# Aster 241P Build Log



## zephyra (Jan 2, 2008)

I received my Aster 241P kit a couple of weeks ago. It came without written instructions but I couldn't resist getting started based on the plans.

First up are the high and low pressure cylinders










Then we install the cylinders inside the frame. I was a little surprised that the output from the high pressure cylinders is combined before going to the low pressure cylinders - I thought these would be paired.










Next comes the wheels, suspension and valve gear. The suspension was a nightmare - the order of assembly really matters and this isn't apparent from the plans. The valve gear was a typical Walschaerts build - fiddly but something I've done a few times before. One of the challenges is that a lot of the parts are 'handed' and this isn't always obvious until after you've painstakingly assembled something.



















The axle pump is interesting with the smallest ram I've ever seen - looks far too small for a locomotive this size. It is also driven direct from the high pressure cylinders rather than the usual eccentric.










The front truck and trailing truck were fairly straightforward. The firebox dampers took about an hour each to install as the springs that hold them shut were really difficult to set up. The alcohol burners are also fitted at this stage and it doesn't look as though they will be easy to service when the build is complete so thoughts of being able to switch the machine between coal and alcohol my be a touch optimistic.



















Interesting to compare the size of this with a typical British prototype...










Reverser also installed but no photo. Next step is to set up the timing but may have to wait for the assembly instructions before contemplating this step.


----------



## Skeeterweazel (Feb 11, 2014)

Very nice. Did the instructions get left out of the box?


----------



## zephyra (Jan 2, 2008)

Skeeterweazel said:


> Very nice. Did the instructions get left out of the box?[/QUOTE
> 
> The assembly instructions are still being translated. Or so I'm told


----------



## rbednarik (Jan 2, 2008)

Robert,

Very nice build log so far. We have one here to build as well, will be interesting to compare notes. Good to know that the parts are handed, I suspected as much given the different part numbers, but the differences are subtle. 

From what I understand, the translated written manuals are due in shortly. 

The pump may be small, but the stroke compensates to generate the volume, the sample at Diamondhead had no trouble keeping up with the boiler demand. The small bore/long stroke pump design allows for less power loss and smoother running.


----------



## John Allman (Jan 2, 2008)

I was told it was challenging, and took about 150 hours to build. Doesn't seem that bad from what I see. Though it looks petty normal from the pictures you posted, I think I will wait to build it. I have to move shortly, and don't want to start it only to pack it back up.

You have done good work Robert. Keep posting please.


----------



## BigRedOne (Dec 13, 2012)

Very exciting! Thanks for the pictures and updates!

When you voiced surprise at finding the high-pressure exhausts merged, is that because your BR96 routes one HP cylinder to an individual LP cylinder?


----------



## zephyra (Jan 2, 2008)

I completed the timing and ran the air test. Runs well although I needed 20 psi to get it started. I run for a couple of minutes at a time disconnecting the air between runs to inject oil into the air intake. After 4 runs, she is moving a lot more freely but hasn't yer reached the point where she will auto-start.

Short video..







Also took photos of the reverser mechanism.


----------



## David Leech (Dec 9, 2008)

Robert,
Looking very nice.
I would imagine that 'maybe', being a compound, and needing the high pressure exhaust to expand to work the low pressure cylinders, that it perhaps will run a lot better on steam.
That might explain the reluctance to self start?
Just a thought.
Regards,
David Leech, Delta, Canada


----------



## zephyra (Jan 2, 2008)

I've never been a fan of working lights on steam engines at this scale. The wiring is always messy and this kit is no exception. In addition, I can't understand why the connectors are rated for several amps when the LED lighting draws only milliamps. Still, I finally got the wiring in place and tested it. 

!0 Amp bullet connectors:










At one point the wiring goes right over the connector between the inside and outside vale gear (and yes, that is exactly how it is shown in the drawings!)










After working on the boiler backhead, tried a test fitting - starting to look like the real thing!


----------



## zephyra (Jan 2, 2008)

David Leech said:


> Robert,
> Looking very nice.
> I would imagine that 'maybe', being a compound, and needing the high pressure exhaust to expand to work the low pressure cylinders, that it perhaps will run a lot better on steam.
> That might explain the reluctance to self start?
> ...


David, good thinking! I did try to run the machine on just the high pressure cylinders by leaving the covers off the steam inlet for the low pressure pair but I couldn't get it to run. 

Robert


----------



## Charles (Jan 2, 2008)

Robert
If you have a separate stationary boiler steam it up and test the build...


