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Author Topic: A Beginners Guide to Steam  (Read 149662 times)

vintagent

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Re: A Beginners Guide to Steam
« Reply #50 on: June 05, 2010, 05:04:36 pm »

I said there would always be an element of the showing off about it. I did not aim the comment at you BB or anyone else.  I DID say "fair enough" if you read it, but my main point was that about forums becoming oracles which books once were.  And so people not in the know might expect to find it all on line.
By scoffing at them and telling them to read books they'll claim they have no time to source and also insulting their intelligence by saying they haven't even o level physics, you WILL put them off.
Now I don't actually spend time worrying about that, but a lot of more committed members of the "movement", steam or otherwise do and so anything likely to drive the raw beginner away is to be discouraged.  Your general attitude is one. " Read me or I'm off", type of thing for example.

My comments about the simpler plants available or makeable with limited equipment were all part of an encouragement into steam, but at a more affordable level than shelling out hundreds on proprietary gas powered, reversing blah, blah installed according to one missive in a model boat magazine.

I have a lot of books and delight in reading them and have designed a vee twin without help.  I shall also use an old design for a spirit fired boiler to use on my local waters.  It will be as the Mamod or Willesco or SEL, because they are what I know and what need no accreditation from a distant boat club.  The basic designs came from an old friend who did his seven years with the Southern Railway and as a steam enginerr had no peers.  he was a major member of the Gauge One Model Railway Society and designed and ran many a fine model, coal and spirit, gas not being around as such at that time.
Of course, I would be as fascinated as the next man to see any of these shiny bought -in palnts at work, just not prepared to pay the prices (except for Maccsteam as I have already indicated)  When I bought the castings for my Stuart Triple a good few years ago, they cost me 64 guineas delivered to my bedsit.

Regards,
Vintagent
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knoby

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Re: A Beginners Guide to Steam
« Reply #51 on: June 05, 2010, 05:08:41 pm »

Hi all, I have dabbled with steam over the years but by no means am I an expert or anywhere near that level. I thank BB for starting this thread & have found it informative so far. I have no engineering facilities & limited engineering skills, so have to rely on ready made parts which I use or modify as required.  I personally learnt what i know from other people, reading up on the subject & trial & error.

Usual beginners questions seem to be i have this hull what steam plant will work in it? or I have this engine what boiler do I need? Whilst they are valid questions, unless someone has experience of that exact installation, there isn't really any definitive answers. i cant think of a single instance where a modeller has installed a steam plant & not continued to modify or change things to overcome problems or improve the performance. Steam really isn't a 'plug & play ' type of propulsion & if thats not your type of thing, then maybe its not for you.

Please don't think I'm trying to put people off trying it, for a first steam model it may be best to copy an existing boat & plant installation, which should eliminate many of the problems. personally my enjoyment of steam  comes from learning to understand my steam plant & work it more efficiently.

Perhaps some of the steam modellers could post details of their models, types of plant installed & a brief description of why they chose that particular route to give an idea of the thinking behind it.

As for it being expensive, well yes a steam engine is always going to cost more than a 540 motor, simply because of the design & engineering that goes in to it, but do you get value for money? thats the real question. Having been reading nicks thread on the development of the new v twin I think you get a masterful piece of equipment at a very reasonable price.

I hope Bunkerbarge  keeps this thread up, its really good to encourage more steam models, the help & advice is second to none on this forum * I thank all who have helped me over the last few years.

cheers Glenn.

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gondolier88

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Re: A Beginners Guide to Steam
« Reply #52 on: June 05, 2010, 10:35:28 pm »

Right,

As promised, even if people do find it hard to pick out the points they need from a thread, I’m going to forge ahead with simple steam postings.

After explaining the principles of boiling water and getting the most from it I think an explanation of different boiler types and their relative advantages and disadvantages-

Following on from explaining that heating surfaces and boiler shapes are the most effective means of controlling the boiling water.

I will explain using examples both full size and model- the principles are EXACTLY the same.

First-

Pot boilers

These are simply a kettle with no lid and have a steam take off, usually permanent (no isolation valve) and run at very low pressures.

