Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: surteanders on September 12, 2008, 10:52:42 am
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Hello!
I was trying to get in contact with Graham industries, but they never answer my mail?
Are they still in business?
Anders.
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hi...............yes,,,,,,,,,,,,,but can be sooo slowwww to replay
regards Bernhard
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Steam power! takes time to get up pressure {-) before results are seen
Sorry just couldn't resist ;D
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He does reply quickly, I emailed him last week, he is away on business this week.
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http://www.grahamind.com/ (http://www.grahamind.com/)
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http://www.grahamind.com/ (http://www.grahamind.com/)
I'd not come across this engine before. Anyone got experience of it in use? It's not a Proteus but it might do for my Wideawake. Pricewise it seems very reasonable b ut is there a reason?
Cheers
Guy
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Thats a nice looking engine, and seems to be very well manufactured, and the price, unbelievable, you can't really go wrong
Tempted myself now O0
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hi.........i have 3 of the 2 cylinders ans 1 .1 cylinder...nice and good looking they are,,,bot not the stronges in the long run,,,bot for that price they are okay..here is a link to 2 off mine
regards Bernhard
http://www.youtube.com/watch?v=CICE-XgTszA
http://www.youtube.com/watch?v=UQlqhgRgz9g
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Hello !
I am planning to power Caldercrafts "Imara" with two TVR1A.
Are they powerful enough?
Planning to use two 75 mm props
Anders.
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hi.........i have 3 of the 2 cylinders ans 1 .1 cylinder...nice and good looking they are,,,bot not the stronges in the long run,,,bot for that price they are okay..here is a link to 2 off mine
regards Bernhard
http://www.youtube.com/watch?v=CICE-XgTszA
http://www.youtube.com/watch?v=UQlqhgRgz9g
Thanks Bernhard. That's useful. I was a little concerned about the mention of machined aluminium parts in the info. Also it'll need a displacement oiler added. That'll add another £20 or so to the cost. Still looks good price-wise compared with other possibles. i also noticed that the forward/reverse lever seems to have a rather long throw. have you had any problem operating it with a servo?
Cheers
Guy
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Guy,
Try searching on TV1A on this forum and you should find the discussion that I started a while back with the same question! Also remember to add postage and tax to the screen price.
Cheers,
Barry M
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Sorry, I meant search on TVR1A
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Sorry, I meant search on TVR1A
Yeah I thought you probably did :)
As you say, useful comments in the previous threads. WRT tax etc. if I buy one, not such a problem. My partner's brother lives in the US so could buy it and send it to me as a "present"! WRT steam control, I imagine that as with Stephenson gear, the forward/reverse might also act as a speed control. Otherwise the usual suspects offer lever operated steam valves, though as you say, it all adds to the cost.
Cheers
Guy
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Guy, which "usual suspects" offer servo operated steam valves for use as a throttle? ACS Engineering used to but they have closed. Searched these forums and came up with quite a list of well reccomended suppliers of steam fittings etc but could not find a throttle valve on any website. I would prefer a rotary disc valve if possible large enough to take 3/16" pipe for a fairly large single cylinder engine similar to a Stuart 10. Thanks, Ian.
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Guy say's
I imagine that as with Stephenson gear, the forward/reverse might also act as a speed control.
Please note.... Neither Stephensons gear, nor the Hackworth gear used by the TVR1a are for the purpose of SPEED control.
Their purpose is to provide a means of adjusting the valve timing (cut-off) to permit better use of STEAM EXPANSION, thus giving better fuel/steam economy and for reversing the direction of engine.
They should be used in conjunction with a steam regulator for correct speed control. (as in full size practice)
O0
AlexC
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HI Alex
Yes I knew/thought/suspected that was the case but also knew/thought/suspected that if the lever is positioned in the middle it effectively stops the engine. In practice, as you say, I'd fit a servo operated steam valve as well. Actually if I was going to machine up the D10 casting set I have, I'd be tempted not to fit the reversing gear kit (which I don't have, and which I gather is fiddly to machine and set up) but to get one of the forward/reverse gearboxes offered by Mainsteam models.
Cheers
Guy
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Kiwi,
RC steam valves can be hard to find, particularly for imperial sizes.
Kramer does a superb metric one, perhaps he's do you a special?
I've bought a couple recently from Polly Engineering in the UK. £16.50
They've been out of stock for a while, not any longer.
http://www.pollymodelengineering.co.uk/
I'm in the UK, and I'd be happy to forward them to you for free if their postage is high.
(assuming you're in NZ, you might not be :)
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Thanks for the offer. I did eventually find a listing in the Bruce Engineering part of their website but without picture or specs of pipe size etc. It is a pity ACS Engineering went out of business as Sandy was extremely helpful and had just the right thing in his stock. I am going to have one more attempt a getting the present system (a tapered needle valve) to work and if not will contact Polly and get back to you if there is any difficulty with posting. I usually get most things sent here without problems. I will also see if anyone else in the club wants to order as the postage on several items is usually not much more. Thanks again, Ian.
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The Polly one is 1/4" 40tpi for 1/8 pipe. not a work of art but would be better than the needle ;)
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Hi Kiwi
Yes, polly/Bruce Engineering was the "usual suspect" that I had in mind.
Cheers
Guy
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Kiwi,
RC steam valves can be hard to find, particularly for imperial sizes.
Kramer does a superb metric one, perhaps he's do you a special?
I've bought a couple recently from Polly Engineering in the UK. £16.50
They've been out of stock for a while, not any longer.
http://www.pollymodelengineering.co.uk/
I'm in the UK, and I'd be happy to forward them to you for free if their postage is high.
