Author Topic: Couplers and more couplers  (Read 1105 times)

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6axlepwr

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Couplers and more couplers
« on: August 19, 2013, 10:59:35 AM »
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It appears the coupler has become a hot topic and is going through many design changes/ improvements. So I thought I would chime in with what I have worked on and tested.

For the past few months I have also been working on a new coupler design. It is a scale operating knuckle coupler. I finally received my test parts in last week. These couplers work on the same concept as the HO scale Sergent couplers. There is a operating knuckle like the prototype. Just like the Sergent couplers, there is a metal ball that is pulled up by a magnet. This releases the knuckle and the knuckle opens. After putting together the test parts, the operation actually works. I was very surprised. It will not be massed produced though. At least not at this time. A lot more R&D needs to be done on them to make them work ALL the time. The issue is not really the design or operation. The problem is due to the weight of N-Scale equipment. It is to light weight. Locomotives are OK, but freight cars just do not have enough weight to stay put and close the knuckle.

The samples I have were cast in brass. Some cleanup needs to be done to assemble them and that is a draw back and why they cannot be mass produced this way. What needs to be done is have them cast in ABS plastic OR have them Die Cast. Both of these processes are much more precise than lost wax casting brass parts. The cost of those two process are prohibitive to me right now and to invest in them on a theory that they would make the couplers work better is not a good idea either.

I'll try to post a video on the couplers and their operation this week. They do look good and are the correct size. I took a drawing of a real coupler, imported it into a 2D drawing program and made the pattern to import into a 3D program. Then built the internal parts in a 3D program. Wish I could develop it more. It was a fun project and I was able to prove it can be done. Just needs more money thrown at it to develop it more and I think for me, the money is better spent on hard detail parts and photo etch. These newer scale couplers are looking good and operate much more reliably.
Brian

VonRyan

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Re: Couplers and more couplers
« Reply #1 on: August 19, 2013, 11:21:30 AM »
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Re-design the coupler around the existing weight or even for cars with no weight.
For me and others I know, weight is a hindrance in prototypical length trains (and even reliable operation in some instances), which is why any car in which the weights are superficial to putting the car together get their weights removed. (like the Atlas 40' woodside reefers for example)

I like the concept of the coupler in that it has a positive lock on the knuckle, but I don't like that it requires a wand as I prefer to bury magnets beneath the track.


-Cody F.
Cody W Fisher - Modeler of the PRR, PRSL, GWR, SZD, and DRG

WWII Clerk/Administration Historian

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6axlepwr

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Re: Couplers and more couplers
« Reply #2 on: August 19, 2013, 11:40:46 AM »
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Cody,

The weight of the car needs to be sufficient to close the knuckle. When the knuckle contacts the back of the coupler body on the mating coupler, it is supposed to fold and close. You only need one knuckle loose. The other can be locked. BUT, there needs to be sufficient weight to keep the car in place and fold the knuckle. If not, the open knuckle will easily push the freight car. Not so much with locomotives, but definitely freight cars. As you will see in my video when I post it, the knuckle does move VERY freely, but there is always something that can cause the knuckle to not close properly and in N-Scale it is the weight of the car.

Now if I was to produce these for just myself, then there would not be an issue. I do not mind fine tuning the knuckle to work properly. But for the mass market, no way. There would be so many complaints about it, that it would most likely not even sell.

No way you can use an under the tie magnet either. The steel ball naturally falls with gravity and that is what locks the knuckle. Also, the magnet under the ties is to far away to have any effect on the ball. Nope, has to be the wand. All couplers are going to have a negative response for some reason or another. Heck if you made a fully prototype operational coupler, modelers would have an issue that you had to lift the coupler lift bar. So for this one, it is a magnetic wand.

The market for these couplers though would be the fine scale modeler. But still, for those with large fleets. There is to much fine tuning that needs to be done to make this a viable alternative coupler.
Brian

VonRyan

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Re: Couplers and more couplers
« Reply #3 on: August 19, 2013, 11:54:51 AM »
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I guess the engineering behind your coupler is way above my pay-grade since I would think that if the knuckle moves freely, then the weight of the car would not be an issue, especially with the weight of a standard micro-trains car. Plus with un-tuned trucks there should still be enough resistance for the knuckles to couple together.

If the ball in the coupler were to be made of neodymium (the same with the buried magnet) then the buried magnet's field could be aligned so as to force the ball upwards.


-Cody F.
Cody W Fisher - Modeler of the PRR, PRSL, GWR, SZD, and DRG

WWII Clerk/Administration Historian

Switchboard Technician - 33rd Signal Construction Battalion (reenacted)

Squadron Clerk - Capital Wing, Airmans Preservation Society

6axlepwr

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Re: Couplers and more couplers
« Reply #4 on: August 19, 2013, 12:02:54 PM »
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If the ball in the coupler were to be made of neodymium (the same with the buried magnet) then the buried magnet's field could be aligned so as to force the ball upwards.


-Cody F.

Now your speaking of stuff above my pay grade. BUT, that sounds cool!

You'll see though in the video. If the knuckle does not close smoothly it will push a locomotive. Also, I failed to mention that in order for the knuckle to move smoothly and close, the coupler NEEDS to be aligned with the mating coupler. I do nto have a centering mechanism in place. I have one designed, but just not put in place.
Brian

garethashenden

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Re: Couplers and more couplers
« Reply #5 on: August 19, 2013, 05:41:41 PM »
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Is it the weight ,or lack there of, that's the problem or is it that the cars are too free rolling? The prototypes have brakes after all.

6axlepwr

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Re: Couplers and more couplers
« Reply #6 on: August 19, 2013, 08:33:28 PM »
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Yes, the lack of weight.

Brian