Ongoing Work
October 2010

Oct 29th - New BC-348 Receiver and Radio Lighting. 

A few days ago, I picked up a second BC-348 Receiver. It has had a few modifications which probably aren't authentic such as the metre on the front, but I'm doing what I can to make it look its best. The handles are missing, but I'm hoping to cast some replacements. The aerial quick release terminal had been replaced with a coax socket and one or two knobs have been replaced. The mounting frame on the bottom is also missing.

I have removed the coax connector and made a replacement from brass tube and chemiwood. The brass mounting plate bolts into the back of the panel face using the holes left by the coax fitting. I've built a spring into it so that it functions like the original. It's a bit clean at present, and the original Ground terminal below it, has lost almost all its paint, making the contrast even greater.
I've also done a bit of re-wiring on the receivers. Of the two bulbs in each receiver band selector, only one of the four worked, and that was a 6 volt bulb. I've ordered some replacement 12 volt bulbs, and rewired the bulb circuits through the master switch, so the lights come on when the master switch is selected on.
 
Oct 23rd -
Instrument Panel Fitted and Weather Vane Connected.
 Dodging in and out between showers ( Very heavy rain! ), I got the instrument panel fitted today. The panel was positioned after dropping the weather vane drive rod down through the ceiling and into the panel. The bottom of this rod rests on a brass plate to act as a bearing surface. This can be seen below.

The panel itself is screwed down to the table with three screws and nylon kitchen cupboard corner blocks, seen below in white. The weather vane mast was then fitted to the roof and the vane aligned with the gauge before gluing the drive gear to the shaft. The front of the panel was then screwed in place.

The only gauge which isn't connected now is the anemometer, which is waiting for me to make the anemometer head which catches the wind.

 The picture to the left shows the meteorological station as it will be viewed by the public. As it is mounted fairly low, all the instruments can be clearly seen when standing outside the truck. From the radio operators seat, between the radios and meteorological station, he is looking square on to the instruments.

Not yet connected is this panel light, which came from a Lancaster ( so I've been told ). I've just ordered some cotton insulated wire, to wire up various pieces of equipment where the cable will be seen, as modern plastic coated wire wouldn't look right. While there is a small switch on the light itself, I'll fit a master switch on the panel.

While I was working on fitting the instrument panel, the rain was running into the weather vane mount in the roof of the truck, and dripping onto the panel. Even when the weather vane mast is fitted, rain water was likely to run down the tube. To stop this, I turned a resin cone on my lathe which fits over the bottom of the weather vane mast and is glued in place.

This cone sits just abover the metal mount in the roof of the truck, with the gap taken up by a large leather washer. This washer should seal the joint fairly well. All that remains to be done is to mix a little grease and oil to pour into the mounting socket in the roof. This should form a last water seal on top of the bearing in the bottom of the vane mast socket.

 
Oct 12th -
Windsock Made

Not much to say about this, other than the cotton sock has a steel hoop in the larger end to maintain the shape. This has a yoke of wire which connects it to the weather vane via a swivel linkage to prevent the wires twisting together.

 
Oct 10th -
Instrument Panel Complete

Finished! The main box of the meteorological station was primed last night and painted this morning. The aircraft compass has been mounted on the top. This is used to calibrate the wind direction indicator once the truck parks up on the end of the runway.

Also done today is the stencilling on the clocks and the wind direction indicator. The only thing that may be added in the future is a toggle switch in the blank upper right side of the panel to switch on a panel light which I have and that can be mounted overhead.

I knew there was a US/UK time difference during WW2, hence the reason for the two clocks, but just read today that all orders from 'Pinetree' ( USAAF HQ ) were written using GMT. The UK however was using British Double Summer Time ( BDST ) during the summer. So one clock is set to GMT and the other adjusted from BST to BDST as necessary.

