Pebbles

Sorry Slip of the keyboard. At the time I believe Ken lived in Heathfield and may have been employed or had a company in Uckfield. As an aside the Heathfield Show was highly attended, and I purchased the first issue of MRJ there.

I'm not sure that the reason why Portescap used bevel gear rather than worm was to avoid end thrust is entirely correct. I first came across this type of motor/gear in the late 1970s at the then Eastbourne Exhibition where Ken Pelling showed me a prototype. After he acquired Maygib he did market this motor under Kean Maygib; I have no idea where this sat with Portescap. Ken's main point was, that unlike a worm drive, bevel gears permitted the motor to turn when the power was removed allowing a model to coast. Was it Micro Metal Smith who also marketed a coreless motor/gear combination?

If I could trouble you, please could you establish the width over the cylinders. The figure quoted is 8'8 1/4", so realistically about 35mm. I also believe that the model is built for 00 track possibly allowing greater side play to the drivers which helps. Whatever, the model catches the look of the prototype.

Oh unhappy day! First taking the B16/1 the figure for overall length of 62' 6" is for an engine with NER buffers. When Group standard buffers were fitted this figure became 62'11". Overall lengths for Both the B16/2 and B16/3 were 63' 61/2". Maybe it's better to quote the more meaningful loco wheelbase. In the case of the B16/1 this comes out at 6'9" + 6'9" + 7'8" + 6'6" = 27' 8" In the case of both the B16/2 and B16/3 this comes out at 6'9" + 6'6" + 8'5" = 6'6" = 28' 5" Difference in wheel base = + 9" this increase being between the leading driving wheel and the trailing bogie wheel, not forward of the cylinders.

Gresley's "conjugated valve gear" only really had relevance where drive was on the middle axle or in the cases of the O2,P1and P2, the second axle. It was not needed on the D49 and B17 where very cynically the only benefit was possibly patent payments. The B16/2 and B16/3, as with the original B16, had the three cylinders on the same horizontal plain driving onto the leading axle, a very similar set up to the D49. The conrods on the B16/2/3 also appear to be of similar length to those on the D49. I'm fairly sure that the overall lengths of both the B16/2 and B16/3 were the same. Whereas the B16/2 had, as in the case of the D49, conjugated valve gear to no real benefit, the Thompson rebuild dispensed with the conjugated gear and had three sets of valve gear. In modelling terms, there were some other fairly minor external differences between the Gresley and Thompson rebuilds. I trust that this makes some form of sense.

From what I remember the footplate was one piece, so the bends are not acute/sharp. For some reason the tender flares are double thickness and Mike had problems in bending these. I would guess that whoever did the design they used Isinglass information so may be more accurate? One very important point about the Barnfield kit was that it was designed for the 3mm Society; if this means 12mm gauge track it would explain the restrictive splashers. Whatever the case, to be viable, the loco needs to handle 2' 6" curves.

It was some years ago better ask Mike.

Dave's kit covers both 4125gal tenders both the self trimming and non-trimming: the tender is the weakest link in this kit. I attempted many years ago to caution about Steve's kit but as it was the only kid in the street people plug on. I feel extremely sorry for John, but he has started with a problem, there is little point in throwing additional resource in up grading. Yes the PDK kit is cheaper and of a much later vintage, but it has it's own issues; see Mike Edge's B16/3 build.

The only suitable wheels were/are in the Sharman range, I believe these were listed as 5' 7". A further thought is that the LNER standard 4200 gal and 3500 gal tenders were most likely Darlington designs. Suitably modified the axleboxes of these tenders could be a way forward.

In his original instructions Steve Barnfield acknowledged his lack of information regarding the 4125gal self trimming tender. As it is, comparing this tender with details found in Hoole's book made we reach for the scotch and a pistol. You were quite lucky in having the test build for Arthur's Q7 tender that would have given you a good way forward. It is a shame that you could not have used this etch, but then it would have defeated the whole purpose of doing the B16 test build. Turning to NER tender axleboxes and springs this appears to be a minefield. Incorporating Dave's longer hangers does not resolve the problem, as the axleboxes are also incorrect for heavier NER tenders.

The problem is that some of the LRM range originates from a variety of sources and designers.

I know of someone who attempted this. The feedback was that it was difficult mixing the precision possible with the graphic package with what had originally been drawn manually. Yes, start from scratch.

This is what modelling is all about!

The tragic demise of the Southwold Show. As I was going to be abroad, I originally thought that I would miss the 2019 show, only to find that the 2018 show was the last one.

I have become confused. Is this a discussion relating to the standard of modelling or a critique of the kit? I believe that we have previously been down this Rabbit Hole.

John Edgson? a much revered gentlemen of memory. You surely meant John Redrup.

I believe that at least early Bachmann diesels used a physically similar engine.

Having looked at this in more detail I would suggest a pivot point above the rear bogie wheel with a central pad resting on the frames to take the weight. This arrangement limits the movement of the rear wheels of the bogie whilst allowing movement of the front wheels.

Peter Denny did much the same with one of his locos.

From memory 38swg wire and around 120 turns for each segment. Draw a diagram of the layout and note where each wire joins the commutator. Check youtube for Mr Snooze he rewound a three pole armature by hand and the principle is much the same.

I'm just wondering whether the performance of the original HD "Duchess" on an incline is as a result of rear weight biases. Apart from any overall weight, the substantial motor/magnet at the rear could give adhesion "bite" on the rear wheels in much the same way that a 4-6-0 would.

There a couple of issues that you need to look at. Firstly make certain that all wires are connected to the commutator they can become loose or de-solder. Secondly if wires are broken it is possible to splice an extension piece of wire and re-connect to the commutator. Should you not feel confident about attempting a re-wind you could contact Scalespeed in Fareham who do re-winds among other things.

I have an idea that Sir George Cayley toyed with the idea of an aircraft powered by a light weight steam engine. His ideas for a "Gunpowder Engine" are better known.

As far as I can make out the "Queen Elizabeth" class carriers have efficient diesels for cruise plus gas turbines when operating. These engines are together coupled to generators that power the ships electric propulsion and other systems. In addition to operating most efficiently at constant outputs, gas turbines suffer from turbine lag. This lag results in reduced responsiveness and makes them unsuitable for normal driving or indeed car racing.

I think there was a Lotus car raced at Indianapolis 500 some time in the 1960s/70s.