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Experimental Janney Knuckle Coupler

Posted: Tue Sep 11, 2018 4:39 pm
by jesse6669
For those of us in North America or Australia (or other parts of the world whose railways use a knuckle coupler), I always had a bit of a bone to pick with the stock T-gauge couplers.

I designed one several years ago but the materials on Shapeways either weren't strong enough (FUD), or the bronze I tried was too strong and expensive. But now, the "professional plastic" I tried recently actually works pretty well. It is strong, and somewhat flexible, and cheap. The coupler I printed is about 100% oversized compared scale, but this was a compromise I made for strength. The coupler works as a press-fit--it isn't too firm and not too loose, but I haven't tried on any trains yet. Material is grainy but after paint looks a bit like cast iron (you can see I painted my test pieces a rust color). I am going to try some smaller versions and see how they work..


Re: Experimental Janney Knuckle Coupler

Posted: Wed Sep 12, 2018 3:31 pm
by jesse6669
I reduced the size a bit, and added draft gear. I'm waiting for test models from Shapeways. Here's a rendering on my revised hopper car:
Coupler Render.jpg
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Of course the draft gear means body mounting, which will surely be problematic, but can be overcome I'm sure.

Re: Experimental Janney Knuckle Coupler

Posted: Wed Oct 24, 2018 1:05 pm
by jesse6669
I reduced the size of the coupler and it still works, and I think looks decent, especially to the naked eye. This is the "rough" coupler as it comes from Shapeways without paint. I give them a coat of Future and paint brown, and I have body mounted them for now by simply gluing in place. In practice--I think they may need to be talgo style/truck mounted, or at least the body mount have more lateral movement allowed (i.e. a pivot) because they are fairly rigid and trains will probably string-line on curves. The ones I designed have pins in the shank for installation in standard T-gauge bogies; I made draft gear (very tiny) but think I need to craft a different draft system or just put a mounting hole/pivot to body mount the coupler.
2018-10-19 11.45.38.jpg
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They seem to be able to take a decent amount of abuse, and given that my operating scheme will be to couple trains and run--no switching-- they should work. As for anything in T, it's an on-going experiment subject to revision. I think it's about as small as I can get it without expensive machining to make it out of metal with a sprung mechanism (which would be awesome, but cost prohibitive). Given the size, a prototypically accurate automatic coupler will be tough, but I keep pondering it. Magnetic systems probably won't work given the magnetic wheels and other features in T scale.

Re: Experimental Janney Knuckle Coupler

Posted: Wed Oct 24, 2018 6:54 pm
by jesse6669
There's nothing like admitting a failure to inspire you to work and find a solution. So I made this today. Self sprung, pivoting, self contained in draft gear. Prototypes are on the way. More details when they come in.

Re: Experimental Janney Knuckle Coupler

Posted: Fri Oct 26, 2018 12:51 pm
by MIHS85
I'm following this with interest, as I am not overly happy with the regular Tgauge couplers.

By the way: I recently got your FP7 A/B units from Shapeways and am really happy with them. Nicely detailed and they fit perfectly on the 36mm chassis.

Best wishes,


Re: Experimental Janney Knuckle Coupler

Posted: Mon Oct 29, 2018 2:36 pm
by jesse6669
Thanks Chris, I'm crossing my fingers they work decently. They look much better, that's for sure.

And thanks for the compliment on the F-unit. I'm currently working through my line-up and upgrading models with better detail and including dummy trucks and couplers. Still don't have the design for a powered locomotive truck (ie Blombergs or Flexicoil), but that's a goal.. A vertical motor with a worm drive is the ideal, not sure how that will pan out. The E8A is "in the shop" now and I will have an early/mid production version mainly the fuel tank skirting on or off, improved underbody and roof details, opened windows/portholes/windshield, and 3-axle dummy trucks. The GP40 is similarly on deck, but I'm only waiting for a test print from Shapeways at this point. It will come with Blomberg M and B's so you can make a 40 or a 40-2. Oh and I made a set of AAR switcher trucks, so an SW1200 or S2 is somewhere on the horizon. So many projects...

Re: Experimental Janney Knuckle Coupler

Posted: Wed Nov 07, 2018 7:35 pm
by jesse6669
2018-11-07 11.29.00.jpg
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The CCE #3 fine plastic, I'm happy to say is a qualified success. It does pivot freely. The coupling action is tight but not too tight. The spring action, well that doesn't seem to work but I'm still fiddling with my prototypes. Even if spring action doesn't work, they are far-and-away better looking than stock, and they seem fairly rugged as well. I'll be posting them for sale up on the Shapeways store very soon if you want to get some, and will be including with all of my models from now on. I'd love to share these with other designers, so PM or email me if you're interested in adding these to your models. I am body mounting these, but I will make a version with a nibbed shank that can replace the stock coupler. There's more info and a video on my blog: