Sketchup Modelling

I have begun modelling my planned case modifications in Sketchup, so far I just have a crude representation of where I will be building out from the initial case. I plan to have a wooden panel on the front as on Victorian laboratory/electrical equipment. The rest will be painted dark green a lined in the stile of a steam engine. 

PC case found

I have finally overcome the problem that has been preventing me from properly starting the build, I have got a starting point PC.

This case was given to me in response to a wanted ad. Fortunately it seems to be exactly what I want. A three drivebay extra-wide full ATX case. This should give me a good starting point for both adding the steampunk details to the outside and for much improvement of the cooling internally.

It currently has all components apart from a harddrive. None of these components I ultimately want to keep making them perfect for testing the fans lights and other decorative features I have planned for the case.

I can finally begin my build!

Valves

I am currently watching a large number of job lots of radio valves on Ebay. After seeing one lot go very cheaply this looks like the best way to obtain them. The seem to be regularly sold along the lines of "I found this box of valves, no idea if they work or what they're for 99p start". Of course for what I want that's perfect I don't need to know what for or if they work as they will be purely decorative. I may drill them out and put LED lights inside them, but I will have to look into that.

Watch this space!

Gauge Clean-up (Ferranti) and testing

I was just going to show the clean-up of one gauge but I've added this one as well because it seems interesting. 

On initial inspection this appeared to be a Ferranti Voltmeter reading 0-500 volts. But during dismantling, cleaning and testing it was found to be something quite different. Firstly opening this meter was different, two screws allowed the face plate and glass to be removed but even after this it proved to be impossible to remove the electrical component. It was also apparent that the dial had been sealed with rubber to prevent water or dust ingress suggesting this gauge had some industrial or outdoor use. With the dirty glass removed it was apparent that everything was not what it seemed. Beneath the handwritten word "VOLTS" it read Milliamperes although this had clearly been scrubbed off, it was also obvious that all the numbers around the dial had been similarly altered. 

Therefore I decided to remove the dial to find out more. The information on the back of the dial showed that it was indeed built as an ampmeter not a voltmeter and was manufactured in 1956.  I progressed cleaning and re-assembling the gauge as before. 

I then decided to test both gauges to see if they worked. This was done using a bench power supply but could be done using batteries. Using a power supply you should insure it has current control as well as voltage as other wise you may end up frying your gauges. I picked up this power supply off Sheffield market about two years ago for three pounds, the man selling it had no clue what it was or what it was worth. It was connecting the Ferranti gauge up to this power supply that gave me my second surprise,  I set the power supply to 4 volts and expected the needle to hardly move (the gauge claiming to measure up to 500 volts) the gauge immediately maxed out. I checked that it was all set up right and tried again, same result. It is clear that for whatever reason someone decided to re-mark this gauge to give a completely false reading. 

Anyone know why?

Happily both gauges move when hooked up to a current meaning it may be possible to have them "working" (needles sweeping) on the front of the PC.

Gauge Clean-up (G.E. Decibel Meter)

Fig. 1. The gauge as found

The only problem with buying gauges cheap from an antique fair is you have no idea if they work and they are often very dirty. The first point is hardly a problem, as the gauges are cosmetic pieces whether or not they work is  really secondary concern. Therefore the priority is to clean the gauges, to do this they must be dismantled and all non-electrical parts can be washed in soapy water.

Fig. 2.  Dismantling a gauge

Figure 2 shows how to dismantle the majority of this type of panel meter. There are three small screws around the rear of the gauge (circled in red). Once these are removed all the electrical part of the gauge should simply slide out. The larger screw visible on the face of the meter is a calibration screw used to zero the meter. This does not in any way hold the gauge together. You should then be left with the components shown in figure 4 though these may vary depending on the type of gauge. All of these components apart from the electrical bit with the meter on the front can be washed in warm soapy water. By the time I had done this my water was brown!

When dismantling the gauge I took lots of photos to ensure that it went together in the right order, it is also vitally important you do not bend the needle as these components can be delicate (these gauges aren't really supposed to be opened). Also make sure everything is thoroughly dry before re-assembling. By the end of this I was left with a clean but still old and worn looking gauge.

If anyone has any idea what the letter U.S.N. (stamped on the back of this gauge) stand for please tell me as I am curious.

Fig. 4.

Fig. 3. Gauge components

Purchases from the Newark International Antiques Fair

Today I went to the Newark Antique Fair searching for more components for my build. I managed to obtain the items pictured. The two gauges (one made by Ferranti reading 0-500 volts, the other made by General Electric reading 100-0 Decibels) were both purchased from the same stall for a total of £5. They were in a box of old dirty junk and tools under the stall and the stallholder seemed happy to be rid of them. It just shows it pays to shop around as another stall was selling similar gauges for £11 each and insisting "you won't get Bakelite gauges any cheaper". The small brass piece I believe is a bell push surround, I intend to use this as a surround for my start button. I will insert a modern push-to-make button switch into the hole which should be more reliable than using any of the period doorbell pushes I was looking at, plus it only cost me £1 ! Unfortunately I missed out on purchasing any valves, I am after old radio/amplifier valves for detailing the top of the PC. The only ones I saw at the fair were either part of valve radios or in a high cost job-lot box with far more than I could ever use.

Finding more bits for the "glass" case

I started looking through the junk box for a few bit which might make the rest of the mystery component in the glass case. I settled on:

• Pins from old mains 13amp plugs
• Some specialist fuses
• A motor coil from an electric shaver
• Tuning pots from an old VCR
• A large capacitor from a stereo speaker
• An iron "choke" piece
• Various copper wire

Again these were stuck down with epoxy to make something which looked right. The fuse holders from the plug pins were bent open to accept the specialist fuses. Items were combined to make their original function less obvious.

First Components inside the "glass" case

I started adding components to the case a bit at a time waiting for the epoxy to dry along the way.

• The small aluminium ring with holes in it is a fixing plate out of a PC hard disk (one of the old 512MB ones!). 
• The small piece with the copper coils is the motor from a dead PC fan (the bearings fell apart) 
• The braided copper wire is from an old power supply.

Small "Glass" Enclosure

I was inspired to make a small "glass" enclosure to house something that appeared to be a high voltage electrical component after looking at pictures of high voltage relays online. These devices seem to usually be housed beneath a squarish glass dome which is held in place by a nut at the top. I decided to try to make something similar. The starting point was a small clear box made of a hard plastic which had held a die-cast car. The box had right look and had entered my junk box after the die-cast car was removed. The other components I used where a long machine screw, a nut and a number of other spacers and washers obtained courtesy of my great uncle's hoarding.

The box already had a small dimple in the top presumable from casting it. This made it very easy to locate the centre to drill out a hole. The top of the box was covered in masking tape to prevent scratches. To drill out the hole I worked slowly up through drill bit sizes from 0.5mm to 4mm holding the drills in a pin vice. Due to the hard brittle nature of the plastic cover I did not use a power drill, and increased drill bit sizes in half mm intervals. After drilling out the hole burrs were removed with a needle file. Then the machine screw and several washers were attached to the base of the box using epoxy. The mounting holes through the base of the box (for the model car) will be covered by other components later.