Screw Coupling Protocol

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iak
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Screw Coupling Protocol

Postby iak » Mon May 15, 2017 6:39 pm

As mentioned in the latest S'nooze, here is the wee illustrated protocol for how I sort screw couplings. This is my standard coupling for all my fitted stock on Mostyn, of which more is being dragged through "The Works" at present. My health is still very much an obstacle to normal modelling. Frustrating but one endeavours to move forwards.

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Here is the Masokits etch - it looks worse than it is to work worth once one is used to it.
You also get some etched hooks and instanters. I prefer to use Exactoscale coupling hooks however.

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Here you see the couplings central assembly.
Drill out to holes, if needed, whilst still on the main etch.
The black rod is 0.7mm pencil lead, you use this to keep the holes aligned once you fold the etch over.
You want a snug fit to keep it all square once its soldered up.

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Once you have the soldering done, remove the pencil lead and take a jewellers broach to the holes - carefully!

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Adding the links involves some careful bending up, using 3/64 rod as a former.
It also pays to clean up things with a file atr this point.
The links are attached using 0.65mm craft pins - Mike Clark {Mr Masokits] uses 0.7mm but hey...
The extra 0.05mm will help things to be free but naer to loose and floppy.
Carefully shallow/thin of the head of the pin by the way - it looks better.

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This is the tricky bit.
The paper/tape allows one to solder the pin in place, without it gumming up the blasted thing; well that it the theory :lol:

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Hark, it looks like a coupling.
Now to clean it up....

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Ahem.... NEXT!

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The solution is 0.5% - 1.0% Neutracon as mentioned elsewhere by myself.
It cleans up all the flux and gunk, leaving a very nice clean piece of work.

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Attaching the coupling to the coupling hook will mean the jewellers broaches come out again.
Care here as you want to fit the coupling in and then close enough metal behind it to hold it in place - don't make the hole too big!
The plates on the stem of the coupling hook are Ambis etches by the way.

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The finished articles in place.
Some use araldite but I use Rocket Max super-glue.
The plastic gets "keyed" using Ambroid Pro Weld before hand by the way which seems to help.

I hope this all makes sense and any questions? Ask away.
I don't suffer from insanity, I enjoy every minute of it....

Perfection is impossible.
But I may choose to serve perfection....
Robert Fripp


https://www.facebook.com/groups/PadgateWorks/

zr2498
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Joined: Wed Jan 06, 2010 4:11 pm

Re: Screw Coupling Protocol

Postby zr2498 » Mon Feb 11, 2019 12:13 pm

Thanks for the photos and description which have proved useful in a build of the Masokits couplings for some Palbrick wagon construction.
There are short and long links in the etch. Are the long links really necessary. My layout will be mostly greater than 30" radius with 24" minimum in the fiddle yard. I was wondering if the short links will do the job. I see you are not using spung draw bars. I could do with a bit of advice on that also. When to use (and when not).
Cheers
David

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iak
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Re: Screw Coupling Protocol

Postby iak » Mon Feb 11, 2019 7:07 pm

The long etch is useful for that added length. A purest might wish to us the short mind.
I do not spring the coupling as I simply do not find it necessary on my stock.
Running stock on Mostyn, we have tried to keep to basics and that appears to work - sprung drawbars "can" be a source of the rake "surging," definitely something to avoid...
I don't suffer from insanity, I enjoy every minute of it....

Perfection is impossible.
But I may choose to serve perfection....
Robert Fripp


https://www.facebook.com/groups/PadgateWorks/

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David B
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Re: Screw Coupling Protocol

Postby David B » Mon Feb 11, 2019 10:58 pm

See also the article on making Masokits screw couplings in S4 News 205 (December 2017) pp27 to 31.

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Noel
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Re: Screw Coupling Protocol

Postby Noel » Tue Feb 12, 2019 11:26 am

zr2498 wrote: My layout will be mostly greater than 30" radius with 24" minimum in the fiddle yard


I use Smith's couplings, which are a little overscale, but I don't much like the look of etched couplings, and the extra length makes dealing with curves a little easier, and coupling and uncoupling a little less fraught. Since my interest is shunting layouts, I have gone in the opposite direction to Iain, and use Instanter on all fitted stock, including NPCCS, so I don't have to deal with screw couplings, which are awkward when shunting. [GWR and BR VB wagons normally had Instanter couplings, and LMSR, LNER and SR screw couplings, as did all NPCCS.]

