Where to position the steam outlet on a horizontal boiler ?

I have tried to bend some 3/16 copper pipe into a ''toaster'' arrangement ie. sharp U bends but it is very difficult to get tight bends like this without crimping. I will order some more copper pipe to give it another try now that I have a proper 3/16 pipe bender. I found that the bending springs were useless for sharp bends.

Hi Howard, (I drive full size steam engines and have never been called an angel)

Most traction engines and portable engines (full size and miniatures) take the steam from the top of the boiler. The steam chest is often mounted directly on top of the boiler and takes steam thru a hole in the boiler barrel under it. Locomotives have a steam dome on top of the boiler and steam is taken from here. Traction engines are the worst for getting water in the steam because they go up and down hills and the water is not level. Also a lot of sloshing of water inside the boiler because of the movement. Water only gets into the steam outlet if the boiler is overfull or if the boiler is tilted when going down hill and it covers the steam outlet. (this causes priming and can damage an engine). The other way water can get into the steam supply is when you try and use steam at a higher rate than it can produce and water droplets are drawn into the steam instead of turning to vapor (called forcing the boiler), This should not be a problem with the small boiler in this post.

Paul

Another reason you can get water in the steam is an uninsulated pipe from boiler to engine. Steam condenses as it hits the cooler copper pipe. One way around this is to fit a throttling valve at the boiler outlet to "wire draw" the steam. This allows only a small amount of steam through so pressure in the pipe is sliightly lower than that in the boiler. But the steam remains at basically the same temperature so can cool down in the pipe a few degrees before it will condense.

So perhaps I should fit a globe valve very close to the steam outlet ?

But my other problem is that I am not producing enough steam to run this engine for more than 60 seconds ; it runs out of puff. I tried my usual trick of inserting a piece of 1/8 brass tube inside the 3/16 steam pipe outlet but it did not help much that I could see. I assume that the reversing link mechanism is the reason for this as I have no problem running my other PMR engines using this boiler ie. more friction hence more energy required.

I am going to have to find way to get more heat to the boiler. This may also solve the steam condensation problem. I was going to build a three wick burner for this boiler then put the job on hold as unnecessary. I think I may go back to this idea.

Brian, have a look at the boiler in this thread, It should not be too hard to add a "U" shaped tube or two under the boiler like it has which will help get the most out of your existing burners.

Another reason you may be getting water carried over to the engine is that on a new boiler the residue left from flux etc can cause the water to throth, how well did you clean out the boiler?

Are you running the engine at full notch? as its not under any load you should be able to use a notch mid way along the quadrant which will make the engine use less steam

J

It is hard to know how well the inside is cleaned. I soaked it overnight in citric acid solution which cleaned the outside so I assume the inside was clean as well.

The engine has three speeds for each direction : slow, medium and fast. Just running on air I can get it to run on slow and medium but the ''fast'' speed seems slower than the medium speed and it does not run well on this top notch. The medium speed is its best.. No amount of fiddling seems to change this.