G Scale Model Train Forum banner
1 - 6 of 6 Posts

·
Premium Member
Joined
·
531 Posts
Discussion Starter · #1 ·
I was trying to append to an earlier thread discussing this model, but can't find it.

I completed the build and, generally, it went well. Biggest problem was that the crosshead guides had not been finished and it took some patience to smooth and polish them. After that, everything was fine and it was an enjoyable build.

I tested the machine on rollers with both air and steam - it worked well.

Out on the track, things are a little more challenging and I'm finding it necessary to use the blower to maintain pressure even with light loads. My immediate thought was that the main blast nozzle was not properly aligned with the smoke stack but that doesn't seem to be the case. The one thing I do notice is that the hole in the blast nozzle is very small compared to anything I've seen before which makes me wonder whether it was finished correctly.

Before I go ahead and widen it, I was wondering if there was any guidance of how the blast nozzle should be configured.

BTW, here's a picture of the finished item against its big brother.

Train Wood Vehicle Rolling Rolling stock
 

·
Registered
Joined
·
395 Posts
I'm no expert so I hope these suggestions from experience with my fleet of Asters help.
First up I would check wicks for height and 'looseness' that is when burner turned upside down do they nearly fall out. Wicks in too tight restricts meths flow and burn also sometimes there needs to be some 'combustion space' above the wicks so you could have them too high all this involves altering and testing while pulling a load.
If all that is OK then assuming the blast pipe is aligned and there are no air leaks around the smokebox/boiler have a check at the height of the blast pipe as it should be the usual 1 in 3 ratio of chimney diameter to start of chimney petticoat and 1 in 6 to top of chimney. I have had Asters that have needed the height of the blast pipe altered a little and it made a big difference.
Another problem could be due to fuel, either level too low in wick holders by starving the chicken feed with too low a fuel height there. Also is your meths good quality? I found buying meths labelled for cleaning has too much water content ( often around 10% plus ) thus a lower heating capability. All meths has some water content ( unless you buy laboratory grade ) and should be less than around 5%. Meths also absorbs water over time if a small amount is stored in a large container with a big air space and if it had 7% water content before it may well have more than 10% now and appear to burn well but less heat. I only know this as I have had 'poor' performance from good loco's that I couldn't trace until I changed my meths.
Having said all the above I found that all my meths burning Asters need a load (that is more regulator and resulting stronger blast) before I can close the blower right off, light engine or two carriages the blower is usually on for slower running, but blower off for warp speed.
I have a friend who has two B1 loco's ( he couldn't decide which colour so he bought one of each) and they are superb runners easily making steam so no doubt this will be a great engine that you will love.
Russell
 

·
Registered
Joined
·
202 Posts
Oh dear, sounds to me like you have leakage past the pistons and rings. I worked on two kits that both had this problem. The pistons did not have parallel faces. they were slightly conical. The grooves for the Rulon O rings were to deep. This caused leakage past the pistons and straight up the smoke stack. Coupled with the cross head problem it caused one cylinder to seize. Here in the UK Accucraft UK sent out replacement pistons, silicon O rings and piston rods to cure the problem.
Wood Material property Gas Rectangle Beige


There are other ways to combat this problem.My kit built loco now runs very well but there was a lot of frustration getting it there.