Usually they are fired by spirit, or in mo re recent years fuel tablets. They are lots of fun, very simple, very safe, pretty much impossible to get wrong and are as reliable as any highly engineered engine. For many, me included, pot boilers and simple engines were the way into the hobby.

Here is an example of a model pot boiler-

(Cant get it to post here- at end of post)

This a Mamod type boiler- the three connections are from the front- water filler cap, safety valve and steam take off.
These boilers are very inefficient, fuel hungry and poor steamers- BUT- they work, and well too. Water goes in- ¾ up the gauge glass (the sight glass in the brass casing on the end plate of the boiler), the fuel is lit and placed under the boiler and once steam is raised in a matter of seconds it starts to drive the engine- normally an oscillating engine (an engine that has no valve gear (the means by which steam admission to the cylinders is controlled) and the cylinders move on a pivot to negate the need for a connecting rod and giving ultimate simplicity)

These boilers can, and have been used in model boats, model buses, cars and fire engines and modified to power all manner of miniature vehicles, mill scenarios and steam workshops.

If you don’t know about steam look on any internet auction site for an example, your local newspaper ad’s, local toy auctions etc- anywhere really, or even buy a new one, they aren’t all that expensive- you will learn far more by having one of these fascinating and endearing hissing and fizzing little beasts than you ever will from any book.

Have a look here for more details of pot boiler models;

www.forest-classics.co.uk/Mamod.htm

More details to follow.

Greg
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PMK

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Re: A Beginners Guide to Steam
« Reply #53 on: June 05, 2010, 11:39:42 pm »

The servo gets it's signal from the control box, which in turn is activated by the temperature probe on the boiler.  The 'pot' you saw would be the pressure (technically temperature) set point so

Yes, that pretty much describes what I saw on that day, so I reckon you've answered my question. Although, as I said in the previous one, we got sidetracked so I didn't really get to see much else. I wish I could remember the gent's name, but if you were at the show, all I can tell you is that he had his pitch in that hall at the far the right-hand end of the building from where FLJ was standing. I'm certain he had at least three models on display - it may have been four. Nice bloke; answered all my Qs with no quibble, and would probably have answered more if the other chap hadn't come along.
I didn't find such a unit on Stuart Turner's page, but did spot this...

http://www.cornwallmodelboats.co.uk/acatalog/graupner-1966.html

This one differs in that it has a 3-digit readout, whereas the one I saw at the show didn't. Making such a 3-digit beast would be do'able, and still far cheaper than the retail price, but this is where I have to concede, because that valve thingy is waaay over my knowledge of anything steam.
As I said, I'm not muscling-in anyone or such, but merely intrigued as to what is was all about.
Listen, thanks for coming back with the answer.
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frazer heslop

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Re: A Beginners Guide to Steam
« Reply #54 on: June 05, 2010, 11:55:55 pm »

Having built various steam plants over the years with varying degrees of complexity including home built electronic boiler level control and gas attenuator valves I find simple steam plants to be the most enjoyable type  and believe that there is a need for simple concise information so that beginners can begin to understand what is required to build a safe working steam plant .At the end of the day how did most of us start out I know that if was not for the kindness of more experienced modellers and machinists I would never have been in the position of building and designing my own plants. It is up to the individual to seek out the relevant information but at least with help they will know where to look and with guidance hopefully model steam and steam boating should flourish and not die out with this generation.I would like to thank Bunkerbarge for trying to show and encourage people to think about steam.
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HS93 (RIP)

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Re: A Beginners Guide to Steam
« Reply #55 on: June 06, 2010, 12:07:51 am »

Yes, that pretty much describes what I saw on that day, so I reckon you've answered my question. Although, as I said in the previous one, we got sidetracked so I didn't really get to see much else. I wish I could remember the gent's name, but if you were at the show, all I can tell you is that he had his pitch in that hall at the far the right-hand end of the building from where FLJ was standing. I'm certain he had at least three models on display - it may have been four. Nice bloke; answered all my Qs with no quibble, and would probably have answered more if the other chap hadn't come along.
I didn't find such a unit on Stuart Turner's page, but did spot this...

