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How much steam ?
david_p (9 posts) , 225 days ago 15:14 09 October 2011
A question for those of you with fleets of locos. How much steam should exit the chimney (passing through the cylinders) ? I have one loco which emits barely as whisp even at full speed and my other is more akin to a kettle boiling before it starts to move off from rest. I think that one's getting worse, but I would like to understand the "normal" range before I start worrying.
A supplemental question - is it possible for the steam to bypass the cylinders and still exit the chimney without doing any useful work ?
Many thanks.OOLiveSteamClub (51 posts) , 225 days ago 20:16 09 October 2011
It varies massively David. A really efficient loco hardly emits any steam (and will pull 30+ coaches!) and others spew it out of every orifice and struggle with half a dozen. You see more when it's cold hence LS is ideal outdoors on a cool day. This clip was recorded in a very cold workshop. The black background and carefully placed lighting also help the effect.
http://www.youtube.com/watch?v=T9jvfSR8vhU
Ref your second question we are having a "Developments" session at the OO Live Steam Club meeting at Peterborough this coming Saturday with the inventor, Richard Hallam. Why not come along and ask the question yourself?Adrian Campbellrgmichel (69 posts) , 225 days ago 01:46 10 October 2011
Most of my locos emit a steady stream of steam when at full speed, and not much different but less at low speeds. If a loco is stationary but its valve open a bit, I see waste steam bypassing the cylinder seals and the safety valve before it gets moving, then it will calm down. This is why it is best to have the valve closed, when the loco is building steam before a run, otherwise the steam will be wasted. If the special O ring between the top of the safety valve and body is not seated properly, the safety valve steam will escape inside the loco and come out from under the body in significant volumes.
david_p (9 posts) , 224 days ago 10:21 10 October 2011
Thanks for the replies. Unfortunately I have family commitments this weekend and cannot make Peterborough :-(
One other point - the loco loses that much steam (all via the chimney) that even with the heater setting on full it will gradually run slower (with a modest load of 3 or 4 coaches) until you stop to allow pressure to build up again. As climing gradients - forget it.
Agreed, I always allow steam to build with the valve closed and then warm the cylinders with it very slightly open before trying to move off.UpperbyJON (19 posts) , 224 days ago 16:58 10 October 2011
david_p said:
Thanks for the replies. Unfortunately I have family commitments this weekend and cannot make Peterborough :-(
One other point - the loco loses that much steam (all via the chimney) that even with the heater setting on full it will gradually run slower (with a modest load of 3 or 4 coaches) until you stop to allow pressure to build up again. As climing gradients - forget it.
Agreed, I always allow steam to build with the valve closed and then warm the cylinders with it very slightly open before trying to move off.
This sounds very much like my Mallard at the moment.
Steam exits via the chimney but fails to allow loco to drive pistons
This loco has been back to Hornby fir this problem a few times now and never seems any better. So I am biting the bullet and doing it myself
After speaking to Richard Hallam at Doncaster on how to set the timing I am stripping down. cleaning . Rectifying and making improvements
Being electronics by trade and working as Rangerover technician I'm sure I can service these marvellous locos
Jonhttp://livesteam.rectang.com/Forums/Brightstar (666 posts) , 223 days ago 11:33 11 October 2011
Hi All,
You have to remember that like the full scale model (12" to 1 foot) each live steam locomotive has individual characteristics. You need hands on control to master these characteristics, some will be better steamers than others, but once you have learned pecularities of each engine, you will beable to judge how much steam to use.
Good steaming!UpperbyJON (19 posts) , 223 days ago 15:12 11 October 2011
I have just picked up my second Mallard set for a very good price. This loco heats up well. Very controllable at all speeds and ouses steam out of the chimney but has plenty of power and even gives a nice whisper from the pistons just like the real thing . The complete opposite to my original mallard I got when live steam first came out
Some live steamers are just like the real things and are poor steamers
I have just stripped my original down cleaned and replaced parts. And set the timing just need to finish assembling it to test
Jonhttp://livesteam.rectang.com/Forums/david_p (9 posts) , 223 days ago 15:54 11 October 2011
I will be very interested to hear how your re-built engine performs. I'm also keen to know what you replaced in it and what is original.
I have just two data points to work from. One engine is great - very controllable, bags of power, can move a few inches at a time...and so on. But the other can't climb hills, gradually slows with only a modest load(unless you stop to build up pressure again), much less controllable etc. Hence my original question to understand the normal spread of tolerances and whether this particular engine is outside the normal spread and therefore in need of an overhaul.UpperbyJON (19 posts) , 223 days ago 16:20 11 October 2011
David it sounds very much like the timing is out on that loco.what loco is it ??
Basically if the timing is out the steam is not sent to the pistons at the correct amount and time so basically you only get a fraction of performance . It is still possible for steam to come out of the chimney with the timing out.
Its A bit like old cars If the timing was out you would get a late or early spark with not the right amount of fuel air to mixture thus giving poor running and possible pops from the exhaust.
The timing on these is not to bad to set as long as your confident and patient.
The piston should be in the fully extended position and the needle in the reversal unit in the right place
If you need more assistance feel free to contact me
Thanks
Jonhttp://livesteam.rectang.com/Forums/david_p (9 posts) , 223 days ago 21:38 11 October 2011
Hi Jon,
It's an A4 "Golden Fleece". I must admit to not really understanding the timing mechanism properly, but I still have a set of feeler gauges somewhere and know what to do with a contact breaker. I would be happy to give it a go with some suitable guidance.
Is this a common problem ? Perhaps something for a "Repair & Maintenance" CD ?
David
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