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"Elementary, my dear Watson"


Ravenser

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This is posted with due diffidence , lest anyone think I'm being provocative. What's to be described is undoubtably a kit, and it's certainly for a loco, and as I intend to build it so that it moves under it's own power - despite the difficulties now coming to light - I suppose it could be described as building a loco kit. But it most certainly isn't a loco kit in any sense a finescale modeller would recognise. I can't really see that it fits under any other section any better: RTR it certainly isn't.

On Thursday evening I went to the club and while I was admiring the contents of the display case, someone came up and said "I've got something for you. Just a minute." And delving in the cupboard, he presented me with a brown paper bag. "I got this at Peterborough , but I said I don't do card. Would you build it for us?"

In the bag was a Street Level Models kit for the Met Bo-Bo electric locos, courtesy of L49 of this forum. This particular one apparently carried the name Sherlock Holmes post war. Thie model is to go in a small display to mark the 150th anniversay of the Underground and all he wanted me to do was build it up as a basic static item. I reckoned I could do a bit better than that.

When I got home I dug in the spares box and found a discarded Tenshodo spud motor bogie . The wheel diameter (14mm) matched the kit, and so, apparently did the wheelbase (36mm) . I'm prepared to be told that these locos have 9'3" wheelbase , but it's certainly close enough to pass muster here. I've got some 14mm Hornby coach wheels, and a rummage provided an MJT 9' coach bogie compensation unit. The only thing I can see this is good for is LMS bogies - as a modern image modeller of ER leanings I've no reason to build any LMS coaches so I don't know why I bought the thing. Gresley bogies and all bogies for BR Mk1 and Mk2 stock are 8'6" wheelbase, and I've plenty of packs of 8'6" units. So that's a trailing bogie sorted , and I should be able to get pick up from at least one side of the trailing bogie

At this point comes a confession. The Tenshodo was ripped out of my Knightwing shunter and replaced with a Beetle because it ran like a dog. A very lame dog. If I had any serious prospect of using this loco on any layout ever, I'd buy a different motor bogie . However as I really can't see where this loco might ever run (It won't be DCC - I understand modifying Tenshodos is a pig - so it can't run on Blacklade,and it will be far too big for the boxfile. ) this is not really an issue. It just has to move after a fashion. And since money is a little tight at present , I can't justify spending £50 on a new motor bogie. This is strictly a £0.00p budget project

Here is what came in the bag:



I was kindly supplied with card , but I've got a stash of my own for modelling and it may well be that the stiffening isn't card

And here's my contribution:




So I started by getting the little box with the bogie side mounting brackets. It rapidly became clear that the keeper plate had to be removed so as to fit the bracket across a slot in the sides of the of the Tenshodo ("Note the slot in the motor-bogie, Watson. It may prove important to the case")

And I found this:

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My knowledge of motor design is minimal , but I really do not think that the green stuff on the 5 metal "pole pieces"(??) outside the copper wire windings should be there. I recall when I built the Knightwing kit, I sprayed the whole lot with matt varnish , and I had to clean the varnish off the backs of the wheels before anything would run at all. But I think I sprayed the pieces of the kit emerald green before I built it. Has paint infiltrated the motor , and is that why it runs like a dog??

I've tried cleaning the metal areas by rubbing with a cotton bud dipped in Slaters Track and Mech solvent - it was the only thing I could think of , and it will remove paint, just about. Whether I've done any damage to the motor in the process I don't know.

And to crown my woes I took the wheels out without thinking - and I've now got no idea which way round they go back for the gears to mesh with the worms.

On the credit size the wheels are getting a good clean , and so will the pickup strips. So the Tenshodo may run better. And the theory that the bogie ran badly because one of the gears had lost a tooth can be discarded - they haven't

At this point advice from those who know what they are doing with mechanisms would be very gratefully recieved .....post-80-0-44221200-1351963033.jpgpost-80-0-33491100-1351963215.jpg

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Panic over...

