Took a piece of flex track and made myself a 15 " radius curve. Still has overhang some in middle with the trucks moved. Found that the longer coupler shaft on the 1016 puts the coupler out to close to outside rail and went back to the standard 1015. That brought it in in closer with my mounting at the rear of the coupler pad on the car plus kept the coupler closer to center of car. With the increased curvature the swing of the 1015s was adequate for the job. This is now the spacing I have on the cars using the 1015s. And the obs and a pullman with American Limited Diaphragms. Found I had to trim a little off the inside ledge of the cars for the springs to clear but only at the top and top.s sides. And back on the 15" curve. And with the cars setting straight on the workbench both with American Limited Diaphragms.
And one last shot with the car on the left having the American Limited and the car on the right with the MT diaphragm. I am now going back and test these on the 11" curved to see what happens. Managed to get that done in time to add the photos here. The first shot is one car with American Limiteds connected to the other with MT's diaphragm. And both cars with American Limited.
Don't know what happened to the rest of the edited post but..... Anyway the American Limited work far better than the supplied diaphragms by MT. They unfortunately are far to stiff in thier action if any action at all with some. And the American limiteds are much better in the 11 inch curve because of their give. But again in summation these cars are best on the larger radius but with the mods that Skipgear came up with you can get them to negotiate 11 inch curvature, although the esthetics and operating leaves a lot to be desired. The issue of the coupler mounting will probably vary some. What I described works for me.
(Bumping an old thread with a lot of great info) I (finally) got around to working on some MT heavyweights to address the poor coupler spacing. This thread still has a lot of relevant information. I started by comparing, side by side, the following three coupler options: a) MT true scale short shank b) MT Z scale 905 short shank c) Red Caboose / Fox Valley 51060 (body mount) I was very surprised when I laid these three coupler options out side-by-side to find that they are all virtually identical in length from the mounting hole to the front face of the coupler pocket (which suggests that they all will produce similar reductions in coupling distance). At that point, the solution for me became obvious. Just use the pre-assembled Z scale 905 and be done with it. That turned the conversion task into an easy one or two minute task for each car, with very predictable results. My calipers measured before distance (diaphragm face to diaphragm face) of .247 inches. After installing the Z scale couplers, I measured .097 inches, or 1.3 scale feet. This is consistent with information Altohorn25 reported earlier in this thread. While still not ideal, this is probably as far as I will go with these, as they look much better and I really don't have any interest in investing more time to get that final 10% improvement. My smallest radius is 17 5/8" (Unitrack) and they seem to operate around those curves just fine. I converted both inner bolster and outer bolster versions of the cars, and they play together just fine around those curves. As Tony explained earlier, tighter radii may certainly make similar cars owned by other N scalers a candidate for the more invasive surgery.
I've messed around with TSC and found out they don't care for tight radius' so I have to be careful where I run them.
This was my first, and likely last, venture into the True Scale coupler (I just bought a small four pack to try them out). I can't envision a scenario where they would be desirable over the Z scale 905. Maybe for those who want to take close-up photos for contest submission. Otherwise, they provide no closer coupling than the 905 and, unlike the 905, they won't couple to anything else. Also, the way they eliminated the spring by moving the pivot to a separate post at the front of the coupler effectively eliminates all side-to-side movement. Had they used the same small geometry, but gone to a design more like the accumate, I would think that better performance would have been achieved with the same super small profile. In fact, had they done this, they could have made an even closer coupling version, yet still with more side-to-side movement. I've been running a test consist around the layout with one of the Z 905's coupled to a Kato engine w/Kato coupler and another coupled to a normal MT 1015. They seem to perform perfectly. I may look into shimming the 905 down slightly so that it rides in the middle of a non-905 mating coupler instead of the upper half. More to come.
They look like a great product to use for N scale. This is the first time I've bought any and, quite frankly, I wish I had tried them years ago. I no longer have any IMR F units, but I believe that they would be a better fix than the Unimate close coupling solution (and at some points in time much easier to find). I still have an ABBA IMR FT set that needs a close coupling solution between the two B units. I believe that the 905's will work perfectly. On a related topic, based upon review of dimensions shown on the Micro-trains website, along with some direct measurements with calipers; it appears that a .010" shim will bring the centerline of a replacement 905 down to within .001" of the original MT 1015 centerline. Does anybody have a recommended source for .010" shims that would work well for this? I certainly understand that I could buy some .010" thick styrene, drill it, cut it and paint it; but some cheap prefabs would be desirable. It looks like Kadee makes a shim set for their HO scale couplers (the Kadee #211). They are molded in black styrene, come in both .010 and .015 inch thicknesses, and the center hole is, I believe, designed for the common "0" screw used for HO couplers, as opposed to the "00" screw in N scale. That should only add about .013" "slop," so likely not an issue. I envision just trimming them to appropriate size and otherwise using as is. They street for under $2 for ten, so cost is a non-issue. That said, if anybody has a better recommendation I would be interested in hearing about it. This issue will likely occur whenever anybody swaps a MT 1015 for the MT 905.
