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Hornby P2


Dick Turpin
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Hi Keith,

            I am fairly sure that these CV are specific to this type of Hornby Decoder as I have never seen them on any other type either, so if you change the CV s that you mention it might do the trick as the ones that I have changed have certainly improved things no end and the loco runs much better, is the motor noisy on the model you have ?

 

Ken.

At-least 2 of my non-sound chip brands have 2 variables like the Hornby CV 151 and 152 for controlling back emf, they are just in different CV locations. The first one is normally labelled P and second one normally labeled with the letter I (not the number 1 as it looks in the Hornby notes). That is short for the P and I in Proportional Integral Control.  They are sometimes described as being like the spring strength and the damper strength on a physical suspension control system.  

I have used the revised Hornby settings of 255 and 1 for these 2 variables, and it did change the way the motor behaved. I would not say it made it better, I would say it made it less bad. My issue is definitely with this chip, as this loco and tender run very well with 2 other chips I have tried.

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Well, my P2 has a voice again. Put on the 4 ohm speaker. I've had to remove the weight from the tender temporarily until I can machine it down to accommodate the rectangular format speaker. It will be lighter for a bit, but this won't affect her too badly. Sound seems about the same quality really. Might be worth packing a little foam in there to soften it.

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A wedge-front P2 in BR green livery should surely have its valances cut away ahead of the cylinders as on the A4's......

 

Even a black one perhaps. Yeadon's book includes a small photograph of 2001 taken (illegally I presume) in  September 1942 at Montrose with valances removed ahead of the cylinders.

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Graeme that's a very interesting question

 

Norman is a keen railway artist and a long-time ember of the Bluebell, so one would expect some technical accuracy, that said when you're photoshopping you are limited to working with the original.

 

It certainly makes for a handsome loco, but as Thompson found you end up with a disproportionately long smokebox. I agree that the firebox on Norma's shot does seem a tad lengthy - perhaps he did some proportional stretching to get it all in and just flexed the sky - without knowing a lot about image manipulation I can't comment.

 

I do however have a spare V2 body shell do if you have any ideas about which bits we could use to cobble something together, I'd be interested!

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In order to check / illustrate as final a finish as possible before I think about dismantling (butchery) for any mould making purposes, I've applied some temporary green finish to the altered areas of the P2. There's not much unaltered is there? I mixed the green in daylight to try to get as close as I could (while it was still slightly wet and had a sheen) to the Hornby version of Doncaster / Grass green. Using Railmatch paints, in order of quantity, the mixture included Darlington green, Doncaster Green, and BR multiple unit green!

How can anbody want to defile one on these locos by painting it in GWR / BR / middle chrome / Brunswick Green?

 

STA79746_zps1901ebf1.jpg

 

STA79749_zpsfd4a5b17.jpg

 

STA79748_zps47754070.jpg

 

==========================================================================================================

        The complete job will look great looking forward to see the end result. 

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... should have typed 2-8-2 V2 as per Norman Cousin's 'what if'...

This doesn't work on a couple more counts. The extra pair of coupled wheels only make sense in the context of a minimum one third uplift in sustained power output over a V2. To achieve that economically a larger grate and the double Kylchap ejector are necessary. And as the V2 could get embarassed for water supply very quickly when opened out, a yet larger potential output loco would run short even more rapidly: it needs a four axle high capacity tender. (Notice that Thompson's pacific adaptions of V2s were initially  fitted with standard 3 axle tenders as the V2, which were subsequently replaced with four axle types.)

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@34C so maybe Norman got it right with the larger firebox!

 

My plan - Graeme please advise if this is going to go badly wrong -  is to take the front end off the spare V2 body and affix that to the back end of a Railroad P2 - not even sure where to start, as if I'm following Norman's pic I need a tapered boiler and banjo dome!

 

I suppose one alternative would be to use an A3 boiler?

