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Post by dewintondave on May 22, 2008 10:35:41 GMT
I've done it again. We had been disappointed with Albus’ steaming on the last run. There's a bit of a leak at the whistle valve but nothing too much. Yesterday a new exhaust nozzle was silver soldered on. We reduced the exhaust nozzle from 1/16” down to 0.9 mm diameter. The gap between the bottom of the boiler flue and the nozzle tip was also extended a little too. We ran the loco this evening in the dark, which is great for observing the meths flames. Albus is the quickest to raise steam. I filled the boiler half-full so that steam would be raised quickly, then used the blower to raise the pressure and add more water until the boiler was full. When the blower was on, a 3 inch flame was visible from the top of the funnel, before I turned it right down! What an improvement the new exhaust nozzle has made. We were just running the loco on a short track, and I could put five pumps of water in at each end of the run without denting the boiler pressure. The nozzle is probably a bit too small, in that it is a little too effective, commonly there was a flame of about 2 inches above the funnel when running moderately. The sound from the exhaust is great as each beat ruffles the flames. When running really slowly, the flame from the funnel alternated with each exhaust pulse. This loco is now such a strong steamer that it blows off a lot and the water consumption is going to be even higher than before. We also noted that there was no more gurgling condensate in the exhaust, nor condensate shooting up the funnel into the air while running. In forward this was particularly the case. Due to increased back-pressure, more exhaust is coming out of the port block drain, which looks great in the cold air. Even in reverse, where the drain is shut off, condensate is hardly present at all. We also acted on an earlier sugestion; and inserted a piece of 8 thou shim between the boiler and the motor mount, as there was a small gap. This is to increase the warming of the motor. The whistle valve was leaking continually during the trials, and much sounding of the whistle was done too.! Dave.     |
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Post by dewintondave on May 25, 2008 7:20:07 GMT
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paul
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Post by paul on May 26, 2008 8:50:16 GMT
Great pics and 'music' Dave, you're making me want one of these  Now some daft questions from someone who knows nothing about these things: Where is the exhaust exactly? How fast does the engine move and do you have to chase after it to adjust the speed? Does it run at a constant speed once the regulator is set? What's the absolute minimum size of a simple circuit to run it on? What will it pull? |
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Post by dewintondave on May 27, 2008 7:41:53 GMT
That's it Paul you must make one! Plans for Dave Watkins' "Idris", on which this loco is based, are available from his website: www.davewatkins.pwp.blueyonder.co.uk/steam.htmThe exhaust is directly below the central boiler flue. I always try to run the loco as slowly as possible, reducing the regulator on the straight sections. The wheels are only about 1" diameter so it doesn't go too fast. 4 beats on the exhaust equals about 3" of progress along the track. No, this loco needs driving. This loco is not a set and forget loco. Loco's # 2 & 3 are more so though. The loco can negiotiate an R1 circle. The sound tracks were recorded with the loco hauling 4 open LGB trucks plus a covered van at the back. There was a load in the trucks too. I think this is a reasonable limit for the loco on my track. Dave. |
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paul
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Post by paul on May 27, 2008 16:42:12 GMT
Thanks Dave - but what would the diameter of a R1 track circle be, just roughly? I'm waiting 'til modeng2000 finishes his so I get to see all the difficult bits in advance - sorry John |
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Post by modeng2000 on May 27, 2008 18:29:40 GMT
Paul, if you read my new post about burner problems you will see that it might be a while yet.  Perhaps Dave has the right idea by using a meths burner. John |
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Post by dewintondave on May 28, 2008 8:13:48 GMT
An R1 circle is about 4 foot diameter. In my opinion Meths is the way to go. On an internally fired boiler, when the loco is stationary the fire is small, and when the loco is moving the fire is large, hopefully matching the steam requirements. There's no adjustments to make, and no sound. The tank can be topped up while the loco is steaming along too  Dave. |
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Post by mackintosh on May 28, 2008 8:59:46 GMT
Hello All Hope this is of interest to you De Winton aficionados at a resent garden railway open week end I had the privilege to meet Dave Watkins (that's him in the straw hat). The photo shows IDRIS (in black) and my unfinished effort next to it. Of course this gave me the opportunity to bombard the poor man with questions. Since the picture was taken at the beginning of May mine is now running but still not painted. "(sorry but it runs on gas and 32mm track)"  |
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Post by dewintondave on May 28, 2008 11:13:25 GMT
Good work Mackintosh! Your loco looks excellent. How does it run?
Dave Watkins' IDRIS is gas fired too isn't it?
Dave.
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Post by mackintosh on May 28, 2008 14:34:49 GMT
Hello Dave it does now run well. I had a few teething problems the odd small steam leak on the gauge glass and a very severe acting regulator. But having increased the length of the taper it now is quite flexible. My only disappointment is with the length of time the gas lasts around 12 minuets and that equates to 7 minuets running unless I get steam up and then refill the tank. Thanks for your kind comments and I do like the idea of pushing the exhaust up from the bottom through the boiler. Yes Dave's is gas fired and his ran for 20 minuets the only difference between the two are the end caps in the tank mine are solid his are flanged. I have made a few modifications to Dave's design along the way if you are interested I will take some close up shots and post them up.
Bob
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Post by modeng2000 on May 28, 2008 15:43:57 GMT
If I may but in, Your effort looks very good Bob. Congratulations.
I am making slow progress but progress it is so one day I'll be able to post a picture of my finished loco.
John
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paul
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Post by paul on May 28, 2008 16:10:29 GMT
Paul, if you read my new post about burner problems you will see that it might be a while yet. I've been following that one John. There's no rush anyway, I've got a list of simple stationary engine I've got to build first I'm still a bit confused by this gauge business; I read that 16mm to the foot is the 'scale' and that engines can be made to suit 32mm or 45mm track. Presumably 32mm represents narrow gauge and 45mm standard gauge?. I think I've got that right! Is it called 'Gauge 1' because it's a step up from traditional model railway sets, which I think are gauge 0? |
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Post by havoc on May 28, 2008 19:02:47 GMT
Well, there is "scale" and there is "gauge". When you have a prototype of gauge A and want to use track of gauge B, then the scale is expressed as 1:(A/B). So you can have different scales using the same track or the same scale using different track.
Just as an example: standard gauge in 1:32 will run on 45mm track but meter gauge prototype in 1:32 will run on 32mm track. Same for standard gauge and 1:45 runs on 32mm track...
The most common railway model is 1:87 or h0.
Oh, there is a whole complication with the UK not following the "strict" scale factors and then calling it 00 (1:76) but running on the same tracks as h0 (1:87). And then there are the complications of "G" what can be anything between 1:13.7 and 1:32 all running on 45mm tracks. Big can of worms.
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Post by dewintondave on May 29, 2008 6:08:25 GMT
if you are interested I will take some close up shots and post them up. Bob Please post some pictures Bob, I'm interested in hearing what modifications you made too. Dave. |
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Post by mackintosh on May 29, 2008 6:08:34 GMT
John Thanks for the kind words. I have been following your progress here on the board and feel your efforts will be rewarded with a fine loco. Remember time is not important it's what you do with it.
Bob
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