic in Belgium, only about 5% of the machines had this equipment. Apart from that there is the German lighting, the wrong buffers, old type of safety valve, superfluous bell and light machine, no light below the boiler because of the worm drive being there.

Pro's are: the wheels are in the correct position, although a bit small but it concerns the right amount of them (4 axles) and it is a Belgian machine. Together with the type 96 the only ones you can buy as R-T-R.

The running properties with a replacement motorising set (Verbeck, no longer available) using a 1016 motor with flywheel are reasonable to good. This depends on the friction in the gearing and this seems to differ from machine to machine. I know because I have several.

I wanted something better than the Arnold model thus decided to tackle this machine using some of the Arnold parts. I ended up using only the cylinders, the crossheads and the cabin less the overwidth.

Below we see the new drivework. The tender is based on 2mm practise, splitaxle technique. The 2 back axles form a splitframe bogie which has 1 springloaded central vertical axle. Pickup is by PB springs to the outerframe. The front axle has 0.5 mm extended steel axles which run in the outer frame plates. Thus we have a 3 point suspension and all wheels on track. The result of this is that the diameter of the flywheel can be maximised because it sits partly between the frame. A large flywheel means mass as working power. Also the weight of the tender is maximised ensuring more reliable pickup.

The front part shows a set of fiNe-scale wheels. These are newly turned steel tyres on Fleischmann half products. A different production method for these is shown elsewhere. Not all of them are entirely wobble free and I probably will replace 1 set somewhere in future. The gearbox uses a module .2 worm and 40 teeth wormwheel in the first stage. Total gearing is ~ 64:1. A compromise is driving the third axle and not the last. This is to obtain better running properties. There are 3 axles with gears, frontaxle is driven by the rods. The compromise is that, on 1 side only, a part of the gearbox is visible in front of the firebox. However I cannot tolerate a compromise in the running properties, trying to drive a geartrain via the last axle will lead to a highly sensitive loco due to play in the gears.

The wheels have the correct diameter, pickup is by PB springs on a pcb keeper plate which also houses the brake detail. Thus brakes cannot make shorts and are live. The frame is massive, built up with 3 layers of 2 mm brass screwed together after profiling the space for the gears in the middle.

On this photo we also see the testruns with dcc decoder. This is a DCX70, which is very good but too large. Its smaller brother DCX73 is now mounted but for optimal performance you need software version 14 or newer. Currently it is the best small footprint decoder for coreless motors on the market.

This photo shows the new body. A question of simply starting out with some brass and soldering irons and files. And yes some parts were turned and others milled. The frontdoor is soldered using a resistance soldering apparatus. The cabin is glued to the firebox and spaces were later filled with Milliput. The boiler is 1 piece massive brass except for the gearbox space. As this space was oversized I filled it again with whitemetal (temperature had to be lower than solder meltpoint)

This is the other side. The ladders were soldered from plain wire. The chimney now has the characteristic setup for controlling the draft when not in use. Note the ribbed buffers with central hole. The new drivework was still missing above, but here it shows in close-up.