Here is a list of all the postings Richard Parsons has made in our forums. Click on a thread name to jump to the thread.
|Thread: Beginners start here in Model Engineer|
This thread is very interesting as it shows just how sophisticated model engineer’s workshops have become. I started with a second hand Unimat SL (which I still have and use). I made things on it like retracts for my
I then bought a Myford ML10. I started work making a fire engine (plans by old LBSC -I still have the plans if My Hobby Store wants them-). I did it the job the way he did using fly cutters, angle plates etc to machine flats. Steam ways were drilled and files out. The cylinder was bored on the cross slide with a between centres boring bar and so on. No vertical slides they were too expensive. It is surprising what you can do with a few cup square bolts a scrap of steel and a lathe tool mounted on the faceplate as a fly cutter. You just have to think about it. Then I built (and sold) Sir Morris de Cowley a nice little Pacific (I still have the plans same as above).
I do not what kit old LBSC had when he built Ayesia, I think it was a round bed Drummond and little else. Actually the making side of Model Engineering is really a question of how can I make it with what I have got?. Highly sophisticated machines make life easier but they can add complications. Ask your self how can you machine the cylinder block of an H10 with your ‘mini lathe’ or what ever? Look at the casting and the lathe and you might be surprised just what you can do. It is all a question of thinking about it. Remember if you cannot spin the work piece round you probably can spin the tool and hold the work piece still. After all a circle/cylinder is only a very large number of ‘flats’
However no one knows it all. In a recent article in Model Engineer the editor showed how to get the bed of such a model flat using a tile, a felt pen, some emery cloth and a file. I learned about a new use of a felt pen from that!
REGARDS TO ALL
|Thread: Diesel engine|
In Mr Diesel’s original engine the fuel was mixed with the air before it entered the cylinder. These are found amongst the Compression Ignition types used in model aeroplanes.
The engines you are looking at are the ‘solid injection’ type where fuel is injected into the cylinder at or about full compression. The real problems are the injector, and the injector pump which contains fuel dosing control to get the fuel correct for the load.
Unless you are using a ‘common rail’ engine with electronic control, which is very different and uses a single pump. The injector has to stay shut until the fuel reaches a certain pressure when it opens squirts in its load and snaps shut. It has a ‘dribble pipe’ which then opens to overcome the ‘water hammer effect’ and return the surplus oil to the feed side of the pump.
The injector pump which is controlled by the governor has a rotating cylinder liner. This has a triangular hole in one side. As the governor decides that more oil is needed it rotates the cylinder exposing a larger opening to the output slot and allowing more oil to be injected. You needed one pump per cylinder. These could be either on the cylinder head driven by individual cams or as a block of pumps driven by the camshaft and supplying the injectors by pipes.By the way do not get confused by the direct/indirect injection systems devised by Ricardo and give better performance by better mixing.
|Thread: Alternative cylinder metal|
Has any one any experiance of using aluminium with PTFE Pistons ans valves to make steam cylinders? I expect to use wet steam at between 50 and 80PSI.
|Thread: Boiler making hearth|
Try this it can be made free -if you have an old paint /oil drum-
Put the tin/drum in the garden and burn it out. This prevents accidents. Now cut out the top and about 1/3 of one side to within 2" to 3" of the base to leave a window now fill with dry sand (I use the dying heat the cooking oven). I work outside and need the high sides to keep the 'heat in". I have to plan the work to happen between late March and end September. After that over here it can get nippy (-20C).
|Thread: "Foundation" book has got me worried|
In winter my old (above ground) workshop had a temperature range when un-heated of -20 to +5 degrees C. A bit nippy! so I built an Omni fuel (burns anything) ‘Kandelo’ from an old 50 gallon oil drum. A ‘Kandelo’ is a directly heated storage unit. The important thing with it is a good flue which should never get above 70º C. If it does it warns me and I close the dampers a little other wise I am wasting fuel!
My new workshop is in the basement and has a year round temperature range of +10 to +30º C. It uses a heat pump built (with some help from a local ‘fridge repairer) from an old butcher’s fridge. This system gives you 3Kws out put for every Kw input. It takes its heat from the ground water some 6 meters below ground.
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