http://www.cornwallmodelboats.co.uk/acatalog/graupner-1966.html

This one differs in that it has a 3-digit readout, whereas the one I saw at the show didn't. Making such a 3-digit beast would be do'able, and still far cheaper than the retail price, but this is where I have to concede, because that valve thingy is waaay over my knowledge of anything steam.
As I said, I'm not muscling-in anyone or such, but merely intrigued as to what is was all about.
Listen, thanks for coming back with the answer.

this is probably similar to what you saw, just gas controle and they work very well.
http://www.stuartmodels.com/accessories.cfm/mainaccess_type/9/the_type/Electronic%20Gas%20Valve

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PMK

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Re: A Beginners Guide to Steam
« Reply #56 on: June 06, 2010, 12:29:26 am »

PeeWee, I think that is indeed it. I suddenly remember that battery holder.
So, just to see if I learnt anything that day, am I right in thinking that...

1) The temperture sensor is connected to the unit?
2) And also a servo?
3) You preset the required temp' with the on-board trimmer...
4) and then, when the temp' is reached, will trigger the servo to operate the valve?

Is there a reason for the unit running from it's own separate battery?
There appears to be 2x servo connectors there. What is the second one for?
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HS93 (RIP)

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Re: A Beginners Guide to Steam
« Reply #57 on: June 06, 2010, 01:33:00 am »

Picture of one, 1234 are for the sensor and battery then the pins are for servo + servo reverse

Peter

PS was that the right tv show the other week ?
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Bunkerbarge

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Re: A Beginners Guide to Steam
« Reply #58 on: June 06, 2010, 03:52:19 am »

PeeWee, I think that is indeed it. I suddenly remember that battery holder.
So, just to see if I learnt anything that day, am I right in thinking that...

1) The temperture sensor is connected to the unit?
2) And also a servo?
3) You preset the required temp' with the on-board trimmer...
4) and then, when the temp' is reached, will trigger the servo to operate the valve?

Is there a reason for the unit running from it's own separate battery?
There appears to be 2x servo connectors there. What is the second one for?


1) The temperature sensor screws into a spare plug in the top of the boiler and connects to two of the terminals in the block.
2) The servo plugs into the servo pins, either way round to reverse the action
3) You preset the desired temp/pressure with the on board pot.
4) When the boiler reaches the desired temp/pressure the unit operates the servo which switches the gas valve over from full flame to pilot flame.

When the boiler pressure drops by about 10 psi the unit operates the servo again which switches the gas valve back over to full flame and the temp/pressure starts to rise again.

The great beauty is that when the model is in the middle of the pond and you are not exactly hammering around the burner turns down and stops wasting gas.  This means your model can stay out longer and you are not relieving pressure with the safety valve and spraying dirty water all over your model.

The unit is supposed to run from a dedicated battery to prevent interference when used in conjunction with an Rx battery.  The instructions also suggest that you attach the micro servo to the valve with a couple of supplied cable ties.  I think this is really naff so I made a much more robust arrangement for my own valve.  I also painted mine blue to match the rest of the boiler fittings.  In the picture you can make out the valve, the micro servo and the control box.
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PMK

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Re: A Beginners Guide to Steam
« Reply #59 on: June 06, 2010, 04:13:16 am »

PS was that the right tv show the other week ?

TV show?
You've lost me.
Rather than mess up the thread, can we take this via PM?

Tnx for the explanation/picture, by the way.
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PMK

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Re: A Beginners Guide to Steam
« Reply #60 on: June 06, 2010, 04:51:06 am »

BB~

Appreciate you coming back with all this info. And apologies if you've had to answer the same questions a millions time already.
Having any linkage other than cable ties makes sense - as too does the the separate battery idea. (Initially I thought the separate batt. was perhaps because of some safety/legal issues or such).
If you don't mind, just one more Q...
When the servo kicks in, does it have to travel at a certain set amount of throw for the valve, or does it only have to travel from full left to full right / vice-versa?
You mentioned that the sensor is screwed into the top of the boiler. Would you have a picture I might see?.. or perhaps point me to where you might have photos already on the forum?
One of my brothers, a heating engineer (plumber to you and I), says that's some of the neatest pipework he's seen. Neat colour blue and all.
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HS93 (RIP)

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Re: A Beginners Guide to Steam
« Reply #61 on: June 06, 2010, 08:13:46 am »

If you think of it as a model carburetor with a slow running valve it move from open to shut BUT still allows it to pass a small amount of gas to maintain the flame, (like tick over) so when it is opens it the flame returns to the pre set max.

