Jump to content

Experimenting with Lin-Cups


antyeates1983

1,117 views

 Share

In my role as Publications Officer for the 2mm Scale Association, I'm currently working on a revamp of the "couplings" chapter of the erstwhile 2mm Handbook. I was intrigued by the reference to Lin-Cup couplings, which I hadn't heard of or seen. So I went back to the June 1976 issue of the 2mm Magazine to read Lindsey Little's original article. His goal of "something inconspicuous, not too unrailwaylike, close coupling, sturdy and capable of being made by a squint-eyed tyro with ten thumbs" sounded promising...

 

I decided to have a go at making some following the instructions in the article. If nothing else, this would allow me to photograph them for the new handbook. Firstly, here is a photo of a completed coupling, glued to the underside of a Buchanan Kits open wagon. The underside of the wagon is a mess because I had to remove the folded-up coupling "boxes" that I had previously fitted before painting. This illustrates a nice feature of the Lin-Cup: the "gubbins" is all hidden behind the solebars, with only a wire hook protruding beneath. Like an Electra, the hook hangs at a 45-degree angle (when the wagon is upright) thanks to the small lead fishing weight behind the pivot. The headstock of the wagon keeps the wire shank horizontal and hence the hook at the correct angle. Unlike the Electra, the pivot is on a 60-degree(-ish) angle to the headstock, so that when another coupling pushes against it, the hook both rotates both down and towards the vertical, allowing the opposing coupling to snap past.

IMG_1714.JPG.84c88537f9149c0a51da2ab785c8a8e8.JPG

 

The coupling seems to have been more utilised in 7mm scale, in the form of the "Lincs" auto coupler (see here). But I haven't seen it during my (comparatively recent) involvement in the 2mm scene.

 

Although I haven't yet tried them in operational use, I think this coupling has several benefits. Firstly, and importantly for me, it is robust and quite forgiving of misalignment. At the same time, it is probably the least conspicuous 2mm auto-coupling other than the fiddly Alex Jackson. Here is a comparison of wagons fitted with Lin-Cups (right) and Electras (left):

IMG_1722.JPG.fc12edc8ac09cd696f3d5ac89890c4b1.JPG

 

It's hard to see here but with the Electras you can actually see the weights hanging down behind the wheels, as well as the pivot tube beneath the headstocks. There is a further advantage to Lin-Cups not visible here: you could still fit dummy representations of real 3-link or screw couplings, hanging down from the coupling hook. This is not true (I don't think) with Electras, where the delay "dropper" would get in the way. (As yet I haven't found the time to try making 3-links, it has to be said.) The next photo is a comparison with DGs, which prevent you even from fitting the coupling hook:

IMG_1716.JPG.77c81f7f9d31cdce922e2e8de5134eb0.JPG

 

When it comes to operation, the Lin-Cup lacks the "delayed action" facility of DGs, Electras or Alex Jacksons, where you can uncouple at one location and propel the wagons to another spot without coupling up again. But it makes up for this, I think, by (a) the above advantages and (b) the fact that you can uncouple using simple permanent magnets underneath the track. This works because the only way to uncouple is to reverse the train (taking the tension off the hooks) while over a magnet. Similar to the "Electra shuffle". Here you see two wagons as they would look while pushing along clear track (top) and while over a magnet (bottom):

IMG_1725.JPG.60b5bb079010b2413f7a01e72d6c3776.JPG

IMG_1726.JPG.d2f347f93872a0f5ce57bcdbdd30da09.JPG

 

Notice that the couplings hang down quite a long way - this could be limited by putting some packing under the wagon floor to stop the "weight" end behind the pivot from moving up so far. Here are two end views to show how the coupling hook moves when over a magnet. The magnet here is actually fixed (temporarily) below the wooden base of my test track.

IMG_1729.JPG.09329ade7662f796b5a14390933af931.JPG

IMG_1728.JPG.2932c7fc551817e5c6917033cab65c73.JPG

 

So why are these couplings not so popular? Perhaps there is a fatal flaw that I am yet to discover, but I suspect it is partly the fact that they are not commercially available and you have to make them yourself. This turned out not to be too difficult, but it would be very hard without first spending a little time to make jigs like those recommended in the original article. The first is for bending the "frame" and just consists of two bits of nickel silver soldered together. The hardest part was cutting/filing one of these into the shape of an equilateral triangle, which I did by guesstimating. I've been making the frames from 28swg phosphor-bronze which makes it easy to spring onto the tube.