Oct 9th - Instrument Panel almost complete
Today, the wind speed gauge was fitted, and then the two clock faces were fitted to ply plates and the clock mechanisms fitted. The pointers needed trimming down and respraying. A wooden framework was then built on the inside of the panel to hold the instruments behind the removable aluminium front face.

After the Wind Speed gauge was fitted, the drive cable was routed to exit the top of the panel ( below right ). A piece of brass tube was crimped and soldered to the square drive of the cable so that a drive wire could then be connected up to the truck roof and the yet to be build anemometer head.

Below left shows the inside of the panel with the wind direction mechanism and wind speed gauges in the foreground. To the left is one of the clocks and below and behind, the barometer and hygrometer. Below right, the virtually complete instrument panel, just needing the box painting and then fitting into the truck.
 
Oct 8th -
Instrument Panel and Wind Direction Mechanism
The bottom of the weather vane shaft is now supported in a bearing seated in a turned resin housing ( blue cylinder ). The gear wheel on the end of the shaft drives a second gear connected to the brass tube shaft seen below. This turns a third gear meshing with a fourth on the pointer shaft.

Also turned up today is the knob to swing the compass face to align it in the correct orientation depending how the truck is parked.

A piece of clear plastic was also cut for the instrument glazing.

The instrument panel was etch primed, followed by a low pressure speckle of grey primer to give the panel some teture. This was followed by a black coat and a matt coat to finish.
 
Oct 3rd -
Meteorological Station, Locker and Instrument Panel
Before the Meteorological station could be built and fitted, the locker lid needed replacing. Because the table and instrument panel need to be mounted low, so as not to obstruct vision when driving, the original rear locker lid wouldn't have opened. 

As a result, I've made a new lid in sections which folds back on itself, minimizing the height of the lid as it opens. While there isn't much room to reach under the table, it still allows use of the locker for smaller items. The catch from the original lid was fitted to the new lid.

With the locker lid fitted, the table which was made yesterday, was fitted into place. This then allowed the instrument panel to be trial fitted to establish the point where the weather vane drive enters the panel. The aluminium panel was slightly over-sized, so that was filed down flush with the box.
Once I knew the position where the weather vane drive goes, I began work on the wind direction indicator. The instrument needs calibrating depending on which direction the truck is parked in. Therefore, the face of the instrument can be rotated using the knob to the upper right of the dial. In the picture to the right during testing, it is some plastic Lego wheels, but a turned aluminium version will be machined.

The instrument face is attached to the yellow gear wheel, which is driven through an intermediate gear ( blue ) to the red shaft for the knob. This gearing down allows finer adjustment of the dial position. The pointer shaft runs through the centre of the yellow gear and is seen above right with a temporary styrene needle. The red gear on the end of the pointer shaft will connect to the weather vane shaft via intermediate gears to make sure the direction of rotation is the same as the weather vane.

 
Oct 1st - Wheel Balancer and Astro-dome

Having tried a number of local garages ( both car and truck ) to find someone who can balance the truck wheels, I finally gave up. The few places where the wheel would fit on the machine, it came up with an error due to the weight of the wheel exceeding the machines limits.

I decided to have a go at making a simple balancer. A device was made that was a snug fit into the opening in the centre of the wheel. A hanging point in the middle of the device allows the wheel to hang from its centre. If the wheel is out of balance, the wheel won't hang level, and needs weight adding to the highest part of the rim.

The wheel is seen below hanging by a rope from the balancer. The knot didn't always sit directly over the centre of the balancer, so a steel hanging hook was made; seen above right.

I also did some further work on the astro-dome. The front corners of the wooden plinth were quite angular and were digging into the cab canvas. I was worried over time that it would cause a rip in the canvas, so took my powerfile to both front corners and rounded them off somewhat. This should put less strain on the canvas.

I also ground off the rusted bolts that held the broken air scoop on the top of the dome. I'd like to make a new air scoop, but for now, the broken part has been removed. I can't put the tarpaulin over the dome when the truck is in storage without risking the broken edge cutting through.

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