Member postings for Dark Knight

I could make hole on the exit for the condensate that I can do, but I dont understand - my cilinder runs with very small friction. If I rotate it with my hand it can easily makes 3 turns. Im more looking towards the size of the piston hole, do you think that surface of piston could be the problem? As steam flow is slower than compressed air.

Martin

Edited By Dark Knight on 02/09/2023 13:59:08

Edited By Dark Knight on 02/09/2023 13:59:46

Edited By Dark Knight on 02/09/2023 14:00:32

I have finished making miniatire steam engine yesterday and tried running it on compressed air. It started moving at about 1bar and I was satisfied with the result. Later on today I tried testing in on actual steam. I opened steam valve at about 1.1bar in boiler and tried running it. Piston only had enough power to push the wheel for half a turn. Then I tried again at 1.5bar and 2bar and it didnt want to start running. Now Im thinking that I havemaybe made a bit to big cilinder and to big piston (8mm diameter). Should I make smaller piston maybe like 5-6mm diameter and smaller cilinder?

Thanks for replies,

Martin

I can make U-tube bend from copper like you said, maybe I should check tables for different types of plasic and their temperature points to see at what temperature range it softens. Also is this gauge-glass tube purchasable, i have never seen it, maybe i could cut glass test tube.

| Posted by Nigel Graham 2 on 10/08/2023 21:28:17:

I'm a bit puzzled by the small holes in the side of the cylinder in the sketch. They make the device look more like a simple pressure-regulator.

I can understand a piston-type gauge working by graduations on the rod protruding from the top though.

However, it is normal practice to give the gauge or sensor some protection from the hot steam by a U-bend in the tube from boiler to gauge. Often called a "syphon" though it is not really a syphon, it becomes partly filled with water so the gauge feels only air at the boiler pressure.

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Maybe i should remove O-Ring on piston and put inside cilinder Φ6mm transparent pneumatic tube and this would seal piston from leaking and the piston position on holes would still be clearly seen becouse of transparent pneumatic tube.

Edited By Dark Knight on 11/08/2023 08:52:30

I do apologize for misunderstanding, in my country we call pressure gauge manometer. Im attaching my sketch of the idea; also the distance between holes must be correct otherwise becouse of the piston the pressure in boiler will drop, so i will have to pick the right spring.

Martin from Slovenia

Edited By Dark Knight on 10/08/2023 13:17:37

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Edited By Dark Knight on 10/08/2023 13:10:02

Hello,

Im building small steam engine on my lathe and I have come to a point where i need manometer on my boiler.

Im looking for ideas how to build it.

My own first idea was making small cilinder with a piston that has piston rod spring loaded. Then i would make vertical dial on cilinder, calculate spring elastic energy and calculate distance for each bar then i drill small hole on proper calculated distance for each bar. (max3). Sorry if my english is bad, Im not from UK,

Any other ideas appreciated.

Martin