Comet V2 Chassis kit

[micklner]

This is the general method I use for choosing motor gearbox combinations

 

HIGH LEVEL GEARBOX USE

 

30:1 Not used

40:1 Passenger & Mixed traffic eg LNER A4 & V2 & V1

54:1 Freight haulers eg LNER J21 & O4

60:1 Shunters/trip freight locos eg LNER J50 & N8

80:1 Pure shunters & banking locos eg LNER J72 & U1

108:1 Dock shunting & Hump shunting eg LNER Y7 & T1

 

One chooses the gearbox design by superstructure requirements.

These are the combinations that I have used, with Mashima motor in brackets.

 

A4 & V2 Use Highflier 40:1 (1628)

O4 Use Highflier 54:1 (1624)

J21 Use Roadrunner Plus 54:1 (1024)

J50 Use Loadhauler Plus 60:1 (1620)

N8 Use Loadhauler 60:1 (1620)

J72 Use Humpshunter 80:1 (1024)

U1 Use Loadhauler Plus 80:1 (1624)

Y7 Use Humpshunter 108:1 (1015)

T1 Use Loadhauler Plus 108:1 (1628)

 

Good luck with your project.

 

Earlswood Nob

 

Many thanks for the list a great reference for the future. I prefer the 1020 to the 1024 I believe it has better performance ??? I know its better than the 1220 for definate !!

 

Mick

[Steve Taylor]

What Mick says with tinsel on. Excellent stuff, much appreciated.

 

Reading that table, gives me the plan for my J24, my second J72 and a heretical thought for the V2. I will never have the space to have mainline locos running at prototypical speeds with appropriate loads, but the odd one will crawl through light or with troop trains so does the learned panel see any reason not to put a 60 or even 80:1 combination in a v2. The station for my layout would have been taken at a crawl with a token change at its west end so I would value a very low stall speed.

 

I am now off to look up motor outputs/loads and bevel cut gears, finish an edit and out some more J72 together. I'm on holiday next week but the v2 wheels and motor will be ordered at payday at the end of the month.

 

BTw this thread is throwing up so much info pertaining to so many things I'm attempting at the moment, ould it be better as a work bench puzzle thread?

 

Cheers for now

Steve

[Horsetan]

.....I am now off to look up motor outputs/loads and bevel cut gears....

 

Ultrascale's offering

[craigwelsh]

Craig. Take your time to build the High Level unit. Couple it to a large Mashima can and you will have a drive the equal of the finest. You won't be sorry. I used a Mashima/High Level combination in my J27 and it's the best drive unit set-up it's ever been my pleasure to use!

Dave.

Think you meant Steve there..

 

Craig, thanks for making me look round the high-level site properly. Methinks I shall try them for the motor and gearboxes - very competitive pricing, and i f I get my maths right a nice set of ratios. Being able to crawl through the platform at a scale walking pace or less would be most usefull.

I'm still trying to work out the hornblocks. How they go together seems very simple but how to spring them seems to require me to have a bit of a think. I might have a set for my other J72 to try compensation on before the V2. I'm certainly getting some in to have a look at though.

Chris is very informative about the motors too if you get the chance to speak to him, he may recommend different sizes in some of the Mashima series due to better performance. Have you downloaded his excel gearbox planner to give you a top speed based on the motor, gearbox and wheel size?

 

They go together very well and he can give you some tags that fit over the bearing to pass a spring wire through. Spring points for continuous beam can be done with handrail knobs or small tags in the correct places based on the equations given on the Clag site.

 

I've heard quite a lot about this - generally seems to affect some of the ones that were packed in the later blue card surrounds and some that were simply bubble-wrapped inside the larger white boxes. Something to do with the moulds for the plastic gears starting to wear out?

 

Quite a while ago, I gave the ones that I have a spin under 9v battery power, and I couldn't detect a squeal on any of them - they all had their original red-tinted lubricant. Maybe I'm going deaf, or can't hear high-frequency sounds?

The ones I heard were in a Black 5 and something like a 4F on a home P4 layout, they would get really irritating if I had them at home! I can hear a CRT monitor on standby or a battery charger across a large room however so its probably more an issue for me than most! You'd lose the noise easily at an exhibition however.

[Steve Taylor]

Thanks to all for the informative replies.

Well I have applied retail therapy at Slaithwaite (can't make Scaleforum due to other commitments) and have a collection of bits.

Having read about the CSB doins on the horizon (ta Craig for the pointer) I'm going down that route. After a chat with Mr High-Level (sorry didn't catch your name chap), i agree, cracking bloke who knows his stuff and has a very tidy product range (I can do character refs for a fee , pays for more gearboxes ). I've also a set of bits to test this on a j72 first/at same time as well as another set for one of Arthur K's J24s (that's saved for when I work up the nerve to try boiler rolling. My name is down for the jig etc as soon as its available and once the NHS work their magic and put me off work for two weeks let the mangling commence.

