Paul's workbench

[jwealleans]

I have a recollection of testing clearances on mine with wagon wheels, so i suspect I used 12mm instead of 13. Since the whole thing is too short (put one next to a DJH and see the difference), it didn't appear odd or out of proportion.

[Woodcock29]

Unfortunately Jonathan's comparison with the DJH C1 is not helpful. Both the DJH C1 and C2 are far from accurate. Both are inconsistently overscale. That is, some dimensions are a greater % overscale than others. The models are flawed because they are scaled up from an overscale driving wheelbase. It's understandable that the driving wheelbase is larger than it should be if one wants to fit near scale driving wheels but the design of the kits has not properly accommodated that to keep other aspects to scale.
The DJH footplate is around 4mm too long and about 1.5mm too wide.
I speak from experience having built a DJH C2 nearly 30 years ago and having undertaken some modifications to improve its scale but not having known about all the issues at the time. I also have an unbuilt DJH C1 - It will probably never get built!
In fact the Ks C1 is a much more accurate model in terms of scale. It's footplate is virtually spot on when compared to the Isinglass drawing and when measured against what the length should be. As an example of the inconsistencies with the DJH kits the elevated section of footplate over the coupling rods is not high enough yet the footplate is too long overall. The Ks kit, although much older and probably not cast as well is correct in the height of this section. Where the Ks kit is let down is that the boiler is about 2mm too short (the DJH boiler is almost 3mm too long). However, the diameter of smokebox and boiler are spot on whereas the DJH smokebox is close to 2mm too big in diameter (and not as round as the Ks) and the boiler about 1mm too big.
I've just got my old dismantled Ks C1 out to check some of these measurements.

Andrew

[mick b]

Interesting last comments. I have made a few DJH kits, and havent been very impressed with any of them . I wonder how many they ever sell nowdays.

It does makes me wonder, how accurate the Bachmann version is as well??.

[Atlantic 3279]

Small wheels to dodge the clearance problems caused by otherwise going closer to true scale, I believe.

[manna]

G'Day Gents

I've restarted another C1, 3279, but this time I've used a B12 chassis fitted with A1/3 Hornby wheels, to that, Hornby Fowler 2-6-4t valve gear, A4 front bogie and a spare wheel fitted to the back of the loco, pic below, this will be the four cylinder version.

manna

[nzpaul]

Hi all.
Funny how a dirty old Ks kit gets the conversation going....
No photos today, not much to see. I've spent most of the day sorting out the slide bars. Threw the instructions over my shoulder and found a completely different way to do it. Still using the supplied nickel silver staples, but so much metal was removed from the casting to get the top slide bars to fit under the foot plate that the rule book didn't apply.
Chassis, cylinder and bogie are now primed awaiting painting. I've cut away the cab from a Hornby A1 body so finally starting on the bit that makes 4419 the unique loco it was.

The discussion around dimensional accuracy of Ks v DJH is all very interesting, although I'm not sure there's much you can do about any of it. I think the biggest argument against the Ks kit is it's difficulty. If this had been the first white metal kit I'd tried, I'm pretty sure it would have put me off for life. If you put it together as instructed it would be a colossal failure. I'd hope the DJH kit at least goes together without masses of corrective surgery, must lead to a more satisfied modeller and one willing to build more.

@Manna, plenty of people on here will be watching that to it's completion I'd say. I'm not sure which ones uglier, 3279 (not Graeme....that wouldn't be very nice) or 4419

Hopefully some progress worthy of pictures tomorrow.

Cheers
Paul

[Pebbles]

As with all his work the late Alistair Rolf did a splendid work on the DJH C1/C2, unfortunately it would appear that his brief was to produce a model that worked rather than a "Scale model".
However, it really doesn't end there, there are a large number of issues totally unrelated to mere running. For example the DJH A1/3 coupled wheelbase for some reason is about 1mm over long. In the case of the A1/3 non streamline tenders, whoever did the artwork appeared not to cater for the curve in at the front. When the curve is incorporated this results in a shortened tender body.
Then there is the very elderly Finecast A3, apart from being based on the Roche drawing, for some reason the coupled wheelbase is slightly less than 58mm.
In the specific case of the old Ks C1, I am slightly uneasy about the distance from the leading driver to the buffer beam, as this is possibly foreshortened.
We live with compromise, for example GWR Castles etc have to have the the spacing between the leading and centre driving wheels extended by 0.5mm or so and similarly with the coupled wheel spacing of the GNR Atlantics.
I suppose that it comes down to not always to expect that a Kit or indeed RTR model will conform to a scale representation of the prototype.

[Atlantic 3279]

At the risk of further digression, I wonder if it is wholly fair to criticize designers of some of the older kits very heavily? Do we know whether they had access to detailed, accurate drawings? If no drawing is available, it isn't always easy to find the best photographs from which to attempt to derive dimensions. Did the designers have, or take, the opportunity to examine and measure preserved examples of the loco in question (and there are not many classes in preservation). Correct scale features sometimes have to be ignored or altered in order to accommodate the requirements of OO gauge.
Having dabbled in a bit of scratch building myself, I have also realized that finding a way to create some of the parts of a scale loco, which must also house an electric motor, gears, and power pick-ups, requires a lot of head scratching. Sometimes it seems only just possible when given the "full freedom" of scratch building. If those tricky parts have to be incorporated into a kit design that can be put together successfully by the maximum number of modellers, and not just by the most highly skilled, there may not be any easy answers.
At least I don't have to think about ways to get a load of electronic toys into the loco too...

