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Discussion Starter · #1 ·
A few years back I acquired an Aster Alisan Shay. This is a very beautiful model with charming character and wonderful working valve gear. However, it was produced very early in Aster's steam model evolution (1977) and does not have operational refinements of the more recent Asters.


I have struggled to get acceptable performance out of this little engine, but short of leaving the electric fan on the stack, I can't get her to travel more than 50' down the track. I've played with the wicks, fixed leaks, etc, but no dice. My theory is the boiler is so small that the blower drops the pressure too fast and no amount of fire can keep up.

My next step is a complete tear down and re-build, but before going that far, I'd like to know what performance I should expect from this engine? Mine appears to have almost no torque, runs fast or not at all, and as stated earlier, quickly looses boiler pressure when running (blower or no blower) unless the electric fan is left on the stack. This engine has been a neglected project of mine for some time, but now I'd like to get her in shape. Suggestions? Were modifications required to achieve acceptable performance on this engine or should a careful tear down and rebuild be sufficient?

Thanks!

Mark
 

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Mark, these little locos should go like a 'bat out of ****' and I have never seen one yet that doesn't merit that description. It is usually the case that we struggle to keep them from racing away. Encouraging them to get started is not the usual trouble!

Initially I would check that the blower jet and blast pipe are pointing up the center of the chimney and secondly I would check no blockage in the fuel supply. Is oil getting through and does the loco run nicely on a little compressed air?

Do not be tempted to take the engine block to pieces since this was provided as a fully assembled unit in the kit. If it needs work then get a specialist to look at it or return it to Aster.

If you decide to tear it apart then this is a nice model to work on. Have fun.
Andrew
 

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Mark, John Squires and I were running another visitor's Alishan Shay last summer for the first time in many years, and found that all the Andrew said was true - it wanted to go like a bat out of ****, even with a good load of Aster log cars behind it., and proved it by outpacing the Daylight on the other track! I have some video of this beautiful model doing what it does best, I'll try and send a couple to you if you pm me with your e-mail address.

Whinemeal, I'll call John and ask him what the trick was - there certainly WAS a knack to getting ti to run well, but he seemed to have it in spades!

Best

tac
http://www.ovgrs.org/
 

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Mark,
I have the American #7 version.
I must admit that it hasn't been running for a few years, but when I last ran it, it did very well, but I did find that the blower was needed a little when pulling a heavy load otherwise it would loose pressure.
With a 'normal' load it seemed fine.
I think that I managed to get a scale 100 mph out of it once.
I would think that perhaps you may have a problem with not enough space between the smithies boiler and the insulated outer shell.
The shell was lined with an asbestos type insulated blanket which has to be glued in place, and then the boiler proper was slid into place and screwed up tight against the top of the shell.
This would leave a gap underneath, lessening up the sides, for the flames and heat to go.
I would suggest taking of the smokebox front and having a look to make sure that the gap is still there as the old asbestos seemed to go hard and if not well glued down would warp and may cause a blockage.
The other thing that I remember is to make sure that the external gears are meshing perfectly. As built per instructions, it would seem that there was too much side play in the axles and the gears would not mate properly. A few washers on the other side will cure that situation.
This summer, when I have my track built, I must get mine out and see how it runs.
All the best,
David Leech,
Delta, Canada
 

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Discussion Starter · #6 ·
Thanks everyone, and great suggestion David. This is the 1st loco I've had with a Smith's boiler, and as we all know, draft is everything to an alki burner...didn't even think about how the air was supposed to flow - I'll check it out.

Cheers,
Mark
 

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Mark,

About six months ago Chris Scott posted a link to a downloadable version of Henry Greenly's 1903 book on model locomotive design. In his book Greenly discusses in detail the subtleties of Smithies boiler design. I have no experience with Aster's Alisan Shay so can't advise you directly, but some digging into Greenly's book might give you some clues about what might be going on with yours.

I do have experience with scratchbuilding locos that wouldn't steam, despite my best intentions. The biggest factor in all cases was the fire: insufficient combustion space, superheater pipe postion interfering with the draft, and vapor lock in the alcohol fuel supply to the burner. David's and Andrew's comments point in those directions.

I've built them with leaks, too. Try running the loco on compressed air, and then use a length of plastic tubing as a stethoscope to listen around the various seals and pipe couplings. Don't forget to make sure the safety and filler cap are tight.

Steve
 

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Mark,
No torque ,inability to maintain boler pressure .the Fire seems ok...runs only fast.....its probably the packing in the cylinders.

Get air at 30psi into it, put it into fwd gear, little crack of throttle, and hold the crankshaft from turning. if you can here a constant exhaust up the stack .either the packings are worn out or a valve is leaking through .. this could be something under the valve or a
scored port face etc..

Gordon.
 

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Discussion Starter · #9 ·
Thanks Gordon - that looks to be the ticket. At 40psi she hardly wants to turn over, constant air is going up the stack, and bubbles are forming on top of two of the cylinders. Sounds like time for a tear down, rebuild.

Steve - thanks for the pointer - I had missed that post, but a good reference and worthwhile read for sure.

Add one more project to my ever growing list :)

Mark
 
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