So spec is comet chassis, Bachmann body shell (ideally I'd like to find one for a monobloc but have 3 for separate cylinders to practice on/trade with), gibson wheels, high-level hornblocks with CSB, high-level g/box 54:1 (should my layout ever get built, nothing will do anymore than a scale 20mph), mashima 1428 (1628 no longer available).

 

I am wondering why I didn't just return to "oo" so i could just run stuff "relatively" cheaply, but this seems to be more exciting and fulfilling - even getting it wrong seems fun.

 

Cheers

Steve

[DougN]

Steve,

 

Good luck with the Comet V2. I built one of their kits years agao and it was on the S4 web site for years until I really thought that it iwas time to take it down as I am really not happy with the set up. I have dug it out of long term storage and had a look at the motor and gear box combo. It has a 1628 flat sided mashima and a 2 stage comet 40:1 gear box. It worked of a fashon but never has really turned a wheel in revenue earning service. The wheels were all Alan Gibson. One important fact about my loco is the chassis kit was pre revision! I think that the "newer" version had better leading and trailing truck arrangements and they had fixed the valve gear lenghts! After building it I think I really should have gone down the track that Horsetan has with the Branchlines chassis. It seemed to be better than the comet offering at the time.(there was a review in a BRM probably about 11 to 12 years ago at the time that the Proscale kit argument occured. That is when Proscale spat the dumby over the review for those that have long memories) Mine only received basic comepensation to the driving wheels with the trailing and leading axles along for the ride. (mine is in LNER Green witha a body from Green Arrow which I think was at the time of the limited edition release!)

 

Pulling it out it still looks OK but things like the valve guides look 2 dimensional.

 

Depending on the motor arrangement that you chose i think you can taylor the drive train better with DCC.

[Steve Taylor]

Doug, cheers for your thoughts. Any chance of posting/sending over some pics? A GA of the underpinnings plus details of what you consider the problem areas would be most useful. Though a member of the Scalefour Society, I'm in the wilderness outside of the area groups so don't get to look at things before wading in and find the forum there very informative but a bit intimidating for a novice!

Cheers

Steve

[Horsetan]

....I really should have gone down the track that Horsetan has with the Branchlines chassis. It seemed to be better than the comet offering at the time......

 

The Branchline frames had more rivet detail than the Comet chassis, and the all-etched cylinder block with cast brass chest and piston valve castings is very very neat. I didn't like the Branchlines representation of the valve gear and motion, which looks a bit too coarse, and I didn't like the crossheads, which look nothing like the real thing. Comet scores in this area, with proper crossheads and a proper split expansion link / die-block assembly that you can make reversible if you're inclined to go the whole hog. The way to go is to combine the two.

[iak]

Hmmmm a hybrid of the two kits sounds interesting.

Mind, with all the updates Comet have and are making to their chassis kits will this V2 one get the treatment?

Certainly foof for thought though... B)

[Horsetan]

Hmmmm a hybrid of the two kits sounds interesting.

 

I love hybrids, 'cos they combine a multitude of design ideas. When you have a kit that is good in parts, and you have another kit for the same engine which is good in other parts, why not mix 'em? It is an approach that is more realistic when you're picking them up for a song.

 

Mind, with all the updates Comet have and are making to their chassis kits will this V2 one get the treatment?

 

Eventually, one would suppose..... I thought they made a good effort in correcting the B1 chassis for the new generation, so much so I bought one to build alongside the Dave Bradwell all-singing, all-dancing version.

[DougN]

OK Well here is the poor dear.

 

 

 

 

John Brighton helped when I was building her in giving me the 8'6" across the cylinder wrappers as the first time I had built them they looked wrong and clouted the wheels. (I really should have dusted her!)

 

Oh yes regarding not getting to the area groups I am in Melbourne Australia and the number of P4 modellers can almost be counted on one hand so our area groups usually include O gauge, EM, and anyone else who is interested in finer modelling.

 

At the time I was quite happy with the outcome in the cosmetic department but it was the running that I needed to improve. I also added weight to the rear truck to keep it on the track. Generally though i think it needs a partial rebuild to fix some of the things I am not happy with. Though it would be better if I had some where to run it. A local member here in Melbourne has a space 4m x 8m where he is building a large P4 layout SO I guess when he has done more I will be able to run in the loco's I have.

 

Opening the box to pull out the tender I found (not really the right word) my Bradwell J27 and the Bradwell B1 that I built years ago. I must get on with some of the other ideas that I have in the back of my head for P4 let alone complete the OO I am building with James (my 7YO) and Ashleigh (almost 5YO) is asking for a Terrier! So she has a train to run also! Though I am going to get Dave Bradwell to send me a Q6! in the near future! .