(assuming you're in NZ, you might not be :)
Hello Miles- welcome to the fray here!! I too just ordered a steam valve from Polly for use on a Graham engine that I will be putting in my Alexandra...
WW- I think you boat is a tad bit too large for the Graham from my understanding.
The reversing shaft used on the Graham twin can actually be run out the other side of the engine for a much shorter throw.
Here is a picture of that set up
(http://i39.photobucket.com/albums/e199/mogogear/AlexandraGraham2steamandreverse.jpg)
The shaft has been reversed to face the opposite side of the engine that it normally projects from. And it has been shortened. A servoe for F/R and one for the steam valve( an ACS valve shown)
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mogogear,
looking at that installation picture, very tidy I must say, it would appear that the steam control valve is connected up the wrong way round.
The steam inlet from the boiler should go to the TOPmost connection and the engine fed from the LOWER connection.
As shown it looks to be the other way round, which will/can lead to the control disc/cam being lifted from the valve port face, leading to less acurate control of the steam.
If connected the correct way round, the steam pressure, in the top half of the valve, holds the disc/cam against the port face thus ensuring correct operation.
Just an observation.
AlexC O0 O0
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Your observation could be correct- but the picture is not of my boat--it is somebody else's( sorry a web-napped photo :embarrassed:) .. It was a good illustration of the Graham installed with reversing and speed control servo's in place. I just wanted to show the reversing gear linkage...
I do agree that the owner used the most circuitous route for the steam supply line, but since it is reversible, I do not know why steam feed can't be to either side of the engine...?
I may just not be thinking enough..
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Mogogear,
Ok, I was not aware it was not your model.
The connections for steam and exhaust at the engine are correct, and cannot be reversed. This is dictated by the valve gear.
The TVR1 is a slide valve engine and the steam and exhaust must allways remain on the correct sides of the slide valve.
Engine Reversing is a mechanical function of the valve gear not the steam/exhaust direction.
The two connections I was referring to are those on the steam control valve. These should be the other way round and should not be reversed as they are in the picture.
I.E the valve connection shown as coming from the boiler, via the displacement lubricator, should be the outlet to the engine, whilst the one shown going to the engine should be the feed from the boiler/lubricator.
Hope that explains it a bit better.
AlexC ;)
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Ahhh.. there we go mate... on the engine side- my oscillator familiarity kicked as opposed to slide vlave..
I have never seen the one from ACS before and you have explained it well ..Thanks!! There are a couple of us over on the Unofficial Mamod site that are about to embark on using the Graham in some launches and see if we like it. The steam valve has been hard to source( and lack of one was an issue as the reversing mechanism on the Graham has no speed control) and now that Polly has them in stock again, and Spektrum has such a nicely affordable TX =DX5e, 3 channel control concerns are waning.
Thanks again for your observations
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The connections for steam and exhaust at the engine are correct, and cannot be reversed. This is dictated by the valve gear.
The TVR1 is a slide valve engine and the steam and exhaust must allways remain on the correct sides of the slide valve.
Engine Reversing is a mechanical function of the valve gear not the steam/exhaust direction.
...
I might be wrong, but I believe on the TVR1A one could simply disassemble the cylinders and mount them upside-down, thereby moving the exhaust holes to the other side of the engine if desired. Same for the steam chests.
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Just seen this thread and as I got towards the end I thought "Bl***y hell, somebody has stolen my Alexander Steam Launch >>:-( but then a bit farther the poster admitted he'd borrowed it from the web, phew! As some smart-eyed person noticed, the ACS steam throttle WAS upside down and it was after seeing this picture that Andy pointed that out to me. This has all been sorted out now and the whole thing runs as sweet as a nut. I am of the opinion that the Graham engines are incredibly good value for money and can be built up into superb little engine.
Greebo
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Kno3
Whilst it is possible to do what you say, there is absolutely no need.
The TVR1A is symetrical (in that it has the same length crankshaft extension at both ends, and the fywheel, if fitted, can be fitted at either end) so all that will be required is to turn the whole engine through 180 degs. and then fit the Steam and Exhaust manifolds the opposite way round.
(i.e. flip them 180degs)
This could also permit the valve operating levers to be adjacent to each other, rather than on opposite sides.
That said, this was not what I was refering to in my previous statement..... what I was trying to get accross was the fact that you cannot just change the pipe connections over (as you could do with an oscillating engine)..... since this would put the incoming steam on the underside of the slide valve....which would cause it to lift off of the valve port face.
Hope that is now clear. :-)) :-))
Best regards.
AlexC
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That's correct Alex, admission and evacuation ports cannot be switched on a slide valve engine.
as you observed, the Graham, being symmetrical, is pretty flexible regarding the placement of the ports. i believe you can even build two engines as a mirror pair, which is really nice for a twin engine boat.
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Just seen this thread and as I got towards the end I thought "Bl***y hell, somebody has stolen my Alexander Steam Launch >>:-( but then a bit farther the poster admitted he'd borrowed it from the web, phew! As some smart-eyed person noticed, the ACS steam throttle WAS upside down and it was after seeing this picture that Andy pointed that out to me. This has all been sorted out now and the whole thing runs as sweet as a nut. I am of the opinion that the Graham engines are incredibly good value for money and can be built up into superb little engine.
Greebo
Didn't mean to scare you / upset you mate...I picture is worth a thousand words and when I saw your set up ( which is what I am heading towards) It was a great way to illustrate the question!!
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No worries, I'm honoured and pleased to be quoted in that way :-)) especially as this was my first ever attempt at steam power! I did get an awful lot of help from the steam guys on Paddleducks.
Greebo