Large Scale Central

Ruby 2 Mystery

I just bought a used Ruby 2. I checked the timing, oiled round, filled the lubricator and boiler while removing 20 ml from the boiler to make room for steam. It came up to pressure as the pop off signaled this. I did the suggested clearing of condensate by forward etc motions with the engine, and while it did turn, it was so weak that it could not carry it’s own weight on the track and if i placed the slightest pressure on the wheels ( very, very slight) the motion stopped. Does the boiler and cylinders require cleaning? I wonder if they are slogged with gummed up oil? Hopefully, an expert can offer some suggestions.

Offhand, I’d suspect the safety is weak, and popping at too low a pressure. I know the early Rubies had this issue–they’d pop off at around 20 pounds, and were horridly lethargic runners pretty much as you describe. The fix (on those safety valves) is to pull the spring out of the safety valve and stretch it out a bit. I can’t remember if you’re supposed to stretch it out to around 3/4" and let it relax again, or stretch it out to where it is 3/4" when relaxed, but 3/4" is the magic number. I think the latter, but I’m in the office and not in a position to take my safeties apart to check. This allows the safeties to pop off closer to the 40 pound mark, and gives the locomotive a good deal more life.

What I do not know is whether Accucraft changed their safeties from the first run of Rubies. Might be worth an e-mail to the original owner to find out if he had done anything to the safety to increase the boiler pressure, and if not, an e-mail to Accucraft asking them the approximate boiler pressure the safeties on the Ruby 2 are set to at the factory.

Later,

K

Thanks Dennis
I could kick myself for this possibility not having occurred to me. In fact I installed a pressure gauge in order to monitor the internal pressure, and have yet to refire the Ruby, so I will take your much appreciated advice and watch for the safety tripping pressure. My hunch is you nailed the problem on the head. Thank heaven for a resource such as this forum and your experience. I am a bit tenuous about how much to slacken the spring tension on the safety, so any further assistance would be really appreciated. This is my first live steam loco after years of LGB, Aristo etc out in the garden, so I am a novice all over again!

Thanks Dennis
I could kick myself for this possibility not having occurred to me. In fact I installed a pressure gauge in order to monitor the internal pressure, and have yet to refire the Ruby, so I will take your much appreciated advice and watch for the safety tripping pressure. My hunch is you nailed the problem on the head. Thank heaven for a resource such as this forum and your experience. I am a bit tenuous about how much to slacken the spring tension on the safety, so any further assistance would be really appreciated. This is my first live steam loco after years of LGB, Aristo etc out in the garden, so I am a novice all over again!

Cool that you installed a pressure gauge; that will tell you a lot. Neither of mine have gauges. Fire it and watch to see where the safety pops. If it’s popping at around 20 pounds, then you can stretch the spring. I pulled mine apart, and you’ll want to stretch it out until it’s about 3/4" stretched. When it relaxes, it will be a bit under 5/8". That should give you in the ballpark of 40 pounds.

Good luck!

Later,

K

I called Cliff at Accucraft and he confirmed that your advice was on target. he said thirty to forty psi is normal so now I have some parameters to do some tuning with the use of the pressure gauge. He warned me that when removing the safety valve to take care that the whole shebang doesn’t take off like a rocket and launch parts all over the place. More great advice that I am sure avoided a minor catastrophe. Thanks again.