DougieL
 

·
Premium Member
Joined
·
531 Posts
Discussion Starter · #4 ·
I'm no expert so I hope these suggestions from experience with my fleet of Asters help.
First up I would check wicks for height and 'looseness' that is when burner turned upside down do they nearly fall out. Wicks in too tight restricts meths flow and burn also sometimes there needs to be some 'combustion space' above the wicks so you could have them too high all this involves altering and testing while pulling a load.
If all that is OK then assuming the blast pipe is aligned and there are no air leaks around the smokebox/boiler have a check at the height of the blast pipe as it should be the usual 1 in 3 ratio of chimney diameter to start of chimney petticoat and 1 in 6 to top of chimney. I have had Asters that have needed the height of the blast pipe altered a little and it made a big difference.
Another problem could be due to fuel, either level too low in wick holders by starving the chicken feed with too low a fuel height there. Also is your meths good quality? I found buying meths labelled for cleaning has too much water content ( often around 10% plus ) thus a lower heating capability. All meths has some water content ( unless you buy laboratory grade ) and should be less than around 5%. Meths also absorbs water over time if a small amount is stored in a large container with a big air space and if it had 7% water content before it may well have more than 10% now and appear to burn well but less heat. I only know this as I have had 'poor' performance from good loco's that I couldn't trace until I changed my meths.
Having said all the above I found that all my meths burning Asters need a load (that is more regulator and resulting stronger blast) before I can close the blower right off, light engine or two carriages the blower is usually on for slower running, but blower off for warp speed.
I have a friend who has two B1 loco's ( he couldn't decide which colour so he bought one of each) and they are superb runners easily making steam so no doubt this will be a great engine that you will love.
Russell
Thanks for the ideas. The machine comes to pressure very quickly with the blower, so I am pretty sure that the wicks, smokebox seal etc are all good. I'm using so-called 'Smart Fuel' which is pure ethanol according to the bottle. This fuel works really well with other engines and doesn't come with the noxious fumes that I associate with de-natured alcohol.

I ran with up to 7 BR coaches and was beginning to see wheel spin so I backed off to 6, so plenty of load.

I need to check the pistons for the problem that Dougiel alludes to. In the low humidity we have here in CA, it is difficult to see steam leaks but I did notice some steam coming from the right hand side at some points of the track.

Robert
 

·
Registered
Joined
·
202 Posts
Robert, did you need to apply a lot of regulator when running ?. Did you notice a constant blow up the chimney ?. All symptoms of two possible problems. I pumped some air into the boiler then listened to it escaping when the regulator was opened with the wheels locked. When listening if you can hear air escaping plug the blast pipe with a long implement down the chimney. If you can still hear air escaping then it is possible the two banjo bolts on the ends of the superheater have come loose. If this is the case cure this before proceeding to check for further leaks.

If you can still hear air escaping slowly rotate the wheels. If it is a fairly consistent blow it will probably be air leaking past the piston rings. The main problem in the two models I built was the difference in size at the front of the piston and the rear and the fact the piston rings did not sit proud of the surface of the piston. There are ways to get round these.

Mine now runs very well and I would love to add a black version to my fleet but here in the UK we no longer have a dealer of the Aster product. My kit had to come from the USA. Bit daft as the next Aster model will be the LNER P2. I would think the main market for this would be the UK !.

DougieL
 

·
Premium Member
Joined
·
531 Posts
Discussion Starter · #6 ·
Robert, did you need to apply a lot of regulator when running ?. Did you notice a constant blow up the chimney ?. All symptoms of two possible problems. I pumped some air into the boiler then listened to it escaping when the regulator was opened with the wheels locked. When listening if you can hear air escaping plug the blast pipe with a long implement down the chimney. If you can still hear air escaping then it is possible the two banjo bolts on the ends of the superheater have come loose. If this is the case cure this before proceeding to check for further leaks.

If you can still hear air escaping slowly rotate the wheels. If it is a fairly consistent blow it will probably be air leaking past the piston rings. The main problem in the two models I built was the difference in size at the front of the piston and the rear and the fact the piston rings did not sit proud of the surface of the piston. There are ways to get round these.

Mine now runs very well and I would love to add a black version to my fleet but here in the UK we no longer have a dealer of the Aster product. My kit had to come from the USA. Bit daft as the next Aster model will be the LNER P2. I would think the main market for this would be the UK !.

DougieL
Many thanks for the tips. The engine runs strongly with very little regulator when the pressure is up. I did find a possible problem - one of the o-rings on the super heater connection to the cylinders was 'nipped' - maybe I used the wrong size o-ring. Not sure whether this was causing a leak, but I replaced it anyway. This is the first kit I've assembled with o-rings on the banjo fittings and I think I must have used a 6-1 rather than a 5.5-1 in this particular case.

I also found a slight blockage in the exhaust nozzle that I have now cleared. So fingers crossed that it runs better next time I have a chance to get it out on the track. If not, I will steel myself to inspect the pistons.

As to the LNER P2, it is very much on my list - I've been harassing the Aster/Accucraft folk (who live locally). They tell me that it is under test and they have some changes they want to work through before they are ready to release. They sent me a short video of it on test rollers - it looked good.

Robert
 
1 - 6 of 6 Posts
Top