I recently got a 4-6-4 Brass Hudson. It doesn't go around an 18" radius curve. I also have an IHC 4-6-2 Pacific that does go around an 18" radius curve. The only difference between the loco drivers are that the pacific's mid driving wheels have no flanges and the hudson has flanges on the middle drivers. Could this be the problem?
I have three, none will go around 18" radius curves. The reason is that the locomotive and tender are opposite polarities. The corner of the cab touches the front of the tender on 18"R curves and so it shorts out. I only know this because I decided to run one for my son on his Thomas EZ-track. In my experience, the draw bar location and trailing/lead trucks usually cause the problems limiting the radius for 6-coupled locomotives. I've run 4-8-4s, 2-8-4s, 2-8-2s, 4-6-2s, and 4-6-4s all around 18" Radius curves without a major problem (other than shorting out). Still, I don't think that it is particularly good for the 8-coupled locomotives as it is the lateral play that allows them to negotiate such curves. Congrats on the upgrade to a brass 4-6-4! If it doesn't run as smooth as silk and silent as a submarine, a new motor and geabox (can be had for $25 total) will cure it. Your IHC 4-6-2 won't get rack up many revenue miles once the hudson's tuned up and in service...as it should run and look 100x better than the IHC 4-6-2 (speaking from personal experience). What is the 4-6-4's prototype? Michael
Big D: Brass steam locos are built to entirely different 'tolerances' than plastic steamers. I know, because 95% of my steam fleet is brass, simply because of the railroad (Rio Grande) that I model. About the only time you'll find a 'blank' driver on a brass loco is if the original locomotive it's patterned after had one, also. Otherwise, the loco is built to the prototype--though curve radius tolerances are somewhat modified. However, on an 18" radius, about the largest brass loco you can reliably run with a trailing truck would be a very small USRA 2-8-2 or 4-6-2. Notice that these locomotives have a two-wheel trailing truck and not a four-wheel one like the Hudson. What you're going to get on a tight radius like that is either a short from the pilot or trailing truck as they touch the frame. You could try using black electrical tape on the inside top of the trailing truck to insulate it when it touches the loco frame on the tight curve, but if the tolerance on the rear truck swing isn't enough, you're going to have a derailment problem anyway. And 'blanking' the center driver isn't going to help, either. You'll still have a locomotive that does not have the sideways give on the drivers that a plastic loco will have. Wish I could give you better news. If it helps, my minimum radius is 34", and I have some non-articulated brass locos (4-8-4, 2-10-2) that almost 'squeal' around a radius even THAT generous. I would think that the absolute minimum radius for a brass 4-6-2 or 4-6-4 would have to be at least 24". Tom
Hi Big D I have a PFM Tenshodo ATSF 4-6-4, it can go araound 18"R, in other hand my Tsubomi-do NYC 4-6-0 cannot do 30"R. It depend sn how designed. But almost very very old Japanese brass locomotives can do very sharp curve, for example my Akane DM&IR Yellowstone 2-8-8-4 can do 24"R. Very simple, very old Japanese models are usualy made for enjoying to run them. But PFM Crown models are for despleying, they are not suitable to enjoy running. Of course, today Korean models are for displaying not for running, indeed super super detailed!! Please remember Katsumi SP AC-4 4-8-8-2 cannot go around 30"R!! so I said it depends on design. Regards, Jun
Big D, congrats on your first brass purchase. If you can, post or email me some more info on the model, brand/importer, prototype like NYC Hudson ect. Most all my Hudsons or Pacifics could handle 18" radius curves, but they didnt like it and I had to run an easy speed, any faster and they tended to lift the lead driver over the rail head from the slight bind in the curve. I do all the brass tune ups for the local club members, espicaly the older steam and diesel engines. Here are my latest two engines, got them at the Wheaton IL show this past weekend, both are PFM Southern PS4 pacifics. The unpainted one will get shipped to my custom painter to get full Southern dress put on her. Both will handle 18" radius, but my PFM NKP Berkshire is 22" only, the wheelbase is to ridged and long for 18". Rule of thumb for older brass steamers is 22" radius min and if you can go larger, do it. I am also the local hobby shops mechanic for brass and plastic engines, any scale. I can give you my home # in a pvt email if you need further help to get your engine to run. Mike T
