Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: BarryM on October 10, 2007, 04:17:02 pm
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I'm attracted to the TVR1A engine found both here http://www.theengineshop.net and here http://www.grahamind.com . Two things hold me back from declaring Merry Christmas to me and here's your present. The first is the price - if something seems too good to be true, then perhaps it is - and the second is the Hackworth gear of which I have no experience, does it have any particular pros and cons?
Thus can any steam nut advise if they have any experience of this model good or bad and also views on the Hackworth valve gear?
Thanks in advance.
Barry M
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Just curious, it seems a very reasonable price but what do all the other bits cost ? ie boiler etc. :-\
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Have a look under live steam on http://www.paddleducks.co.uk/ there is a chap who has just built one ,, Cheddar where agents for them when they where going , they are a good engine for the price , just make sure you get a boiler that is man enough to run it , they run fine.
peter
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Peter,
Thanks for the reassurance. I can take this one forward with more confidence now.
Barry M
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One thing to think about with a slide valve engine such as this is that the reversing gear could well require another channel. You will need one to control the speed and one to change the direction of rotation.
Not knowing just how this hackworth gear works it can only be an added complexity and therefore be potentially something to go wrong. I do know that the reversing gear used on Stuart engines can be a bit of a challenge to get set up to work reliably with a servo.
I tend to think that for RC use simplicity is a big advantage so I would tend to go for a twin, double acting, oscillator wherever possible. These have less moving parts to go wrong and the engine can be controlled entirely by one channel. I would try to get a bit more information about the reversing gear if possible and preferably some feedback from someone who has owned or operated one of these engines.
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Barry if you only have two channel look about on e-bay there have been a few of the cheddar units sold that allow two channel radio to be used with three servos I got another not long ago, there is a wright up on the same site about the valve gear. think about buying the optional flywheel at the price of the engine they have never been so cheap with the pound Dollar.
Peter
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Gents,
Thanks for all your replies.
This engine will certainly need seperate servos for direction and throttle but as I have six available that's not a problem. I'm swayed towards the piston valve engine because of the greater challenge in construction (I get 2/3rds of my modelling satisfation from building) and the potential for increased output. The final result will be fitted in the next project which will be a steam yacht of 4' 4" LOA. Having said all that, I'm open to all advice and info from anyone, especially those who have built this engine and matched it to a boiler.
Some info on Hackworth gear here http://en.wikipedia.org/wiki/Valve_gear.
Thanks again
Barry M
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It's true as Peter said, that Cheddar used to sell these engines as a cheaper alternative to their Gemini and Proteus, but the bit he left out was they didn't sell very many of them, and gave up after a few months. As far as I can remember, the problems were twofold, unsuitable metals were used for some parts, aluminium connecting links I think, with the result that they wore out very rapidly, and Cheddar had problems obtaining replacements for these worn items from the American manufacturers. I remember asking John Woodroofe what he thought of them, and his reply was something along the lines of, "They aren't too bad at the price, but as with most things in life, you get what you pay for". Of course, all this happened a few years ago, and I'd be surprised if the same problems still affected current engines. I doubt if many of them were sold here, and I've never seen a single example outside Cheddar's showroom. If I were you, I'd try Googling US sites for some user feedback, I have one or two useful contacts over there, I'll e-mail one of them and let you know if he comes up with anything useful.
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Thanks Kayem
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Yes I agree with Kayem , But they where only a third the price of the Cheddar engine. and It depended on the day you spoke to John one visit they where the best thing since sliced bread and a month or two later they where not , I have seen two people who had them but only one in steam, they need a boiler similar to a Proteus , also if you look on the web site they seem to have changed some of the parts from what I remember and have gone CNC for a lot more of the parts, its a bit like the Avon steam engine i have only seen one of them and they need a lot of steam.
Peter
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Beware piston valves if materials are suspect, Slide valves are easy to re-lap,
Piston valves have to be RE-BORED.
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Sorry - my error - TVR1A uses slide valves not piston valves. Assembly manual here http://www.grahamind.com/TVR1ABook.pdf is very informative.
