More on Nigel.

October 31st, 2010

Right, where was I up to? Pulling apart old printers I think. Been doing a lot since then so lets see if I can remember everything.

I found some old rusty sheet steel in my spare garage so I nabbed that to make a base for the engine and boiler. I cut a flat piece of that and cleaned the rust off it. I also used some thinner steel I had left over from helping someone repair their car so I used that to make a firebox to sit the boiler on. Again I basically copied the Mamod style here.

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Base and the firebox.

The firebox simple bolts together and I also made brass bands to hold the boiler down onto it. Two small tabs hard soldered to the inside off the box allow it to be bolted to the metal base. I also made up a small copper chimney that attaches to the end of the firebox that I send the exhaust steam up. The chimney is copper instead of brass since my friend Angela said she prefers copper and you should never argue with a woman (well, unless you’ve stacked the odds). I shouldn’t have been surprised really, she’s a copper top herself!

IMG_8935_1_1 Boiler on base and chimney.

I then worked out the general arrangement of the parts on the base and figured out how to make all the piping to interconnect things. The pipes are made from copper tube. To be able to bend it you must first anneal it in the same was as when I made the boiler ends. I just heat the pipe in a gas flame until red hot then let it cool and it then bends easily. If you are gentle you can easily bend the pipes without them kinking. I made all the pipes in one piece then cut them later so I could keep the boiler, engine and throttle separate.

IMG_8947_1 IMG_8949_1 Piping.

At this point I also made the platter. I used some wood I had already glued together into a thick block for another project that never happened. I cut this into a circle roughly with a jig saw then used a router on my home made circle cutting jig to make it truly circular. The platter is slightly less than the diameter of a record and about 40mm thick. I put it in my drill on the slowest speed to carefully sand the edged of it smooth after routing since the router couldn’t cut the whole thickness in one pass so I needed to make a pass from each side leaving a small ridge in the centre of the discs.

IMG_8898_1 IMG_8900_1 IMG_8901_1 Making the platter.

After making the platter I painted the engine base with left over engine enamel I had in my garage. I also painted the fire box with some left over brake caliper paint which should be able to take the high temperatures needed. I added a detail line to the base by carefully masking with Tamiya model masking tape then spraying with yet more left over red spray paint. This gave me a nice pin-strip detailing on the base.

IMG_8964_1 IMG_8966_1 IMG_8972_1 Base plate detailing.

About now I also tackled the problem of how to know how fast Nigel was running. My original plan was to use the opto sensors from the old printer I scrounged and make some kind of optical tachometer using an Arduino. Initial experiments didn’t go well though. Next I considered using a hall effect sensor so I grabbed one from Surplustonics.

With a rare earth magnet stuck to the flywheel and the sensor near it this also didn’t seem to work too well. Then I had an idea. I took a spare automotive relay and pulled it apart and ripped out the coil. I hooked the coil up to my scope and put it close to the flywheel as the engine ran on air. I held it in place with some green Plasticine.  What I got was a beautifully clean signal on the scope each time the magnet passed the coil. From that I was able to work out the time between the spikes and therefore the RPM the engine was doing.

IMG_8956_1 IMG_8961_1 Coil and magnet to sense speed.

I made a small film of doing this and put it on YouTube.

Since I knew my magnet and coil trick would work I threw together a quick circuit using an Arduino to measure and display the RPM. I will describe that in more detail later. Since I knew the coil would work I went back to Surplustronics and for $1.50 bought a small solenoid with two small coils in it. I pulled this apart and extracted one of the coils. I made a copper housing from some old water pipe and inserted the coil into this. I soldered a nut to the outside as a terminal and then soldered one wire of the coil to the copper housing and the other to a steel rod I put through the centre of the solenoid. This steel core is needed for the coil to strongly pick up the effects of the magnet as it passes. I then potted the whole thing using some Araldite epoxy with a little black ink mixed in.

IMG_8983_1 IMG_9000_1 Coil housing potting.

Next I made the wooden base for the engine. This is just some cheap pine I sawed to size then routed a little detailing into the edges. To attach the platter to the wooden base I needed a bearing housing and shaft (figured out what I am making yet?).

I looked in my junk box and found some round plastic stock left over from my Wimshurst machine project. I machined up a bearing carrier that holds a skateboard bearing in each end. The bearings are a tight push fit into the housing. This is a good thing with plastic bearing carriers. You can easily machine them so the bearings are a good friction fit since there will be some give in the plastic when you push the bearing into place. One end of this carrier has a small flange on it. Unfortunately I couldn’t make this big enough to drill mounting holes though as the original nylon bar I used was too small a diameter. Instead I machined a second piece from some of breadboard. This is one of my favourite materials to work with. It cuts and machined beautifully and of course is cheap and available at the supermarket! This second piece is a ring that slides over the carrier and pushes over the flange. Three screws hold it to the base. I used one of the old shafts from the junked printer to make the axle. This has a groove machined on it for a circlip to hold the shaft in the right position.

IMG_8986_1 IMG_8990_1 Platter bearings and shaft.

The platter is a push fit over the axle and I machined up a little stub that pushes into the top of the platter that is the right diameter for a record to fit over. You must know what I am making now! If not the next pictures give the game away.

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I am still trying to find a Sex Pistols LP to go on this thing though. Hmmm, steam and punk. Almost as if it were planned that way…

2 Responses to “More on Nigel.”

  1. Asciimation » Blog Archives » A steam punk record player. Says:

    […] engine ran I started on the next part of my scheme – to use it to turn a record. I made up a firebox and heavy wooden platter. By this stage I already had it in mind to create the only true steampunk project on the […]

  2. zain Says:

    show me simplest way to make a small steam car without a piston.