IMG_1700.JPG.1e20dea3d3a5b4c4de36d13a5a020683.JPG

 

The second jig is for soldering the steel hook to the tube. A jig is essential here as it has to be soldered at a 30 degree angle in one plane (so that it will pivot sideways) and a 45 degree angle in another (so that it will hang at 45 degrees in the resting position). I found a scrap bit of aluminium angle and followed the instructions in the article, drilling and filing a slot to hold the brass tube. It's hard to see but the section of aluminium against which the hook is sitting is bent up at 45 degrees. For the record, my tubes are 0.8mm (O/D) brass from Albion Alloys, which gives a nice free fit over the p/b frame.

IMG_1707.JPG.44707176cddaf037ee4e567b8c3823b3.JPG

 

I scribed a mark at "5mm in front of the frame" to guide me, but I found that slightly longer is needed for the wagons I've tried so far, because the coupling hook extends through the headstock and prevents the coupling frame from being fitted right up against the inside of the headstock. The hook is made from the same spring-steel wire (or guitar string) used for Electras. In use, I fixed the hook to the jig with masking tape and held the tail end down with a bit of wood. I used Carr's Yellow Label flux and plenty of solder. A decently-sized soldering iron bit was helpful as the aluminium acts like a heat sink. Here's a close up of a finished coupling, once the fishing weight has been "crimped" on and secured with cyano. It's certainly no harder to make than an Electra, and I'm quite impressed so far.

IMG_1711.JPG.810a51a6467648db032c0a7014585bab.JPG

 

  • Like 7
  • Informative/Useful 8
  • Interesting/Thought-provoking 3
  • Craftsmanship/clever 1
 Share

5 Comments


Recommended Comments

I use Lincs couplings in 4mm. The 4mm verson uses an etched bracket to hold the pivot tube and it's an art getting it positioned consistently. The equilateral triangle is a really good idea, it's almost self jigging ! 

  • Like 2
  • Informative/Useful 1
Link to comment

I've used Lincs in 7mm, for an exhibition Inglenook, designed for 'hands-on' use.

The controller was at the front and kids were encouraged to have a go at doing

the puzzle (it was named Havatry)

The Lincs were very good, with a couple of comments:-

Firstly, I had some of the steel wires detach, or start to rotate in the solder joint,

I got round this by scraping the wire with the back of a Stanley blade, to create

flats, like an old thrupenny bit.

Secondly, magnetism can be a problem, initially I kept the 3-link couplings, but I

should have converted to brass, eventually they start to interfere with operation.

Also, the actual Lincs need de-magnetising every now and then, otherwise they 

don't uncouple properly.

But overall, they are a very good system, discreet, reliable, cheap, easy to fit and

set up, the only downside is the lack of delay, for shunting.

Although I haven't tried them on bogie stock yet.

 

Link to comment
On 04/10/2020 at 10:52, [email protected] said:

I've used Lincs in 7mm, for an exhibition Inglenook, designed for 'hands-on' use.

The controller was at the front and kids were encouraged to have a go at doing

the puzzle (it was named Havatry)

The Lincs were very good, with a couple of comments:-

Firstly, I had some of the steel wires detach, or start to rotate in the solder joint,

I got round this by scraping the wire with the back of a Stanley blade, to create

flats, like an old thrupenny bit.

Secondly, magnetism can be a problem, initially I kept the 3-link couplings, but I

should have converted to brass, eventually they start to interfere with operation.

Also, the actual Lincs need de-magnetising every now and then, otherwise they 

don't uncouple properly.

But overall, they are a very good system, discreet, reliable, cheap, easy to fit and

set up, the only downside is the lack of delay, for shunting.

Although I haven't tried them on bogie stock yet.

 

 

I have just bought some Lincs AutoCouplers to try out. Currently using Bachmann TLC with the Brian Kirby system, which works well but I wanted something less obtrusive. 

What was the actual problem re. the Lincs becoming magnetised and not uncoupling?

In the instructions for the Lincs it recommends that the track magnets should all have the same pole facing upwards, could this have been a factor? 

Link to comment
4 minutes ago, philsandy said:

 

I have just bought some Lincs AutoCouplers to try out. Currently using Bachmann TLC with the Brian Kirby system, which works well but I wanted something less obtrusive. 

What was the actual problem re. the Lincs becoming magnetised and not uncoupling?

In the instructions for the Lincs it recommends that the track magnets should all have the same pole facing upwards, could this have been a factor? 

 

It's possible that I didn't get the magnets all in the same pole alignment, I honestly don't remember reading that!

When I can get to the layout, it's been stored since the point tie-bars failed (and lock-down), and I'll check. 

  • Thanks 1
Link to comment

Just checked (with another magnet) and all 3 are the same way up.

It's possible that long term use is the problem, I certainly didn't have a problem for the first few years,

but I also didn't use it as often as a home layout would have been used.

It only takes a moment with a de-magnetiser to sort it, but I've no idea where to get one, I'll have to ask

the club member (who did it for me) where his came from, once we re-open.

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...