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[ashgarth]

Hi name is John I have a steam launch with a modeen super minitwin and a crompton boiler set.I have only recently acquired the boat and is my first time into steam the engine runs superb.I dont think it has run much in its life.there is a bit of oil in the tray under neath it.there is a filler for oil on the prop shaft but cant find anywhere on the engine.there is a round fly wheel in between the cylinders or could that be the crankshaft well it has two small holes in it could that be for the oil.I really do not know anything about steam engines I hope somebody knows the engine or can help. cheers John.

[SteamboatPhil]

It sounds like it is a fly wheel between the cranks, and the two holes you describe I think you will find are for grub screws to clamp the flywheel to the shaft. You will need a lubricator for the cylinders which is fitted in the steam line and should have steam oil.If you could you post a pic of the engine I should be able to identify all the bits for you, and let you know if it does have a displacement lubricator for the cylinders.
Phil

[Bunkerbarge]

Hi John and welcome to the forum.  Unfortunately with any steam plant there is every likelyhood that the modeler could have adapted or modified the original manufactured plant to suit his own tastes or model design.  You really need to post some pictures of your own set up so that we can see exactly what you have and hopefully locate an oiler for you.  I would expect it to be a displacement lubricator in which case you will be looking for a device like the one in the attached picture located somewhere in the steam supply line attached to  'T' connection.  It may also be made of glass but it will be in the line from the boiler to the engine and will have some sort of screw cap for filling.

If you can't find it try to get some pictures up and we can have a look at what you actually have.

[ashgarth]

Hi thanks for reply unfortunatly my photos are to big for the site I will have to learn to make them smaller.There is a photo of the engine lower down the forum under the title (STEAM VALVE CONTROL)it is a modene engine but there is nothing between the boiler and the engine.Iwill try and get some photos on soon cheers John.

[Bunkerbarge]

If there is nothing between the boiler and the engine then I would recomend that you do not use it until we can see what is going on or you fit a lubricator.

Resizing pictures is a very easy process but varies slightly depending on the program you are using to do it.  Just make them less than 156 kb and they will attach to your email.

[ashgarth]

HI I think this picture is small enough there is nothing berween the boiler and the engine so I need one is there a good place to get bits for small steam engines.If I had not found this site and all the usefull info on it I would have destroyed it by now thanks a lot for all the help and the info cheers .John

[Bunkerbarge]

Glad we could help John.

What you need is one of these:

http://www.mainsteam.co.uk/lubricators.htm

Fit it into a 'T' branch on the supply steam line to the engine.  The idea is that you fill it with steam oil prior to using the engine then, as the engine is runing steam will enter the lubricator and condense.  This condensate will drop below the oil and hence displace it into the steam supply line, where it will be carried through into the engine.  This will ensure that the internal surfaces of the cylinders are lubricated as well as the extrnal surfaces such as the port faces.

After a run you open the drain valve and blow out the condensate before shutting off the steam valve from the boiler, removing the lubricator cap and topping up with fresh oil ready for another run.

[bogstandard]

Does this help.

These are sketches and bits I made up for use on another site.
No text on the build, but it shows how to make two different types.















John

[ashgarth]

Hi yes it does help I will copy it take it to a friend who is very good with small metalwork.Iwill see what he says and also it gives me an idea of how they work. Thank  you so much.I am itching to take it down to a lake but will wait until I can get this done.thanks a lot John.

[GrahamV]

Hi,  I made a displacement in-line lubricator for a small twin cylinder oscillating engine and found that a 1mm hole in the through pipe delivered far too much oil and emptied the lubricator in a short time, long before the initial boiler water fill was used.  This engine was running at 40 psi with wet steam.  I found that a 0.7mm dia. hole was sufficient with wet steam. 

Perhaps others would like to comment?

Graham

[bogstandard]

Sorry,

I forgot, and should have mentioned that this was designed for 'toy' (as they like to call them), Mamod type models, which usually run at around 15 psi.

You are perfectly correct in saying a slightly smaller hole is required, in fact on my 'batch' steam engines I usually use 0.6mm, running between 25 & 35 psi., which gives them a nice lubrication time of around 45 minutes.

John

[GrahamV]

Thanks John,

I also forgot to mention that I also had to use a more viscous oil with with my 0.7mm hole in the through pipe, i.e. 680 grade in lieu of the usual 460 grade used with small oscillating engines.  So I totally agree that 0.6mm hole would be right for the lighter oil.

It is perhaps surprising that many 'steam people'people do not know that different grades of steam oil are available, even though they may be aware that differing grades and formulations are used in IC engines.  Sound advice is to check with the engine manufacturer as to which grade should be used!

Graham

[bogstandard]

I would like to add that most people actually over lubricate the engine. It is fairly easy to check when first runs of the engine are carried out. Being careful not to scald yourself with the hot steam from the exhaust, let the engine run for about 5 mins, then hold a clean white rag up to the exhaust for about 30 seconds. You should see just a slight tinge of oil, not as some people have them, with oil dripping out of the exhaust port, not only is it wasteful, but you run the risk of running out of lubrication before the end of your steam run. You should always have a bit of oil left in the luber at the end of your run. There is not a lot you can do if you are overlubing, but you must make sure your engine run is timed to stop before the oil runs out. It is the state of no lube that causes the majority of wear problems in a small engine.
I have a small engine that has been correctly lubed for all its life, I run it almost every weekend for over ten years, by a rough calculation, well over a thousand running hours. I only ever changed the o-rings every couple of years. On checking it over at the end of its hard working life (the boiler clagged up), there was hardly any detectable wear on either of the bores. Ready for another ten years steaming, but now resides with my engine collection in tribute to a good design and good lubrication. The engine, the first ever Cheddar Puffin engine, the one that used bronze investment castings in its build. Later designs never really matched it for quality and reliability, and I don't think it could be made at a competitive price nowadays.