I've reassembled the Tenshodo , with a little help from a wiki page on gears, which may be some use to the next bodger faced with a worm /gear set and a good deal of ignorance:

http://en.wikipedia.org/wiki/Worm_drive

The moving graphic is invaluable here

It's been quickly test run on half of the boxfile. It goes. It hasn't gone bang (the solvent had about 3 hours to evaporate). Whether it runs any better I'm not really sure : it may do but I might be decieving myself. At least it's had a good clean

I've cut cardboard. The frame/base has been assembled and partial reinforcing fitted using offcuts of mounting board from my stock . The scored edges have duly been touched in with black felt tip. We are at least under way

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I've made a cerrtain amount of progress, though I don't seem to have anything spectacular to show for it.

First of all, a shot of the underside of the main frames , showing the mounting board reinforcement

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This has dried overnight but will still need some heavy card reinforcement on the top surface (inside the body). The areas cut away to clear the wheels and pickups can be seen. More reinforcement will be needed to build up the ends to provide a mounting surface for some NEM pockets (saved from a couple of Bachmann wagons that received Spratt + Winkles for the Boxfile)

The kit inevitably has its limitatations, imposed by the material and format. The next shot should show up some of the issues with the body:


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There are some colour pictures of Met Bo-Bos in London Transport in Colour 1950-1969 (Kevin McCormack/Ian Allen 2005) . This includes one of 1 (without its name, John Lyons) in the grey and red livery , which was apparently applied between 1933 and 1953. The photo was taken in 1954

A card kit is necessarily flat and without relief, unless you layer and laminate it. The doors are quite noticably recessed , and so are the windows - the latter more noticeably so in this livery, where the red window frames contrast with the grey body , than in the all over crimson. If I had two copies of the kit it might be possible to build up a thickness by adding the sides (with a card backing) as an overlay , or by cutting out the ddors and laminating another copy of the side behind, again with card backing. But the second option would leave the side desperately weak and both are pretty problematic in this particular instance. So I'm chickening out and building the kit as it comes, like I was told to....

On the other hand , the relief of the strips on the body is very slight indeed - the resin Radley Models kit , with its a heavy panelling is arguably very overstated here , again because of the limits of its material. Neither kit is perfect here , but card may just have the edge

There is no provision for the handrails, and they are fairly prominent . I don't feel up to drilling the holes for knobs and adding them : the shapes pose some problems in terms of support with knobs and attempting to drill through the intented clear acetate backing, and fix inside with superglue would bevery awkward. Others may feel bolder , but I'm leaving the kit without.

The ends, judging by the illustration of abuilt up kit on the packaging, are very bare, and don't look right for that reason. I can't help the missing handrails, but 3 white dots really doesn't look right for the headlights, which are prominent bulbous lumps in the same grey as the body. Here I intend to use scraps of kit sprue, rounded with a file and painted as near a match to the grey as I can manage . Similarly the two brake hoses are prominent featuresand their absence noticeable. I have some spare whitemetal steampipes from the Van B which can form the basis of one set of hoses, and a cut down tall vacuum pipe may do for the other. . The absence of the white destination plate is very noticeable : this will need to be represented.

There are 5 black protrusions above the buffers, presumably lamp irons. If I can locate the brass strip I had somewhere, I can fold these up and stick them in place with superglue

The plate surrounding the coupling hook is black , on all liveries, not red as in the kit. Can't be fixed on a preprinted kit . All photos show the 3 links shackled up and to the side , not dangling down. There are two rectangular plate structures below the buffer beam with a faint similarity to an NEM pocket....

There is one further inaccuarcy in the kit, which is very noticeable - the photo shows a red band around the top of the sides and the kit doesn't have it. It is possible this is a livery variation. The Street Level heading isprinted in the right colour but you need either 1 x 32cm or 2 x 16cm strips, and since the red doesn't extend below the letters , the longest you can cut from it is 7cm.... As I don't want lots of joins visible, I've used a red felt tip to colour the white edges of the sheet , so I can cut 2 off 1mm x 32mm strips. Its not a perfect colour match but it's pretty close and should not jar

I've cut out the windows - this was done in the sheet, pricking out the corners with a needle so they come out cleanly (The windows are in fact drawn with a slight radius to the corners) . I cut the windows out in a series - you get more precise alignment if you take the ruler across 3 or 4 windows in a row, and hopefully you get consistancy as well. Cut edges are toned in with felt tip. Card blunts blades quickly , so I've used the disposable cutting knife where possibl;e , even though the blade is a bit flexible, and reserved my Xacto No 1 for places where precise control is essential. It's noticeable that a lot of the cutting out is on edges which are non-critical (tabs) - which is excellent design