Peter

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boatmadman

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Re: A Beginners Guide to Steam
« Reply #62 on: June 06, 2010, 08:41:59 am »

Just a thought on the temperature derived pressure control comments, is there any mileage in using a surface mount temp probe on the boiler shell, below water level and well insulated from the outside?

This would make such a unit an option for many people who dont have a spare connection into the boiler.

Ian
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HS93 (RIP)

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Re: A Beginners Guide to Steam
« Reply #63 on: June 06, 2010, 08:46:55 am »

this is a ABC unit it has the same temperature sensor plus a slotted opto on the gauge glass and a dip stick in the water tank clever unit but not made at present.


Peter
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HS93 (RIP)

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Re: A Beginners Guide to Steam
« Reply #64 on: June 06, 2010, 08:59:25 am »

finall bit of controle units that where available, its a engine controle for engines with valve gear that need an extra servo, it allows the forward reverse to be operated off one channel
it works by having a self centering stick (similar to reversable electric boats) as you open the throttle the second servo stays still, then as soon as you come back and pass the centre position the servo flicks on the valve gear and as you start to move the stick further it opens the throttle again so you only need one controle and two channel radio instead of three.
theses where a handy device, but sadly not available just looking for a Pic programmer to make one and his fortune  :D

none of these items are needed to make a engine go and I would say to anyone if you are new to steam get a basic plant , no extra valves and gizmo's and just run it for a time you will learn a lot more, then if you want start adding extras if you think you need them , the more you have the more that can go wrong.
ill take a few pictures later of the same type of units installed in my boats (when someone gets them off the shelf for me)

Peter
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vintagent

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Re: A Beginners Guide to Steam
« Reply #65 on: June 06, 2010, 10:48:03 am »

Thankyou, Gerald, for the "other" viewpoint.
Somewhere I have one or two of those books.

I'll look up the others.
Once people start that way they can always move up to the more complex stuff, either ready to run or to make themselves.

Regards,
Vintagent
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flashtwo

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Re: A Beginners Guide to Steam
« Reply #66 on: June 06, 2010, 10:49:27 am »

Hi Peter,

I built a PIC version of your description for my flash steam boat "Vital Byte" (see other threads).  The method was as you described with one radio channel representing astern-neutral-ahead and also the throttle position.

There was no problem with the PIC unit, but the flash boiler was directly connected to the engine without the usual throttle valve with the "throttle" signal being used to set the electric feed pump output to the boiler which, for a flash boiler, quite quickly alters the steam output to the engine.

I found in practice that, having found a good throttle/feed flow setting, that, on changing direction, I would loose the exact position on the transmitter throttle stick that I preferred.

In the end I used a separate channel for setting the feed flow ( and normally left the preferred setting) and used the throttle stick just for astern-neutral-ahead. I still retained the PIC in the circuit because I could precisely set the reversing gear linkage independently of the transmitter stick. The stick just had to move 20%, or so, away from the centre position to change direction.

I was using a Robbe F14 with the navy stick, but with the Futaba 6EX I am no longer using the PIC circuit since the transmitter can be set more precisely.

I would think my circuit would work well with a conventional throttle.

As regards the earlier comment about locating the temperature sensor on the outside  of the boiler, I would suggest putting it above the water level  to measure the steam temperature which is the temperature that directly relates to pressure. As long as it has good thermal contact (try using the thermal paste that Maplin sells for heat sinks) with the copper and is well insulated it should work just as well.