[jwealleans]

If it looks like a duck.....

[Hatfield Shed]

...It does makes me wonder, how accurate the Bachmann (C1) version is as well??.

Small wheels to dodge the clearance problems caused by otherwise going closer to true scale, I believe.

This was actively discussed online when it was known that the NRM had commissioned a model from Bachmann, and the suggested compromise was adopted. The driving wheel tyre diameter is at maximum wear condition, 26mm, enabling the axle centres to be close to scale for 6'10" at just under 28mm, which brings the maximum distance over the flanges of the coupled wheelbase in scale. No distortion required to 'the bodywork' in consequence.

You might hope that such intelligent compromises would be 'banked' for future exploitation, but when it came to the Pepp A2, Bachmann simply stretched the coupled wheelbase by 2mm, rather than go for the 'worn tyres' possibility which should have enabled a scale wheelbase. One of these days I will purchase a Hornby P2 and A2/3, and I'll see what they have got up to.

...Having dabbled in a bit of scratch building myself, I have also realized that finding a way to create some of the parts of a scale loco, which must also house an electric motor, gears, and power pick-ups, requires a lot of head scratching. Sometimes it seems only just possible when given the "full freedom" of scratch building. If those tricky parts have to be incorporated into a kit design that can be put together successfully by the maximum number of modellers, and not just by the most highly skilled, there may not be any easy answers...

That's the truth of it, takes a lot of thought to find the best compromises, and often requires a material superior to whitemetal to be effectively implemented; which was a major limitation for a whitemetal kit maker. There was an element of 'make the right choice of subject' for whitemetal kit makers, my K's J50's and later Wills N7, good examples of a usefully 'brick like' exterior which gave plenty of space within for a mechanism, and still stand up well against the current RTR models; whereas the less said about small boilered tender locos in whitemetal, the better.

[nzpaul]

Hi All
The primer applied to the frames etc is taking its time to cure so I've moved on to other parts to keep the project moving along.
The Hornby cab was too wide by a few mm so was cut in half down the centre line and the required amount filed away. The height was also reduced but I'll hold off fitting it permanently until I can assemble it on the chassis and check the final height against another loco.

Driving wheels lined, always a good day when the bow pens work properly. A barbeque skewer was inserted into the wheel hub allowing easy centering of the compass needle.

I began assembly of the tender as well, although the parts needed quite a bit of fettling, it has gone together as expected. The chassis frames are just sitting there at the moment as the wheels need painting before final assembly.

Cheers
Paul

[nzpaul]

Hi All
The last few sessions on the C1 have been spent sorting out the chassis. Making sure rods, crank pins and the crosshead cant come into contact with each other in unwanted ways. The amount of space available for the leading crankpins to pass both the slide bars and the connecting rods are very limited, so I've spent a lot of time making spacers to allow free rotation of the wheels with virtually no side play. The connecting rods are made from very flimsy whitemetal so even the smallest rub could end in disaster. So far, so good. Here's a short clip of it on the rollers. For some reason, just like the Reid Atlantic did, it wobbles on the rollers but it's quite smooth on a piece of track.
https://www.youtube.com/watch?v=HwN-cL2xD_k

The cab height remains an issue. Despite scaling measurements from a very side on photo, the cab has ended up too low. Shown back to back with a Bachmann V2 the discrepancy is about 1mm or so. The easy solution would be to raise it, but then it looks weird in context to the boiler. Also the Ramsbottom Valve (I found this in the kit after I'd asked about the Ross pop valves, sorry) sits nicely as is, with the levers to the cab roof sloping downward. Altering the cab height would stuff up the relationship to the valves, I think I'll live with it like it is.

The tender will need some adjustments to the front end as the real one doesn't quite look the same as the kit version. I've left the front bulkhead off for now and will get busy with some plastic sheet soon.

Cheers
Paul

[nzpaul]

Hi All
Steam supply and exhaust pipes and (what I guess) flexible joints made for the booster. Trickiest parts to sort out were the bell shaped joints between the cab steps. I ended up making all of the booster related parts from a piece of plastic aeroplane sprue turned in my fancy lathe (drill held in a vice with a box for a toolrest). The "pipe" is from a piece of copper cable off cut, about 1.5mm in diameter and looked about right. All just sitting on the model for photo purposes at the moment, to be attached permanently after painting.
The injector under the left side of the cab is made up from brass rod and handrail wire from the kit. At least I think it's an injector, seems to be connected to a pipe from the tender in prototype photos, someone else may know more.
I've made the tender front from plasticard and pieces of plastic ladder. Apart from the sloping bulkhead, the rest is guesswork. Given that it resides behind a big Gresley cab, I'm not overly concerned if it's no quite right. Also did what I could with the existing side sheets to disguise the lack of shape at the front top corners. Ready for priming soon, but that will have to wait until the shops are open again.

Cheers
Paul

[Atlantic 3279]

Looks like a neat job Paul, in short time too.

[Woodcock29]

Looking good Paul
Regards
Andrew