Since I'm opening out the windows, as the instructions note some alterations to the locating tabs for the false roof are needed:

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I've also soldered up an MJT 9'0" wheelbase coach compensation unit for the trailing bogie. Hornby coach wheels have been inserted, and 0.45" brass wire soldered to the frame for additional pickups on one side. I attempted to add a second insulated set of pickups on the other side, below the frame - but there was ahigh chance that the wire that keeps the CCU together would have come in contact with the solder blob and the wire, and have shorted the thing. So I only have 6 wheel pick up , which only cures 50% of the problem. Since the Tenshodo hasnt got damaged gears, the bad running must be a pickup issue ...

Main frames.JPG

the kit and the prototype.JPG

the sides , preparing roof for windows.JPG

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Hi Ravenser,

 

Nice choice of loco - really characterful machines aren't they? And that coming from a steam geek...

 

Have you tried the brilliant 'Rocket Card Glue' from Deluxe Materials at all? It is a really good, very fast drying and strong card glue that I have had much success with. You can even stick card edge on with it! The trick being just very thin coats of the stuff and away you go. Their website is here:

 

http://www.deluxematerials.com

 

I have no connection with them - I am just a satisfied customer. I hope this helps!

 

All the best,

 

Castle

 

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'Rocket Card Glue' is indeed good stuff - I've used it to attach styrene sheet to card.

 

As for the Spud, I tend to strip them down, lubricate the motor bearings (they're usually dry as supplied) and run the motor in with the axles removed for about an hour in each direction at varying speeds. It does make a difference to the overall running qualities, but it'll never be as good as a BB.

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Thanks for the comments. I had come across the name Rocket - I'd even bought a small bottle: in the same spirit that I've bought 3 types of solder flux and 12 different forms of solder when I hardly ever use the iron... But I'd never actually used it, being used to a big bottle of cheap PVA.

 

However I've given it a quick try and it does seem very effective , so I may be using a lot more. Although a lot of the gluing on this model will now be cyanoacrylate. I've got to the stage of gluing the clear acetate sheet behind the card sides as combined glazing /reinforcement. I didn't use quite enough cyano for it to cover completely with capillary action, although as the windows are few and small there were now real problems with it ouzing out where it shouldn't. However the acetate has been rolled up for several years, so it's not flat when cut into strips and it has imparted a very slight curve: the first side is now under a paper weight overnight. I'd forgotten how things tend to slow down at the acetate stage, though at least this time the few windows mean that cutting out the side was fairly quick

 

halfwits comments reminded me to oil the Tenshodo (motor bearings and gears ) as I never have, and it must have been sitting in the bits box for at least 5 years. I've also cut off the projecting axlestubs with a piercing saw . The trailing bogie is now installed , with 2 strips of mounting board glued inside the brass bolster with UHU , and attached to the card floor with Rocket. I've had to pare away a little of the strengthening of the frames to ensure the wheels don't touch

 

I'm out most nights this week so progress will now slow down, but at least a reasonable start has been made - and it's looking promising

 

I've been thinking again about handrails - I reckon the side handrails could be fitted while the side is in the flat. But the end rails couldn't , and stopping the handrail knobs tearing straight out would be very difficult - the cab end will have less reinforcing of the card than elsewhere . Since you have to add all the handrails or none (those on the ends are the most noticable), it's still going to be no handrails....

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  • 2 weeks later...

Despite being out several nights for the last couple of weeks, Sherlock Holmes is making progress, and starting to look like a loco:



Here is the first side fitted - the glazing /reinforcement may not be clear in this shot , so this shot of the second side under preparation may make it clearer:



This represents the only "patent clever bit" in construction - the thin card side is stiffened and glazed in one operation by applying acetate sheet behind , with a reasonably liberal application of superglue (thick) to the card area. The acetate sheet is then pressed down till the glue sets - capillary action will spread it across the whole surface, resulting in reinforcement, glazing and sealing of one side of the card against damp in one operation .