[Horsetan]

That's a lovely one, Doug.

 

Just to annoy you , I suppose you've noticed that the piston valve guides at each end of the cylinders are the wrong ones for 4771, haven't you? She had wedge-shaped ones.

 

 

 

I'll get me coat.....

[DougN]

Yes Mr Tan I am aware of some of these issues. that is why I have never really been that happy with the model .

[Steve Taylor]

Thanks for the posting those up Doug. That was just the reassurance needed that the underpinnings are not too complex when all together - I was looking at the underside detail on a model on High-Level's stand on saturday and given the amount of "things" under there wondered if i should have my fingers turned down or employ child slave labour to undertake that level of work.

Given your situation over in Aus, I'll never bleat about living in the midlands wilderness again.

 

Yours seems to sit well, the proportions feel right, but trust Mr H-Tan to pick nits hehe, but fair point i'd never considered, back to Yeadon's to check my alternative prototypes. Do branchlines still exist - I find a blog page but that hasn"t been updated for quite a while? I'd be interested to have a look at their frames should anyone have a flat set they could photograph/scan and post up as well as the cylinders.

 

Moving on Max Stafford has offered an exchange of monobloc bodyshell for a later style one so that opens up the options. Timewise I'm wandering from 1936 to 1964 for the layout but in the case of this V2 am veering towards 1942-1949 - keeps the painting simple and these would have appeared on troop trains around Broomielaw and Barnard Castle. There is a perverted part though that says a full ex-works job on a running in turn from North Road might appear, but that will likely be for a later one should i happen to get this one to work.

Cheers all for now

[Horsetan]

..... trust Mr H-Tan to pick nits hehe, but fair point i'd never considered, back to Yeadon's to check my alternative prototypes.

 

I'm a happy camper!

 

Do branchlines still exist - I find a blog page but that hasn"t been updated for quite a while? I'd be interested to have a look at their frames should anyone have a flat set they could photograph/scan and post up as well as the cylinders.

 

Very much in existence! I've got PDFs of the lists they sent me a few months ago, and I can forward these on to you if you want.

[Steve Taylor]

Thanks to Mr H-Tan for the branchlines info - lots of goodies, I feel the card may be taking a hit shortly.

Doug, I've been looking at the assembled pile of parts and Comet's recommendations in their instructions and looking at your pics I see you've plumbed for a trailing truck for the trailing wheels (the instructions are a little unclear at this point so please excuse the hesitancy in questioning) and left Comet's extension frames as cosmetic. Could you elaborate on my poor analysis of the pic regarding springs or weight? I'm unclear on the practical operation of a Cartazzi axle but wonder if utilising Comet's sprung hornblocks here might work if put into another frame layer made up to house them inboard of the wheels with suitable allowance for sideplay, or would adapting something like a Bill Bedford W-iron do the job using the axle holes already in the etch but opened up vertically to allow travel?

BTW - I've spoken to the NRM and will be taking detail pics from Green Arrow and the J72 at Shildon on Monday. If anyone has any specific requests for that excercise let me know and within reason I'll try to accomodate anyone elses project pic requests if can.

[DougN]

Yes that is one area that I am not happy about. the leading and trailing axles just along for the ride so to speak. After this loco I have built a Dave bradwell B1 and a LRM N9. Both of which I think I have done better. It was always the annoyance of me that the Comet offering didn't go for a "little" more complexity in order to have a better out come. the cylinders aren't right the valve guides aren't right. Just generally a not happy builder. Once you have had a go at the well thought out and modern products of Dave Bradwell offerings (yes I have lashed out on the new Q6 which no doubt I will start at Christmas when i get some well deserved holidays) the Chassis kits from Comet are way too basic. yes I have complicated the kit into P4 offering but I thought that if the kit has been thought out a little more in the etching department it could have been a lot better product. Then again about 8-10 years have past and we are now expecting more than back then.

 

For the moment the loco will stay on the shelf as a static model.

[artisan100]

It was quite a lot more than 8 - 10 years ago, Doug. Nearer to 15 or so. Over half of the range have been updated in the past couple of years, but time, as ever, is the enemy.

 

Geoff

Comet Models

[DougN]

Hi Geoff it has been a long long time, good to hear from you. I know that it wasn't that long ago as I have been in this house for 11years and I know I built it during that time!

 

Anyhoo I am aware that the revisions are alot better than the earlier offerings So may be I need to rebuild it with the newer kits. I aready have a couple of kits on the go so must finish them first!!

[Horsetan]

I've just spotted a Branchlines V2 chassis kit on eBay, so this is one you should consider grabbing, if only for the good frames and brake pull-rods.

 

It did occur to me that it might be worth seeing if you can combine the Comet and Branchlines V2 brake gear and rigging to get that much closer to a setup that looks like it actually works.... Hybrid time again.