Barry M
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Having looked at this engine, it does look like it is made for the American market where sometimes the totally wrong materials are used in its construction, and are designed for display models only, that run on compressed air.
You only have to look at the 'extras', hex head bolt set?. If it was designed for working hard it would have such items as standard.
I know people have built these for model boat work, but I personally think it will be like juggling a handful of worms.
With reference to the piston valve, these usually work off just two channels, one for rudder, one for engine for speed and fwd/rev. Really the advantage over a good twin cylinder oscillator is negligeable, in fact sometimes the oscillator is a better choice because of the friction incurred by the valve operating gear, plus the oscillator is usually a much smaller package.
I have designed and built a piston valve engine on Paddleducks, geared towards a beginner to build, and if you wanted to build one the whole article is put into PDF format for downloading, if you are into making one try that, all it would require is a good 3.5 inch boiler, but it is physically a large engine but would have no trouble pushing your boat along, and looks great.
Here it is just after I got it running.
http://www.youtube.com/watch?v=gTuET23TkaI
John
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John,
That has to be one of the nicest looking engines I have seen. I'll send you a pm.
Regards
Barry M
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On those TVR1A steam engines, I've had a reply from my friend Steve in the US, who I was pretty sure owned at least one of them, so I'm sure you'll find these comments interesting. Steve is President of NASMA, which is the North American Steamboat Modeller's Association, he has a lot of experience and knows what he's talking about, and he's also in regular contact with a lot of other steam enthusiasts, so if he says that the engine is basically OK, that's good enough for me.
....I do have some experience with the Graham TVR1A, and know
others who have this engine as well, and most of what I can say
about it is quite positive. I have run mine (in your Royal Navy
Pinnace hull, in fact) for years with no problems with wear.
True, there are some aluminum linkages, but with a generous
application of oil before a run, they seem to do just fine. Also,
aluminum-on-brass seems to do better than brass-on-brass in terms of wear.
The only problems I have heard about from others stem from kits that
were not carefully fitted together and as a result a lot of binding resulted.
The price seems very fair for what you get, although I have heard that
the manufacturer is not the best regarding customer service,which
might be one reason Cheddar dropped them. I do like mine, however.
To make all of you jealous, Steve also owns a full-size steam launch, it's a replica of a launch built around 1900, but as it contains no nasties like 107 year old wood etc, it's a much more practical proposition than something really authentic would be, it's a pretty little thing, and vaguely similar to Bat from the Windermere Museum. The steam plant is also new of course, it's wood burning, and Steve tells me that once pressure is up, it's as easy to operate as any modern small outboard. I'll see if I can find a few pics to make you even more envious.
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Found it, this is Mrs Steve enjoying a steam-powered sail on the River Hudson in upstate New York.
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Kayem,
Thanks for your research which is really above and beyond the call of duty! I am now mulling over the pleasure I'll get making my own engine but with the drawback of having to spend money on a vertical slide for my lathe versus obtaining a kit from the USA with all the problems that distance brings. By the way, do you know if Cheddar got their kits from The Engine Shop or Graham Industries, both of whom sell the TVR1A?
Thanks again
Barry M
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I'm building an Envoy class tug with a TVR1A steam engine, after assembling the unit I ran it in for a good two hours on compressed air. During this period you need to give it loads of oil (it was every where). I have since added small oil cups to the crank bearings. The boiler, refillable gas tank, steam valve and lubricator along with a lot of valuable information, were all obtained from Sandy Campbell at ACS Engineering. I have now run this unit on steam for about twenty Min's (one boiler full) with no problems.
The hackworth valve system gives me no problems as I use a Sky Sport Six transmiter (40meg), I use the gear switch to reverse the engine.
The tug has not sailed yet as I am now putting the finishing touches, some electronic gizmo's from action electronics to control flashing mast top nav lights (slow on slow of flash), wheel house and engine room lights, along with some other lights to show though lower deck port holes and an electronic steam horn (cheaper than steam and easy). Will keep you updated if you require.
