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Does anyone have any knowledge of the valve gear on an A3, as modelled by Hornby?
Surely the stub crank (I think that what it's called) is too low- being lower than the axle. I've looked at numerous photos (and compared it to a model A1 and A4) and it appears that the Hornby interpretation is not quite correct- What do others think?

On another note- although an excellent model- doesn't the obvious seam line on the boiler reduce its standard significantly? (perhaps even render it somewhat toyish, albeit there is some very fine detail)

I'd be interested in what other modeller's think. Thanks
Roddo
 

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Not to sure which part you are referring to? Allowing for the fact of manufaturing tolerances and design I think Horby have done a creditable job of recreating the motion. It is perhaps a little to fine and perhaps Hornby should increase the minimum radius from 15" to say 20 or 22" this would take some of the slop out of the motion . The rods themselves should be a tad thicker with a proper joint in the main rods. All this aside they do run well and are a far better model than the Triang stuff I remember from the sixties.

regards
Ozzie21
 

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I do not have a Hornby A3 myself, but I currently have a book out of the library: 'Gresley Pacifics', written by O S Nock. Comparisons of photographs in this with pictures of the A3s in the current Hornby catalogue do seem to indicate a difference.
On the middle driving wheel, to which the connecting rod applies the power from the cylinder, is the Return Crank - this drives the expansion link (the curved bit) via the eccentric rod. I think it is the return crank Roddo is refering to. This would appear to be at the wrong angle.

With the coupling rods on the left side (left as looking forward from the cab) at their lowest, the end of the return crank on the Hornby models would appear on the right of the axle and about level with the axle. The photos in O S Nock's book all show that the return crank should be angled the other way - it should appear to the left of the axle and about level with it.

Who is going to tell Hornby


Regards,
John Webb
 

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I have both 60077 the white knight and 1470 great northern and with regards the boiler line i think it is worse to look at on the BR liveried version htan the LNER one for some reason. Another compromise i suspect but not as worthy of a panning as the class 33 roofline obviously. Also you would expect a pacific to be capable of hauling 8-10 coaches without hassle I find the A1 A3 and A4 struggle at 8 of the new gresleys.
 

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The offending bit of valve gear is the expansion link. It should only reach the centre of the axles so yes the Hornby one is too long.
I'm also a little miffed re the boiler seam, Hornby managed to avoid the problem on the Black Fives with their various boiler fittings, I'm sure they could expain if asked but still it does detract from the model generally. It is fixable with a spot of Milliput and a paint touch up, but would be nice if we didn't have to.
 
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