Getting the amount of cyano to apply right is a little hit and miss. Too much and it will ooze out at the corner of the windows - you will have hastily to wipe it away , and the chances are this will result in a little of the dreaded white cyano bloom, especially if you handle the acetate with your grubby paws. (I have heard that it is a reaction between grease/oils from the skin and the cyano fumes in curing that causes the white bloom) . There is a patch for this - if it doesn't rub away - which it probably won't - apply a thin coat of gloss varnish over the affected area, and the window will dry clear.

So this time I was sparing - even though there are far fewer windows than on the two light rail units I built with this technique. I think I was a bit too sparing to be honest, or perhaps I should have used medium grade cyano. At any rate it didn't spread as far or as easily as I had hoped. Another minor difficulty is that my clear acetate sheet has been kept rolled up, and it wasn't dead flat when cut . I did try keeping one piece under a paperweight for a coupler of days, which almost flattened it but something went wrong in the cutting out of recesses for the tabs to secure the roof and that piece ended up supplying bits for the cab ends

With a couple of extra bits of mounting board, and the roof base fitted , the sides are pretty straight anyway.But in some respects the technique may be more suited to tube stock and coaching stock, where the sides are not necessarily straight and flat anyway.

Card can't give you much surface relief . This is an issue with this loco - the recessing of the doors is quite noticeable in photos of the real thing , and the locos have banding on the bodywork. Radley's resin kit is a bit more like the panelling on a Gresley teak coach - which to my eye is far too heavy. On the other hand representing these bands by light shading lines in drawing out the card kit inevitably lightens the body and isn't quite right either. No one-one has ever made an etched brass kit for these locos : it would certainly allow the right sort of body relief, but I really wouldn't like to have to solder the panelling overlays to the body side



Both sides in place

I've added card reinforcement to form a base to take lead sheet - this recess can be seen. The lead has now been araldited in place and a piece of thin balsa sheet fitted over it .l I did not want the wire from the pick up on the trailing bogie rubbing on a cut lead edge. I also managed to add scraps of mounting board as strengthening either side of the fixing screw for the Tenshodo

I've dug out the bottle of Rocket glue and tried it - it's good stuff. I'm finding a little difficulty keeping the microtip clear in order to apply it : my very finest microdrill bit had to be depolyed a couple of times

The pickup wire has now been soldered to the Tenshodo , and the lid of the "box" glued in place. This means the body is a sealed box with no access - but as the only thing in there is the fixing screw for the Tenshodo spud , I don't think this is going to be a problem

Unfortunately the etched CCU obstructs the area below the buffer beam and I won't be able to get an NEM socket in there . This means couplings will be confined to one endpost-80-0-33623000-1353162116.jpgpost-80-0-32915200-1353162219.jpgpost-80-0-51719900-1353165518.jpg

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  • 3 weeks later...
  • 3 months later...

Despite appearences to the contrary, this project hasn't sunk without trace - in fact while I had some time on my hands about a month ago , I made substantial progress , and with a few bits done since , it is virtually finished . All that still needs to be done is buffer heads and - when I finally steel myself and check whether I can do them neatly - destination boards, followed by a coat of satin varnish to seal and protect the card

 

The first step was the roof and here is work under way: 

 

post-80-0-98748700-1363477283.jpgpost-80-0-98748700-1363477283.jpg

 

The roof is formed out of a block of balsa, sanded to profile with the aid of card templates provided in the kit. As I've said elsewhere, I'm not entirely sure I've got the profile of the roof domes right, or even identical to each other

 

The ribs are very thin and cut out of a single piece of card . Getting them to stick down exactly square and aligning them so that they are exactly the same distance from the end is very difficult if you use Rocket glue because it grabs so fast that there's no time to adjust. I didn't quite manage to get the ribs exactly the same distance from each end...  