With these couplings it is OK to use unsprung drawbars and buffers down to about 3 ft radius, but much below that one or the other, or both, will become essential, as otherwise, once all the clearance has been taken up, something will be pulled off the track. I haven't tried to find out where the limit is, but I suspect that 24 inches may be a bit optimistic, especially for scale length couplings. Sprung buffers will be effective whether pulling or propelling, whereas sprung drawbars will only be effective when pulling.

I suggest that, given your minimum radius, it might be sensible to fit a couple of wagons with your preferred option(s) and see what works, and what doesn't. I suggest including a long wheelbase vehicle, as these will have the biggest sideways movement at the ends on curves, and the 'worst case' scenario is probably a long wheelbase vehicle coupled to a short wheelbase one.
Noel

zr2498
Posts: 6
Joined: Wed Jan 06, 2010 4:11 pm

Re: Screw Coupling Protocol

Postby zr2498 » Tue Feb 12, 2019 12:58 pm

Thanks to you guys for all of your advice. I have made a few of the couplings up (both sizes) and tested on the 24" radius track.
Yes, it would be wise to use the longer link with some of the longer stock - buffers do come pretty close. Shorter stock is not an issue with the short links and it helps to close the gap on these. I will leave off the springing of draw bars as suggested (no need), especially as the plan is to spring the buffers on the Palbricks.
David B - that will teach me to at least skim the Scalefour news when it comes in and not to be too busy doing other things. Great article and I do remember your demo of tiny bits of solder last Autumn at Missenden. Agree - much better to use a broach to open the holes, rather than a drill on a fret of this thickness.
Are Exactoscale hooks still available?
Dave W

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David B
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Re: Screw Coupling Protocol

Postby David B » Tue Feb 12, 2019 3:37 pm

zr2498 wrote:Are Exactoscale hooks still available?

They were not when I last enquired nor, as far as I could be told, were they in the pipeline. I hope they will be reintroduced as I feel they are the best I have used.

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Will L
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Re: Screw Coupling Protocol

Postby Will L » Tue Feb 12, 2019 5:47 pm

When using these couplings, it may just prove more practical to couple routinely if you use the longer link as they get more difficult to use the sorter/tighter they are, although this is less true if you use sprung buffers. But also keep in mind you don't need to make the bend in the loop too tight (hence the link slightly longer) as they get tricky to couple if the loop is too close a fit on the hook and there not enough room for the shunters pole as well as the hook.

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jim s-w
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Re: Screw Coupling Protocol

Postby jim s-w » Tue Feb 12, 2019 6:24 pm

Just a suggestion. Given its one of the common complaints you see from the mostyn guys, the time taken to couple stock at a show, have you considered perminantly coupling the wagons in pairs or longer rakes? Just pairs would halve the coupling up time after all

Cheers

Jim

zr2498
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Joined: Wed Jan 06, 2010 4:11 pm

Re: Screw Coupling Protocol

Postby zr2498 » Tue Feb 12, 2019 6:35 pm

Thanks Will. I guess it will be 'horses for courses'. The screw couplings on planned fixed rakes can be sized to suit best running, whereas links that are frequently coupled / uncoupled need to be easier to loop over the hook as you suggest.
Iain - like the idea of using pencil leads. I ended up using 0.5mm pencil lead (measures 0.55mm diameter) and then using 0.5mm brass wire.

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iak
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Re: Screw Coupling Protocol

Postby iak » Tue Feb 12, 2019 9:06 pm

The coupling up is part of the game Jim...
And as for complaints ? News to me, I'll discuss this with my learned colleagues.
I don't suffer from insanity, I enjoy every minute of it....

Perfection is impossible.
But I may choose to serve perfection....
Robert Fripp


https://www.facebook.com/groups/PadgateWorks/

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iak
Posts: 449
Joined: Thu Nov 05, 2009 10:28 am

Re: Screw Coupling Protocol

Postby iak » Tue Feb 12, 2019 9:11 pm

zr2498 wrote:Thanks Will. I guess it will be 'horses for courses'. The screw couplings on planned fixed rakes can be sized to suit best running, whereas links that are frequently coupled / uncoupled need to be easier to loop over the hook as you suggest.
Iain - like the idea of using pencil leads. I ended up using 0.5mm pencil lead (measures 0.55mm diameter) and then using 0.5mm brass wire.


Mr Masokits recommended one size and I just used what I thought was better for me - horses for courses as one says.
The lace pins are again what Mike Clark recommended using, I just adjusted.
Glad to see my aging thread has been of help... :thumb
I don't suffer from insanity, I enjoy every minute of it....

Perfection is impossible.
But I may choose to serve perfection....
Robert Fripp


https://www.facebook.com/groups/PadgateWorks/


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