Hornby “Vacuum pipe” magnetic couplings: what length should I use?

[teeinox]

I’m thinking of changing the Roco/Hornby couplers on some of my stock to Hornby magnetic couplers, the “vacuum pipe” type.  Hornby apparently offers two lengths: 17mm and 20mm.  Can anyone advise what is suitable for which coach?

 

The candidate coaches are:

Hawksworth

Stanier

LNER Buffet

 

Any experiences and advice would be appreciated.

 

teeinox

[No Decorum]

12 hours ago, teeinox said:

I’m thinking of changing the Roco/Hornby couplers on some of my stock to Hornby magnetic couplers, the “vacuum pipe” type.  Hornby apparently offers two lengths: 17mm and 20mm.  Can anyone advise what is suitable for which coach?

 

The candidate coaches are:

Hawksworth

Stanier

LNER Buffet

 

Any experiences and advice would be appreciated.

 

teeinox

I use Kadees for fixed formations but the same principle applies. Which size you use depends on the tightest curves on your layout, which only you know. Acquire and keep a couple of both sizes and try the smaller size. If they cause derailments, fit the larger size or a combination of large and small on adjacent vehicles..

[scouse889]

On 11/10/2023 at 20:56, teeinox said:

I’m thinking of changing the Roco/Hornby couplers on some of my stock to Hornby magnetic couplers, the “vacuum pipe” type.  Hornby apparently offers two lengths: 17mm and 20mm.  Can anyone advise what is suitable for which coach?

 

The candidate coaches are:

Hawksworth

Stanier

LNER Buffet

 

Any experiences and advice would be appreciated.

 

teeinox

i don’t have any experience of these coaches, but the long Hornby R8220 close couplings are essentially the same length as the 20 mm magnetic vacuum pipe couplings R7399 and the Roco 40270 close couplings are about the same length as the 17 mm magnetic vacuum pipe couplings R7400 (and the buckeye 17 mm magnetic couplings R7398).

The closest length comparison with Hunt Couplings is R8220 approximates the Elite close and 40270 approximates Elite extra close.

My experience is that the Hornby ones are superior to the Hunt ones:

1. The Hornby ones can be removed easily without breaking the dovetails. The 3D printed nature of the Hunts makes them hard to remove without snapping the dovetails. I have a box full of broken ones!

2. The dual magnet system on the Hornby vacuum pipe couplings makes them more resistant to pulling apart than the Hunt Elite equivalents, particularly on curves.

[teeinox]

Many thanks for your reply, scouse889.  It is most helpful.

 

Taking into account the measurements you give, it looks like the spacing would be as it is now if I went ahead as follows:

 

Hawksworth: 20mm.

 

Stanier: 20mm (a pity, they could do with something shorter, but not as short as 17mm).

 

Gresley: 17mm.

 

The 20mm dimension you give for the buckeye variety is interesting since I have some Hornby Pullman coaches for which they would be good.  But the Hornby R8200 gives too large a gap.  So it looks like there would be no improvement in closeness; probably an aesthetic benefit, though.

 

Interesting what you say about Hunt Elite couplings.  The only type I’ve used has been the “clip-fit” type designed to fit over a spigot.  I had to alter them and was struck by the rigidity and the brittleness of the plastic.  That caused me to pause going for the NEM variety.  Given your experience, looks like that was a wise decision.  But then, I have had quite a bit of handling damage with the Hornby close couplings, too, which is why the Hornby magnetic offering seems attractive.

 

On balance, the 20mm seems the safest bet.  So, thank you for your advice.

[scouse889]

1 hour ago, teeinox said:

Stanier: 20mm (a pity, they could do with something shorter, but not as short as 17mm).

Try one 20 mm with one 17 m - just that you would have to be mindful of the orientation of the coaches!

[scouse889]

1 hour ago, teeinox said:

The 20mm dimension you give for the buckeye variety is interesting since I have some Hornby Pullman coaches for which they would be good.  But the Hornby R8200 gives too large a gap.  So it looks like there would be no improvement in closeness; probably an aesthetic benefit, though.

The buckeyes are 17 mm, not 20 mm.

[teeinox]

21 hours ago, scouse889 said:

The buckeyes are 17 mm, not 20 mm.

Whoops!  My misreading your post.  Thanks for correcting me.  17mm would not work on the pullmans.  As you say, one can have the mixed 20/17 mm arrangement.  As you say, orientation becomes a problem.  I resolved it on the pullmans by equipping those types which would not run together with Roco couplings, the others kept the Hornby ones.

[Wheatley]

I've got Hornby/Bachmann Staniers, Mk1s, Thompsons, and Gresleys all operating around 3rd radius curves on the 17mm couplings with no issues. 

[Chrisjh]

I would go for 20mm Magnetic Couplings otherwise traversing over points can be problematic. 

 

Does anybody know if Hornby are going to release longer couplings as 20mm is still rather tight on points and I have had a couple of derailments - 25mm would be ideal ?

 

Best Wishes,

Chris

[Wheatley]

Turns out not all Bachmann Mk1s have the NEM pockets in the same place - I have one with B4 bogies (just the one) and fitting the 17mm coupling it sits too far back compared to the BR1s and Commonwealths on the others. So following my earlier post I'd recommend buying a packet of each and experimenting. 

[No Decorum]

9 hours ago, Wheatley said:

Turns out not all Bachmann Mk1s have the NEM pockets in the same place - I have one with B4 bogies (just the one) and fitting the 17mm coupling it sits too far back compared to the BR1s and Commonwealths on the others. So following my earlier post I'd recommend buying a packet of each and experimenting. 

Agreed. Everyone’s track is different, so a general recommendation won’t suit everyone.

[IOW O2]

I used the 17mm on all my Hornby's which are Bullied 59ft, Maunsell 59ft and 3 Mk1's with no kinematic action.  No issues on 2nd radius on entry and exit in the thru fiddle yard and can happily be left unattended to tail chase.  As above post try both sets.

 

Next order will be buckeye as they will look better.  On the Bachmann Mk1's I used their vac pipe' but will swap out for Hby buckeye.

Edited December 23, 2023 by IOW O2
clarity

[scouse889]

16 hours ago, Chrisjh said:

I would go for 20mm Magnetic Couplings otherwise traversing over points can be problematic. 

 

Does anybody know if Hornby are going to release longer couplings as 20mm is still rather tight on points and I have had a couple of derailments - 25mm would be ideal ?

 

Best Wishes,

Chris

I guess we will have to wait until Jan to find out the answer to this question, but I hope we see the range continuing. These are excellent items from Hornby IMO and are superior to other 3D printed versions in terms of the ease of removal (and general robustness) so it does make experimentation easier. They also work well with coupling cams as there are two magnets on the vac pipe versions and side pips on the buckeyes which are a neat solution to prevent the magnets coming apart on curves when the cams pivot.

[Chrisjh]

Many thanks just been directed to this site which looks excellent 

 

00 Gauge - Porterhouse Models