 

Here the roof is posed unfixed on the model

 

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The roof was then painted with acrylics in a suitable slightly muddy grey and fixed to the model

 

At this point all my sins of  minor flaws in assembly came home to roost. It became apparent that the roof ribs lined up with the bodyside panelling on one side  - but not on the other. This can only be down to some inaccuracy in the assembly of the body. Also there was a noticeable slight gap between the body and the roof at several points - and the pointed footprint of the roof dome at one end did not exactly match the shape of  the cab. Assembling the cab to the correct shape is admittedly the place where it is easiest to introduce slight errors , and since the roof plan was cut to fit the template provided , rather than the model to which it was to be fitted there was no immediate check both matched (The roof left a very slight gap along one wing of the cab - so there was no scope for sanding it back to correct)

 

In an effort to deal with most of these problems I applied one of my enhancements to the kit.

 

As will be apparent from the prototype photo glimpsed in an earlier posting , in this livery the real things had a red band around the base of the roof - the raised  band at the top of the body being so treated. This is omitted in the kit , and it is a little noticeable .

 

I had already decided to try to add this . Since the red strip across the header of the card isn't long enough to do the job, I used a red felt tip to colour both edges of the A4 card sheet on which the kit is printed . This was a bit too bright, so I tried toning it down with grey watercolour . That left it  a bit dull , so I gave it another run over with the felt tip...  I then cut a strip 1mm wide and applied it to the model at the top of the body . It wasn't quite enough to go all the way round so a short additional piece was cut from the other side to fill the gap (the length of one side of one cab)

 

This has cured the gap between roof and body, but has thrown up various other issues

 

Before I added this strip I was pretty happy with the shape of the roof , reservations about cab dome profiles nothwithstanding. Now I'm less so. The strip seems to make the roof slightly shallow. This is probably in part because the red band is too wide - 1mm equals 3" and I doubt if the relevant raised body band on the real thing is more than 2" and perhaps not much more than 1" . Without a drawing I can't check - but I very much doubt my ability to mark and cut accurately and successfully a band of 0.75mm or 0.5mm from card

 

However this has then raised some other questions about the body. I should say that I am inherently sceptical about the approach of peering at photos and attempting to judge by eye whether a model - or an image of a model - matches the shape found in the photo. It's led to some pretty unhappy debates in D+E - for me the reducto ad absurdam of this approach came some years back when one bright spark wrote to MREMag to announce that he'd spent the afternoon staring at photos of class 40s - no doubt 3/4 views - and decided that the Bachmann model was too short (Since the actual length of a class 40 in feet and inches was quoted in even basic spotters books , 30 seconds with a decent ruler would have settled the matter conclusively , but D+E in that era didn't do dimensions , it did looking at photos and guessing)

 

But for what it is worth, here goes....  It is apparent from the prototype photo that in this livery there was first the red recessed window surrounds, then a strip of grey, then the red band around the top of the body side, then the roof. At least at the cab ends, this grey strip appears approximately the same width as the red band . This may just be visible on the prototype photo seen above , though cropping has cut it off at pretty well exactly this point

 

On the model I cannot get any grey gap between the red recessed window surrounds and the red band, nver mind a 1mm grey gap. The band can't go higher - it's already arguably rising too high against the roof. And if it were narrowed to scale width that might fix the problem with the roof profile , but it could not allow the band to move higher as well to create the grey gap..... 

 

And the more I look at the photos and the model the more a nagging voice says that the cab should be broader and more oblong and that the model is a bit narrow and tall, and the cab windows possibly slightly high . I would like to check the width of the body against a drawing but don't have one - my hunch is that the body is at least 1mm too narrow and possibly 2mm , resulting in the ledge along the bodyside  at footplate level being a little wide

 

I appreciate this is being hyper-critical of a very simple kit , never intended to stand the sort of scrutiny applied to a state of the art finescale etched kit priced in 3 figures.. And the current issue of Railway Modeller contains a photo of a model built from a Radley Models resin kit  (bottom of p316)- and I find myself much less convinced by that in this upper cab/roof dome area...   

 

I've also added hoses to the cab ends , which are otherwise bare - these are two types of loco vac pipes from a Langley packet of assorted company types, suitably  cut down  

 

Anyway here for what it's worth are two shots of the almost finished model . Sorry about the quality but as I'm at work in daylight hours now , opportunities for snapping it are limited. I have now added all the shoebeams  And despite any reservations I'm still quite pleased with it. Not finescale but a model that seems to capture the air of the prototype reasonably well for almost no money - and my own work, not Bachmann's

 

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