Now because I make my own lubers, you will notice that my bleed hole is on the top of the pipe, unlike most commercial ones that have the hole hidden underneath, I don't know why, maybe they don't want anyone to find out the size of hole they are using.
Anyway, I do this for a couple of reasons, the first is that if there is ever a blockage, I can prick the hole with a jet cleaner, try doing that with a hole underneath. The other reason is, that if I do make a batch of engines (the lubers vary from batch to batch on the design shape and size) I can start with a smaller hole, and if it needs it, can be opened up to a size bigger. BTW, you can buy some lubers that have an adjusting needle to control the flow, to me just something else to go wrong, by itchy fingers playing with it.

There are basically two levels that your luber needs to be filled to, depending if the hole is on top or underneath. If the hole is underneath, you should fill the luber to the top of the cross pipe, if the hole is on the top, fill it with oil to about 1/16" above the hole. The reason for this is that when you screw the top on, it will force a small quantity of oil into the steam pipe, so that on start up the engine gets a charge of oil almost straight away, and this initial charge will reduce the wear damage until the luber starts to work and feeds the engine by itself.

John

[kno3]

John, which one is the Puffin engine with good quality castings, do you happen to have a picture?

[bogstandard]

Kno3,

The dark blue one is the old style of Puffin. The other one has nothing to do with it.



In the 80's or early 90's they were available as a set of castings to make your own. They called it a different engine name when purchased as castings. Maybe someone with a better memory than me can remember.

I purchased mine ready built from Bruce Engineering.

The only weak point of the early engines was the phos bronze springs that put the tension onto the port faces. There was a later upgrade that changed them to stainless springs, and that cured all the problems.

John

[Roger in France]

John,

What please is an "investment casting"?

Roger in France.

[bogstandard]

Hi Roger,

Investment casting is basically another name for lost wax casting.
In this process a very fine mould is used to produce a wax replica of what needs to be made, or the wax can be carved to very complicated shapes. The wax replicas can be formed or joined onto a wax sprue, like plastic construction kits (I used to work for Rolls Royce Motors, and they used to cast Spirit of Ectsacy in sprues of 6 or 8 out of stainless). The wax bits can then be cleaned up very easily to get rid of any joint lines caused by the moulding process. This is then covered in a ceramic slip which is built up over several layers and allowed to dry. So forming a ceramic shell full of wax.

This shell is then warmed up and the wax poured out.

So, if you then pour molten metal into the ceramic mould, you end up with a perfect replica (but minutely smaller because of contraction rates of different metals) of the wax part. The outer ceramic shell is then broken away from the cast part.
The advantage of this process is that once you have the mould made for making the wax bits, you can make as many as you want, and with this system the items being made are perfect replicas, unlike where sand casting is done, where very fine detail cannot be obtained, and is reliant on the caster to get everything lined up perfectly.

I think Prop Shop must make his props this way. Melting wax blades onto a wax boss, so any number of blades onto almost any size and shape of boss. So when he says it will take a while to make some, it might be a few days before he is even ready to cast the prop. Then it will need machining to your specs, then a final polish. Not a job to be done in a few hours.

A deeper insight is shown here.

http://en.wikipedia.org/wiki/Investment_casting

I hope this little expanation has cleared things up a bit.

John

[Roger in France]

Thanks, John.

Not a name I had ever heard before. A peculiar use of words!

The process you describe is well known to me as "the lost wax process" which is rather more descriptive. It is so called in the art world where it is used to make castings, just as you describe.

Thanks,

Roger in France.

[kno3]

John, thanks for the picture and explanation. I have seen that kind of engine before, but didn't know what it was. Was it also made as a single-cylinder unit? I have a Cheddar Compact with a single cylinder engine made from cast parts. Until now I assumed it was a Stuart, as it wasn't similar to the Cheddar engines I have seen (which had no cast base). But it could be an earlier version.

[Proteus]

I think you have a pipit the compact was a twin.

Proteus

[bogstandard]

I can't be absolutely sure, but the casting kit name might have been called the 'Isis'.
I do know that they were priced at around £38 for the twin cylinder kit in the mid to late 80's, when I first saw them at model engineering shows.

When I bought my Cheddar Puffin Vertical Deluxe set in the late 80's (wood lagging, refillable gas tank etc), it cost me just over £400, and I still have a good engine and gas tank, plus a so so boiler that could be used if it was given a good clean out. To me a rather good investment for the pleasure it has given me. Unfortunately, they will never be used again, I cannot handle model boats any more, so they have retired into my collection, of mainly 'home mades'.

The early Puffins, in my mind were the first 'commercial' plants that took model steam plants from the 'simple playing at it' or the 'expensive big boys toys' into the realms of affordability, and you got a good, well designed, long lasting plant. Unlike nowadays, where it seems to have taken a backwards step with regards to quality and cost.

BTW the continentals are now catching up fast, and are producing some very nice and well made steam plants at very reasonable costs.

Or do as I do, if you can, make your own, great satisfaction in it.

John

[Proteus]

this may help.

Proteus,

[bogstandard]

Thanks for that Proteus,

Looks like my memory isn't all that bad after all.

Now I think we should stop sidetracking this post, otherwise we will have admin on our tails.

John

[kno3]

Thanks a lot, I've added pictures of my steam plant to this topic:
http://www.modelboatmayhem.co.uk/forum/index.php?topic=13094.0
Please reply there because this one is for something else, it was my mistake to ask the question here.

[ashgarth]

Hi thanks a lot to BOGSTANDARD my friend made me an oiler to your plans fitted it today ran beautifully very smooth.The best part is my friend has got an intrest in his lathe again and has started to make a small twin cylinder engine thanks a lot John.