----------



## rbednarik (Jan 2, 2008)

Robert,

One other thing to try on the test stand. If you only support two out of the four driving wheels, there is a chance with the equalized suspension that the drivers will droop too low and bind.

Try supporting all 4 and run another air test, I have had a few engines that refused to run on rollers well unless all driving wheels were supported.


----------



## RP3 (Jan 5, 2008)

My understanding is that the written directions tell you that the steam supply line running to the rear cylinders is supposed to be wrapped with insulation which I didn't see in your pictures. Hope you haven't fitted the boiler permanently if that pipe isn't wrapped yet. Better still, it would be extremely wise to re-check the written directions to make sure you haven't missed anything in your build so far.

One other point no one has made yet. As a four cylinder engine, the 241P has 8 O rings on the piston rods and valve stems. The gland nuts for the piston rods look as though they are down tight. If so, back all 8 (piston and valve nuts) off a bit and see if that doesn't ease your starting issues. They don't have to be tight to function properly.

Good luck,

Ross Schlabach


----------



## zephyra (Jan 2, 2008)

RP3 said:


> My understanding is that the written directions tell you that the steam supply line running to the rear cylinders is supposed to be wrapped with insulation which I didn't see in your pictures. Hope you haven't fitted the boiler permanently if that pipe isn't wrapped yet. Better still, it would be extremely wise to re-check the written directions to make sure you haven't missed anything in your build so far.
> 
> One other point no one has made yet. As a four cylinder engine, the 241P has 8 O rings on the piston rods and valve stems. The gland nuts for the piston rods look as though they are down tight. If so, back all 8 (piston and valve nuts) off a bit and see if that doesn't ease your starting issues. They don't have to be tight to function properly.
> 
> ...


Thanks for the input. The pipes are now insulated - it was tricky to do this well without interfering with moving parts but I think it is OK. Interestingly, the factory built BR96 I have has no insulation on the steam pipes and the runs are rather longer and more exposed that this machine.

The gland nuts are not tight even though they might look this way in the photos. The engine now moves very freely. I tested it with an external steam source and it runs very well. I had a challenge with the drain valves for the high pressure cylinders which were not closing fully - this is critical as it impacts the flow of steam to the low pressure cylinders. I adjusted the linkage between the drains and now have this working well. On a simplex engine, a slight leak from the cylinder drains just affects the blast and actually adds to the feeling of authenticity as the engine runs but a leak from the high pressure drains on a complex engine is a loss of steam to the low pressure cylinders.

Assembly on the engine is now halted as I managed to shear the top of the tiny banjo bolt that attaches the boiler drain to the boiler drain valve :-( Really frustrating as I was really careful to line up the parts to minimize the stress on the banjo bolt. I hand tightened the joint, then applied a 1/4 of a turn with a 6mm wrench - it sheared. This is a 4mm part and the cross hole leaves almost no metal on the shoulders making it very weak - not a great piece of design.

I've ordered a new part but will have to wait for it to come from Japan. 

I have photos on the build so far and will post later.


----------



## zephyra (Jan 2, 2008)

Pictures relating to the previous post:

Broken Banjo Bolt 










Boiler attached to main frame:










Smoke box starting to come together:










And finally, continuing my general unhappiness about the lighting system, the two connectors at the rear of the engine for the LED lighting. Why two, why this big??????


----------



## zephyra (Jan 2, 2008)

Tha assembly of the tender proceeded quickly while I wait for the replacement banjo bolt. Nothing particularly difficult but a lot of M1.2 x 2 screws to attach really small parts. Some detail like the hydraulic brake cylinders under the bogies is 'cool' although will never be seen.

The water container is unusual for a machine that is this expensive. I would have expected a separate container made from stainless steel or galvanized metal. Instead, the tank is the walls of the tender itself. As these have many holes for screws, copious sealing compound needs to be used to make sure it is water tight. Odd - the SNCF 232 U1 which is very similar has a lined water tank.....

My only complaint is, once again, the wiring for the lights. This machine requires four (4) batteries. Two 9V batteries drive the main engine lights and two button style batteries run the rear lights (independently). Definitely on my list of things to rationalize some time in the future.

One of the nice things about taking photos is that you often notice details that need to be fixed when you inspect the images. These were taken prior to those fixes.....

Tender side on (need to fix alignment of the handrails round the water container and rack at front):










Front on:










The infamous battery bank:


----------