Ian.
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Bunkerbarge

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Re: A Beginners Guide to Steam
« Reply #67 on: June 06, 2010, 11:43:27 am »

I think the biggest problem with the sensor mounted outside the boiler is a serious lag as you have to wait for the shell temperature to change rather than just the steam itself.  I stongly suspect the shell temperature actually varies very little so would not produce a useable signal for the unit.  There are usually spare plugs on the shell but if not you may have to connect some other items on a manifold to free one up.

I've attached a picture of the probe in the top of a Hemmens Ribbersdale.  I manufactured a fitting to enable me to combine the safety valve and the isolation valve but most vertical boilers have a couple of spare plugs.
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vintagent

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Re: A Beginners Guide to Steam
« Reply #68 on: June 07, 2010, 11:45:17 am »

Gondolier, many thanks for the descriptions of the simpler end of things.  I think this thread should, perhaps, be split, so that the really simple end isn't mixed with the more complex stuff being described by PMK, BB, et al.
Such as the Beginners' Guide and the Intermediate Guide maybe?

Regards,
Vintagent
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gondolier88

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Re: A Beginners Guide to Steam
« Reply #69 on: June 07, 2010, 06:46:22 pm »

Thanks Vint', at least someone wants the simple things explaining!!!! %)

Greg
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vintagent

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Re: A Beginners Guide to Steam
« Reply #70 on: June 07, 2010, 07:23:32 pm »

Just a suggestion, to start with, so we can build up to all the gassy, sensoring, pooterised boiling systems later!

Regards,
Vintagent
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PMK

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Re: A Beginners Guide to Steam
« Reply #71 on: June 08, 2010, 03:50:12 am »

"...so that the really simple end isn't mixed with the more complex stuff being described by PMK, BB, et al."

No, no - please don't run away with the idea that I know what I'm talking about. My knowledge of anything steam is, to say the least, somewhat thin on the ground and I'm only treading these boards in the hope of seeing what other snippets of info. I might learn from the more knowledgable ones.
BB and HS93 have both answered all my Qs adaquately (thank you, chaps), but (as you can probably make out), I am still very much in the dark as you.
'Twixt you, I and the gatepost, I was quite taken with Flashtwo's gizmo (see his previous threads) which triggered all the interest again. Apart from that, just about everything I know about steam can so far probably be written on the reverse of a postage stamp.
Hopefully all that will change if the steam boys keep writing these articles.
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barryfoote

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Re: A Beginners Guide to Steam
« Reply #72 on: June 08, 2010, 07:58:50 am »

I really am sorry about this guys, but I think the problem lies in the thread title. "Beginners Guide". Whilst full of very useful information, it is NOT a guide for beginners and as such can do no more than put aspiring steam "doers" off!!

A beginner really does need step by step instructions, not separate bits in varying order, scattered about a thread. I do hope you experts understand. What can be done about it, I do not know, but as I have said earlier, the title simply is not right..
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MichaelK

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Re: A Beginners Guide to Steam
« Reply #73 on: June 08, 2010, 08:45:34 am »

Hi Folks, I'm just starting to build my 1st steam powered boat, (and 2nd boat ever)  %%
I personally think this is a brilliant thread. Enough of the simple stuff, and enough experience from many steamers to keep me going onwards. I now know to keep it simple to start with(engine, boiler, burner, gas tank) I'm sure these will keep me busy for a while. Then retrofit all the bells and whistles as I make the mistakes.
Thank you
Mick
 :-))
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vintagent

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Re: A Beginners Guide to Steam
« Reply #74 on: June 08, 2010, 09:04:25 am »

Well, there in a nutshell, eh?  Forums!  One's OK with it, one isn't happy, others are ambivolent.

Still think it could be split in two for easier introduction to new viewers of the topic to choose between, but I wouldn't want to put anyone off of reading anything that's here.  I've just been sifting through the posts and reading the ones that are relevant to me.  If I see "gas" or any proprietary names I pass by.

Maybe that's best, but above all, please don't anyone stop posting.

Oh, did anyone see my question about displacement lubricators?  Size, location, detail?

Regards
Vintagent
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