[Metropolitan]

I am about to build a Comet V2 chassis and will be using this DJH Motor/gearbox ready assembled combo (AM9). I find them unsurpassed for smooth quiet running and well up to the standard of a Portescap. The one thing to watch out for with the gearbox is that the very powerful motor can strip the plastic secondary gear if the chassis locks up!

 

You can order them direct from DJH by phone and they usually arrive the next day.

 

[Steve Taylor]

Not much to report since work keeps getting in the way followed by decorating and all the other nonsense. However Metropolitan's Nu-Cast thread caused a bit of headscratching

 

Having hauled out two different body shells and the isinglass drawing and had a look, may I suggest the following. The Bachman bodies do have a taper in the right boiler cladding sections but it is not as apparent as that on the bare nu-cast boiler or the drawing or indeed on the prototype. The aerial drawing is telling in that the firebox returns to parallel to the running plate whereas the bachman appears to possibly still taper out towards the cab. Looking closely I believe a large part of this is the optical effect of the rather chunky boiler bands which gives a visual step and also the rather coarse softened moulding of the banjo dome, particularly the rear edge. Additionally the running plate swept step up is innaccurate and the length of the cab roof is too short. It is possible also that the cladding section over the firebox may be a touch to low also and also the positioning of the boiler bands is out .

Btw whats the protocol for numbering boiler sections? Do we count up from the front tubeplate back to the backhead or vice-versa? I get six sections on the drawing if the firebox/backhead is counted which places the dome and taper on the centre two sections.

 

I had hoped to do very little to these bodies but I guess its time to step up the learning curve a little and start carving up a bodyshell. Still a stripped shell will reveal if there is a real issue with the taper.

 

Also Branchlines will be getting a call for some detailing bits methinks. On which subject can anyone tell me if the dome is the same as that on an a3, which i suppose depends if the latter's boiler tapers or not?

[Steve Taylor]

Well after a couple of weeks of everyone wanting their pound of flesh I'm on sick leave following surgery yesterday and a start has finally been made.

The obvious place to begin was the viability of using the Bachmann bodyshell since metropolitan has cast doubt on its accuracy, so off came the handrails etc and a file/grind stone taken to the rather chunky boiler bands. Even at a rough stage its apparent that these are a major optical problem being just way too over sized. With a little optical correction to accentuate the taper in boiler sections three and four, this is do-able even at my base level.

 

For those stuck with bodyshells representing later non-monoblock engines, but wanting to depict monoblock engines....... bachman simply stick cover pieces on to represent the outside steam pipes. a quick wheek with a dental probe had those away.

[Steve Taylor]

Moving on, after carefull examination there is a slight coarseness to the scaling of the cab to the boiler but having removed the boiler band moulding and examined some pictures the main problem seems to be the dome and how it lines up to the taper. The shell suggests this goes over two boiler cladding sections but the pics suggest one. Though lining up with the Isinglass drawing suggests the former! Appearances can be decieving. So I'll go with it unless anyone can find a better dome to replace this one.

On a different tack, having gone through Yeadon's looking for a prototype Darlington based V2, I've landed on a choice of 60864 (Darlington - '44-'48, No. 4835-864) or 60848 (51a - '58-'61, No. 4818-848) or 60837 (a brief stay in '55 but unclear) I'm tempted by 60864 since during its stay it very likely didn't carry a lined livery (I'd like to keep it simple for this first major attempt) and the wartime period and the austerity/national service era would fit with use on troop trains around Barnard Castle/Broomielaw. Would anyone have any prototype pics of 60864, esp in late LNER/early BR era.

Thanks all

Steve

[Steve Taylor]

Well having spent a week experimenting with Hi-level hornblocks, csb jigs, Will L and Russ Elliots CSB discourse on the Scalefour forum and the latter's research published on CLAG on a Mainly Trains J-72 chassis (I like the simple tabbed construction, but puzzled as to why its so wasp waisted - anyone done one of these and see any reason why i shouldn't space the frame wider as its for p4) I've moved onto marking out and drilling the V2 frames for CSB using Hi-Levels jig. At this point looking at the frames a thought occurs. I'd like to be able to drop out the wheelsets and not have to build them up in situ so it seems the moulded spring representations will have to go. On a comet j72 I've been playing with some dummy extended springs that were provided (thanks to 97601) that acted as keepers for their sprung axleboxes. These were secured with 16BA nuts and bolts (thanks to Tim V) which is one of the most mind numbing proccesses I've ever done.....

 

... so the question is do i try to keep the dummy springs in the game or bow to the path of least resistance and cut them off (leave the hangers) and put them in the spares box? One thought, if my soldering were only that good, was to attach the dummy spring to the bottom of the axle block so the whole assembly moves together, in much the same way as I've seen wagons done but the margin to create something so out of line that its more of a distraction than the lack of springs is too great with my two left thumbs.