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Having seen and read though (many times!) John Bogstandard's design on Puddleducks I've decided to go down the DIY route. At least then I've nobody but myself to blame. Along with a scratch-built 4'-3" hull (another plank on frame or do I try my first fibre glass hull) I think this is going to be a long term project.
Thanks again to all those who have provided info.
Barry M
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Hi Barry,
So you have decided to go with my design.
I hoped you noticed in the build description how a lot of the problems were easily overcome, like the crankshaft and eccentric, these are the two most offputting things when building an engine from scratch, but if they are made as I describe they are easily made.
I built two engines in two months from scrap materials from the scrapyard and the most expensive bits were the stainless cap screws and I think the total cost comes to about £10 for each engine inclusive of all taxes. If you had to build from purchased material maybe £40-£50, but you would most probably have enough material left over to build another one.
If you have any problems just PM me and I should be able to sort things out for you. I do have a few of the o-rings left if you get stuck.
John
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I'm building an Envoy class tug with a TVR1A steam engine, after assembling the unit I ran it in for a good two hours on compressed air. During this period you need to give it loads of oil (it was every where). I have since added small oil cups to the crank bearings. The boiler, refillable gas tank, steam valve and lubricator along with a lot of valuable information, were all obtained from Sandy Campbell at ACS Engineering. I have now run this unit on steam for about twenty Min's (one boiler full) with no problems.
The hackworth valve system gives me no problems as I use a Sky Sport Six transmiter (40meg), I use the gear switch to reverse the engine.
The tug has not sailed yet as I am now putting the finishing touches, some electronic gizmo's from action electronics to control flashing mast top nav lights (slow on slow of flash), wheel house and engine room lights, along with some other lights to show though lower deck port holes and an electronic steam horn (cheaper than steam and easy). Will keep you updated if you require.
That sounds like an interesting project. I am hoping soon to upgrade my Enigma from electric propulsion to a steam plant so I am soon to be faced with the problems of a retro-fit. I am not sure yet how to arrange the compontents and make them all removeable so I would be interested to see any pictures of your installation.
My preferred option would be a single try with everything on but I don't know if that is going to then be capable of sliding through the main access below the bridge unit.
I'll post a couple of mine under electric power later and maybe you can post me some of your own layout.
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As promised.
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:)If you are still interested in the TVR1A engine watch this space as I have had some experience.
john hemmens O0
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Hello from Denmark
i have 3---------2 cylinder from Graham usa..made with hex bolt ...and 2--1 cylinder...here is a link where you can se them work...allso a wery nice engine from France..Anton...and ..my lLady Jane from Hemmens,,,,,,,,,,,The Tvr1a...is a great looking engine --and run great to....the size is good ,,,bot ..it can take more than 30 psi,,,,and ..rember to use a lot off steam oil...it is not a workhose...there will go on and on fore years...........My engines whas from the Engine shop usa..and they made them ready to run fore me...
regards Bernhard
http://www.youtube.com/watch?v=CICE-XgTszA&feature=user
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hi......some photos off the ones i have
regards Bernhard
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I'm building an Envoy class tug with a TVR1A steam engine, after assembling the unit I ran it in for a good two hours on compressed air. During this period you need to give it loads of oil (it was every where). I have since added small oil cups to the crank bearings. The boiler, refillable gas tank, steam valve and lubricator along with a lot of valuable information, were all obtained from Sandy Campbell at ACS Engineering. I have now run this unit on steam for about twenty Min's (one boiler full) with no problems.
The hackworth valve system gives me no problems as I use a Sky Sport Six transmiter (40meg), I use the gear switch to reverse the engine.
The tug has not sailed yet as I am now putting the finishing touches, some electronic gizmo's from action electronics to control flashing mast top nav lights (slow on slow of flash), wheel house and engine room lights, along with some other lights to show though lower deck port holes and an electronic steam horn (cheaper than steam and easy). Will keep you updated if you require.
Hello! I'm new here and will be building a Graham TVR1A from a kit too. I was wondering how you added the oil cups to the crank bearings?
Do you have any pictures? Are these cups custom made of available for sale?