 

I did have a conversation with Mark Allatt of the P2 Trust a year or so back in which he said that the P2 was to all intents and purposes an '8-coupled V2' which is why they planned to use a V2-style pony truck, and indeed was also what first planted the idea in my head

 

Peter

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My specific concern about the 2-8-2 image was that the lengthening of the boiler had been achieved by inserting an extra section between the front of the normal firebox and the usually coned section carrying the steam collector. In that respect it is unlike any boiler in the Doncaster wide-firebox family. The later tendency to include a combustion chamber extension at the front of the firebox only added a foot to the length in that area. The image suggests something of the order of 4 feet added to length in that position. I wonder if the intention was to maintain the V2 "look" towards the front of the loco. The Original Gresley Pacific boilers from which the V2 boiler evolved were of course longer in the parallel front section. I believe that length would have been maintained had not the boiler been required to fit the shorter 2-6-2 loco. Given that the V2 coupled wheelbase of 15'6" would probably have to be extended to 19'6" in eight coupled form, then unless some Atlantic style cramming-in was done for the rear three coupled wheelsets, simply not chopping a couple of feet off the original Pacific boiler barrel still wouldn't make it quite long enough, so a long smokebox would be required. The first development drawings for the P2 in RCTS 6B show little more than an A3 Pacific with minimal alterations to turn it into a 2-8-2 with 6'2" coupled wheels. The boiler is the same as the A3 standard, only the smokebox is lengthened

 

Had a general mixed traffic Mikado rather than a "special" for Aberdeen heavy passenger trains been contemplated a few years earlier than the eventual V2 design I think it might well have had the then-usual 5'8" express goods size of coupled wheels, but that would only save about a foot on length as the first two coupled axles would still have to have 6'6" minimum spacing in order to accommodate the inevitable 3 cylinder drive with conjugated valve gear. The smaller wheels would certainly increase the potential maximum tractive effort (justifying the extra adhesion) but I doubt it would have been a machine capable of deputising for top-link Pacifics on the fastest duties without losing time, severely testing the fireman, or running out of fuel/water.

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We'll I purchased the TTS version yesterday with some trepidation after reading this topic.Maybe I have been lucky but mine has run straight out of the box with no problems at all. It does need quite a high throttle (60 /128) on my Lenz system with 6 Hornby Gresleys in tow. I am quite impressed with the sound as well. got an excellent price from Scograil at the Ipswich exhibition and overall very happy.

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Got my detailed one today, a nice ebay bargain, unused, £102 delivered.Runs a treat,a very imposing piece of kit.Not too sure about the matt paint finish, whilst it looks nice I'm sure the real thing would have been a lot shinier.Very impressed with the new style packaging too.

Edited by PanzerJohn
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Have had a bit of playing around with decoder settings.

 

I have changed the BEMF from High Frequency to Low Frequency and it seems to run a little bit better at low speeds.

However as I posted earlier it has got somewhat smoother the more it is run.

 

Keith

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When you say high frequency to low frequency is that referring to the CV150=0 or 1, or is it something else ?

It's a setting on Lenz decoder, it's the highest bit in CV50 (which is used for setting motor types and control)

There isn't a CV150 with Lenz decoders

 

Keith

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I made a short video of my new Hornby P2 with TTS Sound being followed by an A4 by Golden Age Models for comparison. I noticed that during reverse running, the model is slightly jerky. Could be my track but haven't noticed this on other models.

 

 

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Wanting to be certain of having a fairly complete and decent-looking pair of P2 conversions in my possession when I attend the Warley and Wakefield shows later this month, I was forced to do some realistic thinking for once this morning. It became obvious to me that short of driving myself into insanity and exhaustion over the next ten days or so, it would be impossible to pull apart the prototypes for the conversions, make up moulds, cast duplicate resin parts, re-assemble, tidy up, and paint to a good finish. As I have plenty of other things that I also ought to be doing, I therefore decided that discretion was the better part of valour. As an interim measure I have therefore simply applied some satin varnish and some basic lining to Lord President, last seen wearing two very noticeably different colours and textures of green paint. The differences between the unmodified and the modified areas now blend in somewhat more effectively.

 

post-3445-0-39549400-1415828087_thumb.jpg

 

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