Accucraft Mogul steaming issues

[maxi-model]

I have an Accucraft Mogul - about 18 months old, only steamed 6 or so times. I have noticed that for the first 5 minutes or so of each run it is difficult to run other than "light engine" on my track that has a 1 in 25 gradient in parts. During this initial part of a run boiler pressure will not rise above 40 psi, even with the burner turned up. As the run progresses the pressure rises to 60 psi and the burner can be turned down and it will handle a modest load, say 4 AMS/Spectrum wagons over the full layout.

I have also noted that the silver chimney is turning a nice shade of bronze, that might indicate an inordinate amount of heat is going up there rather than heating the boiler. I'm used to this heat discolouration on smoke box doors but not chimneys. I draw off the usual 50 ml from the boiler to allow space for steam to form. Is this part of the problem and should I draw off more prior to steaming or have I other issues that need to be attended to ? I've noticed that it is spitting a small amount of water from its chimney for the first two minutes of running, little or none on initial start up. It has R/C on the regulator alone.

Your thoughts and collective experiences would be most welcome. Max.

 

[bobg]

Max, the spitting up the flue may be no more than initial condensation in the cylinders, unless it is excessive, in which case it could be that you are not drawing enough water off at the start. I suggest that a little experimentation should show you what is required. Does it not have water level bled-off valve, some Accus do?

The discolouration of the chimney is an indication of a lot of heat but it could be from you turning the burner up at the start due to the water level (if indeed that is excessive). 1:25 is very steep and will use a lot of steam, especially with a load. It could also be grade that is causing 'pick-up' of the water due to it boiling very hard and getting too close to the take-off point. Again try it with a bit less water to see if it clears. Be careful that you do not run the boiler dry during your experimenting.

A high burner at the start will be compensating for the smaller steam space until some of the water has been used. Experiment and gain experience and you will soon find how to best set it to suit your own track conditions.

Another suggestion is take it to another flatter track and get used to it there.

Hope some of this helps.

 

[Dtsteam]

My mogul took a little while to settle down I have to admit. I have overfilled it a couple of times, but I certainly wouldn't starve it of water. I did add some stainless steel mesh around the burner and in the flue tube, and that seems to have taken some heat out of the smokebox. I tend to fire up on wooden blocks as its very wet at first - I'd seriously see it as a candidate for some automatic draincocks. My loco tends to run best when it has a load to haul, although 1:25 seems a tad steep. Having said that, I think if I was to invest further, its definitely a loco which would benefit from some r/c of the gas tank. There's a lot of metal in this engine so I tend to gas up and leave it for a bit, then fire slowly until steam begins to build.

I did make a silly mistake when fitting a chuffer and buggered the base of the exhaust pipe, so now it doesn't have one. It seems to run better, so I wonder whether the original exhaust pipe was too restrictive.

 

[maxi-model]

I would like to know how you did the stainless steel mesh trick on the burner and flue tube David. Not seen that one before. I'll follow your tip and go slow on the "boiling up" stage. I only mention its reluctance to deal with the grades as my other locos, non tender Roundhouse and Accucraft UK, have no problem with a full load.

Some interesting points you make Bob. I will try drawing off more water, in 10 ml increments above the usual 40 ml, to see if that improves matters over the initial part of a run.

Thank you, Max.

 

[Chris Bird]

I did make a silly mistake when fitting a chuffer and buggered the base of the exhaust pipe, so now it doesn't have one. It seems to run better, so I wonder whether the original exhaust pipe was too restrictive.

Hi David
With a very few exceptions, Accucraft use the same 3mm exhaust fitting and exhaust pipe used in the Mogul. It does apply a little back pressure, but this is not an issue as there are some seriously powerful locos in their line up. A K-27 will pull a small building with that exhaust ;-)

Sorry to hear your Chuffer fitting went wrong. Maybe I can advise on a solution and if it is a Summerlands Chuffer that got damaged (or the thread at the bottom) I would be happy to fix it for you. You can email me on coxhillcottage (at) yahoo.com
Cheers
Chris

 

[Alleyer]

I also have a Mogul that I have just taken apart, repainted and converted to radio control. I have also got the springing working and put mesh around the burner to quieten it.

I can offer little comfort. On the flat it goes reasonably well with 2 or 3 wagons but it slows markedly on a slight gradient and will just haul itself up about a 2% gradient with no wagons. I also have a Roundhouse SR&RL 2-6-2 and a Pearce 2-6-0 with tender. Both manage the gradient with 3 to 4 Bachmann coaches with metal wheels. The Accucraft is significantly heavier than the other two. I have been wondering whether it is set up wrong and have checked the valve timings as best I can using Tag's advice (valve fully in when crank at 6 o'clock). This is equivalent to advice online for a Ruby (connecting rods parallel at 9 oclock or just after). See the link below but note the Ruby has a different valve actuation cam setup - Moguls are I believe set up for inside admission as supplied (in the US but presumably also in the UK). CAUTION I am a relative novice. I hope someone will chime in if I am giving a bum steer.

Overall a loco that can only run as a light engine with gradients or with a few wagons on a very level track is very disappointing. I am contemplating whether to go to the expense of getting it checked over professionally or try to find someone who will buy it warts and all.


http://www.santacruzlumberco.com/MLS_PDFs/InsideAdmissionAndAirTuningARuby.pdf

 

[lotsasteam]

The Mogul has only 1 eccentric so timing it either go forward or reverse at the same performance isn't possible,solution: Split the eccentric in the middle so you can adjust it evenly //pulling issue:my mogul would run on level ground fine till i noticed that when it goes uphill there was no go even with a light load ,the problem: the super heater tube right where it is attached to the valve block was cracked(heat stress) http://forums.mylargescale.com/archive/index.php/f-18.html look up Accucraft Mogul cracked superheater!

RE: Mogul Steam Leak
Dan'
Open the smoke box door.Â* Looking in with a light, you will see the superheater line coming out of the flue about 3/4" and it is nutted to a 90' fitting with a line running straight down into the reversing block.Â* Sometimes the line cracks off at the reversing block.Â* Reach in with a pencil & "LIGHTLY" attempt to move the 90' fitting left & right.Â* If it moves it is broken off at the block.Â* Dave Hottman has a repair for this listed here somewhere but I have been unable to find it.

 

[Ken Tonge]

Could Alleyer please get in touch about mogul. I have a problem that needs removal of smokebox. I guess you must have dismantled that to do the repainting. How do I get the smokebox off? Can only see the ends of screws sticking out underneath and no way to get to them due to the heat shield inside the box.

 

[Ken Tonge]

OK I got it . There are tiny screws, one each side of the smokebox - close to where the diagonal bars go in. Unscrew these and the whole of the front of the smokebox comes off. You can then get at all the things in there. It seems like the best way to put in a Summerlands chuffer, rather than work thro' the constricted smokebox door.