Samson

[Boustrophedon]

Have you tested the anti-vacuum valve?

It seems to work, dribbled a little at first. I opened the oil valve about half a turn and used about a third of the oil.

I may think about adding a more traditional dead leg lubricator. That and a drain cock for the boiler.

[KNO3]

I thought the Samson has a factory original dead leg lubricator?
Why do you want to replace it?

[Boustrophedon]

I thought the Samson has a factory original dead leg lubricator?
Why do you want to replace it?

Because it is not a displacement lubricator and it is very difficult to adjust, being prone to dumping all the oil in the first minute or two or none at all. Having said that I am starting to get the hang of it, half a turn open seems to work.

How it works is another thing entirely.

[LNR]

One slight disadvantage of the displacement lubricator is there tendency to "gulp" depending on how the engine is driven. I use my engine to make up the train first, ie much shunting. On and off with the throttle tends to send fairly wet steam into the lubricator thereby increasing oil displacement. Conversely an engine run under say mainline conditions with a fairly constant throttle setting, will use a far more consistent quantity of oil over a greater time span.
I would stand corrected, but if memory serves the hole in a Roundhouse lubricator is 20 thou. approx. If you work out the surface area of that, and equate it to the peripheral area of an adjustable needle valve (assuming that is the method on your loco) it doesn't have to be open very much. As long as you check oil use initially until you arrive at a suitable adjustment. Just some thoughts.
Grant.

[Chris Cairns]

The lubricator is not of the displacement type

The lubricator is unusual in that it is not the usual displacement type but has a control valve to adjust the oil flow

I opened the oil valve about half a turn and used about a third of the oil.

That is spot on. I'm using some original Cheddar Models steam oil (the dark treacle coloured 460) and have settled on just under 1/8th of a turn open works best for my Samson.

Tag Gorton advised me to start with the control valve closed until you had cleared the cylinders of the condensate, open it for the run, close it during any water refills (I do this at least once during a run) then open it again, and at the end of a run fully close it again.

That and a drain cock for the boiler.

I was given a good tip for emptying centre flue boilers. Use your 50 mls syringe & tubing to suck as much water out of the boiler as possible. Pull the syringe's plunger fully out, insert the tubing as far as possible into the boiler, hold the loco upside down & depress the syringe's plunger. Repeat as necessary until no more water is ejected from the boiler.

It is rather tricky initially holding the loco upside down in one hand & pushing the plunger with the other hand, but you soon work out how to do it for each loco.

Watch out for the baffle plate in Samson's steam dome - there are only 2 holes through which you can insert the tubing.

Chris Cairns

[Boustrophedon]

I had to replace the receiver battery, it ran out quietly after 30 minutes and I discovered that I had no control, Samson just bimbled on around the track. Actually I am pretty surprised given that the batteries are NiCd, that they worked at all after all this time. Replaced with NiMH.

I think I have a pretty good idea of when it was made.

[LNR]

I would love to see a pic. of the lubricator in question.
Grant.

[Boustrophedon]

I would love to see a pic. of the lubricator in question.
Grant.

This is it.  There is no riser inside, the oil exits at the bottom. The valve controls the flow.

[LNR]

Thank you for the pic., that's very interesting. I know the Samson has a hole in the side of the smokebox adjacent to the lubricator. Is that just a mounting hole for a screw.
I'm wondering if there's more of a hydrostatic principal used, by simply pressurising the tube, an "ooze" of oil finds its way down the tube. How it still manages to pass oil once condensate reaches the level of the valve that low down, I don't know.
Grant.

[Boustrophedon]

Yes the hole in the smokebox is just for mounting. There does not appear to be any condensate in the lubricator at the end of the run, it just empties. Any remaining oil does appear to be emulsified though. My theory is that there is pulsating flow in and out of the lubricator, perhaps with changes of throttle openings or with piston strokes that gradually empties the oil out.

[LNR]

And because steam oil is miscible in water even if the lubricator is passing condensate, it would be oily. Our small engines use pretty wet steam and we are probably over lubricating to some extent. Your pulsing theory brings to mind Bourinelli' (spelling? it's a long time ago!!) law, something about the turbulence in the boundry layer around the inside of a pipe depending on velocity!!!. I guess the important thing is, it works and obviously works well if you consider the reputation Cheddar locos have earned.
Grant.

[KNO3]

I'd also like to know how this lubricator works. Does anyone have a good explanation?
In my Samson it is always empty at the end of a run, I gues I keep the valve open too much.

[LNR]

Hi,
After Boustrophedon mentioned there was no condensate left in the lubricator at the end of a run, I got to thinking that it's a little unusual to find anywhere in a system open to steam with no condensate. I wonder if this indicates a venturi effect in the lubricator line?
Grant

[Boustrophedon]

I am at a los to know how it works. I suspect that it stays too hot for water to condense. Having said that I am surprised at how cool Samson stays during a run, Both Katie and Ragleth are too hot to handle all over after a run, but Samson stays very cool. Samson does not use superheated steam which may have a bearing on how the lubricator works.

[Chris Cairns]

The only thing that comes close to Samson's lubricator is a Furness lubricator.

We have these fitted to our Andrew Barclay 0-4-0ST. They are mounted on the front of the cylinders and rely on a vacuum effect during the exhaust stroke or when coasting to open a non return valve allowing some steam oil to be sucked into the cylinder.

Both Katie and Ragleth are too hot to handle all over after a run, but Samson stays very cool.

An classic example of thermal conductivity. Samson is an all steel construction, whereas Katie & Ragleth Mark II have brass bodies.

I also had problems with the power switch/battery harness. The previous owner had fitted a new NiMh 4 x AA battery pack which did not fit into the side tank. Whilst fault finding power problems with a replacement 2 x 2 x AA loose battery holder I discovered the power harness had suffered from black wire corrosion - a known problem when using Nicad batteries.

Chris Cairns

[Boustrophedon]

Just had a very successful one hour plus run in the garden, with stops only for fluids and gas top ups.

New batteries work well, I was careful to buy the same form factor so that they would fit down into the side tank. I was only getting 20 minutes or so with the old ones.

I have also fitted a new spring into the gas regulator, which now works so much better. I bought a generic spring of the right wire diameter and outside diameter off Ebay and cut them down with a dremel

As for heat conduction you may well be right. However all three loco's have steel chassis, stainless in the case of Ragleth which is a very bad heat conductor. When I go to pick them up the chassis of both Ragleth and Katie are much hotter than Sampson and they have brass bodies bolted to the chassis to carry the heat away. I suppose it depends on conduction paths from the hot bits to the cold.

It just seems odd.

[JMORG]

I can imagine the Samson uses much thicker material (Cheddar are renowned for over engineering their products). This would obviously require more energy to heat up, so the locomotive would be much cooler at the end of the run compared to it's contemporaries.
Hope you're enjoying your Samson! One of our members had a Samson and Hercules (a very suitable name) and still currently has his Riesa. They are fantastic engines and extremely powerful!

[Boustrophedon]

I want a Hercules next.